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postgres/src/backend/tcop/postgres.c
Nathan Bossart a99cc6c6b4 Use PqMsg_* macros in more places. 
Commit f4b54e1ed9, which introduced macros for protocol characters,
missed updating a few places.  It also did not introduce macros for
messages sent from parallel workers to their leader processes.
This commit adds a new section in protocol.h for those.

Author: Aleksander Alekseev
Discussion: https://postgr.es/m/CAJ7c6TNTd09AZq8tGaHS3LDyH_CCnpv0oOz2wN1dGe8zekxrdQ%40mail.gmail.com
Backpatch-through: 17
2024-07-17 10:51:00 -05:00

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/*-------------------------------------------------------------------------
*
* postgres.c
* POSTGRES C Backend Interface
*
* Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/backend/tcop/postgres.c
*
* NOTES
* this is the "main" module of the postgres backend and
* hence the main module of the "traffic cop".
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <fcntl.h>
#include <limits.h>
#include <signal.h>
#include <unistd.h>
#include <sys/resource.h>
#include <sys/socket.h>
#include <sys/time.h>
#ifdef USE_VALGRIND
#include <valgrind/valgrind.h>
#endif
#include "access/parallel.h"
#include "access/printtup.h"
#include "access/xact.h"
#include "catalog/pg_type.h"
#include "commands/async.h"
#include "commands/event_trigger.h"
#include "commands/prepare.h"
#include "common/pg_prng.h"
#include "jit/jit.h"
#include "libpq/libpq.h"
#include "libpq/pqformat.h"
#include "libpq/pqsignal.h"
#include "mb/pg_wchar.h"
#include "mb/stringinfo_mb.h"
#include "miscadmin.h"
#include "nodes/print.h"
#include "optimizer/optimizer.h"
#include "parser/analyze.h"
#include "parser/parser.h"
#include "pg_getopt.h"
#include "pg_trace.h"
#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "postmaster/interrupt.h"
#include "postmaster/postmaster.h"
#include "replication/logicallauncher.h"
#include "replication/logicalworker.h"
#include "replication/slot.h"
#include "replication/walsender.h"
#include "rewrite/rewriteHandler.h"
#include "storage/bufmgr.h"
#include "storage/ipc.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "storage/procsignal.h"
#include "storage/sinval.h"
#include "tcop/fastpath.h"
#include "tcop/pquery.h"
#include "tcop/tcopprot.h"
#include "tcop/utility.h"
#include "utils/guc_hooks.h"
#include "utils/injection_point.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/ps_status.h"
#include "utils/snapmgr.h"
#include "utils/timeout.h"
#include "utils/timestamp.h"
/* ----------------
* global variables
* ----------------
*/
const char *debug_query_string; /* client-supplied query string */
/* Note: whereToSendOutput is initialized for the bootstrap/standalone case */
CommandDest whereToSendOutput = DestDebug;
/* flag for logging end of session */
bool Log_disconnections = false;
int log_statement = LOGSTMT_NONE;
/* GUC variable for maximum stack depth (measured in kilobytes) */
int max_stack_depth = 100;
/* wait N seconds to allow attach from a debugger */
int PostAuthDelay = 0;
/* Time between checks that the client is still connected. */
int client_connection_check_interval = 0;
/* ----------------
* private typedefs etc
* ----------------
*/
/* type of argument for bind_param_error_callback */
typedef struct BindParamCbData
{
const char *portalName;
int paramno; /* zero-based param number, or -1 initially */
const char *paramval; /* textual input string, if available */
} BindParamCbData;
/* ----------------
* private variables
* ----------------
*/
/* max_stack_depth converted to bytes for speed of checking */
static long max_stack_depth_bytes = 100 * 1024L;
/*
* Stack base pointer -- initialized by PostmasterMain and inherited by
* subprocesses (but see also InitPostmasterChild).
*/
static char *stack_base_ptr = NULL;
/*
* Flag to keep track of whether we have started a transaction.
* For extended query protocol this has to be remembered across messages.
*/
static bool xact_started = false;
/*
* Flag to indicate that we are doing the outer loop's read-from-client,
* as opposed to any random read from client that might happen within
* commands like COPY FROM STDIN.
*/
static bool DoingCommandRead = false;
/*
* Flags to implement skip-till-Sync-after-error behavior for messages of
* the extended query protocol.
*/
static bool doing_extended_query_message = false;
static bool ignore_till_sync = false;
/*
* If an unnamed prepared statement exists, it's stored here.
* We keep it separate from the hashtable kept by commands/prepare.c
* in order to reduce overhead for short-lived queries.
*/
static CachedPlanSource *unnamed_stmt_psrc = NULL;
/* assorted command-line switches */
static const char *userDoption = NULL; /* -D switch */
static bool EchoQuery = false; /* -E switch */
static bool UseSemiNewlineNewline = false; /* -j switch */
/* whether or not, and why, we were canceled by conflict with recovery */
static volatile sig_atomic_t RecoveryConflictPending = false;
static volatile sig_atomic_t RecoveryConflictPendingReasons[NUM_PROCSIGNALS];
/* reused buffer to pass to SendRowDescriptionMessage() */
static MemoryContext row_description_context = NULL;
static StringInfoData row_description_buf;
/* ----------------------------------------------------------------
* decls for routines only used in this file
* ----------------------------------------------------------------
*/
static int InteractiveBackend(StringInfo inBuf);
static int interactive_getc(void);
static int SocketBackend(StringInfo inBuf);
static int ReadCommand(StringInfo inBuf);
static void forbidden_in_wal_sender(char firstchar);
static bool check_log_statement(List *stmt_list);
static int errdetail_execute(List *raw_parsetree_list);
static int errdetail_params(ParamListInfo params);
static int errdetail_abort(void);
static void bind_param_error_callback(void *arg);
static void start_xact_command(void);
static void finish_xact_command(void);
static bool IsTransactionExitStmt(Node *parsetree);
static bool IsTransactionExitStmtList(List *pstmts);
static bool IsTransactionStmtList(List *pstmts);
static void drop_unnamed_stmt(void);
static void log_disconnections(int code, Datum arg);
static void enable_statement_timeout(void);
static void disable_statement_timeout(void);
/* ----------------------------------------------------------------
* infrastructure for valgrind debugging
* ----------------------------------------------------------------
*/
#ifdef USE_VALGRIND
/* This variable should be set at the top of the main loop. */
static unsigned int old_valgrind_error_count;
/*
* If Valgrind detected any errors since old_valgrind_error_count was updated,
* report the current query as the cause. This should be called at the end
* of message processing.
*/
static void
valgrind_report_error_query(const char *query)
{
unsigned int valgrind_error_count = VALGRIND_COUNT_ERRORS;
if (unlikely(valgrind_error_count != old_valgrind_error_count) &&
query != NULL)
VALGRIND_PRINTF("Valgrind detected %u error(s) during execution of \"%s\"\n",
valgrind_error_count - old_valgrind_error_count,
query);
}
#else /* !USE_VALGRIND */
#define valgrind_report_error_query(query) ((void) 0)
#endif /* USE_VALGRIND */
/* ----------------------------------------------------------------
* routines to obtain user input
* ----------------------------------------------------------------
*/
/* ----------------
* InteractiveBackend() is called for user interactive connections
*
* the string entered by the user is placed in its parameter inBuf,
* and we act like a Q message was received.
*
* EOF is returned if end-of-file input is seen; time to shut down.
* ----------------
*/
static int
InteractiveBackend(StringInfo inBuf)
{
int c; /* character read from getc() */
/*
* display a prompt and obtain input from the user
*/
printf("backend> ");
fflush(stdout);
resetStringInfo(inBuf);
/*
* Read characters until EOF or the appropriate delimiter is seen.
*/
while ((c = interactive_getc()) != EOF)
{
if (c == '\n')
{
if (UseSemiNewlineNewline)
{
/*
* In -j mode, semicolon followed by two newlines ends the
* command; otherwise treat newline as regular character.
*/
if (inBuf->len > 1 &&
inBuf->data[inBuf->len - 1] == '\n' &&
inBuf->data[inBuf->len - 2] == ';')
{
/* might as well drop the second newline */
break;
}
}
else
{
/*
* In plain mode, newline ends the command unless preceded by
* backslash.
*/
if (inBuf->len > 0 &&
inBuf->data[inBuf->len - 1] == '\\')
{
/* discard backslash from inBuf */
inBuf->data[--inBuf->len] = '\0';
/* discard newline too */
continue;
}
else
{
/* keep the newline character, but end the command */
appendStringInfoChar(inBuf, '\n');
break;
}
}
}
/* Not newline, or newline treated as regular character */
appendStringInfoChar(inBuf, (char) c);
}
/* No input before EOF signal means time to quit. */
if (c == EOF && inBuf->len == 0)
return EOF;
/*
* otherwise we have a user query so process it.
*/
/* Add '\0' to make it look the same as message case. */
appendStringInfoChar(inBuf, (char) '\0');
/*
* if the query echo flag was given, print the query..
*/
if (EchoQuery)
printf("statement: %s\n", inBuf->data);
fflush(stdout);
return 'Q';
}
/*
* interactive_getc -- collect one character from stdin
*
* Even though we are not reading from a "client" process, we still want to
* respond to signals, particularly SIGTERM/SIGQUIT.
*/
static int
interactive_getc(void)
{
int c;
/*
* This will not process catchup interrupts or notifications while
* reading. But those can't really be relevant for a standalone backend
* anyway. To properly handle SIGTERM there's a hack in die() that
* directly processes interrupts at this stage...
*/
CHECK_FOR_INTERRUPTS();
c = getc(stdin);
ProcessClientReadInterrupt(false);
return c;
}
/* ----------------
* SocketBackend() Is called for frontend-backend connections
*
* Returns the message type code, and loads message body data into inBuf.
*
* EOF is returned if the connection is lost.
* ----------------
*/
static int
SocketBackend(StringInfo inBuf)
{
int qtype;
int maxmsglen;
/*
* Get message type code from the frontend.
*/
HOLD_CANCEL_INTERRUPTS();
pq_startmsgread();
qtype = pq_getbyte();
if (qtype == EOF) /* frontend disconnected */
{
if (IsTransactionState())
ereport(COMMERROR,
(errcode(ERRCODE_CONNECTION_FAILURE),
errmsg("unexpected EOF on client connection with an open transaction")));
else
{
/*
* Can't send DEBUG log messages to client at this point. Since
* we're disconnecting right away, we don't need to restore
* whereToSendOutput.
*/
whereToSendOutput = DestNone;
ereport(DEBUG1,
(errcode(ERRCODE_CONNECTION_DOES_NOT_EXIST),
errmsg_internal("unexpected EOF on client connection")));
}
return qtype;
}
/*
* Validate message type code before trying to read body; if we have lost
* sync, better to say "command unknown" than to run out of memory because
* we used garbage as a length word. We can also select a type-dependent
* limit on what a sane length word could be. (The limit could be chosen
* more granularly, but it's not clear it's worth fussing over.)
*
* This also gives us a place to set the doing_extended_query_message flag
* as soon as possible.
*/
switch (qtype)
{
case PqMsg_Query:
maxmsglen = PQ_LARGE_MESSAGE_LIMIT;
doing_extended_query_message = false;
break;
case PqMsg_FunctionCall:
maxmsglen = PQ_LARGE_MESSAGE_LIMIT;
doing_extended_query_message = false;
break;
case PqMsg_Terminate:
maxmsglen = PQ_SMALL_MESSAGE_LIMIT;
doing_extended_query_message = false;
ignore_till_sync = false;
break;
case PqMsg_Bind:
case PqMsg_Parse:
maxmsglen = PQ_LARGE_MESSAGE_LIMIT;
doing_extended_query_message = true;
break;
case PqMsg_Close:
case PqMsg_Describe:
case PqMsg_Execute:
case PqMsg_Flush:
maxmsglen = PQ_SMALL_MESSAGE_LIMIT;
doing_extended_query_message = true;
break;
case PqMsg_Sync:
maxmsglen = PQ_SMALL_MESSAGE_LIMIT;
/* stop any active skip-till-Sync */
ignore_till_sync = false;
/* mark not-extended, so that a new error doesn't begin skip */
doing_extended_query_message = false;
break;
case PqMsg_CopyData:
maxmsglen = PQ_LARGE_MESSAGE_LIMIT;
doing_extended_query_message = false;
break;
case PqMsg_CopyDone:
case PqMsg_CopyFail:
maxmsglen = PQ_SMALL_MESSAGE_LIMIT;
doing_extended_query_message = false;
break;
default:
/*
* Otherwise we got garbage from the frontend. We treat this as
* fatal because we have probably lost message boundary sync, and
* there's no good way to recover.
*/
ereport(FATAL,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid frontend message type %d", qtype)));
maxmsglen = 0; /* keep compiler quiet */
break;
}
/*
* In protocol version 3, all frontend messages have a length word next
* after the type code; we can read the message contents independently of
* the type.
*/
if (pq_getmessage(inBuf, maxmsglen))
return EOF; /* suitable message already logged */
RESUME_CANCEL_INTERRUPTS();
return qtype;
}
/* ----------------
* ReadCommand reads a command from either the frontend or
* standard input, places it in inBuf, and returns the
* message type code (first byte of the message).
* EOF is returned if end of file.
* ----------------
*/
static int
ReadCommand(StringInfo inBuf)
{
int result;
if (whereToSendOutput == DestRemote)
result = SocketBackend(inBuf);
else
result = InteractiveBackend(inBuf);
return result;
}
/*
* ProcessClientReadInterrupt() - Process interrupts specific to client reads
*
* This is called just before and after low-level reads.
* 'blocked' is true if no data was available to read and we plan to retry,
* false if about to read or done reading.
*
* Must preserve errno!
*/
void
ProcessClientReadInterrupt(bool blocked)
{
int save_errno = errno;
if (DoingCommandRead)
{
/* Check for general interrupts that arrived before/while reading */
CHECK_FOR_INTERRUPTS();
/* Process sinval catchup interrupts, if any */
if (catchupInterruptPending)
ProcessCatchupInterrupt();
/* Process notify interrupts, if any */
if (notifyInterruptPending)
ProcessNotifyInterrupt(true);
}
else if (ProcDiePending)
{
/*
* We're dying. If there is no data available to read, then it's safe
* (and sane) to handle that now. If we haven't tried to read yet,
* make sure the process latch is set, so that if there is no data
* then we'll come back here and die. If we're done reading, also
* make sure the process latch is set, as we might've undesirably
* cleared it while reading.
*/
if (blocked)
CHECK_FOR_INTERRUPTS();
else
SetLatch(MyLatch);
}
errno = save_errno;
}
/*
* ProcessClientWriteInterrupt() - Process interrupts specific to client writes
*
* This is called just before and after low-level writes.
* 'blocked' is true if no data could be written and we plan to retry,
* false if about to write or done writing.
*
* Must preserve errno!
*/
void
ProcessClientWriteInterrupt(bool blocked)
{
int save_errno = errno;
if (ProcDiePending)
{
/*
* We're dying. If it's not possible to write, then we should handle
* that immediately, else a stuck client could indefinitely delay our
* response to the signal. If we haven't tried to write yet, make
* sure the process latch is set, so that if the write would block
* then we'll come back here and die. If we're done writing, also
* make sure the process latch is set, as we might've undesirably
* cleared it while writing.
*/
if (blocked)
{
/*
* Don't mess with whereToSendOutput if ProcessInterrupts wouldn't
* service ProcDiePending.
*/
if (InterruptHoldoffCount == 0 && CritSectionCount == 0)
{
/*
* We don't want to send the client the error message, as a)
* that would possibly block again, and b) it would likely
* lead to loss of protocol sync because we may have already
* sent a partial protocol message.
*/
if (whereToSendOutput == DestRemote)
whereToSendOutput = DestNone;
CHECK_FOR_INTERRUPTS();
}
}
else
SetLatch(MyLatch);
}
errno = save_errno;
}
/*
* Do raw parsing (only).
*
* A list of parsetrees (RawStmt nodes) is returned, since there might be
* multiple commands in the given string.
*
* NOTE: for interactive queries, it is important to keep this routine
* separate from the analysis & rewrite stages. Analysis and rewriting
* cannot be done in an aborted transaction, since they require access to
* database tables. So, we rely on the raw parser to determine whether
* we've seen a COMMIT or ABORT command; when we are in abort state, other
* commands are not processed any further than the raw parse stage.
*/
List *
pg_parse_query(const char *query_string)
{
List *raw_parsetree_list;
TRACE_POSTGRESQL_QUERY_PARSE_START(query_string);
if (log_parser_stats)
ResetUsage();
raw_parsetree_list = raw_parser(query_string, RAW_PARSE_DEFAULT);
if (log_parser_stats)
ShowUsage("PARSER STATISTICS");
#ifdef COPY_PARSE_PLAN_TREES
/* Optional debugging check: pass raw parsetrees through copyObject() */
{
List *new_list = copyObject(raw_parsetree_list);
/* This checks both copyObject() and the equal() routines... */
if (!equal(new_list, raw_parsetree_list))
elog(WARNING, "copyObject() failed to produce an equal raw parse tree");
else
raw_parsetree_list = new_list;
}
#endif
/*
* Optional debugging check: pass raw parsetrees through
* outfuncs/readfuncs
*/
#ifdef WRITE_READ_PARSE_PLAN_TREES
{
char *str = nodeToStringWithLocations(raw_parsetree_list);
List *new_list = stringToNodeWithLocations(str);
pfree(str);
/* This checks both outfuncs/readfuncs and the equal() routines... */
if (!equal(new_list, raw_parsetree_list))
elog(WARNING, "outfuncs/readfuncs failed to produce an equal raw parse tree");
else
raw_parsetree_list = new_list;
}
#endif
TRACE_POSTGRESQL_QUERY_PARSE_DONE(query_string);
return raw_parsetree_list;
}
/*
* Given a raw parsetree (gram.y output), and optionally information about
* types of parameter symbols ($n), perform parse analysis and rule rewriting.
*
* A list of Query nodes is returned, since either the analyzer or the
* rewriter might expand one query to several.
*
* NOTE: for reasons mentioned above, this must be separate from raw parsing.
*/
List *
pg_analyze_and_rewrite_fixedparams(RawStmt *parsetree,
const char *query_string,
const Oid *paramTypes,
int numParams,
QueryEnvironment *queryEnv)
{
Query *query;
List *querytree_list;
TRACE_POSTGRESQL_QUERY_REWRITE_START(query_string);
/*
* (1) Perform parse analysis.
*/
if (log_parser_stats)
ResetUsage();
query = parse_analyze_fixedparams(parsetree, query_string, paramTypes, numParams,
queryEnv);
if (log_parser_stats)
ShowUsage("PARSE ANALYSIS STATISTICS");
/*
* (2) Rewrite the queries, as necessary
*/
querytree_list = pg_rewrite_query(query);
TRACE_POSTGRESQL_QUERY_REWRITE_DONE(query_string);
return querytree_list;
}
/*
* Do parse analysis and rewriting. This is the same as
* pg_analyze_and_rewrite_fixedparams except that it's okay to deduce
* information about $n symbol datatypes from context.
*/
List *
pg_analyze_and_rewrite_varparams(RawStmt *parsetree,
const char *query_string,
Oid **paramTypes,
int *numParams,
QueryEnvironment *queryEnv)
{
Query *query;
List *querytree_list;
TRACE_POSTGRESQL_QUERY_REWRITE_START(query_string);
/*
* (1) Perform parse analysis.
*/
if (log_parser_stats)
ResetUsage();
query = parse_analyze_varparams(parsetree, query_string, paramTypes, numParams,
queryEnv);
/*
* Check all parameter types got determined.
*/
for (int i = 0; i < *numParams; i++)
{
Oid ptype = (*paramTypes)[i];
if (ptype == InvalidOid || ptype == UNKNOWNOID)
ereport(ERROR,
(errcode(ERRCODE_INDETERMINATE_DATATYPE),
errmsg("could not determine data type of parameter $%d",
i + 1)));
}
if (log_parser_stats)
ShowUsage("PARSE ANALYSIS STATISTICS");
/*
* (2) Rewrite the queries, as necessary
*/
querytree_list = pg_rewrite_query(query);
TRACE_POSTGRESQL_QUERY_REWRITE_DONE(query_string);
return querytree_list;
}
/*
* Do parse analysis and rewriting. This is the same as
* pg_analyze_and_rewrite_fixedparams except that, instead of a fixed list of
* parameter datatypes, a parser callback is supplied that can do
* external-parameter resolution and possibly other things.
*/
List *
pg_analyze_and_rewrite_withcb(RawStmt *parsetree,
const char *query_string,
ParserSetupHook parserSetup,
void *parserSetupArg,
QueryEnvironment *queryEnv)
{
Query *query;
List *querytree_list;
TRACE_POSTGRESQL_QUERY_REWRITE_START(query_string);
/*
* (1) Perform parse analysis.
*/
if (log_parser_stats)
ResetUsage();
query = parse_analyze_withcb(parsetree, query_string, parserSetup, parserSetupArg,
queryEnv);
if (log_parser_stats)
ShowUsage("PARSE ANALYSIS STATISTICS");
/*
* (2) Rewrite the queries, as necessary
*/
querytree_list = pg_rewrite_query(query);
TRACE_POSTGRESQL_QUERY_REWRITE_DONE(query_string);
return querytree_list;
}
/*
* Perform rewriting of a query produced by parse analysis.
*
* Note: query must just have come from the parser, because we do not do
* AcquireRewriteLocks() on it.
*/
List *
pg_rewrite_query(Query *query)
{
List *querytree_list;
if (Debug_print_parse)
elog_node_display(LOG, "parse tree", query,
Debug_pretty_print);
if (log_parser_stats)
ResetUsage();
if (query->commandType == CMD_UTILITY)
{
/* don't rewrite utilities, just dump 'em into result list */
querytree_list = list_make1(query);
}
else
{
/* rewrite regular queries */
querytree_list = QueryRewrite(query);
}
if (log_parser_stats)
ShowUsage("REWRITER STATISTICS");
#ifdef COPY_PARSE_PLAN_TREES
/* Optional debugging check: pass querytree through copyObject() */
{
List *new_list;
new_list = copyObject(querytree_list);
/* This checks both copyObject() and the equal() routines... */
if (!equal(new_list, querytree_list))
elog(WARNING, "copyObject() failed to produce an equal rewritten parse tree");
else
querytree_list = new_list;
}
#endif
#ifdef WRITE_READ_PARSE_PLAN_TREES
/* Optional debugging check: pass querytree through outfuncs/readfuncs */
{
List *new_list = NIL;
ListCell *lc;
foreach(lc, querytree_list)
{
Query *curr_query = lfirst_node(Query, lc);
char *str = nodeToStringWithLocations(curr_query);
Query *new_query = stringToNodeWithLocations(str);
/*
* queryId is not saved in stored rules, but we must preserve it
* here to avoid breaking pg_stat_statements.
*/
new_query->queryId = curr_query->queryId;
new_list = lappend(new_list, new_query);
pfree(str);
}
/* This checks both outfuncs/readfuncs and the equal() routines... */
if (!equal(new_list, querytree_list))
elog(WARNING, "outfuncs/readfuncs failed to produce an equal rewritten parse tree");
else
querytree_list = new_list;
}
#endif
if (Debug_print_rewritten)
elog_node_display(LOG, "rewritten parse tree", querytree_list,
Debug_pretty_print);
return querytree_list;
}
/*
* Generate a plan for a single already-rewritten query.
* This is a thin wrapper around planner() and takes the same parameters.
*/
PlannedStmt *
pg_plan_query(Query *querytree, const char *query_string, int cursorOptions,
ParamListInfo boundParams)
{
PlannedStmt *plan;
/* Utility commands have no plans. */
if (querytree->commandType == CMD_UTILITY)
return NULL;
/* Planner must have a snapshot in case it calls user-defined functions. */
Assert(ActiveSnapshotSet());
TRACE_POSTGRESQL_QUERY_PLAN_START();
if (log_planner_stats)
ResetUsage();
/* call the optimizer */
plan = planner(querytree, query_string, cursorOptions, boundParams);
if (log_planner_stats)
ShowUsage("PLANNER STATISTICS");
#ifdef COPY_PARSE_PLAN_TREES
/* Optional debugging check: pass plan tree through copyObject() */
{
PlannedStmt *new_plan = copyObject(plan);
/*
* equal() currently does not have routines to compare Plan nodes, so
* don't try to test equality here. Perhaps fix someday?
*/
#ifdef NOT_USED
/* This checks both copyObject() and the equal() routines... */
if (!equal(new_plan, plan))
elog(WARNING, "copyObject() failed to produce an equal plan tree");
else
#endif
plan = new_plan;
}
#endif
#ifdef WRITE_READ_PARSE_PLAN_TREES
/* Optional debugging check: pass plan tree through outfuncs/readfuncs */
{
char *str;
PlannedStmt *new_plan;
str = nodeToStringWithLocations(plan);
new_plan = stringToNodeWithLocations(str);
pfree(str);
/*
* equal() currently does not have routines to compare Plan nodes, so
* don't try to test equality here. Perhaps fix someday?
*/
#ifdef NOT_USED
/* This checks both outfuncs/readfuncs and the equal() routines... */
if (!equal(new_plan, plan))
elog(WARNING, "outfuncs/readfuncs failed to produce an equal plan tree");
else
#endif
plan = new_plan;
}
#endif
/*
* Print plan if debugging.
*/
if (Debug_print_plan)
elog_node_display(LOG, "plan", plan, Debug_pretty_print);
TRACE_POSTGRESQL_QUERY_PLAN_DONE();
return plan;
}
/*
* Generate plans for a list of already-rewritten queries.
*
* For normal optimizable statements, invoke the planner. For utility
* statements, just make a wrapper PlannedStmt node.
*
* The result is a list of PlannedStmt nodes.
*/
List *
pg_plan_queries(List *querytrees, const char *query_string, int cursorOptions,
ParamListInfo boundParams)
{
List *stmt_list = NIL;
ListCell *query_list;
foreach(query_list, querytrees)
{
Query *query = lfirst_node(Query, query_list);
PlannedStmt *stmt;
if (query->commandType == CMD_UTILITY)
{
/* Utility commands require no planning. */
stmt = makeNode(PlannedStmt);
stmt->commandType = CMD_UTILITY;
stmt->canSetTag = query->canSetTag;
stmt->utilityStmt = query->utilityStmt;
stmt->stmt_location = query->stmt_location;
stmt->stmt_len = query->stmt_len;
stmt->queryId = query->queryId;
}
else
{
stmt = pg_plan_query(query, query_string, cursorOptions,
boundParams);
}
stmt_list = lappend(stmt_list, stmt);
}
return stmt_list;
}
/*
* exec_simple_query
*
* Execute a "simple Query" protocol message.
*/
static void
exec_simple_query(const char *query_string)
{
CommandDest dest = whereToSendOutput;
MemoryContext oldcontext;
List *parsetree_list;
ListCell *parsetree_item;
bool save_log_statement_stats = log_statement_stats;
bool was_logged = false;
bool use_implicit_block;
char msec_str[32];
/*
* Report query to various monitoring facilities.
*/
debug_query_string = query_string;
pgstat_report_activity(STATE_RUNNING, query_string);
TRACE_POSTGRESQL_QUERY_START(query_string);
/*
* We use save_log_statement_stats so ShowUsage doesn't report incorrect
* results because ResetUsage wasn't called.
*/
if (save_log_statement_stats)
ResetUsage();
/*
* Start up a transaction command. All queries generated by the
* query_string will be in this same command block, *unless* we find a
* BEGIN/COMMIT/ABORT statement; we have to force a new xact command after
* one of those, else bad things will happen in xact.c. (Note that this
* will normally change current memory context.)
*/
start_xact_command();
/*
* Zap any pre-existing unnamed statement. (While not strictly necessary,
* it seems best to define simple-Query mode as if it used the unnamed
* statement and portal; this ensures we recover any storage used by prior
* unnamed operations.)
*/
drop_unnamed_stmt();
/*
* Switch to appropriate context for constructing parsetrees.
*/
oldcontext = MemoryContextSwitchTo(MessageContext);
/*
* Do basic parsing of the query or queries (this should be safe even if
* we are in aborted transaction state!)
*/
parsetree_list = pg_parse_query(query_string);
/* Log immediately if dictated by log_statement */
if (check_log_statement(parsetree_list))
{
ereport(LOG,
(errmsg("statement: %s", query_string),
errhidestmt(true),
errdetail_execute(parsetree_list)));
was_logged = true;
}
/*
* Switch back to transaction context to enter the loop.
*/
MemoryContextSwitchTo(oldcontext);
/*
* For historical reasons, if multiple SQL statements are given in a
* single "simple Query" message, we execute them as a single transaction,
* unless explicit transaction control commands are included to make
* portions of the list be separate transactions. To represent this
* behavior properly in the transaction machinery, we use an "implicit"
* transaction block.
*/
use_implicit_block = (list_length(parsetree_list) > 1);
/*
* Run through the raw parsetree(s) and process each one.
*/
foreach(parsetree_item, parsetree_list)
{
RawStmt *parsetree = lfirst_node(RawStmt, parsetree_item);
bool snapshot_set = false;
CommandTag commandTag;
QueryCompletion qc;
MemoryContext per_parsetree_context = NULL;
List *querytree_list,
*plantree_list;
Portal portal;
DestReceiver *receiver;
int16 format;
const char *cmdtagname;
size_t cmdtaglen;
pgstat_report_query_id(0, true);
/*
* Get the command name for use in status display (it also becomes the
* default completion tag, down inside PortalRun). Set ps_status and
* do any special start-of-SQL-command processing needed by the
* destination.
*/
commandTag = CreateCommandTag(parsetree->stmt);
cmdtagname = GetCommandTagNameAndLen(commandTag, &cmdtaglen);
set_ps_display_with_len(cmdtagname, cmdtaglen);
BeginCommand(commandTag, dest);
/*
* If we are in an aborted transaction, reject all commands except
* COMMIT/ABORT. It is important that this test occur before we try
* to do parse analysis, rewrite, or planning, since all those phases
* try to do database accesses, which may fail in abort state. (It
* might be safe to allow some additional utility commands in this
* state, but not many...)
*/
if (IsAbortedTransactionBlockState() &&
!IsTransactionExitStmt(parsetree->stmt))
ereport(ERROR,
(errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
errmsg("current transaction is aborted, "
"commands ignored until end of transaction block"),
errdetail_abort()));
/* Make sure we are in a transaction command */
start_xact_command();
/*
* If using an implicit transaction block, and we're not already in a
* transaction block, start an implicit block to force this statement
* to be grouped together with any following ones. (We must do this
* each time through the loop; otherwise, a COMMIT/ROLLBACK in the
* list would cause later statements to not be grouped.)
*/
if (use_implicit_block)
BeginImplicitTransactionBlock();
/* If we got a cancel signal in parsing or prior command, quit */
CHECK_FOR_INTERRUPTS();
/*
* Set up a snapshot if parse analysis/planning will need one.
*/
if (analyze_requires_snapshot(parsetree))
{
PushActiveSnapshot(GetTransactionSnapshot());
snapshot_set = true;
}
/*
* OK to analyze, rewrite, and plan this query.
*
* Switch to appropriate context for constructing query and plan trees
* (these can't be in the transaction context, as that will get reset
* when the command is COMMIT/ROLLBACK). If we have multiple
* parsetrees, we use a separate context for each one, so that we can
* free that memory before moving on to the next one. But for the
* last (or only) parsetree, just use MessageContext, which will be
* reset shortly after completion anyway. In event of an error, the
* per_parsetree_context will be deleted when MessageContext is reset.
*/
if (lnext(parsetree_list, parsetree_item) != NULL)
{
per_parsetree_context =
AllocSetContextCreate(MessageContext,
"per-parsetree message context",
ALLOCSET_DEFAULT_SIZES);
oldcontext = MemoryContextSwitchTo(per_parsetree_context);
}
else
oldcontext = MemoryContextSwitchTo(MessageContext);
querytree_list = pg_analyze_and_rewrite_fixedparams(parsetree, query_string,
NULL, 0, NULL);
plantree_list = pg_plan_queries(querytree_list, query_string,
CURSOR_OPT_PARALLEL_OK, NULL);
/*
* Done with the snapshot used for parsing/planning.
*
* While it looks promising to reuse the same snapshot for query
* execution (at least for simple protocol), unfortunately it causes
* execution to use a snapshot that has been acquired before locking
* any of the tables mentioned in the query. This creates user-
* visible anomalies, so refrain. Refer to
* https://postgr.es/m/flat/5075D8DF.6050500@fuzzy.cz for details.
*/
if (snapshot_set)
PopActiveSnapshot();
/* If we got a cancel signal in analysis or planning, quit */
CHECK_FOR_INTERRUPTS();
/*
* Create unnamed portal to run the query or queries in. If there
* already is one, silently drop it.
*/
portal = CreatePortal("", true, true);
/* Don't display the portal in pg_cursors */
portal->visible = false;
/*
* We don't have to copy anything into the portal, because everything
* we are passing here is in MessageContext or the
* per_parsetree_context, and so will outlive the portal anyway.
*/
PortalDefineQuery(portal,
NULL,
query_string,
commandTag,
plantree_list,
NULL);
/*
* Start the portal. No parameters here.
*/
PortalStart(portal, NULL, 0, InvalidSnapshot);
/*
* Select the appropriate output format: text unless we are doing a
* FETCH from a binary cursor. (Pretty grotty to have to do this here
* --- but it avoids grottiness in other places. Ah, the joys of
* backward compatibility...)
*/
format = 0; /* TEXT is default */
if (IsA(parsetree->stmt, FetchStmt))
{
FetchStmt *stmt = (FetchStmt *) parsetree->stmt;
if (!stmt->ismove)
{
Portal fportal = GetPortalByName(stmt->portalname);
if (PortalIsValid(fportal) &&
(fportal->cursorOptions & CURSOR_OPT_BINARY))
format = 1; /* BINARY */
}
}
PortalSetResultFormat(portal, 1, &format);
/*
* Now we can create the destination receiver object.
*/
receiver = CreateDestReceiver(dest);
if (dest == DestRemote)
SetRemoteDestReceiverParams(receiver, portal);
/*
* Switch back to transaction context for execution.
*/
MemoryContextSwitchTo(oldcontext);
/*
* Run the portal to completion, and then drop it (and the receiver).
*/
(void) PortalRun(portal,
FETCH_ALL,
true, /* always top level */
true,
receiver,
receiver,
&qc);
receiver->rDestroy(receiver);
PortalDrop(portal, false);
if (lnext(parsetree_list, parsetree_item) == NULL)
{
/*
* If this is the last parsetree of the query string, close down
* transaction statement before reporting command-complete. This
* is so that any end-of-transaction errors are reported before
* the command-complete message is issued, to avoid confusing
* clients who will expect either a command-complete message or an
* error, not one and then the other. Also, if we're using an
* implicit transaction block, we must close that out first.
*/
if (use_implicit_block)
EndImplicitTransactionBlock();
finish_xact_command();
}
else if (IsA(parsetree->stmt, TransactionStmt))
{
/*
* If this was a transaction control statement, commit it. We will
* start a new xact command for the next command.
*/
finish_xact_command();
}
else
{
/*
* We had better not see XACT_FLAGS_NEEDIMMEDIATECOMMIT set if
* we're not calling finish_xact_command(). (The implicit
* transaction block should have prevented it from getting set.)
*/
Assert(!(MyXactFlags & XACT_FLAGS_NEEDIMMEDIATECOMMIT));
/*
* We need a CommandCounterIncrement after every query, except
* those that start or end a transaction block.
*/
CommandCounterIncrement();
/*
* Disable statement timeout between queries of a multi-query
* string, so that the timeout applies separately to each query.
* (Our next loop iteration will start a fresh timeout.)
*/
disable_statement_timeout();
}
/*
* Tell client that we're done with this query. Note we emit exactly
* one EndCommand report for each raw parsetree, thus one for each SQL
* command the client sent, regardless of rewriting. (But a command
* aborted by error will not send an EndCommand report at all.)
*/
EndCommand(&qc, dest, false);
/* Now we may drop the per-parsetree context, if one was created. */
if (per_parsetree_context)
MemoryContextDelete(per_parsetree_context);
} /* end loop over parsetrees */
/*
* Close down transaction statement, if one is open. (This will only do
* something if the parsetree list was empty; otherwise the last loop
* iteration already did it.)
*/
finish_xact_command();
/*
* If there were no parsetrees, return EmptyQueryResponse message.
*/
if (!parsetree_list)
NullCommand(dest);
/*
* Emit duration logging if appropriate.
*/
switch (check_log_duration(msec_str, was_logged))
{
case 1:
ereport(LOG,
(errmsg("duration: %s ms", msec_str),
errhidestmt(true)));
break;
case 2:
ereport(LOG,
(errmsg("duration: %s ms statement: %s",
msec_str, query_string),
errhidestmt(true),
errdetail_execute(parsetree_list)));
break;
}
if (save_log_statement_stats)
ShowUsage("QUERY STATISTICS");
TRACE_POSTGRESQL_QUERY_DONE(query_string);
debug_query_string = NULL;
}
/*
* exec_parse_message
*
* Execute a "Parse" protocol message.
*/
static void
exec_parse_message(const char *query_string, /* string to execute */
const char *stmt_name, /* name for prepared stmt */
Oid *paramTypes, /* parameter types */
int numParams) /* number of parameters */
{
MemoryContext unnamed_stmt_context = NULL;
MemoryContext oldcontext;
List *parsetree_list;
RawStmt *raw_parse_tree;
List *querytree_list;
CachedPlanSource *psrc;
bool is_named;
bool save_log_statement_stats = log_statement_stats;
char msec_str[32];
/*
* Report query to various monitoring facilities.
*/
debug_query_string = query_string;
pgstat_report_activity(STATE_RUNNING, query_string);
set_ps_display("PARSE");
if (save_log_statement_stats)
ResetUsage();
ereport(DEBUG2,
(errmsg_internal("parse %s: %s",
*stmt_name ? stmt_name : "<unnamed>",
query_string)));
/*
* Start up a transaction command so we can run parse analysis etc. (Note
* that this will normally change current memory context.) Nothing happens
* if we are already in one. This also arms the statement timeout if
* necessary.
*/
start_xact_command();
/*
* Switch to appropriate context for constructing parsetrees.
*
* We have two strategies depending on whether the prepared statement is
* named or not. For a named prepared statement, we do parsing in
* MessageContext and copy the finished trees into the prepared
* statement's plancache entry; then the reset of MessageContext releases
* temporary space used by parsing and rewriting. For an unnamed prepared
* statement, we assume the statement isn't going to hang around long, so
* getting rid of temp space quickly is probably not worth the costs of
* copying parse trees. So in this case, we create the plancache entry's
* query_context here, and do all the parsing work therein.
*/
is_named = (stmt_name[0] != '\0');
if (is_named)
{
/* Named prepared statement --- parse in MessageContext */
oldcontext = MemoryContextSwitchTo(MessageContext);
}
else
{
/* Unnamed prepared statement --- release any prior unnamed stmt */
drop_unnamed_stmt();
/* Create context for parsing */
unnamed_stmt_context =
AllocSetContextCreate(MessageContext,
"unnamed prepared statement",
ALLOCSET_DEFAULT_SIZES);
oldcontext = MemoryContextSwitchTo(unnamed_stmt_context);
}
/*
* Do basic parsing of the query or queries (this should be safe even if
* we are in aborted transaction state!)
*/
parsetree_list = pg_parse_query(query_string);
/*
* We only allow a single user statement in a prepared statement. This is
* mainly to keep the protocol simple --- otherwise we'd need to worry
* about multiple result tupdescs and things like that.
*/
if (list_length(parsetree_list) > 1)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot insert multiple commands into a prepared statement")));
if (parsetree_list != NIL)
{
bool snapshot_set = false;
raw_parse_tree = linitial_node(RawStmt, parsetree_list);
/*
* If we are in an aborted transaction, reject all commands except
* COMMIT/ROLLBACK. It is important that this test occur before we
* try to do parse analysis, rewrite, or planning, since all those
* phases try to do database accesses, which may fail in abort state.
* (It might be safe to allow some additional utility commands in this
* state, but not many...)
*/
if (IsAbortedTransactionBlockState() &&
!IsTransactionExitStmt(raw_parse_tree->stmt))
ereport(ERROR,
(errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
errmsg("current transaction is aborted, "
"commands ignored until end of transaction block"),
errdetail_abort()));
/*
* Create the CachedPlanSource before we do parse analysis, since it
* needs to see the unmodified raw parse tree.
*/
psrc = CreateCachedPlan(raw_parse_tree, query_string,
CreateCommandTag(raw_parse_tree->stmt));
/*
* Set up a snapshot if parse analysis will need one.
*/
if (analyze_requires_snapshot(raw_parse_tree))
{
PushActiveSnapshot(GetTransactionSnapshot());
snapshot_set = true;
}
/*
* Analyze and rewrite the query. Note that the originally specified
* parameter set is not required to be complete, so we have to use
* pg_analyze_and_rewrite_varparams().
*/
querytree_list = pg_analyze_and_rewrite_varparams(raw_parse_tree,
query_string,
&paramTypes,
&numParams,
NULL);
/* Done with the snapshot used for parsing */
if (snapshot_set)
PopActiveSnapshot();
}
else
{
/* Empty input string. This is legal. */
raw_parse_tree = NULL;
psrc = CreateCachedPlan(raw_parse_tree, query_string,
CMDTAG_UNKNOWN);
querytree_list = NIL;
}
/*
* CachedPlanSource must be a direct child of MessageContext before we
* reparent unnamed_stmt_context under it, else we have a disconnected
* circular subgraph. Klugy, but less so than flipping contexts even more
* above.
*/
if (unnamed_stmt_context)
MemoryContextSetParent(psrc->context, MessageContext);
/* Finish filling in the CachedPlanSource */
CompleteCachedPlan(psrc,
querytree_list,
unnamed_stmt_context,
paramTypes,
numParams,
NULL,
NULL,
CURSOR_OPT_PARALLEL_OK, /* allow parallel mode */
true); /* fixed result */
/* If we got a cancel signal during analysis, quit */
CHECK_FOR_INTERRUPTS();
if (is_named)
{
/*
* Store the query as a prepared statement.
*/
StorePreparedStatement(stmt_name, psrc, false);
}
else
{
/*
* We just save the CachedPlanSource into unnamed_stmt_psrc.
*/
SaveCachedPlan(psrc);
unnamed_stmt_psrc = psrc;
}
MemoryContextSwitchTo(oldcontext);
/*
* We do NOT close the open transaction command here; that only happens
* when the client sends Sync. Instead, do CommandCounterIncrement just
* in case something happened during parse/plan.
*/
CommandCounterIncrement();
/*
* Send ParseComplete.
*/
if (whereToSendOutput == DestRemote)
pq_putemptymessage(PqMsg_ParseComplete);
/*
* Emit duration logging if appropriate.
*/
switch (check_log_duration(msec_str, false))
{
case 1:
ereport(LOG,
(errmsg("duration: %s ms", msec_str),
errhidestmt(true)));
break;
case 2:
ereport(LOG,
(errmsg("duration: %s ms parse %s: %s",
msec_str,
*stmt_name ? stmt_name : "<unnamed>",
query_string),
errhidestmt(true)));
break;
}
if (save_log_statement_stats)
ShowUsage("PARSE MESSAGE STATISTICS");
debug_query_string = NULL;
}
/*
* exec_bind_message
*
* Process a "Bind" message to create a portal from a prepared statement
*/
static void
exec_bind_message(StringInfo input_message)
{
const char *portal_name;
const char *stmt_name;
int numPFormats;
int16 *pformats = NULL;
int numParams;
int numRFormats;
int16 *rformats = NULL;
CachedPlanSource *psrc;
CachedPlan *cplan;
Portal portal;
char *query_string;
char *saved_stmt_name;
ParamListInfo params;
MemoryContext oldContext;
bool save_log_statement_stats = log_statement_stats;
bool snapshot_set = false;
char msec_str[32];
ParamsErrorCbData params_data;
ErrorContextCallback params_errcxt;
/* Get the fixed part of the message */
portal_name = pq_getmsgstring(input_message);
stmt_name = pq_getmsgstring(input_message);
ereport(DEBUG2,
(errmsg_internal("bind %s to %s",
*portal_name ? portal_name : "<unnamed>",
*stmt_name ? stmt_name : "<unnamed>")));
/* Find prepared statement */
if (stmt_name[0] != '\0')
{
PreparedStatement *pstmt;
pstmt = FetchPreparedStatement(stmt_name, true);
psrc = pstmt->plansource;
}
else
{
/* special-case the unnamed statement */
psrc = unnamed_stmt_psrc;
if (!psrc)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_PSTATEMENT),
errmsg("unnamed prepared statement does not exist")));
}
/*
* Report query to various monitoring facilities.
*/
debug_query_string = psrc->query_string;
pgstat_report_activity(STATE_RUNNING, psrc->query_string);
set_ps_display("BIND");
if (save_log_statement_stats)
ResetUsage();
/*
* Start up a transaction command so we can call functions etc. (Note that
* this will normally change current memory context.) Nothing happens if
* we are already in one. This also arms the statement timeout if
* necessary.
*/
start_xact_command();
/* Switch back to message context */
MemoryContextSwitchTo(MessageContext);
/* Get the parameter format codes */
numPFormats = pq_getmsgint(input_message, 2);
if (numPFormats > 0)
{
pformats = palloc_array(int16, numPFormats);
for (int i = 0; i < numPFormats; i++)
pformats[i] = pq_getmsgint(input_message, 2);
}
/* Get the parameter value count */
numParams = pq_getmsgint(input_message, 2);
if (numPFormats > 1 && numPFormats != numParams)
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("bind message has %d parameter formats but %d parameters",
numPFormats, numParams)));
if (numParams != psrc->num_params)
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("bind message supplies %d parameters, but prepared statement \"%s\" requires %d",
numParams, stmt_name, psrc->num_params)));
/*
* If we are in aborted transaction state, the only portals we can
* actually run are those containing COMMIT or ROLLBACK commands. We
* disallow binding anything else to avoid problems with infrastructure
* that expects to run inside a valid transaction. We also disallow
* binding any parameters, since we can't risk calling user-defined I/O
* functions.
*/
if (IsAbortedTransactionBlockState() &&
(!(psrc->raw_parse_tree &&
IsTransactionExitStmt(psrc->raw_parse_tree->stmt)) ||
numParams != 0))
ereport(ERROR,
(errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
errmsg("current transaction is aborted, "
"commands ignored until end of transaction block"),
errdetail_abort()));
/*
* Create the portal. Allow silent replacement of an existing portal only
* if the unnamed portal is specified.
*/
if (portal_name[0] == '\0')
portal = CreatePortal(portal_name, true, true);
else
portal = CreatePortal(portal_name, false, false);
/*
* Prepare to copy stuff into the portal's memory context. We do all this
* copying first, because it could possibly fail (out-of-memory) and we
* don't want a failure to occur between GetCachedPlan and
* PortalDefineQuery; that would result in leaking our plancache refcount.
*/
oldContext = MemoryContextSwitchTo(portal->portalContext);
/* Copy the plan's query string into the portal */
query_string = pstrdup(psrc->query_string);
/* Likewise make a copy of the statement name, unless it's unnamed */
if (stmt_name[0])
saved_stmt_name = pstrdup(stmt_name);
else
saved_stmt_name = NULL;
/*
* Set a snapshot if we have parameters to fetch (since the input
* functions might need it) or the query isn't a utility command (and
* hence could require redoing parse analysis and planning). We keep the
* snapshot active till we're done, so that plancache.c doesn't have to
* take new ones.
*/
if (numParams > 0 ||
(psrc->raw_parse_tree &&
analyze_requires_snapshot(psrc->raw_parse_tree)))
{
PushActiveSnapshot(GetTransactionSnapshot());
snapshot_set = true;
}
/*
* Fetch parameters, if any, and store in the portal's memory context.
*/
if (numParams > 0)
{
char **knownTextValues = NULL; /* allocate on first use */
BindParamCbData one_param_data;
/*
* Set up an error callback so that if there's an error in this phase,
* we can report the specific parameter causing the problem.
*/
one_param_data.portalName = portal->name;
one_param_data.paramno = -1;
one_param_data.paramval = NULL;
params_errcxt.previous = error_context_stack;
params_errcxt.callback = bind_param_error_callback;
params_errcxt.arg = (void *) &one_param_data;
error_context_stack = &params_errcxt;
params = makeParamList(numParams);
for (int paramno = 0; paramno < numParams; paramno++)
{
Oid ptype = psrc->param_types[paramno];
int32 plength;
Datum pval;
bool isNull;
StringInfoData pbuf;
char csave;
int16 pformat;
one_param_data.paramno = paramno;
one_param_data.paramval = NULL;
plength = pq_getmsgint(input_message, 4);
isNull = (plength == -1);
if (!isNull)
{
char *pvalue;
/*
* Rather than copying data around, we just initialize a
* StringInfo pointing to the correct portion of the message
* buffer. We assume we can scribble on the message buffer to
* add a trailing NUL which is required for the input function
* call.
*/
pvalue = unconstify(char *, pq_getmsgbytes(input_message, plength));
csave = pvalue[plength];
pvalue[plength] = '\0';
initReadOnlyStringInfo(&pbuf, pvalue, plength);
}
else
{
pbuf.data = NULL; /* keep compiler quiet */
csave = 0;
}
if (numPFormats > 1)
pformat = pformats[paramno];
else if (numPFormats > 0)
pformat = pformats[0];
else
pformat = 0; /* default = text */
if (pformat == 0) /* text mode */
{
Oid typinput;
Oid typioparam;
char *pstring;
getTypeInputInfo(ptype, &typinput, &typioparam);
/*
* We have to do encoding conversion before calling the
* typinput routine.
*/
if (isNull)
pstring = NULL;
else
pstring = pg_client_to_server(pbuf.data, plength);
/* Now we can log the input string in case of error */
one_param_data.paramval = pstring;
pval = OidInputFunctionCall(typinput, pstring, typioparam, -1);
one_param_data.paramval = NULL;
/*
* If we might need to log parameters later, save a copy of
* the converted string in MessageContext; then free the
* result of encoding conversion, if any was done.
*/
if (pstring)
{
if (log_parameter_max_length_on_error != 0)
{
MemoryContext oldcxt;
oldcxt = MemoryContextSwitchTo(MessageContext);
if (knownTextValues == NULL)
knownTextValues = palloc0_array(char *, numParams);
if (log_parameter_max_length_on_error < 0)
knownTextValues[paramno] = pstrdup(pstring);
else
{
/*
* We can trim the saved string, knowing that we
* won't print all of it. But we must copy at
* least two more full characters than
* BuildParamLogString wants to use; otherwise it
* might fail to include the trailing ellipsis.
*/
knownTextValues[paramno] =
pnstrdup(pstring,
log_parameter_max_length_on_error
+ 2 * MAX_MULTIBYTE_CHAR_LEN);
}
MemoryContextSwitchTo(oldcxt);
}
if (pstring != pbuf.data)
pfree(pstring);
}
}
else if (pformat == 1) /* binary mode */
{
Oid typreceive;
Oid typioparam;
StringInfo bufptr;
/*
* Call the parameter type's binary input converter
*/
getTypeBinaryInputInfo(ptype, &typreceive, &typioparam);
if (isNull)
bufptr = NULL;
else
bufptr = &pbuf;
pval = OidReceiveFunctionCall(typreceive, bufptr, typioparam, -1);
/* Trouble if it didn't eat the whole buffer */
if (!isNull && pbuf.cursor != pbuf.len)
ereport(ERROR,
(errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
errmsg("incorrect binary data format in bind parameter %d",
paramno + 1)));
}
else
{
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unsupported format code: %d",
pformat)));
pval = 0; /* keep compiler quiet */
}
/* Restore message buffer contents */
if (!isNull)
pbuf.data[plength] = csave;
params->params[paramno].value = pval;
params->params[paramno].isnull = isNull;
/*
* We mark the params as CONST. This ensures that any custom plan
* makes full use of the parameter values.
*/
params->params[paramno].pflags = PARAM_FLAG_CONST;
params->params[paramno].ptype = ptype;
}
/* Pop the per-parameter error callback */
error_context_stack = error_context_stack->previous;
/*
* Once all parameters have been received, prepare for printing them
* in future errors, if configured to do so. (This is saved in the
* portal, so that they'll appear when the query is executed later.)
*/
if (log_parameter_max_length_on_error != 0)
params->paramValuesStr =
BuildParamLogString(params,
knownTextValues,
log_parameter_max_length_on_error);
}
else
params = NULL;
/* Done storing stuff in portal's context */
MemoryContextSwitchTo(oldContext);
/*
* Set up another error callback so that all the parameters are logged if
* we get an error during the rest of the BIND processing.
*/
params_data.portalName = portal->name;
params_data.params = params;
params_errcxt.previous = error_context_stack;
params_errcxt.callback = ParamsErrorCallback;
params_errcxt.arg = (void *) &params_data;
error_context_stack = &params_errcxt;
/* Get the result format codes */
numRFormats = pq_getmsgint(input_message, 2);
if (numRFormats > 0)
{
rformats = palloc_array(int16, numRFormats);
for (int i = 0; i < numRFormats; i++)
rformats[i] = pq_getmsgint(input_message, 2);
}
pq_getmsgend(input_message);
/*
* Obtain a plan from the CachedPlanSource. Any cruft from (re)planning
* will be generated in MessageContext. The plan refcount will be
* assigned to the Portal, so it will be released at portal destruction.
*/
cplan = GetCachedPlan(psrc, params, NULL, NULL);
/*
* Now we can define the portal.
*
* DO NOT put any code that could possibly throw an error between the
* above GetCachedPlan call and here.
*/
PortalDefineQuery(portal,
saved_stmt_name,
query_string,
psrc->commandTag,
cplan->stmt_list,
cplan);
/* Done with the snapshot used for parameter I/O and parsing/planning */
if (snapshot_set)
PopActiveSnapshot();
/*
* And we're ready to start portal execution.
*/
PortalStart(portal, params, 0, InvalidSnapshot);
/*
* Apply the result format requests to the portal.
*/
PortalSetResultFormat(portal, numRFormats, rformats);
/*
* Done binding; remove the parameters error callback. Entries emitted
* later determine independently whether to log the parameters or not.
*/
error_context_stack = error_context_stack->previous;
/*
* Send BindComplete.
*/
if (whereToSendOutput == DestRemote)
pq_putemptymessage(PqMsg_BindComplete);
/*
* Emit duration logging if appropriate.
*/
switch (check_log_duration(msec_str, false))
{
case 1:
ereport(LOG,
(errmsg("duration: %s ms", msec_str),
errhidestmt(true)));
break;
case 2:
ereport(LOG,
(errmsg("duration: %s ms bind %s%s%s: %s",
msec_str,
*stmt_name ? stmt_name : "<unnamed>",
*portal_name ? "/" : "",
*portal_name ? portal_name : "",
psrc->query_string),
errhidestmt(true),
errdetail_params(params)));
break;
}
if (save_log_statement_stats)
ShowUsage("BIND MESSAGE STATISTICS");
valgrind_report_error_query(debug_query_string);
debug_query_string = NULL;
}
/*
* exec_execute_message
*
* Process an "Execute" message for a portal
*/
static void
exec_execute_message(const char *portal_name, long max_rows)
{
CommandDest dest;
DestReceiver *receiver;
Portal portal;
bool completed;
QueryCompletion qc;
const char *sourceText;
const char *prepStmtName;
ParamListInfo portalParams;
bool save_log_statement_stats = log_statement_stats;
bool is_xact_command;
bool execute_is_fetch;
bool was_logged = false;
char msec_str[32];
ParamsErrorCbData params_data;
ErrorContextCallback params_errcxt;
const char *cmdtagname;
size_t cmdtaglen;
/* Adjust destination to tell printtup.c what to do */
dest = whereToSendOutput;
if (dest == DestRemote)
dest = DestRemoteExecute;
portal = GetPortalByName(portal_name);
if (!PortalIsValid(portal))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_CURSOR),
errmsg("portal \"%s\" does not exist", portal_name)));
/*
* If the original query was a null string, just return
* EmptyQueryResponse.
*/
if (portal->commandTag == CMDTAG_UNKNOWN)
{
Assert(portal->stmts == NIL);
NullCommand(dest);
return;
}
/* Does the portal contain a transaction command? */
is_xact_command = IsTransactionStmtList(portal->stmts);
/*
* We must copy the sourceText and prepStmtName into MessageContext in
* case the portal is destroyed during finish_xact_command. We do not
* make a copy of the portalParams though, preferring to just not print
* them in that case.
*/
sourceText = pstrdup(portal->sourceText);
if (portal->prepStmtName)
prepStmtName = pstrdup(portal->prepStmtName);
else
prepStmtName = "<unnamed>";
portalParams = portal->portalParams;
/*
* Report query to various monitoring facilities.
*/
debug_query_string = sourceText;
pgstat_report_activity(STATE_RUNNING, sourceText);
cmdtagname = GetCommandTagNameAndLen(portal->commandTag, &cmdtaglen);
set_ps_display_with_len(cmdtagname, cmdtaglen);
if (save_log_statement_stats)
ResetUsage();
BeginCommand(portal->commandTag, dest);
/*
* Create dest receiver in MessageContext (we don't want it in transaction
* context, because that may get deleted if portal contains VACUUM).
*/
receiver = CreateDestReceiver(dest);
if (dest == DestRemoteExecute)
SetRemoteDestReceiverParams(receiver, portal);
/*
* Ensure we are in a transaction command (this should normally be the
* case already due to prior BIND).
*/
start_xact_command();
/*
* If we re-issue an Execute protocol request against an existing portal,
* then we are only fetching more rows rather than completely re-executing
* the query from the start. atStart is never reset for a v3 portal, so we
* are safe to use this check.
*/
execute_is_fetch = !portal->atStart;
/* Log immediately if dictated by log_statement */
if (check_log_statement(portal->stmts))
{
ereport(LOG,
(errmsg("%s %s%s%s: %s",
execute_is_fetch ?
_("execute fetch from") :
_("execute"),
prepStmtName,
*portal_name ? "/" : "",
*portal_name ? portal_name : "",
sourceText),
errhidestmt(true),
errdetail_params(portalParams)));
was_logged = true;
}
/*
* If we are in aborted transaction state, the only portals we can
* actually run are those containing COMMIT or ROLLBACK commands.
*/
if (IsAbortedTransactionBlockState() &&
!IsTransactionExitStmtList(portal->stmts))
ereport(ERROR,
(errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
errmsg("current transaction is aborted, "
"commands ignored until end of transaction block"),
errdetail_abort()));
/* Check for cancel signal before we start execution */
CHECK_FOR_INTERRUPTS();
/*
* Okay to run the portal. Set the error callback so that parameters are
* logged. The parameters must have been saved during the bind phase.
*/
params_data.portalName = portal->name;
params_data.params = portalParams;
params_errcxt.previous = error_context_stack;
params_errcxt.callback = ParamsErrorCallback;
params_errcxt.arg = (void *) &params_data;
error_context_stack = &params_errcxt;
if (max_rows <= 0)
max_rows = FETCH_ALL;
completed = PortalRun(portal,
max_rows,
true, /* always top level */
!execute_is_fetch && max_rows == FETCH_ALL,
receiver,
receiver,
&qc);
receiver->rDestroy(receiver);
/* Done executing; remove the params error callback */
error_context_stack = error_context_stack->previous;
if (completed)
{
if (is_xact_command || (MyXactFlags & XACT_FLAGS_NEEDIMMEDIATECOMMIT))
{
/*
* If this was a transaction control statement, commit it. We
* will start a new xact command for the next command (if any).
* Likewise if the statement required immediate commit. Without
* this provision, we wouldn't force commit until Sync is
* received, which creates a hazard if the client tries to
* pipeline immediate-commit statements.
*/
finish_xact_command();
/*
* These commands typically don't have any parameters, and even if
* one did we couldn't print them now because the storage went
* away during finish_xact_command. So pretend there were none.
*/
portalParams = NULL;
}
else
{
/*
* We need a CommandCounterIncrement after every query, except
* those that start or end a transaction block.
*/
CommandCounterIncrement();
/*
* Set XACT_FLAGS_PIPELINING whenever we complete an Execute
* message without immediately committing the transaction.
*/
MyXactFlags |= XACT_FLAGS_PIPELINING;
/*
* Disable statement timeout whenever we complete an Execute
* message. The next protocol message will start a fresh timeout.
*/
disable_statement_timeout();
}
/* Send appropriate CommandComplete to client */
EndCommand(&qc, dest, false);
}
else
{
/* Portal run not complete, so send PortalSuspended */
if (whereToSendOutput == DestRemote)
pq_putemptymessage(PqMsg_PortalSuspended);
/*
* Set XACT_FLAGS_PIPELINING whenever we suspend an Execute message,
* too.
*/
MyXactFlags |= XACT_FLAGS_PIPELINING;
}
/*
* Emit duration logging if appropriate.
*/
switch (check_log_duration(msec_str, was_logged))
{
case 1:
ereport(LOG,
(errmsg("duration: %s ms", msec_str),
errhidestmt(true)));
break;
case 2:
ereport(LOG,
(errmsg("duration: %s ms %s %s%s%s: %s",
msec_str,
execute_is_fetch ?
_("execute fetch from") :
_("execute"),
prepStmtName,
*portal_name ? "/" : "",
*portal_name ? portal_name : "",
sourceText),
errhidestmt(true),
errdetail_params(portalParams)));
break;
}
if (save_log_statement_stats)
ShowUsage("EXECUTE MESSAGE STATISTICS");
valgrind_report_error_query(debug_query_string);
debug_query_string = NULL;
}
/*
* check_log_statement
* Determine whether command should be logged because of log_statement
*
* stmt_list can be either raw grammar output or a list of planned
* statements
*/
static bool
check_log_statement(List *stmt_list)
{
ListCell *stmt_item;
if (log_statement == LOGSTMT_NONE)
return false;
if (log_statement == LOGSTMT_ALL)
return true;
/* Else we have to inspect the statement(s) to see whether to log */
foreach(stmt_item, stmt_list)
{
Node *stmt = (Node *) lfirst(stmt_item);
if (GetCommandLogLevel(stmt) <= log_statement)
return true;
}
return false;
}
/*
* check_log_duration
* Determine whether current command's duration should be logged
* We also check if this statement in this transaction must be logged
* (regardless of its duration).
*
* Returns:
* 0 if no logging is needed
* 1 if just the duration should be logged
* 2 if duration and query details should be logged
*
* If logging is needed, the duration in msec is formatted into msec_str[],
* which must be a 32-byte buffer.
*
* was_logged should be true if caller already logged query details (this
* essentially prevents 2 from being returned).
*/
int
check_log_duration(char *msec_str, bool was_logged)
{
if (log_duration || log_min_duration_sample >= 0 ||
log_min_duration_statement >= 0 || xact_is_sampled)
{
long secs;
int usecs;
int msecs;
bool exceeded_duration;
bool exceeded_sample_duration;
bool in_sample = false;
TimestampDifference(GetCurrentStatementStartTimestamp(),
GetCurrentTimestamp(),
&secs, &usecs);
msecs = usecs / 1000;
/*
* This odd-looking test for log_min_duration_* being exceeded is
* designed to avoid integer overflow with very long durations: don't
* compute secs * 1000 until we've verified it will fit in int.
*/
exceeded_duration = (log_min_duration_statement == 0 ||
(log_min_duration_statement > 0 &&
(secs > log_min_duration_statement / 1000 ||
secs * 1000 + msecs >= log_min_duration_statement)));
exceeded_sample_duration = (log_min_duration_sample == 0 ||
(log_min_duration_sample > 0 &&
(secs > log_min_duration_sample / 1000 ||
secs * 1000 + msecs >= log_min_duration_sample)));
/*
* Do not log if log_statement_sample_rate = 0. Log a sample if
* log_statement_sample_rate <= 1 and avoid unnecessary PRNG call if
* log_statement_sample_rate = 1.
*/
if (exceeded_sample_duration)
in_sample = log_statement_sample_rate != 0 &&
(log_statement_sample_rate == 1 ||
pg_prng_double(&pg_global_prng_state) <= log_statement_sample_rate);
if (exceeded_duration || in_sample || log_duration || xact_is_sampled)
{
snprintf(msec_str, 32, "%ld.%03d",
secs * 1000 + msecs, usecs % 1000);
if ((exceeded_duration || in_sample || xact_is_sampled) && !was_logged)
return 2;
else
return 1;
}
}
return 0;
}
/*
* errdetail_execute
*
* Add an errdetail() line showing the query referenced by an EXECUTE, if any.
* The argument is the raw parsetree list.
*/
static int
errdetail_execute(List *raw_parsetree_list)
{
ListCell *parsetree_item;
foreach(parsetree_item, raw_parsetree_list)
{
RawStmt *parsetree = lfirst_node(RawStmt, parsetree_item);
if (IsA(parsetree->stmt, ExecuteStmt))
{
ExecuteStmt *stmt = (ExecuteStmt *) parsetree->stmt;
PreparedStatement *pstmt;
pstmt = FetchPreparedStatement(stmt->name, false);
if (pstmt)
{
errdetail("prepare: %s", pstmt->plansource->query_string);
return 0;
}
}
}
return 0;
}
/*
* errdetail_params
*
* Add an errdetail() line showing bind-parameter data, if available.
* Note that this is only used for statement logging, so it is controlled
* by log_parameter_max_length not log_parameter_max_length_on_error.
*/
static int
errdetail_params(ParamListInfo params)
{
if (params && params->numParams > 0 && log_parameter_max_length != 0)
{
char *str;
str = BuildParamLogString(params, NULL, log_parameter_max_length);
if (str && str[0] != '\0')
errdetail("Parameters: %s", str);
}
return 0;
}
/*
* errdetail_abort
*
* Add an errdetail() line showing abort reason, if any.
*/
static int
errdetail_abort(void)
{
if (MyProc->recoveryConflictPending)
errdetail("Abort reason: recovery conflict");
return 0;
}
/*
* errdetail_recovery_conflict
*
* Add an errdetail() line showing conflict source.
*/
static int
errdetail_recovery_conflict(ProcSignalReason reason)
{
switch (reason)
{
case PROCSIG_RECOVERY_CONFLICT_BUFFERPIN:
errdetail("User was holding shared buffer pin for too long.");
break;
case PROCSIG_RECOVERY_CONFLICT_LOCK:
errdetail("User was holding a relation lock for too long.");
break;
case PROCSIG_RECOVERY_CONFLICT_TABLESPACE:
errdetail("User was or might have been using tablespace that must be dropped.");
break;
case PROCSIG_RECOVERY_CONFLICT_SNAPSHOT:
errdetail("User query might have needed to see row versions that must be removed.");
break;
case PROCSIG_RECOVERY_CONFLICT_LOGICALSLOT:
errdetail("User was using a logical replication slot that must be invalidated.");
break;
case PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK:
errdetail("User transaction caused buffer deadlock with recovery.");
break;
case PROCSIG_RECOVERY_CONFLICT_DATABASE:
errdetail("User was connected to a database that must be dropped.");
break;
default:
break;
/* no errdetail */
}
return 0;
}
/*
* bind_param_error_callback
*
* Error context callback used while parsing parameters in a Bind message
*/
static void
bind_param_error_callback(void *arg)
{
BindParamCbData *data = (BindParamCbData *) arg;
StringInfoData buf;
char *quotedval;
if (data->paramno < 0)
return;
/* If we have a textual value, quote it, and trim if necessary */
if (data->paramval)
{
initStringInfo(&buf);
appendStringInfoStringQuoted(&buf, data->paramval,
log_parameter_max_length_on_error);
quotedval = buf.data;
}
else
quotedval = NULL;
if (data->portalName && data->portalName[0] != '\0')
{
if (quotedval)
errcontext("portal \"%s\" parameter $%d = %s",
data->portalName, data->paramno + 1, quotedval);
else
errcontext("portal \"%s\" parameter $%d",
data->portalName, data->paramno + 1);
}
else
{
if (quotedval)
errcontext("unnamed portal parameter $%d = %s",
data->paramno + 1, quotedval);
else
errcontext("unnamed portal parameter $%d",
data->paramno + 1);
}
if (quotedval)
pfree(quotedval);
}
/*
* exec_describe_statement_message
*
* Process a "Describe" message for a prepared statement
*/
static void
exec_describe_statement_message(const char *stmt_name)
{
CachedPlanSource *psrc;
/*
* Start up a transaction command. (Note that this will normally change
* current memory context.) Nothing happens if we are already in one.
*/
start_xact_command();
/* Switch back to message context */
MemoryContextSwitchTo(MessageContext);
/* Find prepared statement */
if (stmt_name[0] != '\0')
{
PreparedStatement *pstmt;
pstmt = FetchPreparedStatement(stmt_name, true);
psrc = pstmt->plansource;
}
else
{
/* special-case the unnamed statement */
psrc = unnamed_stmt_psrc;
if (!psrc)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_PSTATEMENT),
errmsg("unnamed prepared statement does not exist")));
}
/* Prepared statements shouldn't have changeable result descs */
Assert(psrc->fixed_result);
/*
* If we are in aborted transaction state, we can't run
* SendRowDescriptionMessage(), because that needs catalog accesses.
* Hence, refuse to Describe statements that return data. (We shouldn't
* just refuse all Describes, since that might break the ability of some
* clients to issue COMMIT or ROLLBACK commands, if they use code that
* blindly Describes whatever it does.) We can Describe parameters
* without doing anything dangerous, so we don't restrict that.
*/
if (IsAbortedTransactionBlockState() &&
psrc->resultDesc)
ereport(ERROR,
(errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
errmsg("current transaction is aborted, "
"commands ignored until end of transaction block"),
errdetail_abort()));
if (whereToSendOutput != DestRemote)
return; /* can't actually do anything... */
/*
* First describe the parameters...
*/
pq_beginmessage_reuse(&row_description_buf, PqMsg_ParameterDescription);
pq_sendint16(&row_description_buf, psrc->num_params);
for (int i = 0; i < psrc->num_params; i++)
{
Oid ptype = psrc->param_types[i];
pq_sendint32(&row_description_buf, (int) ptype);
}
pq_endmessage_reuse(&row_description_buf);
/*
* Next send RowDescription or NoData to describe the result...
*/
if (psrc->resultDesc)
{
List *tlist;
/* Get the plan's primary targetlist */
tlist = CachedPlanGetTargetList(psrc, NULL);
SendRowDescriptionMessage(&row_description_buf,
psrc->resultDesc,
tlist,
NULL);
}
else
pq_putemptymessage(PqMsg_NoData);
}
/*
* exec_describe_portal_message
*
* Process a "Describe" message for a portal
*/
static void
exec_describe_portal_message(const char *portal_name)
{
Portal portal;
/*
* Start up a transaction command. (Note that this will normally change
* current memory context.) Nothing happens if we are already in one.
*/
start_xact_command();
/* Switch back to message context */
MemoryContextSwitchTo(MessageContext);
portal = GetPortalByName(portal_name);
if (!PortalIsValid(portal))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_CURSOR),
errmsg("portal \"%s\" does not exist", portal_name)));
/*
* If we are in aborted transaction state, we can't run
* SendRowDescriptionMessage(), because that needs catalog accesses.
* Hence, refuse to Describe portals that return data. (We shouldn't just
* refuse all Describes, since that might break the ability of some
* clients to issue COMMIT or ROLLBACK commands, if they use code that
* blindly Describes whatever it does.)
*/
if (IsAbortedTransactionBlockState() &&
portal->tupDesc)
ereport(ERROR,
(errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
errmsg("current transaction is aborted, "
"commands ignored until end of transaction block"),
errdetail_abort()));
if (whereToSendOutput != DestRemote)
return; /* can't actually do anything... */
if (portal->tupDesc)
SendRowDescriptionMessage(&row_description_buf,
portal->tupDesc,
FetchPortalTargetList(portal),
portal->formats);
else
pq_putemptymessage(PqMsg_NoData);
}
/*
* Convenience routines for starting/committing a single command.
*/
static void
start_xact_command(void)
{
if (!xact_started)
{
StartTransactionCommand();
xact_started = true;
}
/*
* Start statement timeout if necessary. Note that this'll intentionally
* not reset the clock on an already started timeout, to avoid the timing
* overhead when start_xact_command() is invoked repeatedly, without an
* interceding finish_xact_command() (e.g. parse/bind/execute). If that's
* not desired, the timeout has to be disabled explicitly.
*/
enable_statement_timeout();
/* Start timeout for checking if the client has gone away if necessary. */
if (client_connection_check_interval > 0 &&
IsUnderPostmaster &&
MyProcPort &&
!get_timeout_active(CLIENT_CONNECTION_CHECK_TIMEOUT))
enable_timeout_after(CLIENT_CONNECTION_CHECK_TIMEOUT,
client_connection_check_interval);
}
static void
finish_xact_command(void)
{
/* cancel active statement timeout after each command */
disable_statement_timeout();
if (xact_started)
{
CommitTransactionCommand();
#ifdef MEMORY_CONTEXT_CHECKING
/* Check all memory contexts that weren't freed during commit */
/* (those that were, were checked before being deleted) */
MemoryContextCheck(TopMemoryContext);
#endif
#ifdef SHOW_MEMORY_STATS
/* Print mem stats after each commit for leak tracking */
MemoryContextStats(TopMemoryContext);
#endif
xact_started = false;
}
}
/*
* Convenience routines for checking whether a statement is one of the
* ones that we allow in transaction-aborted state.
*/
/* Test a bare parsetree */
static bool
IsTransactionExitStmt(Node *parsetree)
{
if (parsetree && IsA(parsetree, TransactionStmt))
{
TransactionStmt *stmt = (TransactionStmt *) parsetree;
if (stmt->kind == TRANS_STMT_COMMIT ||
stmt->kind == TRANS_STMT_PREPARE ||
stmt->kind == TRANS_STMT_ROLLBACK ||
stmt->kind == TRANS_STMT_ROLLBACK_TO)
return true;
}
return false;
}
/* Test a list that contains PlannedStmt nodes */
static bool
IsTransactionExitStmtList(List *pstmts)
{
if (list_length(pstmts) == 1)
{
PlannedStmt *pstmt = linitial_node(PlannedStmt, pstmts);
if (pstmt->commandType == CMD_UTILITY &&
IsTransactionExitStmt(pstmt->utilityStmt))
return true;
}
return false;
}
/* Test a list that contains PlannedStmt nodes */
static bool
IsTransactionStmtList(List *pstmts)
{
if (list_length(pstmts) == 1)
{
PlannedStmt *pstmt = linitial_node(PlannedStmt, pstmts);
if (pstmt->commandType == CMD_UTILITY &&
IsA(pstmt->utilityStmt, TransactionStmt))
return true;
}
return false;
}
/* Release any existing unnamed prepared statement */
static void
drop_unnamed_stmt(void)
{
/* paranoia to avoid a dangling pointer in case of error */
if (unnamed_stmt_psrc)
{
CachedPlanSource *psrc = unnamed_stmt_psrc;
unnamed_stmt_psrc = NULL;
DropCachedPlan(psrc);
}
}
/* --------------------------------
* signal handler routines used in PostgresMain()
* --------------------------------
*/
/*
* quickdie() occurs when signaled SIGQUIT by the postmaster.
*
* Either some backend has bought the farm, or we've been told to shut down
* "immediately"; so we need to stop what we're doing and exit.
*/
void
quickdie(SIGNAL_ARGS)
{
sigaddset(&BlockSig, SIGQUIT); /* prevent nested calls */
sigprocmask(SIG_SETMASK, &BlockSig, NULL);
/*
* Prevent interrupts while exiting; though we just blocked signals that
* would queue new interrupts, one may have been pending. We don't want a
* quickdie() downgraded to a mere query cancel.
*/
HOLD_INTERRUPTS();
/*
* If we're aborting out of client auth, don't risk trying to send
* anything to the client; we will likely violate the protocol, not to
* mention that we may have interrupted the guts of OpenSSL or some
* authentication library.
*/
if (ClientAuthInProgress && whereToSendOutput == DestRemote)
whereToSendOutput = DestNone;
/*
* Notify the client before exiting, to give a clue on what happened.
*
* It's dubious to call ereport() from a signal handler. It is certainly
* not async-signal safe. But it seems better to try, than to disconnect
* abruptly and leave the client wondering what happened. It's remotely
* possible that we crash or hang while trying to send the message, but
* receiving a SIGQUIT is a sign that something has already gone badly
* wrong, so there's not much to lose. Assuming the postmaster is still
* running, it will SIGKILL us soon if we get stuck for some reason.
*
* One thing we can do to make this a tad safer is to clear the error
* context stack, so that context callbacks are not called. That's a lot
* less code that could be reached here, and the context info is unlikely
* to be very relevant to a SIGQUIT report anyway.
*/
error_context_stack = NULL;
/*
* When responding to a postmaster-issued signal, we send the message only
* to the client; sending to the server log just creates log spam, plus
* it's more code that we need to hope will work in a signal handler.
*
* Ideally these should be ereport(FATAL), but then we'd not get control
* back to force the correct type of process exit.
*/
switch (GetQuitSignalReason())
{
case PMQUIT_NOT_SENT:
/* Hmm, SIGQUIT arrived out of the blue */
ereport(WARNING,
(errcode(ERRCODE_ADMIN_SHUTDOWN),
errmsg("terminating connection because of unexpected SIGQUIT signal")));
break;
case PMQUIT_FOR_CRASH:
/* A crash-and-restart cycle is in progress */
ereport(WARNING_CLIENT_ONLY,
(errcode(ERRCODE_CRASH_SHUTDOWN),
errmsg("terminating connection because of crash of another server process"),
errdetail("The postmaster has commanded this server process to roll back"
" the current transaction and exit, because another"
" server process exited abnormally and possibly corrupted"
" shared memory."),
errhint("In a moment you should be able to reconnect to the"
" database and repeat your command.")));
break;
case PMQUIT_FOR_STOP:
/* Immediate-mode stop */
ereport(WARNING_CLIENT_ONLY,
(errcode(ERRCODE_ADMIN_SHUTDOWN),
errmsg("terminating connection due to immediate shutdown command")));
break;
}
/*
* We DO NOT want to run proc_exit() or atexit() callbacks -- we're here
* because shared memory may be corrupted, so we don't want to try to
* clean up our transaction. Just nail the windows shut and get out of
* town. The callbacks wouldn't be safe to run from a signal handler,
* anyway.
*
* Note we do _exit(2) not _exit(0). This is to force the postmaster into
* a system reset cycle if someone sends a manual SIGQUIT to a random
* backend. This is necessary precisely because we don't clean up our
* shared memory state. (The "dead man switch" mechanism in pmsignal.c
* should ensure the postmaster sees this as a crash, too, but no harm in
* being doubly sure.)
*/
_exit(2);
}
/*
* Shutdown signal from postmaster: abort transaction and exit
* at soonest convenient time
*/
void
die(SIGNAL_ARGS)
{
/* Don't joggle the elbow of proc_exit */
if (!proc_exit_inprogress)
{
InterruptPending = true;
ProcDiePending = true;
}
/* for the cumulative stats system */
pgStatSessionEndCause = DISCONNECT_KILLED;
/* If we're still here, waken anything waiting on the process latch */
SetLatch(MyLatch);
/*
* If we're in single user mode, we want to quit immediately - we can't
* rely on latches as they wouldn't work when stdin/stdout is a file.
* Rather ugly, but it's unlikely to be worthwhile to invest much more
* effort just for the benefit of single user mode.
*/
if (DoingCommandRead && whereToSendOutput != DestRemote)
ProcessInterrupts();
}
/*
* Query-cancel signal from postmaster: abort current transaction
* at soonest convenient time
*/
void
StatementCancelHandler(SIGNAL_ARGS)
{
/*
* Don't joggle the elbow of proc_exit
*/
if (!proc_exit_inprogress)
{
InterruptPending = true;
QueryCancelPending = true;
}
/* If we're still here, waken anything waiting on the process latch */
SetLatch(MyLatch);
}
/* signal handler for floating point exception */
void
FloatExceptionHandler(SIGNAL_ARGS)
{
/* We're not returning, so no need to save errno */
ereport(ERROR,
(errcode(ERRCODE_FLOATING_POINT_EXCEPTION),
errmsg("floating-point exception"),
errdetail("An invalid floating-point operation was signaled. "
"This probably means an out-of-range result or an "
"invalid operation, such as division by zero.")));
}
/*
* Tell the next CHECK_FOR_INTERRUPTS() to check for a particular type of
* recovery conflict. Runs in a SIGUSR1 handler.
*/
void
HandleRecoveryConflictInterrupt(ProcSignalReason reason)
{
RecoveryConflictPendingReasons[reason] = true;
RecoveryConflictPending = true;
InterruptPending = true;
/* latch will be set by procsignal_sigusr1_handler */
}
/*
* Check one individual conflict reason.
*/
static void
ProcessRecoveryConflictInterrupt(ProcSignalReason reason)
{
switch (reason)
{
case PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK:
/*
* If we aren't waiting for a lock we can never deadlock.
*/
if (!IsWaitingForLock())
return;
/* Intentional fall through to check wait for pin */
/* FALLTHROUGH */
case PROCSIG_RECOVERY_CONFLICT_BUFFERPIN:
/*
* If PROCSIG_RECOVERY_CONFLICT_BUFFERPIN is requested but we
* aren't blocking the Startup process there is nothing more to
* do.
*
* When PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK is requested,
* if we're waiting for locks and the startup process is not
* waiting for buffer pin (i.e., also waiting for locks), we set
* the flag so that ProcSleep() will check for deadlocks.
*/
if (!HoldingBufferPinThatDelaysRecovery())
{
if (reason == PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK &&
GetStartupBufferPinWaitBufId() < 0)
CheckDeadLockAlert();
return;
}
MyProc->recoveryConflictPending = true;
/* Intentional fall through to error handling */
/* FALLTHROUGH */
case PROCSIG_RECOVERY_CONFLICT_LOCK:
case PROCSIG_RECOVERY_CONFLICT_TABLESPACE:
case PROCSIG_RECOVERY_CONFLICT_SNAPSHOT:
/*
* If we aren't in a transaction any longer then ignore.
*/
if (!IsTransactionOrTransactionBlock())
return;
/* FALLTHROUGH */
case PROCSIG_RECOVERY_CONFLICT_LOGICALSLOT:
/*
* If we're not in a subtransaction then we are OK to throw an
* ERROR to resolve the conflict. Otherwise drop through to the
* FATAL case.
*
* PROCSIG_RECOVERY_CONFLICT_LOGICALSLOT is a special case that
* always throws an ERROR (ie never promotes to FATAL), though it
* still has to respect QueryCancelHoldoffCount, so it shares this
* code path. Logical decoding slots are only acquired while
* performing logical decoding. During logical decoding no user
* controlled code is run. During [sub]transaction abort, the
* slot is released. Therefore user controlled code cannot
* intercept an error before the replication slot is released.
*
* XXX other times that we can throw just an ERROR *may* be
* PROCSIG_RECOVERY_CONFLICT_LOCK if no locks are held in parent
* transactions
*
* PROCSIG_RECOVERY_CONFLICT_SNAPSHOT if no snapshots are held by
* parent transactions and the transaction is not
* transaction-snapshot mode
*
* PROCSIG_RECOVERY_CONFLICT_TABLESPACE if no temp files or
* cursors open in parent transactions
*/
if (reason == PROCSIG_RECOVERY_CONFLICT_LOGICALSLOT ||
!IsSubTransaction())
{
/*
* If we already aborted then we no longer need to cancel. We
* do this here since we do not wish to ignore aborted
* subtransactions, which must cause FATAL, currently.
*/
if (IsAbortedTransactionBlockState())
return;
/*
* If a recovery conflict happens while we are waiting for
* input from the client, the client is presumably just
* sitting idle in a transaction, preventing recovery from
* making progress. We'll drop through to the FATAL case
* below to dislodge it, in that case.
*/
if (!DoingCommandRead)
{
/* Avoid losing sync in the FE/BE protocol. */
if (QueryCancelHoldoffCount != 0)
{
/*
* Re-arm and defer this interrupt until later. See
* similar code in ProcessInterrupts().
*/
RecoveryConflictPendingReasons[reason] = true;
RecoveryConflictPending = true;
InterruptPending = true;
return;
}
/*
* We are cleared to throw an ERROR. Either it's the
* logical slot case, or we have a top-level transaction
* that we can abort and a conflict that isn't inherently
* non-retryable.
*/
LockErrorCleanup();
pgstat_report_recovery_conflict(reason);
ereport(ERROR,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("canceling statement due to conflict with recovery"),
errdetail_recovery_conflict(reason)));
break;
}
}
/* Intentional fall through to session cancel */
/* FALLTHROUGH */
case PROCSIG_RECOVERY_CONFLICT_DATABASE:
/*
* Retrying is not possible because the database is dropped, or we
* decided above that we couldn't resolve the conflict with an
* ERROR and fell through. Terminate the session.
*/
pgstat_report_recovery_conflict(reason);
ereport(FATAL,
(errcode(reason == PROCSIG_RECOVERY_CONFLICT_DATABASE ?
ERRCODE_DATABASE_DROPPED :
ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("terminating connection due to conflict with recovery"),
errdetail_recovery_conflict(reason),
errhint("In a moment you should be able to reconnect to the"
" database and repeat your command.")));
break;
default:
elog(FATAL, "unrecognized conflict mode: %d", (int) reason);
}
}
/*
* Check each possible recovery conflict reason.
*/
static void
ProcessRecoveryConflictInterrupts(void)
{
/*
* We don't need to worry about joggling the elbow of proc_exit, because
* proc_exit_prepare() holds interrupts, so ProcessInterrupts() won't call
* us.
*/
Assert(!proc_exit_inprogress);
Assert(InterruptHoldoffCount == 0);
Assert(RecoveryConflictPending);
RecoveryConflictPending = false;
for (ProcSignalReason reason = PROCSIG_RECOVERY_CONFLICT_FIRST;
reason <= PROCSIG_RECOVERY_CONFLICT_LAST;
reason++)
{
if (RecoveryConflictPendingReasons[reason])
{
RecoveryConflictPendingReasons[reason] = false;
ProcessRecoveryConflictInterrupt(reason);
}
}
}
/*
* ProcessInterrupts: out-of-line portion of CHECK_FOR_INTERRUPTS() macro
*
* If an interrupt condition is pending, and it's safe to service it,
* then clear the flag and accept the interrupt. Called only when
* InterruptPending is true.
*
* Note: if INTERRUPTS_CAN_BE_PROCESSED() is true, then ProcessInterrupts
* is guaranteed to clear the InterruptPending flag before returning.
* (This is not the same as guaranteeing that it's still clear when we
* return; another interrupt could have arrived. But we promise that
* any pre-existing one will have been serviced.)
*/
void
ProcessInterrupts(void)
{
/* OK to accept any interrupts now? */
if (InterruptHoldoffCount != 0 || CritSectionCount != 0)
return;
InterruptPending = false;
if (ProcDiePending)
{
ProcDiePending = false;
QueryCancelPending = false; /* ProcDie trumps QueryCancel */
LockErrorCleanup();
/* As in quickdie, don't risk sending to client during auth */
if (ClientAuthInProgress && whereToSendOutput == DestRemote)
whereToSendOutput = DestNone;
if (ClientAuthInProgress)
ereport(FATAL,
(errcode(ERRCODE_QUERY_CANCELED),
errmsg("canceling authentication due to timeout")));
else if (AmAutoVacuumWorkerProcess())
ereport(FATAL,
(errcode(ERRCODE_ADMIN_SHUTDOWN),
errmsg("terminating autovacuum process due to administrator command")));
else if (IsLogicalWorker())
ereport(FATAL,
(errcode(ERRCODE_ADMIN_SHUTDOWN),
errmsg("terminating logical replication worker due to administrator command")));
else if (IsLogicalLauncher())
{
ereport(DEBUG1,
(errmsg_internal("logical replication launcher shutting down")));
/*
* The logical replication launcher can be stopped at any time.
* Use exit status 1 so the background worker is restarted.
*/
proc_exit(1);
}
else if (AmBackgroundWorkerProcess())
ereport(FATAL,
(errcode(ERRCODE_ADMIN_SHUTDOWN),
errmsg("terminating background worker \"%s\" due to administrator command",
MyBgworkerEntry->bgw_type)));
else
ereport(FATAL,
(errcode(ERRCODE_ADMIN_SHUTDOWN),
errmsg("terminating connection due to administrator command")));
}
if (CheckClientConnectionPending)
{
CheckClientConnectionPending = false;
/*
* Check for lost connection and re-arm, if still configured, but not
* if we've arrived back at DoingCommandRead state. We don't want to
* wake up idle sessions, and they already know how to detect lost
* connections.
*/
if (!DoingCommandRead && client_connection_check_interval > 0)
{
if (!pq_check_connection())
ClientConnectionLost = true;
else
enable_timeout_after(CLIENT_CONNECTION_CHECK_TIMEOUT,
client_connection_check_interval);
}
}
if (ClientConnectionLost)
{
QueryCancelPending = false; /* lost connection trumps QueryCancel */
LockErrorCleanup();
/* don't send to client, we already know the connection to be dead. */
whereToSendOutput = DestNone;
ereport(FATAL,
(errcode(ERRCODE_CONNECTION_FAILURE),
errmsg("connection to client lost")));
}
/*
* Don't allow query cancel interrupts while reading input from the
* client, because we might lose sync in the FE/BE protocol. (Die
* interrupts are OK, because we won't read any further messages from the
* client in that case.)
*
* See similar logic in ProcessRecoveryConflictInterrupts().
*/
if (QueryCancelPending && QueryCancelHoldoffCount != 0)
{
/*
* Re-arm InterruptPending so that we process the cancel request as
* soon as we're done reading the message. (XXX this is seriously
* ugly: it complicates INTERRUPTS_CAN_BE_PROCESSED(), and it means we
* can't use that macro directly as the initial test in this function,
* meaning that this code also creates opportunities for other bugs to
* appear.)
*/
InterruptPending = true;
}
else if (QueryCancelPending)
{
bool lock_timeout_occurred;
bool stmt_timeout_occurred;
QueryCancelPending = false;
/*
* If LOCK_TIMEOUT and STATEMENT_TIMEOUT indicators are both set, we
* need to clear both, so always fetch both.
*/
lock_timeout_occurred = get_timeout_indicator(LOCK_TIMEOUT, true);
stmt_timeout_occurred = get_timeout_indicator(STATEMENT_TIMEOUT, true);
/*
* If both were set, we want to report whichever timeout completed
* earlier; this ensures consistent behavior if the machine is slow
* enough that the second timeout triggers before we get here. A tie
* is arbitrarily broken in favor of reporting a lock timeout.
*/
if (lock_timeout_occurred && stmt_timeout_occurred &&
get_timeout_finish_time(STATEMENT_TIMEOUT) < get_timeout_finish_time(LOCK_TIMEOUT))
lock_timeout_occurred = false; /* report stmt timeout */
if (lock_timeout_occurred)
{
LockErrorCleanup();
ereport(ERROR,
(errcode(ERRCODE_LOCK_NOT_AVAILABLE),
errmsg("canceling statement due to lock timeout")));
}
if (stmt_timeout_occurred)
{
LockErrorCleanup();
ereport(ERROR,
(errcode(ERRCODE_QUERY_CANCELED),
errmsg("canceling statement due to statement timeout")));
}
if (AmAutoVacuumWorkerProcess())
{
LockErrorCleanup();
ereport(ERROR,
(errcode(ERRCODE_QUERY_CANCELED),
errmsg("canceling autovacuum task")));
}
/*
* If we are reading a command from the client, just ignore the cancel
* request --- sending an extra error message won't accomplish
* anything. Otherwise, go ahead and throw the error.
*/
if (!DoingCommandRead)
{
LockErrorCleanup();
ereport(ERROR,
(errcode(ERRCODE_QUERY_CANCELED),
errmsg("canceling statement due to user request")));
}
}
if (RecoveryConflictPending)
ProcessRecoveryConflictInterrupts();
if (IdleInTransactionSessionTimeoutPending)
{
/*
* If the GUC has been reset to zero, ignore the signal. This is
* important because the GUC update itself won't disable any pending
* interrupt. We need to unset the flag before the injection point,
* otherwise we could loop in interrupts checking.
*/
IdleInTransactionSessionTimeoutPending = false;
if (IdleInTransactionSessionTimeout > 0)
{
INJECTION_POINT("idle-in-transaction-session-timeout");
ereport(FATAL,
(errcode(ERRCODE_IDLE_IN_TRANSACTION_SESSION_TIMEOUT),
errmsg("terminating connection due to idle-in-transaction timeout")));
}
}
if (TransactionTimeoutPending)
{
/* As above, ignore the signal if the GUC has been reset to zero. */
TransactionTimeoutPending = false;
if (TransactionTimeout > 0)
{
INJECTION_POINT("transaction-timeout");
ereport(FATAL,
(errcode(ERRCODE_TRANSACTION_TIMEOUT),
errmsg("terminating connection due to transaction timeout")));
}
}
if (IdleSessionTimeoutPending)
{
/* As above, ignore the signal if the GUC has been reset to zero. */
IdleSessionTimeoutPending = false;
if (IdleSessionTimeout > 0)
{
INJECTION_POINT("idle-session-timeout");
ereport(FATAL,
(errcode(ERRCODE_IDLE_SESSION_TIMEOUT),
errmsg("terminating connection due to idle-session timeout")));
}
}
/*
* If there are pending stats updates and we currently are truly idle
* (matching the conditions in PostgresMain(), report stats now.
*/
if (IdleStatsUpdateTimeoutPending &&
DoingCommandRead && !IsTransactionOrTransactionBlock())
{
IdleStatsUpdateTimeoutPending = false;
pgstat_report_stat(true);
}
if (ProcSignalBarrierPending)
ProcessProcSignalBarrier();
if (ParallelMessagePending)
HandleParallelMessages();
if (LogMemoryContextPending)
ProcessLogMemoryContextInterrupt();
if (ParallelApplyMessagePending)
HandleParallelApplyMessages();
}
/*
* set_stack_base: set up reference point for stack depth checking
*
* Returns the old reference point, if any.
*/
pg_stack_base_t
set_stack_base(void)
{
#ifndef HAVE__BUILTIN_FRAME_ADDRESS
char stack_base;
#endif
pg_stack_base_t old;
old = stack_base_ptr;
/*
* Set up reference point for stack depth checking. On recent gcc we use
* __builtin_frame_address() to avoid a warning about storing a local
* variable's address in a long-lived variable.
*/
#ifdef HAVE__BUILTIN_FRAME_ADDRESS
stack_base_ptr = __builtin_frame_address(0);
#else
stack_base_ptr = &stack_base;
#endif
return old;
}
/*
* restore_stack_base: restore reference point for stack depth checking
*
* This can be used after set_stack_base() to restore the old value. This
* is currently only used in PL/Java. When PL/Java calls a backend function
* from different thread, the thread's stack is at a different location than
* the main thread's stack, so it sets the base pointer before the call, and
* restores it afterwards.
*/
void
restore_stack_base(pg_stack_base_t base)
{
stack_base_ptr = base;
}
/*
* check_stack_depth/stack_is_too_deep: check for excessively deep recursion
*
* This should be called someplace in any recursive routine that might possibly
* recurse deep enough to overflow the stack. Most Unixen treat stack
* overflow as an unrecoverable SIGSEGV, so we want to error out ourselves
* before hitting the hardware limit.
*
* check_stack_depth() just throws an error summarily. stack_is_too_deep()
* can be used by code that wants to handle the error condition itself.
*/
void
check_stack_depth(void)
{
if (stack_is_too_deep())
{
ereport(ERROR,
(errcode(ERRCODE_STATEMENT_TOO_COMPLEX),
errmsg("stack depth limit exceeded"),
errhint("Increase the configuration parameter \"max_stack_depth\" (currently %dkB), "
"after ensuring the platform's stack depth limit is adequate.",
max_stack_depth)));
}
}
bool
stack_is_too_deep(void)
{
char stack_top_loc;
long stack_depth;
/*
* Compute distance from reference point to my local variables
*/
stack_depth = (long) (stack_base_ptr - &stack_top_loc);
/*
* Take abs value, since stacks grow up on some machines, down on others
*/
if (stack_depth < 0)
stack_depth = -stack_depth;
/*
* Trouble?
*
* The test on stack_base_ptr prevents us from erroring out if called
* during process setup or in a non-backend process. Logically it should
* be done first, but putting it here avoids wasting cycles during normal
* cases.
*/
if (stack_depth > max_stack_depth_bytes &&
stack_base_ptr != NULL)
return true;
return false;
}
/* GUC check hook for max_stack_depth */
bool
check_max_stack_depth(int *newval, void **extra, GucSource source)
{
long newval_bytes = *newval * 1024L;
long stack_rlimit = get_stack_depth_rlimit();
if (stack_rlimit > 0 && newval_bytes > stack_rlimit - STACK_DEPTH_SLOP)
{
GUC_check_errdetail("\"max_stack_depth\" must not exceed %ldkB.",
(stack_rlimit - STACK_DEPTH_SLOP) / 1024L);
GUC_check_errhint("Increase the platform's stack depth limit via \"ulimit -s\" or local equivalent.");
return false;
}
return true;
}
/* GUC assign hook for max_stack_depth */
void
assign_max_stack_depth(int newval, void *extra)
{
long newval_bytes = newval * 1024L;
max_stack_depth_bytes = newval_bytes;
}
/*
* GUC check_hook for client_connection_check_interval
*/
bool
check_client_connection_check_interval(int *newval, void **extra, GucSource source)
{
if (!WaitEventSetCanReportClosed() && *newval != 0)
{
GUC_check_errdetail("\"client_connection_check_interval\" must be set to 0 on this platform.");
return false;
}
return true;
}
/*
* GUC check_hook for log_parser_stats, log_planner_stats, log_executor_stats
*
* This function and check_log_stats interact to prevent their variables from
* being set in a disallowed combination. This is a hack that doesn't really
* work right; for example it might fail while applying pg_db_role_setting
* values even though the final state would have been acceptable. However,
* since these variables are legacy settings with little production usage,
* we tolerate that.
*/
bool
check_stage_log_stats(bool *newval, void **extra, GucSource source)
{
if (*newval && log_statement_stats)
{
GUC_check_errdetail("Cannot enable parameter when \"log_statement_stats\" is true.");
return false;
}
return true;
}
/*
* GUC check_hook for log_statement_stats
*/
bool
check_log_stats(bool *newval, void **extra, GucSource source)
{
if (*newval &&
(log_parser_stats || log_planner_stats || log_executor_stats))
{
GUC_check_errdetail("Cannot enable \"log_statement_stats\" when "
"\"log_parser_stats\", \"log_planner_stats\", "
"or \"log_executor_stats\" is true.");
return false;
}
return true;
}
/* GUC assign hook for transaction_timeout */
void
assign_transaction_timeout(int newval, void *extra)
{
if (IsTransactionState())
{
/*
* If transaction_timeout GUC has changed within the transaction block
* enable or disable the timer correspondingly.
*/
if (newval > 0 && !get_timeout_active(TRANSACTION_TIMEOUT))
enable_timeout_after(TRANSACTION_TIMEOUT, newval);
else if (newval <= 0 && get_timeout_active(TRANSACTION_TIMEOUT))
disable_timeout(TRANSACTION_TIMEOUT, false);
}
}
/*
* set_debug_options --- apply "-d N" command line option
*
* -d is not quite the same as setting log_min_messages because it enables
* other output options.
*/
void
set_debug_options(int debug_flag, GucContext context, GucSource source)
{
if (debug_flag > 0)
{
char debugstr[64];
sprintf(debugstr, "debug%d", debug_flag);
SetConfigOption("log_min_messages", debugstr, context, source);
}
else
SetConfigOption("log_min_messages", "notice", context, source);
if (debug_flag >= 1 && context == PGC_POSTMASTER)
{
SetConfigOption("log_connections", "true", context, source);
SetConfigOption("log_disconnections", "true", context, source);
}
if (debug_flag >= 2)
SetConfigOption("log_statement", "all", context, source);
if (debug_flag >= 3)
SetConfigOption("debug_print_parse", "true", context, source);
if (debug_flag >= 4)
SetConfigOption("debug_print_plan", "true", context, source);
if (debug_flag >= 5)
SetConfigOption("debug_print_rewritten", "true", context, source);
}
bool
set_plan_disabling_options(const char *arg, GucContext context, GucSource source)
{
const char *tmp = NULL;
switch (arg[0])
{
case 's': /* seqscan */
tmp = "enable_seqscan";
break;
case 'i': /* indexscan */
tmp = "enable_indexscan";
break;
case 'o': /* indexonlyscan */
tmp = "enable_indexonlyscan";
break;
case 'b': /* bitmapscan */
tmp = "enable_bitmapscan";
break;
case 't': /* tidscan */
tmp = "enable_tidscan";
break;
case 'n': /* nestloop */
tmp = "enable_nestloop";
break;
case 'm': /* mergejoin */
tmp = "enable_mergejoin";
break;
case 'h': /* hashjoin */
tmp = "enable_hashjoin";
break;
}
if (tmp)
{
SetConfigOption(tmp, "false", context, source);
return true;
}
else
return false;
}
const char *
get_stats_option_name(const char *arg)
{
switch (arg[0])
{
case 'p':
if (optarg[1] == 'a') /* "parser" */
return "log_parser_stats";
else if (optarg[1] == 'l') /* "planner" */
return "log_planner_stats";
break;
case 'e': /* "executor" */
return "log_executor_stats";
break;
}
return NULL;
}
/* ----------------------------------------------------------------
* process_postgres_switches
* Parse command line arguments for backends
*
* This is called twice, once for the "secure" options coming from the
* postmaster or command line, and once for the "insecure" options coming
* from the client's startup packet. The latter have the same syntax but
* may be restricted in what they can do.
*
* argv[0] is ignored in either case (it's assumed to be the program name).
*
* ctx is PGC_POSTMASTER for secure options, PGC_BACKEND for insecure options
* coming from the client, or PGC_SU_BACKEND for insecure options coming from
* a superuser client.
*
* If a database name is present in the command line arguments, it's
* returned into *dbname (this is allowed only if *dbname is initially NULL).
* ----------------------------------------------------------------
*/
void
process_postgres_switches(int argc, char *argv[], GucContext ctx,
const char **dbname)
{
bool secure = (ctx == PGC_POSTMASTER);
int errs = 0;
GucSource gucsource;
int flag;
if (secure)
{
gucsource = PGC_S_ARGV; /* switches came from command line */
/* Ignore the initial --single argument, if present */
if (argc > 1 && strcmp(argv[1], "--single") == 0)
{
argv++;
argc--;
}
}
else
{
gucsource = PGC_S_CLIENT; /* switches came from client */
}
#ifdef HAVE_INT_OPTERR
/*
* Turn this off because it's either printed to stderr and not the log
* where we'd want it, or argv[0] is now "--single", which would make for
* a weird error message. We print our own error message below.
*/
opterr = 0;
#endif
/*
* Parse command-line options. CAUTION: keep this in sync with
* postmaster/postmaster.c (the option sets should not conflict) and with
* the common help() function in main/main.c.
*/
while ((flag = getopt(argc, argv, "B:bC:c:D:d:EeFf:h:ijk:lN:nOPp:r:S:sTt:v:W:-:")) != -1)
{
switch (flag)
{
case 'B':
SetConfigOption("shared_buffers", optarg, ctx, gucsource);
break;
case 'b':
/* Undocumented flag used for binary upgrades */
if (secure)
IsBinaryUpgrade = true;
break;
case 'C':
/* ignored for consistency with the postmaster */
break;
case 'c':
case '-':
{
char *name,
*value;
ParseLongOption(optarg, &name, &value);
if (!value)
{
if (flag == '-')
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("--%s requires a value",
optarg)));
else
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("-c %s requires a value",
optarg)));
}
SetConfigOption(name, value, ctx, gucsource);
pfree(name);
pfree(value);
break;
}
case 'D':
if (secure)
userDoption = strdup(optarg);
break;
case 'd':
set_debug_options(atoi(optarg), ctx, gucsource);
break;
case 'E':
if (secure)
EchoQuery = true;
break;
case 'e':
SetConfigOption("datestyle", "euro", ctx, gucsource);
break;
case 'F':
SetConfigOption("fsync", "false", ctx, gucsource);
break;
case 'f':
if (!set_plan_disabling_options(optarg, ctx, gucsource))
errs++;
break;
case 'h':
SetConfigOption("listen_addresses", optarg, ctx, gucsource);
break;
case 'i':
SetConfigOption("listen_addresses", "*", ctx, gucsource);
break;
case 'j':
if (secure)
UseSemiNewlineNewline = true;
break;
case 'k':
SetConfigOption("unix_socket_directories", optarg, ctx, gucsource);
break;
case 'l':
SetConfigOption("ssl", "true", ctx, gucsource);
break;
case 'N':
SetConfigOption("max_connections", optarg, ctx, gucsource);
break;
case 'n':
/* ignored for consistency with postmaster */
break;
case 'O':
SetConfigOption("allow_system_table_mods", "true", ctx, gucsource);
break;
case 'P':
SetConfigOption("ignore_system_indexes", "true", ctx, gucsource);
break;
case 'p':
SetConfigOption("port", optarg, ctx, gucsource);
break;
case 'r':
/* send output (stdout and stderr) to the given file */
if (secure)
strlcpy(OutputFileName, optarg, MAXPGPATH);
break;
case 'S':
SetConfigOption("work_mem", optarg, ctx, gucsource);
break;
case 's':
SetConfigOption("log_statement_stats", "true", ctx, gucsource);
break;
case 'T':
/* ignored for consistency with the postmaster */
break;
case 't':
{
const char *tmp = get_stats_option_name(optarg);
if (tmp)
SetConfigOption(tmp, "true", ctx, gucsource);
else
errs++;
break;
}
case 'v':
/*
* -v is no longer used in normal operation, since
* FrontendProtocol is already set before we get here. We keep
* the switch only for possible use in standalone operation,
* in case we ever support using normal FE/BE protocol with a
* standalone backend.
*/
if (secure)
FrontendProtocol = (ProtocolVersion) atoi(optarg);
break;
case 'W':
SetConfigOption("post_auth_delay", optarg, ctx, gucsource);
break;
default:
errs++;
break;
}
if (errs)
break;
}
/*
* Optional database name should be there only if *dbname is NULL.
*/
if (!errs && dbname && *dbname == NULL && argc - optind >= 1)
*dbname = strdup(argv[optind++]);
if (errs || argc != optind)
{
if (errs)
optind--; /* complain about the previous argument */
/* spell the error message a bit differently depending on context */
if (IsUnderPostmaster)
ereport(FATAL,
errcode(ERRCODE_SYNTAX_ERROR),
errmsg("invalid command-line argument for server process: %s", argv[optind]),
errhint("Try \"%s --help\" for more information.", progname));
else
ereport(FATAL,
errcode(ERRCODE_SYNTAX_ERROR),
errmsg("%s: invalid command-line argument: %s",
progname, argv[optind]),
errhint("Try \"%s --help\" for more information.", progname));
}
/*
* Reset getopt(3) library so that it will work correctly in subprocesses
* or when this function is called a second time with another array.
*/
optind = 1;
#ifdef HAVE_INT_OPTRESET
optreset = 1; /* some systems need this too */
#endif
}
/*
* PostgresSingleUserMain
* Entry point for single user mode. argc/argv are the command line
* arguments to be used.
*
* Performs single user specific setup then calls PostgresMain() to actually
* process queries. Single user mode specific setup should go here, rather
* than PostgresMain() or InitPostgres() when reasonably possible.
*/
void
PostgresSingleUserMain(int argc, char *argv[],
const char *username)
{
const char *dbname = NULL;
Assert(!IsUnderPostmaster);
/* Initialize startup process environment. */
InitStandaloneProcess(argv[0]);
/*
* Set default values for command-line options.
*/
InitializeGUCOptions();
/*
* Parse command-line options.
*/
process_postgres_switches(argc, argv, PGC_POSTMASTER, &dbname);
/* Must have gotten a database name, or have a default (the username) */
if (dbname == NULL)
{
dbname = username;
if (dbname == NULL)
ereport(FATAL,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("%s: no database nor user name specified",
progname)));
}
/* Acquire configuration parameters */
if (!SelectConfigFiles(userDoption, progname))
proc_exit(1);
/*
* Validate we have been given a reasonable-looking DataDir and change
* into it.
*/
checkDataDir();
ChangeToDataDir();
/*
* Create lockfile for data directory.
*/
CreateDataDirLockFile(false);
/* read control file (error checking and contains config ) */
LocalProcessControlFile(false);
/*
* process any libraries that should be preloaded at postmaster start
*/
process_shared_preload_libraries();
/* Initialize MaxBackends */
InitializeMaxBackends();
/*
* Give preloaded libraries a chance to request additional shared memory.
*/
process_shmem_requests();
/*
* Now that loadable modules have had their chance to request additional
* shared memory, determine the value of any runtime-computed GUCs that
* depend on the amount of shared memory required.
*/
InitializeShmemGUCs();
/*
* Now that modules have been loaded, we can process any custom resource
* managers specified in the wal_consistency_checking GUC.
*/
InitializeWalConsistencyChecking();
CreateSharedMemoryAndSemaphores();
/*
* Remember stand-alone backend startup time,roughly at the same point
* during startup that postmaster does so.
*/
PgStartTime = GetCurrentTimestamp();
/*
* Create a per-backend PGPROC struct in shared memory. We must do this
* before we can use LWLocks.
*/
InitProcess();
/*
* Now that sufficient infrastructure has been initialized, PostgresMain()
* can do the rest.
*/
PostgresMain(dbname, username);
}
/* ----------------------------------------------------------------
* PostgresMain
* postgres main loop -- all backends, interactive or otherwise loop here
*
* dbname is the name of the database to connect to, username is the
* PostgreSQL user name to be used for the session.
*
* NB: Single user mode specific setup should go to PostgresSingleUserMain()
* if reasonably possible.
* ----------------------------------------------------------------
*/
void
PostgresMain(const char *dbname, const char *username)
{
sigjmp_buf local_sigjmp_buf;
/* these must be volatile to ensure state is preserved across longjmp: */
volatile bool send_ready_for_query = true;
volatile bool idle_in_transaction_timeout_enabled = false;
volatile bool idle_session_timeout_enabled = false;
Assert(dbname != NULL);
Assert(username != NULL);
Assert(GetProcessingMode() == InitProcessing);
/*
* Set up signal handlers. (InitPostmasterChild or InitStandaloneProcess
* has already set up BlockSig and made that the active signal mask.)
*
* Note that postmaster blocked all signals before forking child process,
* so there is no race condition whereby we might receive a signal before
* we have set up the handler.
*
* Also note: it's best not to use any signals that are SIG_IGNored in the
* postmaster. If such a signal arrives before we are able to change the
* handler to non-SIG_IGN, it'll get dropped. Instead, make a dummy
* handler in the postmaster to reserve the signal. (Of course, this isn't
* an issue for signals that are locally generated, such as SIGALRM and
* SIGPIPE.)
*/
if (am_walsender)
WalSndSignals();
else
{
pqsignal(SIGHUP, SignalHandlerForConfigReload);
pqsignal(SIGINT, StatementCancelHandler); /* cancel current query */
pqsignal(SIGTERM, die); /* cancel current query and exit */
/*
* In a postmaster child backend, replace SignalHandlerForCrashExit
* with quickdie, so we can tell the client we're dying.
*
* In a standalone backend, SIGQUIT can be generated from the keyboard
* easily, while SIGTERM cannot, so we make both signals do die()
* rather than quickdie().
*/
if (IsUnderPostmaster)
pqsignal(SIGQUIT, quickdie); /* hard crash time */
else
pqsignal(SIGQUIT, die); /* cancel current query and exit */
InitializeTimeouts(); /* establishes SIGALRM handler */
/*
* Ignore failure to write to frontend. Note: if frontend closes
* connection, we will notice it and exit cleanly when control next
* returns to outer loop. This seems safer than forcing exit in the
* midst of output during who-knows-what operation...
*/
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN);
pqsignal(SIGFPE, FloatExceptionHandler);
/*
* Reset some signals that are accepted by postmaster but not by
* backend
*/
pqsignal(SIGCHLD, SIG_DFL); /* system() requires this on some
* platforms */
}
/* Early initialization */
BaseInit();
/* We need to allow SIGINT, etc during the initial transaction */
sigprocmask(SIG_SETMASK, &UnBlockSig, NULL);
/*
* General initialization.
*
* NOTE: if you are tempted to add code in this vicinity, consider putting
* it inside InitPostgres() instead. In particular, anything that
* involves database access should be there, not here.
*
* Honor session_preload_libraries if not dealing with a WAL sender.
*/
InitPostgres(dbname, InvalidOid, /* database to connect to */
username, InvalidOid, /* role to connect as */
(!am_walsender) ? INIT_PG_LOAD_SESSION_LIBS : 0,
NULL); /* no out_dbname */
/*
* If the PostmasterContext is still around, recycle the space; we don't
* need it anymore after InitPostgres completes.
*/
if (PostmasterContext)
{
MemoryContextDelete(PostmasterContext);
PostmasterContext = NULL;
}
SetProcessingMode(NormalProcessing);
/*
* Now all GUC states are fully set up. Report them to client if
* appropriate.
*/
BeginReportingGUCOptions();
/*
* Also set up handler to log session end; we have to wait till now to be
* sure Log_disconnections has its final value.
*/
if (IsUnderPostmaster && Log_disconnections)
on_proc_exit(log_disconnections, 0);
pgstat_report_connect(MyDatabaseId);
/* Perform initialization specific to a WAL sender process. */
if (am_walsender)
InitWalSender();
/*
* Send this backend's cancellation info to the frontend.
*/
if (whereToSendOutput == DestRemote)
{
StringInfoData buf;
pq_beginmessage(&buf, PqMsg_BackendKeyData);
pq_sendint32(&buf, (int32) MyProcPid);
pq_sendint32(&buf, (int32) MyCancelKey);
pq_endmessage(&buf);
/* Need not flush since ReadyForQuery will do it. */
}
/* Welcome banner for standalone case */
if (whereToSendOutput == DestDebug)
printf("\nPostgreSQL stand-alone backend %s\n", PG_VERSION);
/*
* Create the memory context we will use in the main loop.
*
* MessageContext is reset once per iteration of the main loop, ie, upon
* completion of processing of each command message from the client.
*/
MessageContext = AllocSetContextCreate(TopMemoryContext,
"MessageContext",
ALLOCSET_DEFAULT_SIZES);
/*
* Create memory context and buffer used for RowDescription messages. As
* SendRowDescriptionMessage(), via exec_describe_statement_message(), is
* frequently executed for ever single statement, we don't want to
* allocate a separate buffer every time.
*/
row_description_context = AllocSetContextCreate(TopMemoryContext,
"RowDescriptionContext",
ALLOCSET_DEFAULT_SIZES);
MemoryContextSwitchTo(row_description_context);
initStringInfo(&row_description_buf);
MemoryContextSwitchTo(TopMemoryContext);
/* Fire any defined login event triggers, if appropriate */
EventTriggerOnLogin();
/*
* POSTGRES main processing loop begins here
*
* If an exception is encountered, processing resumes here so we abort the
* current transaction and start a new one.
*
* You might wonder why this isn't coded as an infinite loop around a
* PG_TRY construct. The reason is that this is the bottom of the
* exception stack, and so with PG_TRY there would be no exception handler
* in force at all during the CATCH part. By leaving the outermost setjmp
* always active, we have at least some chance of recovering from an error
* during error recovery. (If we get into an infinite loop thereby, it
* will soon be stopped by overflow of elog.c's internal state stack.)
*
* Note that we use sigsetjmp(..., 1), so that this function's signal mask
* (to wit, UnBlockSig) will be restored when longjmp'ing to here. This
* is essential in case we longjmp'd out of a signal handler on a platform
* where that leaves the signal blocked. It's not redundant with the
* unblock in AbortTransaction() because the latter is only called if we
* were inside a transaction.
*/
if (sigsetjmp(local_sigjmp_buf, 1) != 0)
{
/*
* NOTE: if you are tempted to add more code in this if-block,
* consider the high probability that it should be in
* AbortTransaction() instead. The only stuff done directly here
* should be stuff that is guaranteed to apply *only* for outer-level
* error recovery, such as adjusting the FE/BE protocol status.
*/
/* Since not using PG_TRY, must reset error stack by hand */
error_context_stack = NULL;
/* Prevent interrupts while cleaning up */
HOLD_INTERRUPTS();
/*
* Forget any pending QueryCancel request, since we're returning to
* the idle loop anyway, and cancel any active timeout requests. (In
* future we might want to allow some timeout requests to survive, but
* at minimum it'd be necessary to do reschedule_timeouts(), in case
* we got here because of a query cancel interrupting the SIGALRM
* interrupt handler.) Note in particular that we must clear the
* statement and lock timeout indicators, to prevent any future plain
* query cancels from being misreported as timeouts in case we're
* forgetting a timeout cancel.
*/
disable_all_timeouts(false); /* do first to avoid race condition */
QueryCancelPending = false;
idle_in_transaction_timeout_enabled = false;
idle_session_timeout_enabled = false;
/* Not reading from the client anymore. */
DoingCommandRead = false;
/* Make sure libpq is in a good state */
pq_comm_reset();
/* Report the error to the client and/or server log */
EmitErrorReport();
/*
* If Valgrind noticed something during the erroneous query, print the
* query string, assuming we have one.
*/
valgrind_report_error_query(debug_query_string);
/*
* Make sure debug_query_string gets reset before we possibly clobber
* the storage it points at.
*/
debug_query_string = NULL;
/*
* Abort the current transaction in order to recover.
*/
AbortCurrentTransaction();
if (am_walsender)
WalSndErrorCleanup();
PortalErrorCleanup();
/*
* We can't release replication slots inside AbortTransaction() as we
* need to be able to start and abort transactions while having a slot
* acquired. But we never need to hold them across top level errors,
* so releasing here is fine. There also is a before_shmem_exit()
* callback ensuring correct cleanup on FATAL errors.
*/
if (MyReplicationSlot != NULL)
ReplicationSlotRelease();
/* We also want to cleanup temporary slots on error. */
ReplicationSlotCleanup(false);
jit_reset_after_error();
/*
* Now return to normal top-level context and clear ErrorContext for
* next time.
*/
MemoryContextSwitchTo(MessageContext);
FlushErrorState();
/*
* If we were handling an extended-query-protocol message, initiate
* skip till next Sync. This also causes us not to issue
* ReadyForQuery (until we get Sync).
*/
if (doing_extended_query_message)
ignore_till_sync = true;
/* We don't have a transaction command open anymore */
xact_started = false;
/*
* If an error occurred while we were reading a message from the
* client, we have potentially lost track of where the previous
* message ends and the next one begins. Even though we have
* otherwise recovered from the error, we cannot safely read any more
* messages from the client, so there isn't much we can do with the
* connection anymore.
*/
if (pq_is_reading_msg())
ereport(FATAL,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("terminating connection because protocol synchronization was lost")));
/* Now we can allow interrupts again */
RESUME_INTERRUPTS();
}
/* We can now handle ereport(ERROR) */
PG_exception_stack = &local_sigjmp_buf;
if (!ignore_till_sync)
send_ready_for_query = true; /* initially, or after error */
/*
* Non-error queries loop here.
*/
for (;;)
{
int firstchar;
StringInfoData input_message;
/*
* At top of loop, reset extended-query-message flag, so that any
* errors encountered in "idle" state don't provoke skip.
*/
doing_extended_query_message = false;
/*
* For valgrind reporting purposes, the "current query" begins here.
*/
#ifdef USE_VALGRIND
old_valgrind_error_count = VALGRIND_COUNT_ERRORS;
#endif
/*
* Release storage left over from prior query cycle, and create a new
* query input buffer in the cleared MessageContext.
*/
MemoryContextSwitchTo(MessageContext);
MemoryContextReset(MessageContext);
initStringInfo(&input_message);
/*
* Also consider releasing our catalog snapshot if any, so that it's
* not preventing advance of global xmin while we wait for the client.
*/
InvalidateCatalogSnapshotConditionally();
/*
* (1) If we've reached idle state, tell the frontend we're ready for
* a new query.
*
* Note: this includes fflush()'ing the last of the prior output.
*
* This is also a good time to flush out collected statistics to the
* cumulative stats system, and to update the PS stats display. We
* avoid doing those every time through the message loop because it'd
* slow down processing of batched messages, and because we don't want
* to report uncommitted updates (that confuses autovacuum). The
* notification processor wants a call too, if we are not in a
* transaction block.
*
* Also, if an idle timeout is enabled, start the timer for that.
*/
if (send_ready_for_query)
{
if (IsAbortedTransactionBlockState())
{
set_ps_display("idle in transaction (aborted)");
pgstat_report_activity(STATE_IDLEINTRANSACTION_ABORTED, NULL);
/* Start the idle-in-transaction timer */
if (IdleInTransactionSessionTimeout > 0
&& (IdleInTransactionSessionTimeout < TransactionTimeout || TransactionTimeout == 0))
{
idle_in_transaction_timeout_enabled = true;
enable_timeout_after(IDLE_IN_TRANSACTION_SESSION_TIMEOUT,
IdleInTransactionSessionTimeout);
}
}
else if (IsTransactionOrTransactionBlock())
{
set_ps_display("idle in transaction");
pgstat_report_activity(STATE_IDLEINTRANSACTION, NULL);
/* Start the idle-in-transaction timer */
if (IdleInTransactionSessionTimeout > 0
&& (IdleInTransactionSessionTimeout < TransactionTimeout || TransactionTimeout == 0))
{
idle_in_transaction_timeout_enabled = true;
enable_timeout_after(IDLE_IN_TRANSACTION_SESSION_TIMEOUT,
IdleInTransactionSessionTimeout);
}
}
else
{
long stats_timeout;
/*
* Process incoming notifies (including self-notifies), if
* any, and send relevant messages to the client. Doing it
* here helps ensure stable behavior in tests: if any notifies
* were received during the just-finished transaction, they'll
* be seen by the client before ReadyForQuery is.
*/
if (notifyInterruptPending)
ProcessNotifyInterrupt(false);
/*
* Check if we need to report stats. If pgstat_report_stat()
* decides it's too soon to flush out pending stats / lock
* contention prevented reporting, it'll tell us when we
* should try to report stats again (so that stats updates
* aren't unduly delayed if the connection goes idle for a
* long time). We only enable the timeout if we don't already
* have a timeout in progress, because we don't disable the
* timeout below. enable_timeout_after() needs to determine
* the current timestamp, which can have a negative
* performance impact. That's OK because pgstat_report_stat()
* won't have us wake up sooner than a prior call.
*/
stats_timeout = pgstat_report_stat(false);
if (stats_timeout > 0)
{
if (!get_timeout_active(IDLE_STATS_UPDATE_TIMEOUT))
enable_timeout_after(IDLE_STATS_UPDATE_TIMEOUT,
stats_timeout);
}
else
{
/* all stats flushed, no need for the timeout */
if (get_timeout_active(IDLE_STATS_UPDATE_TIMEOUT))
disable_timeout(IDLE_STATS_UPDATE_TIMEOUT, false);
}
set_ps_display("idle");
pgstat_report_activity(STATE_IDLE, NULL);
/* Start the idle-session timer */
if (IdleSessionTimeout > 0)
{
idle_session_timeout_enabled = true;
enable_timeout_after(IDLE_SESSION_TIMEOUT,
IdleSessionTimeout);
}
}
/* Report any recently-changed GUC options */
ReportChangedGUCOptions();
ReadyForQuery(whereToSendOutput);
send_ready_for_query = false;
}
/*
* (2) Allow asynchronous signals to be executed immediately if they
* come in while we are waiting for client input. (This must be
* conditional since we don't want, say, reads on behalf of COPY FROM
* STDIN doing the same thing.)
*/
DoingCommandRead = true;
/*
* (3) read a command (loop blocks here)
*/
firstchar = ReadCommand(&input_message);
/*
* (4) turn off the idle-in-transaction and idle-session timeouts if
* active. We do this before step (5) so that any last-moment timeout
* is certain to be detected in step (5).
*
* At most one of these timeouts will be active, so there's no need to
* worry about combining the timeout.c calls into one.
*/
if (idle_in_transaction_timeout_enabled)
{
disable_timeout(IDLE_IN_TRANSACTION_SESSION_TIMEOUT, false);
idle_in_transaction_timeout_enabled = false;
}
if (idle_session_timeout_enabled)
{
disable_timeout(IDLE_SESSION_TIMEOUT, false);
idle_session_timeout_enabled = false;
}
/*
* (5) disable async signal conditions again.
*
* Query cancel is supposed to be a no-op when there is no query in
* progress, so if a query cancel arrived while we were idle, just
* reset QueryCancelPending. ProcessInterrupts() has that effect when
* it's called when DoingCommandRead is set, so check for interrupts
* before resetting DoingCommandRead.
*/
CHECK_FOR_INTERRUPTS();
DoingCommandRead = false;
/*
* (6) check for any other interesting events that happened while we
* slept.
*/
if (ConfigReloadPending)
{
ConfigReloadPending = false;
ProcessConfigFile(PGC_SIGHUP);
}
/*
* (7) process the command. But ignore it if we're skipping till
* Sync.
*/
if (ignore_till_sync && firstchar != EOF)
continue;
switch (firstchar)
{
case PqMsg_Query:
{
const char *query_string;
/* Set statement_timestamp() */
SetCurrentStatementStartTimestamp();
query_string = pq_getmsgstring(&input_message);
pq_getmsgend(&input_message);
if (am_walsender)
{
if (!exec_replication_command(query_string))
exec_simple_query(query_string);
}
else
exec_simple_query(query_string);
valgrind_report_error_query(query_string);
send_ready_for_query = true;
}
break;
case PqMsg_Parse:
{
const char *stmt_name;
const char *query_string;
int numParams;
Oid *paramTypes = NULL;
forbidden_in_wal_sender(firstchar);
/* Set statement_timestamp() */
SetCurrentStatementStartTimestamp();
stmt_name = pq_getmsgstring(&input_message);
query_string = pq_getmsgstring(&input_message);
numParams = pq_getmsgint(&input_message, 2);
if (numParams > 0)
{
paramTypes = palloc_array(Oid, numParams);
for (int i = 0; i < numParams; i++)
paramTypes[i] = pq_getmsgint(&input_message, 4);
}
pq_getmsgend(&input_message);
exec_parse_message(query_string, stmt_name,
paramTypes, numParams);
valgrind_report_error_query(query_string);
}
break;
case PqMsg_Bind:
forbidden_in_wal_sender(firstchar);
/* Set statement_timestamp() */
SetCurrentStatementStartTimestamp();
/*
* this message is complex enough that it seems best to put
* the field extraction out-of-line
*/
exec_bind_message(&input_message);
/* exec_bind_message does valgrind_report_error_query */
break;
case PqMsg_Execute:
{
const char *portal_name;
int max_rows;
forbidden_in_wal_sender(firstchar);
/* Set statement_timestamp() */
SetCurrentStatementStartTimestamp();
portal_name = pq_getmsgstring(&input_message);
max_rows = pq_getmsgint(&input_message, 4);
pq_getmsgend(&input_message);
exec_execute_message(portal_name, max_rows);
/* exec_execute_message does valgrind_report_error_query */
}
break;
case PqMsg_FunctionCall:
forbidden_in_wal_sender(firstchar);
/* Set statement_timestamp() */
SetCurrentStatementStartTimestamp();
/* Report query to various monitoring facilities. */
pgstat_report_activity(STATE_FASTPATH, NULL);
set_ps_display("<FASTPATH>");
/* start an xact for this function invocation */
start_xact_command();
/*
* Note: we may at this point be inside an aborted
* transaction. We can't throw error for that until we've
* finished reading the function-call message, so
* HandleFunctionRequest() must check for it after doing so.
* Be careful not to do anything that assumes we're inside a
* valid transaction here.
*/
/* switch back to message context */
MemoryContextSwitchTo(MessageContext);
HandleFunctionRequest(&input_message);
/* commit the function-invocation transaction */
finish_xact_command();
valgrind_report_error_query("fastpath function call");
send_ready_for_query = true;
break;
case PqMsg_Close:
{
int close_type;
const char *close_target;
forbidden_in_wal_sender(firstchar);
close_type = pq_getmsgbyte(&input_message);
close_target = pq_getmsgstring(&input_message);
pq_getmsgend(&input_message);
switch (close_type)
{
case 'S':
if (close_target[0] != '\0')
DropPreparedStatement(close_target, false);
else
{
/* special-case the unnamed statement */
drop_unnamed_stmt();
}
break;
case 'P':
{
Portal portal;
portal = GetPortalByName(close_target);
if (PortalIsValid(portal))
PortalDrop(portal, false);
}
break;
default:
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid CLOSE message subtype %d",
close_type)));
break;
}
if (whereToSendOutput == DestRemote)
pq_putemptymessage(PqMsg_CloseComplete);
valgrind_report_error_query("CLOSE message");
}
break;
case PqMsg_Describe:
{
int describe_type;
const char *describe_target;
forbidden_in_wal_sender(firstchar);
/* Set statement_timestamp() (needed for xact) */
SetCurrentStatementStartTimestamp();
describe_type = pq_getmsgbyte(&input_message);
describe_target = pq_getmsgstring(&input_message);
pq_getmsgend(&input_message);
switch (describe_type)
{
case 'S':
exec_describe_statement_message(describe_target);
break;
case 'P':
exec_describe_portal_message(describe_target);
break;
default:
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid DESCRIBE message subtype %d",
describe_type)));
break;
}
valgrind_report_error_query("DESCRIBE message");
}
break;
case PqMsg_Flush:
pq_getmsgend(&input_message);
if (whereToSendOutput == DestRemote)
pq_flush();
break;
case PqMsg_Sync:
pq_getmsgend(&input_message);
finish_xact_command();
valgrind_report_error_query("SYNC message");
send_ready_for_query = true;
break;
/*
* 'X' means that the frontend is closing down the socket. EOF
* means unexpected loss of frontend connection. Either way,
* perform normal shutdown.
*/
case EOF:
/* for the cumulative statistics system */
pgStatSessionEndCause = DISCONNECT_CLIENT_EOF;
/* FALLTHROUGH */
case PqMsg_Terminate:
/*
* Reset whereToSendOutput to prevent ereport from attempting
* to send any more messages to client.
*/
if (whereToSendOutput == DestRemote)
whereToSendOutput = DestNone;
/*
* NOTE: if you are tempted to add more code here, DON'T!
* Whatever you had in mind to do should be set up as an
* on_proc_exit or on_shmem_exit callback, instead. Otherwise
* it will fail to be called during other backend-shutdown
* scenarios.
*/
proc_exit(0);
case PqMsg_CopyData:
case PqMsg_CopyDone:
case PqMsg_CopyFail:
/*
* Accept but ignore these messages, per protocol spec; we
* probably got here because a COPY failed, and the frontend
* is still sending data.
*/
break;
default:
ereport(FATAL,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid frontend message type %d",
firstchar)));
}
} /* end of input-reading loop */
}
/*
* Throw an error if we're a WAL sender process.
*
* This is used to forbid anything else than simple query protocol messages
* in a WAL sender process. 'firstchar' specifies what kind of a forbidden
* message was received, and is used to construct the error message.
*/
static void
forbidden_in_wal_sender(char firstchar)
{
if (am_walsender)
{
if (firstchar == PqMsg_FunctionCall)
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("fastpath function calls not supported in a replication connection")));
else
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("extended query protocol not supported in a replication connection")));
}
}
/*
* Obtain platform stack depth limit (in bytes)
*
* Return -1 if unknown
*/
long
get_stack_depth_rlimit(void)
{
#if defined(HAVE_GETRLIMIT)
static long val = 0;
/* This won't change after process launch, so check just once */
if (val == 0)
{
struct rlimit rlim;
if (getrlimit(RLIMIT_STACK, &rlim) < 0)
val = -1;
else if (rlim.rlim_cur == RLIM_INFINITY)
val = LONG_MAX;
/* rlim_cur is probably of an unsigned type, so check for overflow */
else if (rlim.rlim_cur >= LONG_MAX)
val = LONG_MAX;
else
val = rlim.rlim_cur;
}
return val;
#else
/* On Windows we set the backend stack size in src/backend/Makefile */
return WIN32_STACK_RLIMIT;
#endif
}
static struct rusage Save_r;
static struct timeval Save_t;
void
ResetUsage(void)
{
getrusage(RUSAGE_SELF, &Save_r);
gettimeofday(&Save_t, NULL);
}
void
ShowUsage(const char *title)
{
StringInfoData str;
struct timeval user,
sys;
struct timeval elapse_t;
struct rusage r;
getrusage(RUSAGE_SELF, &r);
gettimeofday(&elapse_t, NULL);
memcpy((char *) &user, (char *) &r.ru_utime, sizeof(user));
memcpy((char *) &sys, (char *) &r.ru_stime, sizeof(sys));
if (elapse_t.tv_usec < Save_t.tv_usec)
{
elapse_t.tv_sec--;
elapse_t.tv_usec += 1000000;
}
if (r.ru_utime.tv_usec < Save_r.ru_utime.tv_usec)
{
r.ru_utime.tv_sec--;
r.ru_utime.tv_usec += 1000000;
}
if (r.ru_stime.tv_usec < Save_r.ru_stime.tv_usec)
{
r.ru_stime.tv_sec--;
r.ru_stime.tv_usec += 1000000;
}
/*
* The only stats we don't show here are ixrss, idrss, isrss. It takes
* some work to interpret them, and most platforms don't fill them in.
*/
initStringInfo(&str);
appendStringInfoString(&str, "! system usage stats:\n");
appendStringInfo(&str,
"!\t%ld.%06ld s user, %ld.%06ld s system, %ld.%06ld s elapsed\n",
(long) (r.ru_utime.tv_sec - Save_r.ru_utime.tv_sec),
(long) (r.ru_utime.tv_usec - Save_r.ru_utime.tv_usec),
(long) (r.ru_stime.tv_sec - Save_r.ru_stime.tv_sec),
(long) (r.ru_stime.tv_usec - Save_r.ru_stime.tv_usec),
(long) (elapse_t.tv_sec - Save_t.tv_sec),
(long) (elapse_t.tv_usec - Save_t.tv_usec));
appendStringInfo(&str,
"!\t[%ld.%06ld s user, %ld.%06ld s system total]\n",
(long) user.tv_sec,
(long) user.tv_usec,
(long) sys.tv_sec,
(long) sys.tv_usec);
#ifndef WIN32
/*
* The following rusage fields are not defined by POSIX, but they're
* present on all current Unix-like systems so we use them without any
* special checks. Some of these could be provided in our Windows
* emulation in src/port/win32getrusage.c with more work.
*/
appendStringInfo(&str,
"!\t%ld kB max resident size\n",
#if defined(__darwin__)
/* in bytes on macOS */
r.ru_maxrss / 1024
#else
/* in kilobytes on most other platforms */
r.ru_maxrss
#endif
);
appendStringInfo(&str,
"!\t%ld/%ld [%ld/%ld] filesystem blocks in/out\n",
r.ru_inblock - Save_r.ru_inblock,
/* they only drink coffee at dec */
r.ru_oublock - Save_r.ru_oublock,
r.ru_inblock, r.ru_oublock);
appendStringInfo(&str,
"!\t%ld/%ld [%ld/%ld] page faults/reclaims, %ld [%ld] swaps\n",
r.ru_majflt - Save_r.ru_majflt,
r.ru_minflt - Save_r.ru_minflt,
r.ru_majflt, r.ru_minflt,
r.ru_nswap - Save_r.ru_nswap,
r.ru_nswap);
appendStringInfo(&str,
"!\t%ld [%ld] signals rcvd, %ld/%ld [%ld/%ld] messages rcvd/sent\n",
r.ru_nsignals - Save_r.ru_nsignals,
r.ru_nsignals,
r.ru_msgrcv - Save_r.ru_msgrcv,
r.ru_msgsnd - Save_r.ru_msgsnd,
r.ru_msgrcv, r.ru_msgsnd);
appendStringInfo(&str,
"!\t%ld/%ld [%ld/%ld] voluntary/involuntary context switches\n",
r.ru_nvcsw - Save_r.ru_nvcsw,
r.ru_nivcsw - Save_r.ru_nivcsw,
r.ru_nvcsw, r.ru_nivcsw);
#endif /* !WIN32 */
/* remove trailing newline */
if (str.data[str.len - 1] == '\n')
str.data[--str.len] = '\0';
ereport(LOG,
(errmsg_internal("%s", title),
errdetail_internal("%s", str.data)));
pfree(str.data);
}
/*
* on_proc_exit handler to log end of session
*/
static void
log_disconnections(int code, Datum arg)
{
Port *port = MyProcPort;
long secs;
int usecs;
int msecs;
int hours,
minutes,
seconds;
TimestampDifference(MyStartTimestamp,
GetCurrentTimestamp(),
&secs, &usecs);
msecs = usecs / 1000;
hours = secs / SECS_PER_HOUR;
secs %= SECS_PER_HOUR;
minutes = secs / SECS_PER_MINUTE;
seconds = secs % SECS_PER_MINUTE;
ereport(LOG,
(errmsg("disconnection: session time: %d:%02d:%02d.%03d "
"user=%s database=%s host=%s%s%s",
hours, minutes, seconds, msecs,
port->user_name, port->database_name, port->remote_host,
port->remote_port[0] ? " port=" : "", port->remote_port)));
}
/*
* Start statement timeout timer, if enabled.
*
* If there's already a timeout running, don't restart the timer. That
* enables compromises between accuracy of timeouts and cost of starting a
* timeout.
*/
static void
enable_statement_timeout(void)
{
/* must be within an xact */
Assert(xact_started);
if (StatementTimeout > 0
&& (StatementTimeout < TransactionTimeout || TransactionTimeout == 0))
{
if (!get_timeout_active(STATEMENT_TIMEOUT))
enable_timeout_after(STATEMENT_TIMEOUT, StatementTimeout);
}
else
{
if (get_timeout_active(STATEMENT_TIMEOUT))
disable_timeout(STATEMENT_TIMEOUT, false);
}
}
/*
* Disable statement timeout, if active.
*/
static void
disable_statement_timeout(void)
{
if (get_timeout_active(STATEMENT_TIMEOUT))
disable_timeout(STATEMENT_TIMEOUT, false);
}
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