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A bit of code beautification/cleanup of obsolete comments. Rethink

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ordering of startup operations in one or two places.
This commit is contained in:
Tom Lane 2001-06-21 16:43:24 +00:00
parent 90e2663313
commit f3868f8af9
1 changed files with 64 additions and 48 deletions

112
src/backend/postmaster/postmaster.c

@ -22,13 +22,22 @@
* if it did much with shared memory then it would be prone to crashing * if it did much with shared memory then it would be prone to crashing
* along with the backends. * along with the backends.
* *
* When a request message is received, we now fork() immediately.
* The child process performs authentication of the request, and
* then becomes a backend if successful. This allows the auth code
* to be written in a simple single-threaded style (as opposed to the
* crufty "poor man's multitasking" code that used to be needed).
* More importantly, it ensures that blockages in non-multithreaded
* libraries like SSL or PAM cannot cause denial of service to other
* clients.
*
* *
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California * Portions Copyright (c) 1994, Regents of the University of California
* *
* *
* IDENTIFICATION * IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.224 2001/06/20 18:07:55 petere Exp $ * $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.225 2001/06/21 16:43:24 tgl Exp $
* *
* NOTES * NOTES
* *
@ -102,17 +111,16 @@
#ifdef HAVE_SIGPROCMASK #ifdef HAVE_SIGPROCMASK
sigset_t UnBlockSig, sigset_t UnBlockSig,
BlockSig; BlockSig;
#else #else
int UnBlockSig, int UnBlockSig,
BlockSig; BlockSig;
#endif #endif
/* /*
* Info for garbage collection. Whenever a process dies, the Postmaster * List of active backends (or child processes anyway; we don't actually
* cleans up after it. Currently, NO information is required for cleanup, * know whether a given child has become a backend or is still in the
* but I left this structure around in case that changed. * authorization phase). This is used mainly to keep track of how many
* children we have and send them appropriate signals when necessary.
*/ */
typedef struct bkend typedef struct bkend
{ {
@ -120,7 +128,6 @@ typedef struct bkend
long cancel_key; /* cancel key for cancels for this backend */ long cancel_key; /* cancel key for cancels for this backend */
} Backend; } Backend;
/* list of active backends. For garbage collection only now. */
static Dllist *BackendList; static Dllist *BackendList;
/* The socket number we are listening for connections on */ /* The socket number we are listening for connections on */
@ -155,12 +162,10 @@ static int ServerSock_INET = INVALID_SOCK; /* stream socket server */
#ifdef HAVE_UNIX_SOCKETS #ifdef HAVE_UNIX_SOCKETS
static int ServerSock_UNIX = INVALID_SOCK; /* stream socket server */ static int ServerSock_UNIX = INVALID_SOCK; /* stream socket server */
#endif #endif
#ifdef USE_SSL #ifdef USE_SSL
static SSL_CTX *SSL_context = NULL; /* Global SSL context */ static SSL_CTX *SSL_context = NULL; /* Global SSL context */
#endif #endif
/* /*
@ -178,12 +183,14 @@ static char ExtraOptions[MAXPGPATH];
static bool Reinit = true; static bool Reinit = true;
static int SendStop = false; static int SendStop = false;
/* still more option variables */
bool NetServer = false; /* listen on TCP/IP */ bool NetServer = false; /* listen on TCP/IP */
bool EnableSSL = false; bool EnableSSL = false;
bool SilentMode = false; /* silent mode (-S) */ bool SilentMode = false; /* silent mode (-S) */
int CheckPointTimeout = 300; int CheckPointTimeout = 300;
/* Startup/shutdown state */
static pid_t StartupPID = 0, static pid_t StartupPID = 0,
ShutdownPID = 0, ShutdownPID = 0,
CheckPointPID = 0; CheckPointPID = 0;
@ -230,7 +237,7 @@ static void ExitPostmaster(int status);
static void usage(const char *); static void usage(const char *);
static int ServerLoop(void); static int ServerLoop(void);
static int BackendStartup(Port *port); static int BackendStartup(Port *port);
static int ProcessStartupPacket(Port *port); static int ProcessStartupPacket(Port *port, bool SSLdone);
static void processCancelRequest(Port *port, void *pkt); static void processCancelRequest(Port *port, void *pkt);
static int initMasks(fd_set *rmask, fd_set *wmask); static int initMasks(fd_set *rmask, fd_set *wmask);
static char *canAcceptConnections(void); static char *canAcceptConnections(void);
@ -579,6 +586,20 @@ PostmasterMain(int argc, char *argv[])
fprintf(stderr, "-----------------------------------------\n"); fprintf(stderr, "-----------------------------------------\n");
} }
/*
* Initialize SSL library, if specified.
*/
#ifdef USE_SSL
if (EnableSSL && !NetServer)
{
postmaster_error("For SSL, TCP/IP connections must be enabled.");
fprintf(stderr, gettext("Try '%s --help' for more information.\n"), progname);
ExitPostmaster(1);
}
if (EnableSSL)
InitSSL();
#endif
/* /*
* Fork away from controlling terminal, if -S specified. * Fork away from controlling terminal, if -S specified.
* *
@ -609,17 +630,6 @@ PostmasterMain(int argc, char *argv[])
/* /*
* Establish input sockets. * Establish input sockets.
*/ */
#ifdef USE_SSL
if (EnableSSL && !NetServer)
{
postmaster_error("For SSL, TCP/IP connections must be enabled.");
fprintf(stderr, gettext("Try '%s --help' for more information.\n"), progname);
ExitPostmaster(1);
}
if (EnableSSL)
InitSSL();
#endif
if (NetServer) if (NetServer)
{ {
status = StreamServerPort(AF_INET, VirtualHost, status = StreamServerPort(AF_INET, VirtualHost,
@ -653,8 +663,7 @@ PostmasterMain(int argc, char *argv[])
reset_shared(PostPortNumber); reset_shared(PostPortNumber);
/* /*
* Initialize the list of active backends. This list is only used for * Initialize the list of active backends.
* garbage collecting the backend processes.
*/ */
BackendList = DLNewList(); BackendList = DLNewList();
@ -811,7 +820,6 @@ ServerLoop(void)
if (CheckPointTimeout + checkpointed > now) if (CheckPointTimeout + checkpointed > now)
{ {
/* /*
* Not time for checkpoint yet, so set a timeout for * Not time for checkpoint yet, so set a timeout for
* select * select
@ -883,7 +891,8 @@ ServerLoop(void)
} }
/* /*
* new connection pending on our well-known port's socket? * New connection pending on our well-known port's socket?
* If so, fork a child process to deal with it.
*/ */
#ifdef HAVE_UNIX_SOCKETS #ifdef HAVE_UNIX_SOCKETS
@ -892,9 +901,15 @@ ServerLoop(void)
{ {
port = ConnCreate(ServerSock_UNIX); port = ConnCreate(ServerSock_UNIX);
if (port) if (port)
{
BackendStartup(port); BackendStartup(port);
StreamClose(port->sock); /*
ConnFree(port); * We no longer need the open socket or port structure
* in this process
*/
StreamClose(port->sock);
ConnFree(port);
}
} }
#endif #endif
@ -903,9 +918,15 @@ ServerLoop(void)
{ {
port = ConnCreate(ServerSock_INET); port = ConnCreate(ServerSock_INET);
if (port) if (port)
{
BackendStartup(port); BackendStartup(port);
StreamClose(port->sock); /*
ConnFree(port); * We no longer need the open socket or port structure
* in this process
*/
StreamClose(port->sock);
ConnFree(port);
}
} }
} }
} }
@ -952,7 +973,7 @@ initMasks(fd_set *rmask, fd_set *wmask)
* not return at all. * not return at all.
*/ */
static int static int
ProcessStartupPacket(Port *port) ProcessStartupPacket(Port *port, bool SSLdone)
{ {
StartupPacket *packet; StartupPacket *packet;
char *rejectMsg; char *rejectMsg;
@ -983,7 +1004,7 @@ ProcessStartupPacket(Port *port)
return 127; /* XXX */ return 127; /* XXX */
} }
if (port->proto == NEGOTIATE_SSL_CODE) if (port->proto == NEGOTIATE_SSL_CODE && !SSLdone)
{ {
char SSLok; char SSLok;
@ -1016,10 +1037,9 @@ ProcessStartupPacket(Port *port)
} }
} }
#endif #endif
/* regular startup packet should follow... */ /* regular startup packet, cancel, etc packet should follow... */
/* FIXME: by continuing to send SSL negotiation packets, a /* but not another SSL negotiation request */
client could run us out of stack space */ return ProcessStartupPacket(port, true);
return ProcessStartupPacket(port);
} }
/* Could add additional special packet types here */ /* Could add additional special packet types here */
@ -1211,11 +1231,8 @@ ConnFree(Port *conn)
* ClosePostmasterPorts -- close all the postmaster's open sockets * ClosePostmasterPorts -- close all the postmaster's open sockets
* *
* This is called during child process startup to release file descriptors * This is called during child process startup to release file descriptors
* that are not needed by that child process. * that are not needed by that child process. The postmaster still has
* * them open, of course.
* Note that closing the child's descriptor does not destroy the client
* connection prematurely, since the parent (postmaster) process still
* has the socket open.
*/ */
static void static void
ClosePostmasterPorts(void) ClosePostmasterPorts(void)
@ -1685,9 +1702,7 @@ SignalChildren(int signal)
/* /*
* BackendStartup -- start backend process * BackendStartup -- start backend process
* *
* returns: STATUS_ERROR if the fork/exec failed, STATUS_OK * returns: STATUS_ERROR if the fork/exec failed, STATUS_OK otherwise.
* otherwise.
*
*/ */
static int static int
BackendStartup(Port *port) BackendStartup(Port *port)
@ -1814,7 +1829,8 @@ split_opts(char **argv, int *argcp, char *s)
} }
/* /*
* DoBackend -- set up the backend's argument list and invoke backend main(). * DoBackend -- perform authentication, and if successful, set up the
* backend's argument list and invoke backend main().
* *
* This used to perform an execv() but we no longer exec the backend; * This used to perform an execv() but we no longer exec the backend;
* it's the same executable as the postmaster. * it's the same executable as the postmaster.
@ -1849,6 +1865,9 @@ DoBackend(Port *port)
* Signal handlers setting is moved to tcop/postgres... * Signal handlers setting is moved to tcop/postgres...
*/ */
/* Close the postmaster's other sockets */
ClosePostmasterPorts();
SetProcessingMode(InitProcessing); SetProcessingMode(InitProcessing);
/* Save port etc. for ps status */ /* Save port etc. for ps status */
@ -1859,13 +1878,10 @@ DoBackend(Port *port)
whereToSendOutput = Remote; whereToSendOutput = Remote;
status = ProcessStartupPacket(port); status = ProcessStartupPacket(port, false);
if (status == 127) if (status == 127)
return 0; /* cancel request processed */ return 0; /* cancel request processed */
/* Close the postmaster's other sockets */
ClosePostmasterPorts();
/* /*
* Don't want backend to be able to see the postmaster random number * Don't want backend to be able to see the postmaster random number
* generator state. We have to clobber the static random_seed *and* * generator state. We have to clobber the static random_seed *and*