weston/libweston/log.c

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/*
* Copyright © 2012 Martin Minarik
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include "config.h"
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <time.h>
#include <wayland-util.h>
#include "shared/timespec-util.h"
#include <libweston/libweston.h>
#include "weston-log-internal.h"
/**
* \defgroup wlog weston-logging
*/
static int
default_log_handler(const char *fmt, va_list ap);
/** Needs to be set, defaults to default_log_handler
*
* \ingroup wlog
*/
static log_func_t log_handler = default_log_handler;
/** Needs to be set, defaults to default_log_handler
*
* \ingroup wlog
*/
static log_func_t log_continue_handler = default_log_handler;
/** Sentinel log message handler
*
* This function is used as the default handler for log messages. It
* exists only to issue a noisy reminder to the user that a real handler
* must be installed prior to issuing logging calls. The process is
* immediately aborted after the reminder is printed.
*
* \param fmt The format string. Ignored.
* \param ap The variadic argument list. Ignored.
*
* \ingroup wlog
*/
static int
default_log_handler(const char *fmt, va_list ap)
{
fprintf(stderr, "weston_log_set_handler() must be called before using of weston_log().\n");
abort();
}
/** Install the log handler
*
* The given functions will be called to output text as passed to the
* \a weston_log and \a weston_log_continue functions.
*
* \param log The log function. This function will be called when
* \a weston_log is called, and should begin a new line,
* with user defined line headers, if any.
* \param cont The continue log function. This function will be called
* when \a weston_log_continue is called, and should append
* its output to the current line, without any header or
* other content in between.
*
* \ingroup wlog
*/
WL_EXPORT void
weston_log_set_handler(log_func_t log, log_func_t cont)
{
log_handler = log;
log_continue_handler = cont;
}
/** weston_vlog calls log_handler
* \ingroup wlog
*/
WL_EXPORT int
weston_vlog(const char *fmt, va_list ap)
{
return log_handler(fmt, ap);
}
/** printf() equivalent in weston compositor.
*
* \rststar
* .. note::
*
* Needs :var:`log_handler` to be set-up!
* \endrststar
*
* \ingroup wlog
*/
WL_EXPORT int
weston_log(const char *fmt, ...)
{
int l;
va_list argp;
va_start(argp, fmt);
l = weston_vlog(fmt, argp);
va_end(argp);
return l;
}
/** weston logger with throttling
*
* Throttled logger that will suppress a message after a fixed number of
* prints, and optionally reset the counter reset_ms miliseconds after
* the first message in a burst.
*
* On the first new message printed with this pacer after the timeout
* expires, a count of suppressed messages will also be printed.
*
* Note that the "initialized" member of struct weston_log_pacer must be
* set to 0 before first call.
*
* \param pacer The pacer instance
* \param max_burst Number of messages to allow before throttling - must
* not be zero.
* \param reset_ms Duration from burst start before the count is reset, or
* zero to never reset.
* \param fmt The format string
*
* \ingroup wlog
*/
WL_EXPORT void
weston_log_paced(struct weston_log_pacer *pacer,
unsigned int max_burst,
unsigned int reset_ms,
const char *fmt, ...)
{
va_list argp;
struct timespec now;
int64_t since_burst_start;
int64_t suppressed = 0;
assert(max_burst != 0);
/* If CLOCK_MONOTONIC fails we silently give up on ever
* reseting the timer. */
if (clock_gettime(CLOCK_MONOTONIC, &now) != 0) {
now.tv_sec = 0;
now.tv_nsec = 0;
pacer->burst_start = now;
}
if (!pacer->initialized) {
pacer->initialized = true;
pacer->burst_start = now;
pacer->max_burst = max_burst;
pacer->reset_ms = reset_ms;
} else {
assert(pacer->max_burst == max_burst);
assert(pacer->reset_ms == reset_ms);
}
since_burst_start = timespec_sub_to_msec(&now, &pacer->burst_start);
if (pacer->reset_ms && since_burst_start > pacer->reset_ms) {
if (pacer->event_count > pacer->max_burst) {
suppressed = pacer->event_count -
pacer->max_burst;
}
pacer->event_count = 0;
}
if (pacer->event_count == 0) {
pacer->burst_start = now;
since_burst_start = 0;
}
pacer->event_count++;
if (pacer->event_count > pacer->max_burst)
return;
va_start(argp, fmt);
weston_vlog(fmt, argp);
va_end(argp);
if (suppressed) {
weston_log_continue(STAMP_SPACE "Warning: %" PRId64 " similar "
"messages previously suppressed\n",
suppressed);
}
/* If we're not going to throttle next time, return immediately,
* otherwise print a little more information */
if (pacer->event_count != pacer->max_burst)
return;
if (pacer->reset_ms) {
int64_t next_reset = pacer->reset_ms - since_burst_start;
weston_log_continue(STAMP_SPACE "Warning: the above message "
"will be suppresssed for the next %"
PRId64 " ms.\n", next_reset);
} else {
weston_log_continue(STAMP_SPACE "Warning: the above message "
"will not be printed again.\n");
}
}
/** weston_vlog_continue calls log_continue_handler
*
* \ingroup wlog
*/
WL_EXPORT int
weston_vlog_continue(const char *fmt, va_list argp)
{
return log_continue_handler(fmt, argp);
}
/** weston_log_continue
*
* \ingroup wlog
*/
WL_EXPORT int
weston_log_continue(const char *fmt, ...)
{
int l;
va_list argp;
va_start(argp, fmt);
l = weston_vlog_continue(fmt, argp);
va_end(argp);
return l;
}