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timeout.c
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1 /*-------------------------------------------------------------------------
2  *
3  * timeout.c
4  * Routines to multiplex SIGALRM interrupts for multiple timeout reasons.
5  *
6  * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
7  * Portions Copyright (c) 1994, Regents of the University of California
8  *
9  *
10  * IDENTIFICATION
11  * src/backend/utils/misc/timeout.c
12  *
13  *-------------------------------------------------------------------------
14  */
15 #include "postgres.h"
16 
17 #include <sys/time.h>
18 
19 #include "miscadmin.h"
20 #include "storage/proc.h"
21 #include "utils/timeout.h"
22 #include "utils/timestamp.h"
23 
24 
25 /* Data about any one timeout reason */
26 typedef struct timeout_params
27 {
28  TimeoutId index; /* identifier of timeout reason */
29 
30  /* volatile because these may be changed from the signal handler */
31  volatile bool active; /* true if timeout is in active_timeouts[] */
32  volatile bool indicator; /* true if timeout has occurred */
33 
34  /* callback function for timeout, or NULL if timeout not registered */
36 
37  TimestampTz start_time; /* time that timeout was last activated */
38  TimestampTz fin_time; /* time it is, or was last, due to fire */
40 
41 /*
42  * List of possible timeout reasons in the order of enum TimeoutId.
43  */
45 static bool all_timeouts_initialized = false;
46 
47 /*
48  * List of active timeouts ordered by their fin_time and priority.
49  * This list is subject to change by the interrupt handler, so it's volatile.
50  */
51 static volatile int num_active_timeouts = 0;
53 
54 /*
55  * Flag controlling whether the signal handler is allowed to do anything.
56  * This is useful to avoid race conditions with the handler. Note in
57  * particular that this lets us make changes in the data structures without
58  * tediously disabling and re-enabling the timer signal. Most of the time,
59  * no interrupt would happen anyway during such critical sections, but if
60  * one does, this rule ensures it's safe. Leaving the signal enabled across
61  * multiple operations can greatly reduce the number of kernel calls we make,
62  * too. See comments in schedule_alarm() about that.
63  *
64  * We leave this "false" when we're not expecting interrupts, just in case.
65  */
66 static volatile sig_atomic_t alarm_enabled = false;
67 
68 #define disable_alarm() (alarm_enabled = false)
69 #define enable_alarm() (alarm_enabled = true)
70 
71 /*
72  * State recording if and when we next expect the interrupt to fire.
73  * Note that the signal handler will unconditionally reset signal_pending to
74  * false, so that can change asynchronously even when alarm_enabled is false.
75  */
76 static volatile sig_atomic_t signal_pending = false;
77 static TimestampTz signal_due_at = 0; /* valid only when signal_pending */
78 
79 
80 /*****************************************************************************
81  * Internal helper functions
82  *
83  * For all of these, it is caller's responsibility to protect them from
84  * interruption by the signal handler. Generally, call disable_alarm()
85  * first to prevent interruption, then update state, and last call
86  * schedule_alarm(), which will re-enable the signal handler if needed.
87  *****************************************************************************/
88 
89 /*
90  * Find the index of a given timeout reason in the active array.
91  * If it's not there, return -1.
92  */
93 static int
95 {
96  int i;
97 
98  for (i = 0; i < num_active_timeouts; i++)
99  {
100  if (active_timeouts[i]->index == id)
101  return i;
102  }
103 
104  return -1;
105 }
106 
107 /*
108  * Insert specified timeout reason into the list of active timeouts
109  * at the given index.
110  */
111 static void
113 {
114  int i;
115 
117  elog(FATAL, "timeout index %d out of range 0..%d", index,
118  num_active_timeouts);
119 
120  Assert(!all_timeouts[id].active);
121  all_timeouts[id].active = true;
122 
123  for (i = num_active_timeouts - 1; i >= index; i--)
124  active_timeouts[i + 1] = active_timeouts[i];
125 
126  active_timeouts[index] = &all_timeouts[id];
127 
128  num_active_timeouts++;
129 }
130 
131 /*
132  * Remove the index'th element from the timeout list.
133  */
134 static void
136 {
137  int i;
138 
140  elog(FATAL, "timeout index %d out of range 0..%d", index,
141  num_active_timeouts - 1);
142 
143  Assert(active_timeouts[index]->active);
144  active_timeouts[index]->active = false;
145 
146  for (i = index + 1; i < num_active_timeouts; i++)
147  active_timeouts[i - 1] = active_timeouts[i];
148 
149  num_active_timeouts--;
150 }
151 
152 /*
153  * Enable the specified timeout reason
154  */
155 static void
157 {
158  int i;
159 
160  /* Assert request is sane */
162  Assert(all_timeouts[id].timeout_handler != NULL);
163 
164  /*
165  * If this timeout was already active, momentarily disable it. We
166  * interpret the call as a directive to reschedule the timeout.
167  */
168  if (all_timeouts[id].active)
170 
171  /*
172  * Find out the index where to insert the new timeout. We sort by
173  * fin_time, and for equal fin_time by priority.
174  */
175  for (i = 0; i < num_active_timeouts; i++)
176  {
177  timeout_params *old_timeout = active_timeouts[i];
178 
179  if (fin_time < old_timeout->fin_time)
180  break;
181  if (fin_time == old_timeout->fin_time && id < old_timeout->index)
182  break;
183  }
184 
185  /*
186  * Mark the timeout active, and insert it into the active list.
187  */
188  all_timeouts[id].indicator = false;
189  all_timeouts[id].start_time = now;
190  all_timeouts[id].fin_time = fin_time;
191 
192  insert_timeout(id, i);
193 }
194 
195 /*
196  * Schedule alarm for the next active timeout, if any
197  *
198  * We assume the caller has obtained the current time, or a close-enough
199  * approximation. (It's okay if a tick or two has passed since "now", or
200  * if a little more time elapses before we reach the kernel call; that will
201  * cause us to ask for an interrupt a tick or two later than the nearest
202  * timeout, which is no big deal. Passing a "now" value that's in the future
203  * would be bad though.)
204  */
205 static void
207 {
208  if (num_active_timeouts > 0)
209  {
210  struct itimerval timeval;
211  TimestampTz nearest_timeout;
212  long secs;
213  int usecs;
214 
215  MemSet(&timeval, 0, sizeof(struct itimerval));
216 
217  /*
218  * Get the time remaining till the nearest pending timeout. If it is
219  * negative, assume that we somehow missed an interrupt, and force
220  * signal_pending off. This gives us a chance to recover if the
221  * kernel drops a timeout request for some reason.
222  */
223  nearest_timeout = active_timeouts[0]->fin_time;
224  if (now > nearest_timeout)
225  {
226  signal_pending = false;
227  /* force an interrupt as soon as possible */
228  secs = 0;
229  usecs = 1;
230  }
231  else
232  {
233  TimestampDifference(now, nearest_timeout,
234  &secs, &usecs);
235 
236  /*
237  * It's possible that the difference is less than a microsecond;
238  * ensure we don't cancel, rather than set, the interrupt.
239  */
240  if (secs == 0 && usecs == 0)
241  usecs = 1;
242  }
243 
244  timeval.it_value.tv_sec = secs;
245  timeval.it_value.tv_usec = usecs;
246 
247  /*
248  * We must enable the signal handler before calling setitimer(); if we
249  * did it in the other order, we'd have a race condition wherein the
250  * interrupt could occur before we can set alarm_enabled, so that the
251  * signal handler would fail to do anything.
252  *
253  * Because we didn't bother to disable the timer in disable_alarm(),
254  * it's possible that a previously-set interrupt will fire between
255  * enable_alarm() and setitimer(). This is safe, however. There are
256  * two possible outcomes:
257  *
258  * 1. The signal handler finds nothing to do (because the nearest
259  * timeout event is still in the future). It will re-set the timer
260  * and return. Then we'll overwrite the timer value with a new one.
261  * This will mean that the timer fires a little later than we
262  * intended, but only by the amount of time it takes for the signal
263  * handler to do nothing useful, which shouldn't be much.
264  *
265  * 2. The signal handler executes and removes one or more timeout
266  * events. When it returns, either the queue is now empty or the
267  * frontmost event is later than the one we looked at above. So we'll
268  * overwrite the timer value with one that is too soon (plus or minus
269  * the signal handler's execution time), causing a useless interrupt
270  * to occur. But the handler will then re-set the timer and
271  * everything will still work as expected.
272  *
273  * Since these cases are of very low probability (the window here
274  * being quite narrow), it's not worth adding cycles to the mainline
275  * code to prevent occasional wasted interrupts.
276  */
277  enable_alarm();
278 
279  /*
280  * If there is already an interrupt pending that's at or before the
281  * needed time, we need not do anything more. The signal handler will
282  * do the right thing in the first case, and re-schedule the interrupt
283  * for later in the second case. It might seem that the extra
284  * interrupt is wasted work, but it's not terribly much work, and this
285  * method has very significant advantages in the common use-case where
286  * we repeatedly set a timeout that we don't expect to reach and then
287  * cancel it. Instead of invoking setitimer() every time the timeout
288  * is set or canceled, we perform one interrupt and a re-scheduling
289  * setitimer() call at intervals roughly equal to the timeout delay.
290  * For example, with statement_timeout = 1s and a throughput of
291  * thousands of queries per second, this method requires an interrupt
292  * and setitimer() call roughly once a second, rather than thousands
293  * of setitimer() calls per second.
294  *
295  * Because of the possible passage of time between when we obtained
296  * "now" and when we reach setitimer(), the kernel's opinion of when
297  * to trigger the interrupt is likely to be a bit later than
298  * signal_due_at. That's fine, for the same reasons described above.
299  */
300  if (signal_pending && nearest_timeout >= signal_due_at)
301  return;
302 
303  /*
304  * As with calling enable_alarm(), we must set signal_pending *before*
305  * calling setitimer(); if we did it after, the signal handler could
306  * trigger before we set it, leaving us with a false opinion that a
307  * signal is still coming.
308  *
309  * Other race conditions involved with setting/checking signal_pending
310  * are okay, for the reasons described above. One additional point is
311  * that the signal handler could fire after we set signal_due_at, but
312  * still before the setitimer() call. Then the handler could
313  * overwrite signal_due_at with a value it computes, which will be the
314  * same as or perhaps later than what we just computed. After we
315  * perform setitimer(), the net effect would be that signal_due_at
316  * gives a time later than when the interrupt will really happen;
317  * which is a safe situation.
318  */
319  signal_due_at = nearest_timeout;
320  signal_pending = true;
321 
322  /* Set the alarm timer */
323  if (setitimer(ITIMER_REAL, &timeval, NULL) != 0)
324  {
325  /*
326  * Clearing signal_pending here is a bit pro forma, but not
327  * entirely so, since something in the FATAL exit path could try
328  * to use timeout facilities.
329  */
330  signal_pending = false;
331  elog(FATAL, "could not enable SIGALRM timer: %m");
332  }
333  }
334 }
335 
336 
337 /*****************************************************************************
338  * Signal handler
339  *****************************************************************************/
340 
341 /*
342  * Signal handler for SIGALRM
343  *
344  * Process any active timeout reasons and then reschedule the interrupt
345  * as needed.
346  */
347 static void
349 {
350  int save_errno = errno;
351 
352  /*
353  * Bump the holdoff counter, to make sure nothing we call will process
354  * interrupts directly. No timeout handler should do that, but these
355  * failures are hard to debug, so better be sure.
356  */
357  HOLD_INTERRUPTS();
358 
359  /*
360  * SIGALRM is always cause for waking anything waiting on the process
361  * latch.
362  */
363  SetLatch(MyLatch);
364 
365  /*
366  * Always reset signal_pending, even if !alarm_enabled, since indeed no
367  * signal is now pending.
368  */
369  signal_pending = false;
370 
371  /*
372  * Fire any pending timeouts, but only if we're enabled to do so.
373  */
374  if (alarm_enabled)
375  {
376  /*
377  * Disable alarms, just in case this platform allows signal handlers
378  * to interrupt themselves. schedule_alarm() will re-enable if
379  * appropriate.
380  */
381  disable_alarm();
382 
383  if (num_active_timeouts > 0)
384  {
386 
387  /* While the first pending timeout has been reached ... */
388  while (num_active_timeouts > 0 &&
389  now >= active_timeouts[0]->fin_time)
390  {
391  timeout_params *this_timeout = active_timeouts[0];
392 
393  /* Remove it from the active list */
395 
396  /* Mark it as fired */
397  this_timeout->indicator = true;
398 
399  /* And call its handler function */
400  this_timeout->timeout_handler();
401 
402  /*
403  * The handler might not take negligible time (CheckDeadLock
404  * for instance isn't too cheap), so let's update our idea of
405  * "now" after each one.
406  */
407  now = GetCurrentTimestamp();
408  }
409 
410  /* Done firing timeouts, so reschedule next interrupt if any */
411  schedule_alarm(now);
412  }
413  }
414 
416 
417  errno = save_errno;
418 }
419 
420 
421 /*****************************************************************************
422  * Public API
423  *****************************************************************************/
424 
425 /*
426  * Initialize timeout module.
427  *
428  * This must be called in every process that wants to use timeouts.
429  *
430  * If the process was forked from another one that was also using this
431  * module, be sure to call this before re-enabling signals; else handlers
432  * meant to run in the parent process might get invoked in this one.
433  */
434 void
436 {
437  int i;
438 
439  /* Initialize, or re-initialize, all local state */
440  disable_alarm();
441 
443 
444  for (i = 0; i < MAX_TIMEOUTS; i++)
445  {
446  all_timeouts[i].index = i;
447  all_timeouts[i].active = false;
448  all_timeouts[i].indicator = false;
449  all_timeouts[i].timeout_handler = NULL;
450  all_timeouts[i].start_time = 0;
451  all_timeouts[i].fin_time = 0;
452  }
453 
455 
456  /* Now establish the signal handler */
458 }
459 
460 /*
461  * Register a timeout reason
462  *
463  * For predefined timeouts, this just registers the callback function.
464  *
465  * For user-defined timeouts, pass id == USER_TIMEOUT; we then allocate and
466  * return a timeout ID.
467  */
468 TimeoutId
470 {
472 
473  /* There's no need to disable the signal handler here. */
474 
475  if (id >= USER_TIMEOUT)
476  {
477  /* Allocate a user-defined timeout reason */
478  for (id = USER_TIMEOUT; id < MAX_TIMEOUTS; id++)
479  if (all_timeouts[id].timeout_handler == NULL)
480  break;
481  if (id >= MAX_TIMEOUTS)
482  ereport(FATAL,
483  (errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
484  errmsg("cannot add more timeout reasons")));
485  }
486 
487  Assert(all_timeouts[id].timeout_handler == NULL);
488 
489  all_timeouts[id].timeout_handler = handler;
490 
491  return id;
492 }
493 
494 /*
495  * Reschedule any pending SIGALRM interrupt.
496  *
497  * This can be used during error recovery in case query cancel resulted in loss
498  * of a SIGALRM event (due to longjmp'ing out of handle_sig_alarm before it
499  * could do anything). But note it's not necessary if any of the public
500  * enable_ or disable_timeout functions are called in the same area, since
501  * those all do schedule_alarm() internally if needed.
502  */
503 void
505 {
506  /* For flexibility, allow this to be called before we're initialized. */
508  return;
509 
510  /* Disable timeout interrupts for safety. */
511  disable_alarm();
512 
513  /* Reschedule the interrupt, if any timeouts remain active. */
514  if (num_active_timeouts > 0)
516 }
517 
518 /*
519  * Enable the specified timeout to fire after the specified delay.
520  *
521  * Delay is given in milliseconds.
522  */
523 void
525 {
528 
529  /* Disable timeout interrupts for safety. */
530  disable_alarm();
531 
532  /* Queue the timeout at the appropriate time. */
533  now = GetCurrentTimestamp();
534  fin_time = TimestampTzPlusMilliseconds(now, delay_ms);
535  enable_timeout(id, now, fin_time);
536 
537  /* Set the timer interrupt. */
538  schedule_alarm(now);
539 }
540 
541 /*
542  * Enable the specified timeout to fire at the specified time.
543  *
544  * This is provided to support cases where there's a reason to calculate
545  * the timeout by reference to some point other than "now". If there isn't,
546  * use enable_timeout_after(), to avoid calling GetCurrentTimestamp() twice.
547  */
548 void
550 {
552 
553  /* Disable timeout interrupts for safety. */
554  disable_alarm();
555 
556  /* Queue the timeout at the appropriate time. */
557  now = GetCurrentTimestamp();
558  enable_timeout(id, now, fin_time);
559 
560  /* Set the timer interrupt. */
561  schedule_alarm(now);
562 }
563 
564 /*
565  * Enable multiple timeouts at once.
566  *
567  * This works like calling enable_timeout_after() and/or enable_timeout_at()
568  * multiple times. Use this to reduce the number of GetCurrentTimestamp()
569  * and setitimer() calls needed to establish multiple timeouts.
570  */
571 void
572 enable_timeouts(const EnableTimeoutParams *timeouts, int count)
573 {
575  int i;
576 
577  /* Disable timeout interrupts for safety. */
578  disable_alarm();
579 
580  /* Queue the timeout(s) at the appropriate times. */
581  now = GetCurrentTimestamp();
582 
583  for (i = 0; i < count; i++)
584  {
585  TimeoutId id = timeouts[i].id;
587 
588  switch (timeouts[i].type)
589  {
590  case TMPARAM_AFTER:
591  fin_time = TimestampTzPlusMilliseconds(now,
592  timeouts[i].delay_ms);
593  enable_timeout(id, now, fin_time);
594  break;
595 
596  case TMPARAM_AT:
597  enable_timeout(id, now, timeouts[i].fin_time);
598  break;
599 
600  default:
601  elog(ERROR, "unrecognized timeout type %d",
602  (int) timeouts[i].type);
603  break;
604  }
605  }
606 
607  /* Set the timer interrupt. */
608  schedule_alarm(now);
609 }
610 
611 /*
612  * Cancel the specified timeout.
613  *
614  * The timeout's I've-been-fired indicator is reset,
615  * unless keep_indicator is true.
616  *
617  * When a timeout is canceled, any other active timeout remains in force.
618  * It's not an error to disable a timeout that is not enabled.
619  */
620 void
621 disable_timeout(TimeoutId id, bool keep_indicator)
622 {
623  /* Assert request is sane */
625  Assert(all_timeouts[id].timeout_handler != NULL);
626 
627  /* Disable timeout interrupts for safety. */
628  disable_alarm();
629 
630  /* Find the timeout and remove it from the active list. */
631  if (all_timeouts[id].active)
633 
634  /* Mark it inactive, whether it was active or not. */
635  if (!keep_indicator)
636  all_timeouts[id].indicator = false;
637 
638  /* Reschedule the interrupt, if any timeouts remain active. */
639  if (num_active_timeouts > 0)
641 }
642 
643 /*
644  * Cancel multiple timeouts at once.
645  *
646  * The timeouts' I've-been-fired indicators are reset,
647  * unless timeouts[i].keep_indicator is true.
648  *
649  * This works like calling disable_timeout() multiple times.
650  * Use this to reduce the number of GetCurrentTimestamp()
651  * and setitimer() calls needed to cancel multiple timeouts.
652  */
653 void
654 disable_timeouts(const DisableTimeoutParams *timeouts, int count)
655 {
656  int i;
657 
659 
660  /* Disable timeout interrupts for safety. */
661  disable_alarm();
662 
663  /* Cancel the timeout(s). */
664  for (i = 0; i < count; i++)
665  {
666  TimeoutId id = timeouts[i].id;
667 
668  Assert(all_timeouts[id].timeout_handler != NULL);
669 
670  if (all_timeouts[id].active)
672 
673  if (!timeouts[i].keep_indicator)
674  all_timeouts[id].indicator = false;
675  }
676 
677  /* Reschedule the interrupt, if any timeouts remain active. */
678  if (num_active_timeouts > 0)
680 }
681 
682 /*
683  * Disable the signal handler, remove all timeouts from the active list,
684  * and optionally reset their timeout indicators.
685  */
686 void
687 disable_all_timeouts(bool keep_indicators)
688 {
689  int i;
690 
691  disable_alarm();
692 
693  /*
694  * We used to disable the timer interrupt here, but in common usage
695  * patterns it's cheaper to leave it enabled; that may save us from having
696  * to enable it again shortly. See comments in schedule_alarm().
697  */
698 
700 
701  for (i = 0; i < MAX_TIMEOUTS; i++)
702  {
703  all_timeouts[i].active = false;
704  if (!keep_indicators)
705  all_timeouts[i].indicator = false;
706  }
707 }
708 
709 /*
710  * Return true if the timeout is active (enabled and not yet fired)
711  *
712  * This is, of course, subject to race conditions, as the timeout could fire
713  * immediately after we look.
714  */
715 bool
717 {
718  return all_timeouts[id].active;
719 }
720 
721 /*
722  * Return the timeout's I've-been-fired indicator
723  *
724  * If reset_indicator is true, reset the indicator when returning true.
725  * To avoid missing timeouts due to race conditions, we are careful not to
726  * reset the indicator when returning false.
727  */
728 bool
729 get_timeout_indicator(TimeoutId id, bool reset_indicator)
730 {
731  if (all_timeouts[id].indicator)
732  {
733  if (reset_indicator)
734  all_timeouts[id].indicator = false;
735  return true;
736  }
737  return false;
738 }
739 
740 /*
741  * Return the time when the timeout was most recently activated
742  *
743  * Note: will return 0 if timeout has never been activated in this process.
744  * However, we do *not* reset the start_time when a timeout occurs, so as
745  * not to create a race condition if SIGALRM fires just as some code is
746  * about to fetch the value.
747  */
750 {
751  return all_timeouts[id].start_time;
752 }
753 
754 /*
755  * Return the time when the timeout is, or most recently was, due to fire
756  *
757  * Note: will return 0 if timeout has never been activated in this process.
758  * However, we do *not* reset the fin_time when a timeout occurs, so as
759  * not to create a race condition if SIGALRM fires just as some code is
760  * about to fetch the value.
761  */
764 {
765  return all_timeouts[id].fin_time;
766 }
static bool all_timeouts_initialized
Definition: timeout.c:45
TimestampTz get_timeout_start_time(TimeoutId id)
Definition: timeout.c:749
void InitializeTimeouts(void)
Definition: timeout.c:435
static void remove_timeout_index(int index)
Definition: timeout.c:135
TimeoutId id
Definition: timeout.h:56
TimestampTz get_timeout_finish_time(TimeoutId id)
Definition: timeout.c:763
#define enable_alarm()
Definition: timeout.c:69
TimestampTz GetCurrentTimestamp(void)
Definition: timestamp.c:1580
int64 TimestampTz
Definition: timestamp.h:39
TimestampTz fin_time
Definition: timeout.c:38
static TimestampTz signal_due_at
Definition: timeout.c:77
int errcode(int sqlerrcode)
Definition: elog.c:698
struct timeval it_value
Definition: win32_port.h:191
#define MemSet(start, val, len)
Definition: c.h:1008
#define disable_alarm()
Definition: timeout.c:68
timeout_handler_proc timeout_handler
Definition: timeout.c:35
volatile bool indicator
Definition: timeout.c:32
void SetLatch(Latch *latch)
Definition: latch.c:567
void disable_timeouts(const DisableTimeoutParams *timeouts, int count)
Definition: timeout.c:654
void reschedule_timeouts(void)
Definition: timeout.c:504
volatile bool active
Definition: timeout.c:31
Definition: type.h:89
#define RESUME_INTERRUPTS()
Definition: miscadmin.h:133
void enable_timeouts(const EnableTimeoutParams *timeouts, int count)
Definition: timeout.c:572
void(* timeout_handler_proc)(void)
Definition: timeout.h:43
void enable_timeout_at(TimeoutId id, TimestampTz fin_time)
Definition: timeout.c:549
void disable_all_timeouts(bool keep_indicators)
Definition: timeout.c:687
#define ERROR
Definition: elog.h:46
#define FATAL
Definition: elog.h:49
TimeoutId id
Definition: timeout.h:67
static timeout_params all_timeouts[MAX_TIMEOUTS]
Definition: timeout.c:44
static void enable_timeout(TimeoutId id, TimestampTz now, TimestampTz fin_time)
Definition: timeout.c:156
TimestampTz start_time
Definition: timeout.c:37
static void insert_timeout(TimeoutId id, int index)
Definition: timeout.c:112
int setitimer(int which, const struct itimerval *value, struct itimerval *ovalue)
Definition: timer.c:86
static volatile sig_atomic_t alarm_enabled
Definition: timeout.c:66
static volatile sig_atomic_t signal_pending
Definition: timeout.c:76
static void schedule_alarm(TimestampTz now)
Definition: timeout.c:206
bool get_timeout_indicator(TimeoutId id, bool reset_indicator)
Definition: timeout.c:729
#define TimestampTzPlusMilliseconds(tz, ms)
Definition: timestamp.h:56
#define ereport(elevel,...)
Definition: elog.h:157
pqsigfunc pqsignal(int signum, pqsigfunc handler)
Definition: signal.c:170
TimeoutId RegisterTimeout(TimeoutId id, timeout_handler_proc handler)
Definition: timeout.c:469
void enable_timeout_after(TimeoutId id, int delay_ms)
Definition: timeout.c:524
TimeoutId index
Definition: timeout.c:28
#define SIGNAL_ARGS
Definition: c.h:1333
#define Assert(condition)
Definition: c.h:804
TimeoutId
Definition: timeout.h:23
#define SIGALRM
Definition: win32_port.h:165
static timeout_params *volatile active_timeouts[MAX_TIMEOUTS]
Definition: timeout.c:52
static int find_active_timeout(TimeoutId id)
Definition: timeout.c:94
int errmsg(const char *fmt,...)
Definition: elog.c:909
#define HOLD_INTERRUPTS()
Definition: miscadmin.h:131
#define elog(elevel,...)
Definition: elog.h:232
int i
struct timeout_params timeout_params
struct Latch * MyLatch
Definition: globals.c:57
void disable_timeout(TimeoutId id, bool keep_indicator)
Definition: timeout.c:621
void TimestampDifference(TimestampTz start_time, TimestampTz stop_time, long *secs, int *microsecs)
Definition: timestamp.c:1656
static volatile int num_active_timeouts
Definition: timeout.c:51
Datum now(PG_FUNCTION_ARGS)
Definition: timestamp.c:1544
#define ITIMER_REAL
Definition: win32_port.h:187
bool get_timeout_active(TimeoutId id)
Definition: timeout.c:716
static void handle_sig_alarm(SIGNAL_ARGS)
Definition: timeout.c:348