PostgreSQL Source Code git master
All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Pages
procsignal.c
Go to the documentation of this file.
1/*-------------------------------------------------------------------------
2 *
3 * procsignal.c
4 * Routines for interprocess signaling
5 *
6 *
7 * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
8 * Portions Copyright (c) 1994, Regents of the University of California
9 *
10 * IDENTIFICATION
11 * src/backend/storage/ipc/procsignal.c
12 *
13 *-------------------------------------------------------------------------
14 */
15#include "postgres.h"
16
17#include <signal.h>
18#include <unistd.h>
19
20#include "access/parallel.h"
21#include "commands/async.h"
22#include "miscadmin.h"
23#include "pgstat.h"
24#include "port/pg_bitutils.h"
28#include "storage/ipc.h"
29#include "storage/latch.h"
30#include "storage/shmem.h"
31#include "storage/sinval.h"
32#include "storage/smgr.h"
33#include "tcop/tcopprot.h"
34#include "utils/memutils.h"
35
36/*
37 * The SIGUSR1 signal is multiplexed to support signaling multiple event
38 * types. The specific reason is communicated via flags in shared memory.
39 * We keep a boolean flag for each possible "reason", so that different
40 * reasons can be signaled to a process concurrently. (However, if the same
41 * reason is signaled more than once nearly simultaneously, the process may
42 * observe it only once.)
43 *
44 * Each process that wants to receive signals registers its process ID
45 * in the ProcSignalSlots array. The array is indexed by ProcNumber to make
46 * slot allocation simple, and to avoid having to search the array when you
47 * know the ProcNumber of the process you're signaling. (We do support
48 * signaling without ProcNumber, but it's a bit less efficient.)
49 *
50 * The fields in each slot are protected by a spinlock, pss_mutex. pss_pid can
51 * also be read without holding the spinlock, as a quick preliminary check
52 * when searching for a particular PID in the array.
53 *
54 * pss_signalFlags are intended to be set in cases where we don't need to
55 * keep track of whether or not the target process has handled the signal,
56 * but sometimes we need confirmation, as when making a global state change
57 * that cannot be considered complete until all backends have taken notice
58 * of it. For such use cases, we set a bit in pss_barrierCheckMask and then
59 * increment the current "barrier generation"; when the new barrier generation
60 * (or greater) appears in the pss_barrierGeneration flag of every process,
61 * we know that the message has been received everywhere.
62 */
63typedef struct
64{
68 volatile sig_atomic_t pss_signalFlags[NUM_PROCSIGNALS];
69 slock_t pss_mutex; /* protects the above fields */
70
71 /* Barrier-related fields (not protected by pss_mutex) */
76
77/*
78 * Information that is global to the entire ProcSignal system can be stored
79 * here.
80 *
81 * psh_barrierGeneration is the highest barrier generation in existence.
82 */
84{
87};
88
89/*
90 * We reserve a slot for each possible ProcNumber, plus one for each
91 * possible auxiliary process type. (This scheme assumes there is not
92 * more than one of any auxiliary process type at a time.)
93 */
94#define NumProcSignalSlots (MaxBackends + NUM_AUXILIARY_PROCS)
95
96/* Check whether the relevant type bit is set in the flags. */
97#define BARRIER_SHOULD_CHECK(flags, type) \
98 (((flags) & (((uint32) 1) << (uint32) (type))) != 0)
99
100/* Clear the relevant type bit from the flags. */
101#define BARRIER_CLEAR_BIT(flags, type) \
102 ((flags) &= ~(((uint32) 1) << (uint32) (type)))
103
106
107static bool CheckProcSignal(ProcSignalReason reason);
108static void CleanupProcSignalState(int status, Datum arg);
109static void ResetProcSignalBarrierBits(uint32 flags);
110
111/*
112 * ProcSignalShmemSize
113 * Compute space needed for ProcSignal's shared memory
114 */
115Size
117{
118 Size size;
119
121 size = add_size(size, offsetof(ProcSignalHeader, psh_slot));
122 return size;
123}
124
125/*
126 * ProcSignalShmemInit
127 * Allocate and initialize ProcSignal's shared memory
128 */
129void
131{
133 bool found;
134
136 ShmemInitStruct("ProcSignal", size, &found);
137
138 /* If we're first, initialize. */
139 if (!found)
140 {
141 int i;
142
144
145 for (i = 0; i < NumProcSignalSlots; ++i)
146 {
148
149 SpinLockInit(&slot->pss_mutex);
150 pg_atomic_init_u32(&slot->pss_pid, 0);
151 slot->pss_cancel_key_valid = false;
152 slot->pss_cancel_key = 0;
153 MemSet(slot->pss_signalFlags, 0, sizeof(slot->pss_signalFlags));
157 }
158 }
159}
160
161/*
162 * ProcSignalInit
163 * Register the current process in the ProcSignal array
164 */
165void
166ProcSignalInit(bool cancel_key_valid, int32 cancel_key)
167{
168 ProcSignalSlot *slot;
169 uint64 barrier_generation;
170
171 if (MyProcNumber < 0)
172 elog(ERROR, "MyProcNumber not set");
174 elog(ERROR, "unexpected MyProcNumber %d in ProcSignalInit (max %d)", MyProcNumber, NumProcSignalSlots);
176
177 /* sanity check */
179 if (pg_atomic_read_u32(&slot->pss_pid) != 0)
180 {
182 elog(LOG, "process %d taking over ProcSignal slot %d, but it's not empty",
184 }
185
186 /* Clear out any leftover signal reasons */
187 MemSet(slot->pss_signalFlags, 0, NUM_PROCSIGNALS * sizeof(sig_atomic_t));
188
189 /*
190 * Initialize barrier state. Since we're a brand-new process, there
191 * shouldn't be any leftover backend-private state that needs to be
192 * updated. Therefore, we can broadcast the latest barrier generation and
193 * disregard any previously-set check bits.
194 *
195 * NB: This only works if this initialization happens early enough in the
196 * startup sequence that we haven't yet cached any state that might need
197 * to be invalidated. That's also why we have a memory barrier here, to be
198 * sure that any later reads of memory happen strictly after this.
199 */
201 barrier_generation =
203 pg_atomic_write_u64(&slot->pss_barrierGeneration, barrier_generation);
204
205 slot->pss_cancel_key_valid = cancel_key_valid;
206 slot->pss_cancel_key = cancel_key;
208
210
211 /* Remember slot location for CheckProcSignal */
212 MyProcSignalSlot = slot;
213
214 /* Set up to release the slot on process exit */
216}
217
218/*
219 * CleanupProcSignalState
220 * Remove current process from ProcSignal mechanism
221 *
222 * This function is called via on_shmem_exit() during backend shutdown.
223 */
224static void
226{
227 pid_t old_pid;
229
230 /*
231 * Clear MyProcSignalSlot, so that a SIGUSR1 received after this point
232 * won't try to access it after it's no longer ours (and perhaps even
233 * after we've unmapped the shared memory segment).
234 */
235 Assert(MyProcSignalSlot != NULL);
236 MyProcSignalSlot = NULL;
237
238 /* sanity check */
240 old_pid = pg_atomic_read_u32(&slot->pss_pid);
241 if (old_pid != MyProcPid)
242 {
243 /*
244 * don't ERROR here. We're exiting anyway, and don't want to get into
245 * infinite loop trying to exit
246 */
248 elog(LOG, "process %d releasing ProcSignal slot %d, but it contains %d",
249 MyProcPid, (int) (slot - ProcSignal->psh_slot), (int) old_pid);
250 return; /* XXX better to zero the slot anyway? */
251 }
252
253 /* Mark the slot as unused */
254 pg_atomic_write_u32(&slot->pss_pid, 0);
255 slot->pss_cancel_key_valid = false;
256 slot->pss_cancel_key = 0;
257
258 /*
259 * Make this slot look like it's absorbed all possible barriers, so that
260 * no barrier waits block on it.
261 */
263
265
267}
268
269/*
270 * SendProcSignal
271 * Send a signal to a Postgres process
272 *
273 * Providing procNumber is optional, but it will speed up the operation.
274 *
275 * On success (a signal was sent), zero is returned.
276 * On error, -1 is returned, and errno is set (typically to ESRCH or EPERM).
277 *
278 * Not to be confused with ProcSendSignal
279 */
280int
281SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber)
282{
283 volatile ProcSignalSlot *slot;
284
285 if (procNumber != INVALID_PROC_NUMBER)
286 {
287 Assert(procNumber < NumProcSignalSlots);
288 slot = &ProcSignal->psh_slot[procNumber];
289
291 if (pg_atomic_read_u32(&slot->pss_pid) == pid)
292 {
293 /* Atomically set the proper flag */
294 slot->pss_signalFlags[reason] = true;
296 /* Send signal */
297 return kill(pid, SIGUSR1);
298 }
300 }
301 else
302 {
303 /*
304 * procNumber not provided, so search the array using pid. We search
305 * the array back to front so as to reduce search overhead. Passing
306 * INVALID_PROC_NUMBER means that the target is most likely an
307 * auxiliary process, which will have a slot near the end of the
308 * array.
309 */
310 int i;
311
312 for (i = NumProcSignalSlots - 1; i >= 0; i--)
313 {
314 slot = &ProcSignal->psh_slot[i];
315
316 if (pg_atomic_read_u32(&slot->pss_pid) == pid)
317 {
319 if (pg_atomic_read_u32(&slot->pss_pid) == pid)
320 {
321 /* Atomically set the proper flag */
322 slot->pss_signalFlags[reason] = true;
324 /* Send signal */
325 return kill(pid, SIGUSR1);
326 }
328 }
329 }
330 }
331
332 errno = ESRCH;
333 return -1;
334}
335
336/*
337 * EmitProcSignalBarrier
338 * Send a signal to every Postgres process
339 *
340 * The return value of this function is the barrier "generation" created
341 * by this operation. This value can be passed to WaitForProcSignalBarrier
342 * to wait until it is known that every participant in the ProcSignal
343 * mechanism has absorbed the signal (or started afterwards).
344 *
345 * Note that it would be a bad idea to use this for anything that happens
346 * frequently, as interrupting every backend could cause a noticeable
347 * performance hit.
348 *
349 * Callers are entitled to assume that this function will not throw ERROR
350 * or FATAL.
351 */
352uint64
354{
355 uint32 flagbit = 1 << (uint32) type;
356 uint64 generation;
357
358 /*
359 * Set all the flags.
360 *
361 * Note that pg_atomic_fetch_or_u32 has full barrier semantics, so this is
362 * totally ordered with respect to anything the caller did before, and
363 * anything that we do afterwards. (This is also true of the later call to
364 * pg_atomic_add_fetch_u64.)
365 */
366 for (int i = 0; i < NumProcSignalSlots; i++)
367 {
368 volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i];
369
371 }
372
373 /*
374 * Increment the generation counter.
375 */
376 generation =
378
379 /*
380 * Signal all the processes, so that they update their advertised barrier
381 * generation.
382 *
383 * Concurrency is not a problem here. Backends that have exited don't
384 * matter, and new backends that have joined since we entered this
385 * function must already have current state, since the caller is
386 * responsible for making sure that the relevant state is entirely visible
387 * before calling this function in the first place. We still have to wake
388 * them up - because we can't distinguish between such backends and older
389 * backends that need to update state - but they won't actually need to
390 * change any state.
391 */
392 for (int i = NumProcSignalSlots - 1; i >= 0; i--)
393 {
394 volatile ProcSignalSlot *slot = &ProcSignal->psh_slot[i];
395 pid_t pid = pg_atomic_read_u32(&slot->pss_pid);
396
397 if (pid != 0)
398 {
400 pid = pg_atomic_read_u32(&slot->pss_pid);
401 if (pid != 0)
402 {
403 /* see SendProcSignal for details */
404 slot->pss_signalFlags[PROCSIG_BARRIER] = true;
406 kill(pid, SIGUSR1);
407 }
408 else
410 }
411 }
412
413 return generation;
414}
415
416/*
417 * WaitForProcSignalBarrier - wait until it is guaranteed that all changes
418 * requested by a specific call to EmitProcSignalBarrier() have taken effect.
419 */
420void
422{
424
425 elog(DEBUG1,
426 "waiting for all backends to process ProcSignalBarrier generation "
428 generation);
429
430 for (int i = NumProcSignalSlots - 1; i >= 0; i--)
431 {
433 uint64 oldval;
434
435 /*
436 * It's important that we check only pss_barrierGeneration here and
437 * not pss_barrierCheckMask. Bits in pss_barrierCheckMask get cleared
438 * before the barrier is actually absorbed, but pss_barrierGeneration
439 * is updated only afterward.
440 */
442 while (oldval < generation)
443 {
445 5000,
446 WAIT_EVENT_PROC_SIGNAL_BARRIER))
447 ereport(LOG,
448 (errmsg("still waiting for backend with PID %d to accept ProcSignalBarrier",
449 (int) pg_atomic_read_u32(&slot->pss_pid))));
451 }
453 }
454
455 elog(DEBUG1,
456 "finished waiting for all backends to process ProcSignalBarrier generation "
458 generation);
459
460 /*
461 * The caller is probably calling this function because it wants to read
462 * the shared state or perform further writes to shared state once all
463 * backends are known to have absorbed the barrier. However, the read of
464 * pss_barrierGeneration was performed unlocked; insert a memory barrier
465 * to separate it from whatever follows.
466 */
468}
469
470/*
471 * Handle receipt of an interrupt indicating a global barrier event.
472 *
473 * All the actual work is deferred to ProcessProcSignalBarrier(), because we
474 * cannot safely access the barrier generation inside the signal handler as
475 * 64bit atomics might use spinlock based emulation, even for reads. As this
476 * routine only gets called when PROCSIG_BARRIER is sent that won't cause a
477 * lot of unnecessary work.
478 */
479static void
481{
482 InterruptPending = true;
484 /* latch will be set by procsignal_sigusr1_handler */
485}
486
487/*
488 * Perform global barrier related interrupt checking.
489 *
490 * Any backend that participates in ProcSignal signaling must arrange to
491 * call this function periodically. It is called from CHECK_FOR_INTERRUPTS(),
492 * which is enough for normal backends, but not necessarily for all types of
493 * background processes.
494 */
495void
497{
498 uint64 local_gen;
499 uint64 shared_gen;
500 volatile uint32 flags;
501
503
504 /* Exit quickly if there's no work to do. */
506 return;
508
509 /*
510 * It's not unlikely to process multiple barriers at once, before the
511 * signals for all the barriers have arrived. To avoid unnecessary work in
512 * response to subsequent signals, exit early if we already have processed
513 * all of them.
514 */
517
518 Assert(local_gen <= shared_gen);
519
520 if (local_gen == shared_gen)
521 return;
522
523 /*
524 * Get and clear the flags that are set for this backend. Note that
525 * pg_atomic_exchange_u32 is a full barrier, so we're guaranteed that the
526 * read of the barrier generation above happens before we atomically
527 * extract the flags, and that any subsequent state changes happen
528 * afterward.
529 *
530 * NB: In order to avoid race conditions, we must zero
531 * pss_barrierCheckMask first and only afterwards try to do barrier
532 * processing. If we did it in the other order, someone could send us
533 * another barrier of some type right after we called the
534 * barrier-processing function but before we cleared the bit. We would
535 * have no way of knowing that the bit needs to stay set in that case, so
536 * the need to call the barrier-processing function again would just get
537 * forgotten. So instead, we tentatively clear all the bits and then put
538 * back any for which we don't manage to successfully absorb the barrier.
539 */
541
542 /*
543 * If there are no flags set, then we can skip doing any real work.
544 * Otherwise, establish a PG_TRY block, so that we don't lose track of
545 * which types of barrier processing are needed if an ERROR occurs.
546 */
547 if (flags != 0)
548 {
549 bool success = true;
550
551 PG_TRY();
552 {
553 /*
554 * Process each type of barrier. The barrier-processing functions
555 * should normally return true, but may return false if the
556 * barrier can't be absorbed at the current time. This should be
557 * rare, because it's pretty expensive. Every single
558 * CHECK_FOR_INTERRUPTS() will return here until we manage to
559 * absorb the barrier, and that cost will add up in a hurry.
560 *
561 * NB: It ought to be OK to call the barrier-processing functions
562 * unconditionally, but it's more efficient to call only the ones
563 * that might need us to do something based on the flags.
564 */
565 while (flags != 0)
566 {
568 bool processed = true;
569
571 switch (type)
572 {
574 processed = ProcessBarrierSmgrRelease();
575 break;
576 }
577
578 /*
579 * To avoid an infinite loop, we must always unset the bit in
580 * flags.
581 */
582 BARRIER_CLEAR_BIT(flags, type);
583
584 /*
585 * If we failed to process the barrier, reset the shared bit
586 * so we try again later, and set a flag so that we don't bump
587 * our generation.
588 */
589 if (!processed)
590 {
592 success = false;
593 }
594 }
595 }
596 PG_CATCH();
597 {
598 /*
599 * If an ERROR occurred, we'll need to try again later to handle
600 * that barrier type and any others that haven't been handled yet
601 * or weren't successfully absorbed.
602 */
604 PG_RE_THROW();
605 }
606 PG_END_TRY();
607
608 /*
609 * If some barrier types were not successfully absorbed, we will have
610 * to try again later.
611 */
612 if (!success)
613 return;
614 }
615
616 /*
617 * State changes related to all types of barriers that might have been
618 * emitted have now been handled, so we can update our notion of the
619 * generation to the one we observed before beginning the updates. If
620 * things have changed further, it'll get fixed up when this function is
621 * next called.
622 */
625}
626
627/*
628 * If it turns out that we couldn't absorb one or more barrier types, either
629 * because the barrier-processing functions returned false or due to an error,
630 * arrange for processing to be retried later.
631 */
632static void
634{
637 InterruptPending = true;
638}
639
640/*
641 * CheckProcSignal - check to see if a particular reason has been
642 * signaled, and clear the signal flag. Should be called after receiving
643 * SIGUSR1.
644 */
645static bool
647{
648 volatile ProcSignalSlot *slot = MyProcSignalSlot;
649
650 if (slot != NULL)
651 {
652 /*
653 * Careful here --- don't clear flag if we haven't seen it set.
654 * pss_signalFlags is of type "volatile sig_atomic_t" to allow us to
655 * read it here safely, without holding the spinlock.
656 */
657 if (slot->pss_signalFlags[reason])
658 {
659 slot->pss_signalFlags[reason] = false;
660 return true;
661 }
662 }
663
664 return false;
665}
666
667/*
668 * procsignal_sigusr1_handler - handle SIGUSR1 signal.
669 */
670void
672{
675
678
681
684
687
690
693
696
699
702
705
708
711
714
716}
717
718/*
719 * Send a query cancellation signal to backend.
720 *
721 * Note: This is called from a backend process before authentication. We
722 * cannot take LWLocks yet, but that's OK; we rely on atomic reads of the
723 * fields in the ProcSignal slots.
724 */
725void
726SendCancelRequest(int backendPID, int32 cancelAuthCode)
727{
728 Assert(backendPID != 0);
729
730 /*
731 * See if we have a matching backend. Reading the pss_pid and
732 * pss_cancel_key fields is racy, a backend might die and remove itself
733 * from the array at any time. The probability of the cancellation key
734 * matching wrong process is miniscule, however, so we can live with that.
735 * PIDs are reused too, so sending the signal based on PID is inherently
736 * racy anyway, although OS's avoid reusing PIDs too soon.
737 */
738 for (int i = 0; i < NumProcSignalSlots; i++)
739 {
741 bool match;
742
743 if (pg_atomic_read_u32(&slot->pss_pid) != backendPID)
744 continue;
745
746 /* Acquire the spinlock and re-check */
748 if (pg_atomic_read_u32(&slot->pss_pid) != backendPID)
749 {
751 continue;
752 }
753 else
754 {
755 match = slot->pss_cancel_key_valid && slot->pss_cancel_key == cancelAuthCode;
756
758
759 if (match)
760 {
761 /* Found a match; signal that backend to cancel current op */
763 (errmsg_internal("processing cancel request: sending SIGINT to process %d",
764 backendPID)));
765
766 /*
767 * If we have setsid(), signal the backend's whole process
768 * group
769 */
770#ifdef HAVE_SETSID
771 kill(-backendPID, SIGINT);
772#else
773 kill(backendPID, SIGINT);
774#endif
775 }
776 else
777 {
778 /* Right PID, wrong key: no way, Jose */
779 ereport(LOG,
780 (errmsg("wrong key in cancel request for process %d",
781 backendPID)));
782 }
783 return;
784 }
785 }
786
787 /* No matching backend */
788 ereport(LOG,
789 (errmsg("PID %d in cancel request did not match any process",
790 backendPID)));
791}
void HandleParallelApplyMessageInterrupt(void)
void HandleNotifyInterrupt(void)
Definition: async.c:1804
static void pg_atomic_write_u64(volatile pg_atomic_uint64 *ptr, uint64 val)
Definition: atomics.h:485
static uint32 pg_atomic_fetch_or_u32(volatile pg_atomic_uint32 *ptr, uint32 or_)
Definition: atomics.h:410
#define pg_memory_barrier()
Definition: atomics.h:143
static void pg_atomic_init_u32(volatile pg_atomic_uint32 *ptr, uint32 val)
Definition: atomics.h:221
static void pg_atomic_write_u32(volatile pg_atomic_uint32 *ptr, uint32 val)
Definition: atomics.h:276
static uint32 pg_atomic_read_u32(volatile pg_atomic_uint32 *ptr)
Definition: atomics.h:239
static uint64 pg_atomic_add_fetch_u64(volatile pg_atomic_uint64 *ptr, int64 add_)
Definition: atomics.h:559
static uint32 pg_atomic_exchange_u32(volatile pg_atomic_uint32 *ptr, uint32 newval)
Definition: atomics.h:330
static void pg_atomic_init_u64(volatile pg_atomic_uint64 *ptr, uint64 val)
Definition: atomics.h:453
static uint64 pg_atomic_read_u64(volatile pg_atomic_uint64 *ptr)
Definition: atomics.h:467
void HandleParallelMessageInterrupt(void)
Definition: parallel.c:1033
#define SIGNAL_ARGS
Definition: c.h:1303
#define Assert(condition)
Definition: c.h:812
#define FLEXIBLE_ARRAY_MEMBER
Definition: c.h:417
#define UINT64_FORMAT
Definition: c.h:504
int32_t int32
Definition: c.h:481
uint64_t uint64
Definition: c.h:486
uint32_t uint32
Definition: c.h:485
#define PG_UINT64_MAX
Definition: c.h:547
#define MemSet(start, val, len)
Definition: c.h:974
size_t Size
Definition: c.h:559
bool ConditionVariableCancelSleep(void)
bool ConditionVariableTimedSleep(ConditionVariable *cv, long timeout, uint32 wait_event_info)
void ConditionVariableBroadcast(ConditionVariable *cv)
void ConditionVariableInit(ConditionVariable *cv)
int errmsg_internal(const char *fmt,...)
Definition: elog.c:1157
int errmsg(const char *fmt,...)
Definition: elog.c:1070
#define LOG
Definition: elog.h:31
#define PG_RE_THROW()
Definition: elog.h:412
#define PG_TRY(...)
Definition: elog.h:371
#define DEBUG2
Definition: elog.h:29
#define PG_END_TRY(...)
Definition: elog.h:396
#define DEBUG1
Definition: elog.h:30
#define ERROR
Definition: elog.h:39
#define PG_CATCH(...)
Definition: elog.h:381
#define elog(elevel,...)
Definition: elog.h:225
#define ereport(elevel,...)
Definition: elog.h:149
volatile sig_atomic_t ProcSignalBarrierPending
Definition: globals.c:39
volatile sig_atomic_t InterruptPending
Definition: globals.c:31
int MyProcPid
Definition: globals.c:46
ProcNumber MyProcNumber
Definition: globals.c:89
struct Latch * MyLatch
Definition: globals.c:62
static bool success
Definition: initdb.c:186
void on_shmem_exit(pg_on_exit_callback function, Datum arg)
Definition: ipc.c:365
int i
Definition: isn.c:72
void SetLatch(Latch *latch)
Definition: latch.c:632
void HandleLogMemoryContextInterrupt(void)
Definition: mcxt.c:1272
void * arg
static int pg_rightmost_one_pos32(uint32 word)
Definition: pg_bitutils.h:111
void HandleRecoveryConflictInterrupt(ProcSignalReason reason)
Definition: postgres.c:3064
uintptr_t Datum
Definition: postgres.h:64
#define NON_EXEC_STATIC
Definition: postgres.h:576
#define INVALID_PROC_NUMBER
Definition: procnumber.h:26
int ProcNumber
Definition: procnumber.h:24
void SendCancelRequest(int backendPID, int32 cancelAuthCode)
Definition: procsignal.c:726
static void CleanupProcSignalState(int status, Datum arg)
Definition: procsignal.c:225
int SendProcSignal(pid_t pid, ProcSignalReason reason, ProcNumber procNumber)
Definition: procsignal.c:281
void ProcSignalShmemInit(void)
Definition: procsignal.c:130
#define NumProcSignalSlots
Definition: procsignal.c:94
static bool CheckProcSignal(ProcSignalReason reason)
Definition: procsignal.c:646
void ProcessProcSignalBarrier(void)
Definition: procsignal.c:496
void WaitForProcSignalBarrier(uint64 generation)
Definition: procsignal.c:421
void ProcSignalInit(bool cancel_key_valid, int32 cancel_key)
Definition: procsignal.c:166
NON_EXEC_STATIC ProcSignalHeader * ProcSignal
Definition: procsignal.c:104
static void ResetProcSignalBarrierBits(uint32 flags)
Definition: procsignal.c:633
uint64 EmitProcSignalBarrier(ProcSignalBarrierType type)
Definition: procsignal.c:353
Size ProcSignalShmemSize(void)
Definition: procsignal.c:116
static void HandleProcSignalBarrierInterrupt(void)
Definition: procsignal.c:480
static ProcSignalSlot * MyProcSignalSlot
Definition: procsignal.c:105
#define BARRIER_CLEAR_BIT(flags, type)
Definition: procsignal.c:101
void procsignal_sigusr1_handler(SIGNAL_ARGS)
Definition: procsignal.c:671
#define NUM_PROCSIGNALS
Definition: procsignal.h:52
ProcSignalReason
Definition: procsignal.h:31
@ PROCSIG_PARALLEL_MESSAGE
Definition: procsignal.h:34
@ PROCSIG_RECOVERY_CONFLICT_BUFFERPIN
Definition: procsignal.h:47
@ PROCSIG_CATCHUP_INTERRUPT
Definition: procsignal.h:32
@ PROCSIG_RECOVERY_CONFLICT_LOCK
Definition: procsignal.h:44
@ PROCSIG_LOG_MEMORY_CONTEXT
Definition: procsignal.h:37
@ PROCSIG_RECOVERY_CONFLICT_LOGICALSLOT
Definition: procsignal.h:46
@ PROCSIG_BARRIER
Definition: procsignal.h:36
@ PROCSIG_RECOVERY_CONFLICT_DATABASE
Definition: procsignal.h:42
@ PROCSIG_WALSND_INIT_STOPPING
Definition: procsignal.h:35
@ PROCSIG_PARALLEL_APPLY_MESSAGE
Definition: procsignal.h:38
@ PROCSIG_RECOVERY_CONFLICT_SNAPSHOT
Definition: procsignal.h:45
@ PROCSIG_NOTIFY_INTERRUPT
Definition: procsignal.h:33
@ PROCSIG_RECOVERY_CONFLICT_TABLESPACE
Definition: procsignal.h:43
@ PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK
Definition: procsignal.h:48
ProcSignalBarrierType
Definition: procsignal.h:55
@ PROCSIGNAL_BARRIER_SMGRRELEASE
Definition: procsignal.h:56
Size add_size(Size s1, Size s2)
Definition: shmem.c:488
Size mul_size(Size s1, Size s2)
Definition: shmem.c:505
void * ShmemInitStruct(const char *name, Size size, bool *foundPtr)
Definition: shmem.c:382
void HandleCatchupInterrupt(void)
Definition: sinval.c:154
static pg_noinline void Size size
Definition: slab.c:607
bool ProcessBarrierSmgrRelease(void)
Definition: smgr.c:845
#define SpinLockInit(lock)
Definition: spin.h:57
#define SpinLockRelease(lock)
Definition: spin.h:61
#define SpinLockAcquire(lock)
Definition: spin.h:59
ProcSignalSlot psh_slot[FLEXIBLE_ARRAY_MEMBER]
Definition: procsignal.c:86
pg_atomic_uint64 psh_barrierGeneration
Definition: procsignal.c:85
int32 pss_cancel_key
Definition: procsignal.c:67
ConditionVariable pss_barrierCV
Definition: procsignal.c:74
pg_atomic_uint64 pss_barrierGeneration
Definition: procsignal.c:72
volatile sig_atomic_t pss_signalFlags[NUM_PROCSIGNALS]
Definition: procsignal.c:68
bool pss_cancel_key_valid
Definition: procsignal.c:66
slock_t pss_mutex
Definition: procsignal.c:69
pg_atomic_uint32 pss_pid
Definition: procsignal.c:65
pg_atomic_uint32 pss_barrierCheckMask
Definition: procsignal.c:73
const char * type
void HandleWalSndInitStopping(void)
Definition: walsender.c:3533
#define kill(pid, sig)
Definition: win32_port.h:503
#define SIGUSR1
Definition: win32_port.h:180