Branch data Line data Source code
1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * proc.c
4 : : * routines to manage per-process shared memory data structure
5 : : *
6 : : * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
7 : : * Portions Copyright (c) 1994, Regents of the University of California
8 : : *
9 : : *
10 : : * IDENTIFICATION
11 : : * src/backend/storage/lmgr/proc.c
12 : : *
13 : : *-------------------------------------------------------------------------
14 : : */
15 : : /*
16 : : * Interface (a):
17 : : * JoinWaitQueue(), ProcSleep(), ProcWakeup()
18 : : *
19 : : * Waiting for a lock causes the backend to be put to sleep. Whoever releases
20 : : * the lock wakes the process up again (and gives it an error code so it knows
21 : : * whether it was awoken on an error condition).
22 : : *
23 : : * Interface (b):
24 : : *
25 : : * ProcReleaseLocks -- frees the locks associated with current transaction
26 : : *
27 : : * ProcKill -- destroys the shared memory state (and locks)
28 : : * associated with the process.
29 : : */
30 : : #include "postgres.h"
31 : :
32 : : #include <signal.h>
33 : : #include <unistd.h>
34 : : #include <sys/time.h>
35 : :
36 : : #include "access/transam.h"
37 : : #include "access/twophase.h"
38 : : #include "access/xlogutils.h"
39 : : #include "access/xlogwait.h"
40 : : #include "miscadmin.h"
41 : : #include "pgstat.h"
42 : : #include "postmaster/autovacuum.h"
43 : : #include "replication/slotsync.h"
44 : : #include "replication/syncrep.h"
45 : : #include "storage/condition_variable.h"
46 : : #include "storage/ipc.h"
47 : : #include "storage/lmgr.h"
48 : : #include "storage/pmsignal.h"
49 : : #include "storage/proc.h"
50 : : #include "storage/procarray.h"
51 : : #include "storage/procsignal.h"
52 : : #include "storage/spin.h"
53 : : #include "storage/standby.h"
54 : : #include "utils/timeout.h"
55 : : #include "utils/timestamp.h"
56 : :
57 : : /* GUC variables */
58 : : int DeadlockTimeout = 1000;
59 : : int StatementTimeout = 0;
60 : : int LockTimeout = 0;
61 : : int IdleInTransactionSessionTimeout = 0;
62 : : int TransactionTimeout = 0;
63 : : int IdleSessionTimeout = 0;
64 : : bool log_lock_waits = true;
65 : :
66 : : /* Pointer to this process's PGPROC struct, if any */
67 : : PGPROC *MyProc = NULL;
68 : :
69 : : /*
70 : : * This spinlock protects the freelist of recycled PGPROC structures.
71 : : * We cannot use an LWLock because the LWLock manager depends on already
72 : : * having a PGPROC and a wait semaphore! But these structures are touched
73 : : * relatively infrequently (only at backend startup or shutdown) and not for
74 : : * very long, so a spinlock is okay.
75 : : */
76 : : NON_EXEC_STATIC slock_t *ProcStructLock = NULL;
77 : :
78 : : /* Pointers to shared-memory structures */
79 : : PROC_HDR *ProcGlobal = NULL;
80 : : NON_EXEC_STATIC PGPROC *AuxiliaryProcs = NULL;
81 : : PGPROC *PreparedXactProcs = NULL;
82 : :
83 : : static DeadLockState deadlock_state = DS_NOT_YET_CHECKED;
84 : :
85 : : /* Is a deadlock check pending? */
86 : : static volatile sig_atomic_t got_deadlock_timeout;
87 : :
88 : : static void RemoveProcFromArray(int code, Datum arg);
89 : : static void ProcKill(int code, Datum arg);
90 : : static void AuxiliaryProcKill(int code, Datum arg);
91 : : static void CheckDeadLock(void);
92 : :
93 : :
94 : : /*
95 : : * Report shared-memory space needed by PGPROC.
96 : : */
97 : : static Size
98 : 15 : PGProcShmemSize(void)
99 : : {
100 : 15 : Size size = 0;
101 : 30 : Size TotalProcs =
102 : 15 : add_size(MaxBackends, add_size(NUM_AUXILIARY_PROCS, max_prepared_xacts));
103 : :
104 : 15 : size = add_size(size, mul_size(TotalProcs, sizeof(PGPROC)));
105 : 15 : size = add_size(size, mul_size(TotalProcs, sizeof(*ProcGlobal->xids)));
106 : 15 : size = add_size(size, mul_size(TotalProcs, sizeof(*ProcGlobal->subxidStates)));
107 : 15 : size = add_size(size, mul_size(TotalProcs, sizeof(*ProcGlobal->statusFlags)));
108 : :
109 : 30 : return size;
110 : 15 : }
111 : :
112 : : /*
113 : : * Report shared-memory space needed by Fast-Path locks.
114 : : */
115 : : static Size
116 : 15 : FastPathLockShmemSize(void)
117 : : {
118 : 15 : Size size = 0;
119 : 30 : Size TotalProcs =
120 : 15 : add_size(MaxBackends, add_size(NUM_AUXILIARY_PROCS, max_prepared_xacts));
121 : 15 : Size fpLockBitsSize,
122 : : fpRelIdSize;
123 : :
124 : : /*
125 : : * Memory needed for PGPROC fast-path lock arrays. Make sure the sizes are
126 : : * nicely aligned in each backend.
127 : : */
128 : 15 : fpLockBitsSize = MAXALIGN(FastPathLockGroupsPerBackend * sizeof(uint64));
129 : 15 : fpRelIdSize = MAXALIGN(FastPathLockSlotsPerBackend() * sizeof(Oid));
130 : :
131 : 15 : size = add_size(size, mul_size(TotalProcs, (fpLockBitsSize + fpRelIdSize)));
132 : :
133 : 30 : return size;
134 : 15 : }
135 : :
136 : : /*
137 : : * Report shared-memory space needed by InitProcGlobal.
138 : : */
139 : : Size
140 : 9 : ProcGlobalShmemSize(void)
141 : : {
142 : 9 : Size size = 0;
143 : :
144 : : /* ProcGlobal */
145 : 9 : size = add_size(size, sizeof(PROC_HDR));
146 : 9 : size = add_size(size, sizeof(slock_t));
147 : :
148 : 9 : size = add_size(size, PGSemaphoreShmemSize(ProcGlobalSemas()));
149 : 9 : size = add_size(size, PGProcShmemSize());
150 : 9 : size = add_size(size, FastPathLockShmemSize());
151 : :
152 : 18 : return size;
153 : 9 : }
154 : :
155 : : /*
156 : : * Report number of semaphores needed by InitProcGlobal.
157 : : */
158 : : int
159 : 18 : ProcGlobalSemas(void)
160 : : {
161 : : /*
162 : : * We need a sema per backend (including autovacuum), plus one for each
163 : : * auxiliary process.
164 : : */
165 : 18 : return MaxBackends + NUM_AUXILIARY_PROCS;
166 : : }
167 : :
168 : : /*
169 : : * InitProcGlobal -
170 : : * Initialize the global process table during postmaster or standalone
171 : : * backend startup.
172 : : *
173 : : * We also create all the per-process semaphores we will need to support
174 : : * the requested number of backends. We used to allocate semaphores
175 : : * only when backends were actually started up, but that is bad because
176 : : * it lets Postgres fail under load --- a lot of Unix systems are
177 : : * (mis)configured with small limits on the number of semaphores, and
178 : : * running out when trying to start another backend is a common failure.
179 : : * So, now we grab enough semaphores to support the desired max number
180 : : * of backends immediately at initialization --- if the sysadmin has set
181 : : * MaxConnections, max_worker_processes, max_wal_senders, or
182 : : * autovacuum_worker_slots higher than his kernel will support, he'll
183 : : * find out sooner rather than later.
184 : : *
185 : : * Another reason for creating semaphores here is that the semaphore
186 : : * implementation typically requires us to create semaphores in the
187 : : * postmaster, not in backends.
188 : : *
189 : : * Note: this is NOT called by individual backends under a postmaster,
190 : : * not even in the EXEC_BACKEND case. The ProcGlobal and AuxiliaryProcs
191 : : * pointers must be propagated specially for EXEC_BACKEND operation.
192 : : */
193 : : void
194 : 6 : InitProcGlobal(void)
195 : : {
196 : 6 : PGPROC *procs;
197 : 6 : int i,
198 : : j;
199 : 6 : bool found;
200 : 6 : uint32 TotalProcs = MaxBackends + NUM_AUXILIARY_PROCS + max_prepared_xacts;
201 : :
202 : : /* Used for setup of per-backend fast-path slots. */
203 : 6 : char *fpPtr,
204 : : *fpEndPtr PG_USED_FOR_ASSERTS_ONLY;
205 : 6 : Size fpLockBitsSize,
206 : : fpRelIdSize;
207 : 6 : Size requestSize;
208 : 6 : char *ptr;
209 : :
210 : : /* Create the ProcGlobal shared structure */
211 : 6 : ProcGlobal = (PROC_HDR *)
212 : 6 : ShmemInitStruct("Proc Header", sizeof(PROC_HDR), &found);
213 [ + - ]: 6 : Assert(!found);
214 : :
215 : : /*
216 : : * Initialize the data structures.
217 : : */
218 : 6 : ProcGlobal->spins_per_delay = DEFAULT_SPINS_PER_DELAY;
219 : 6 : dlist_init(&ProcGlobal->freeProcs);
220 : 6 : dlist_init(&ProcGlobal->autovacFreeProcs);
221 : 6 : dlist_init(&ProcGlobal->bgworkerFreeProcs);
222 : 6 : dlist_init(&ProcGlobal->walsenderFreeProcs);
223 : 6 : ProcGlobal->startupBufferPinWaitBufId = -1;
224 : 6 : ProcGlobal->walwriterProc = INVALID_PROC_NUMBER;
225 : 6 : ProcGlobal->checkpointerProc = INVALID_PROC_NUMBER;
226 : 6 : pg_atomic_init_u32(&ProcGlobal->procArrayGroupFirst, INVALID_PROC_NUMBER);
227 : 6 : pg_atomic_init_u32(&ProcGlobal->clogGroupFirst, INVALID_PROC_NUMBER);
228 : :
229 : : /*
230 : : * Create and initialize all the PGPROC structures we'll need. There are
231 : : * six separate consumers: (1) normal backends, (2) autovacuum workers and
232 : : * special workers, (3) background workers, (4) walsenders, (5) auxiliary
233 : : * processes, and (6) prepared transactions. (For largely-historical
234 : : * reasons, we combine autovacuum and special workers into one category
235 : : * with a single freelist.) Each PGPROC structure is dedicated to exactly
236 : : * one of these purposes, and they do not move between groups.
237 : : */
238 : 6 : requestSize = PGProcShmemSize();
239 : :
240 : 6 : ptr = ShmemInitStruct("PGPROC structures",
241 : 6 : requestSize,
242 : : &found);
243 : :
244 [ + - + + : 6 : MemSet(ptr, 0, requestSize);
+ - + - #
# ]
245 : :
246 : 6 : procs = (PGPROC *) ptr;
247 : 6 : ptr = ptr + TotalProcs * sizeof(PGPROC);
248 : :
249 : 6 : ProcGlobal->allProcs = procs;
250 : : /* XXX allProcCount isn't really all of them; it excludes prepared xacts */
251 : 6 : ProcGlobal->allProcCount = MaxBackends + NUM_AUXILIARY_PROCS;
252 : :
253 : : /*
254 : : * Allocate arrays mirroring PGPROC fields in a dense manner. See
255 : : * PROC_HDR.
256 : : *
257 : : * XXX: It might make sense to increase padding for these arrays, given
258 : : * how hotly they are accessed.
259 : : */
260 : 6 : ProcGlobal->xids = (TransactionId *) ptr;
261 : 6 : ptr = ptr + (TotalProcs * sizeof(*ProcGlobal->xids));
262 : :
263 : 6 : ProcGlobal->subxidStates = (XidCacheStatus *) ptr;
264 : 6 : ptr = ptr + (TotalProcs * sizeof(*ProcGlobal->subxidStates));
265 : :
266 : 6 : ProcGlobal->statusFlags = (uint8 *) ptr;
267 : 6 : ptr = ptr + (TotalProcs * sizeof(*ProcGlobal->statusFlags));
268 : :
269 : : /* make sure wer didn't overflow */
270 [ + - ]: 6 : Assert((ptr > (char *) procs) && (ptr <= (char *) procs + requestSize));
271 : :
272 : : /*
273 : : * Allocate arrays for fast-path locks. Those are variable-length, so
274 : : * can't be included in PGPROC directly. We allocate a separate piece of
275 : : * shared memory and then divide that between backends.
276 : : */
277 : 6 : fpLockBitsSize = MAXALIGN(FastPathLockGroupsPerBackend * sizeof(uint64));
278 : 6 : fpRelIdSize = MAXALIGN(FastPathLockSlotsPerBackend() * sizeof(Oid));
279 : :
280 : 6 : requestSize = FastPathLockShmemSize();
281 : :
282 : 6 : fpPtr = ShmemInitStruct("Fast-Path Lock Array",
283 : 6 : requestSize,
284 : : &found);
285 : :
286 [ + - + - : 6 : MemSet(fpPtr, 0, requestSize);
+ - + - #
# ]
287 : :
288 : : /* For asserts checking we did not overflow. */
289 : 6 : fpEndPtr = fpPtr + requestSize;
290 : :
291 : : /* Reserve space for semaphores. */
292 : 6 : PGReserveSemaphores(ProcGlobalSemas());
293 : :
294 [ + + ]: 1042 : for (i = 0; i < TotalProcs; i++)
295 : : {
296 : 1036 : PGPROC *proc = &procs[i];
297 : :
298 : : /* Common initialization for all PGPROCs, regardless of type. */
299 : :
300 : : /*
301 : : * Set the fast-path lock arrays, and move the pointer. We interleave
302 : : * the two arrays, to (hopefully) get some locality for each backend.
303 : : */
304 : 1036 : proc->fpLockBits = (uint64 *) fpPtr;
305 : 1036 : fpPtr += fpLockBitsSize;
306 : :
307 : 1036 : proc->fpRelId = (Oid *) fpPtr;
308 : 1036 : fpPtr += fpRelIdSize;
309 : :
310 [ + - ]: 1036 : Assert(fpPtr <= fpEndPtr);
311 : :
312 : : /*
313 : : * Set up per-PGPROC semaphore, latch, and fpInfoLock. Prepared xact
314 : : * dummy PGPROCs don't need these though - they're never associated
315 : : * with a real process
316 : : */
317 [ + + ]: 1036 : if (i < MaxBackends + NUM_AUXILIARY_PROCS)
318 : : {
319 : 1034 : proc->sem = PGSemaphoreCreate();
320 : 1034 : InitSharedLatch(&(proc->procLatch));
321 : 1034 : LWLockInitialize(&(proc->fpInfoLock), LWTRANCHE_LOCK_FASTPATH);
322 : 1034 : }
323 : :
324 : : /*
325 : : * Newly created PGPROCs for normal backends, autovacuum workers,
326 : : * special workers, bgworkers, and walsenders must be queued up on the
327 : : * appropriate free list. Because there can only ever be a small,
328 : : * fixed number of auxiliary processes, no free list is used in that
329 : : * case; InitAuxiliaryProcess() instead uses a linear search. PGPROCs
330 : : * for prepared transactions are added to a free list by
331 : : * TwoPhaseShmemInit().
332 : : */
333 [ + + ]: 1036 : if (i < MaxConnections)
334 : : {
335 : : /* PGPROC for normal backend, add to freeProcs list */
336 : 600 : dlist_push_tail(&ProcGlobal->freeProcs, &proc->links);
337 : 600 : proc->procgloballist = &ProcGlobal->freeProcs;
338 : 600 : }
339 [ + + ]: 436 : else if (i < MaxConnections + autovacuum_worker_slots + NUM_SPECIAL_WORKER_PROCS)
340 : : {
341 : : /* PGPROC for AV or special worker, add to autovacFreeProcs list */
342 : 108 : dlist_push_tail(&ProcGlobal->autovacFreeProcs, &proc->links);
343 : 108 : proc->procgloballist = &ProcGlobal->autovacFreeProcs;
344 : 108 : }
345 [ + + ]: 328 : else if (i < MaxConnections + autovacuum_worker_slots + NUM_SPECIAL_WORKER_PROCS + max_worker_processes)
346 : : {
347 : : /* PGPROC for bgworker, add to bgworkerFreeProcs list */
348 : 48 : dlist_push_tail(&ProcGlobal->bgworkerFreeProcs, &proc->links);
349 : 48 : proc->procgloballist = &ProcGlobal->bgworkerFreeProcs;
350 : 48 : }
351 [ + + ]: 280 : else if (i < MaxBackends)
352 : : {
353 : : /* PGPROC for walsender, add to walsenderFreeProcs list */
354 : 50 : dlist_push_tail(&ProcGlobal->walsenderFreeProcs, &proc->links);
355 : 50 : proc->procgloballist = &ProcGlobal->walsenderFreeProcs;
356 : 50 : }
357 : :
358 : : /* Initialize myProcLocks[] shared memory queues. */
359 [ + + ]: 17612 : for (j = 0; j < NUM_LOCK_PARTITIONS; j++)
360 : 16576 : dlist_init(&(proc->myProcLocks[j]));
361 : :
362 : : /* Initialize lockGroupMembers list. */
363 : 1036 : dlist_init(&proc->lockGroupMembers);
364 : :
365 : : /*
366 : : * Initialize the atomic variables, otherwise, it won't be safe to
367 : : * access them for backends that aren't currently in use.
368 : : */
369 : 1036 : pg_atomic_init_u32(&(proc->procArrayGroupNext), INVALID_PROC_NUMBER);
370 : 1036 : pg_atomic_init_u32(&(proc->clogGroupNext), INVALID_PROC_NUMBER);
371 : 1036 : pg_atomic_init_u64(&(proc->waitStart), 0);
372 : 1036 : }
373 : :
374 : : /* Should have consumed exactly the expected amount of fast-path memory. */
375 [ + - ]: 6 : Assert(fpPtr == fpEndPtr);
376 : :
377 : : /*
378 : : * Save pointers to the blocks of PGPROC structures reserved for auxiliary
379 : : * processes and prepared transactions.
380 : : */
381 : 6 : AuxiliaryProcs = &procs[MaxBackends];
382 : 6 : PreparedXactProcs = &procs[MaxBackends + NUM_AUXILIARY_PROCS];
383 : :
384 : : /* Create ProcStructLock spinlock, too */
385 : 6 : ProcStructLock = (slock_t *) ShmemInitStruct("ProcStructLock spinlock",
386 : : sizeof(slock_t),
387 : : &found);
388 : 6 : SpinLockInit(ProcStructLock);
389 : 6 : }
390 : :
391 : : /*
392 : : * InitProcess -- initialize a per-process PGPROC entry for this backend
393 : : */
394 : : void
395 : 798 : InitProcess(void)
396 : : {
397 : 798 : dlist_head *procgloballist;
398 : :
399 : : /*
400 : : * ProcGlobal should be set up already (if we are a backend, we inherit
401 : : * this by fork() or EXEC_BACKEND mechanism from the postmaster).
402 : : */
403 [ + - ]: 798 : if (ProcGlobal == NULL)
404 [ # # # # ]: 0 : elog(PANIC, "proc header uninitialized");
405 : :
406 [ + - ]: 798 : if (MyProc != NULL)
407 [ # # # # ]: 0 : elog(ERROR, "you already exist");
408 : :
409 : : /*
410 : : * Before we start accessing the shared memory in a serious way, mark
411 : : * ourselves as an active postmaster child; this is so that the postmaster
412 : : * can detect it if we exit without cleaning up.
413 : : */
414 [ + + ]: 798 : if (IsUnderPostmaster)
415 : 796 : RegisterPostmasterChildActive();
416 : :
417 : : /*
418 : : * Decide which list should supply our PGPROC. This logic must match the
419 : : * way the freelists were constructed in InitProcGlobal().
420 : : */
421 [ + + + + : 798 : if (AmAutoVacuumWorkerProcess() || AmSpecialWorkerProcess())
- + ]
422 : 2 : procgloballist = &ProcGlobal->autovacFreeProcs;
423 [ + + ]: 796 : else if (AmBackgroundWorkerProcess())
424 : 479 : procgloballist = &ProcGlobal->bgworkerFreeProcs;
425 [ - + ]: 317 : else if (AmWalSenderProcess())
426 : 0 : procgloballist = &ProcGlobal->walsenderFreeProcs;
427 : : else
428 : 317 : procgloballist = &ProcGlobal->freeProcs;
429 : :
430 : : /*
431 : : * Try to get a proc struct from the appropriate free list. If this
432 : : * fails, we must be out of PGPROC structures (not to mention semaphores).
433 : : *
434 : : * While we are holding the ProcStructLock, also copy the current shared
435 : : * estimate of spins_per_delay to local storage.
436 : : */
437 [ + + ]: 798 : SpinLockAcquire(ProcStructLock);
438 : :
439 : 798 : set_spins_per_delay(ProcGlobal->spins_per_delay);
440 : :
441 [ + - ]: 798 : if (!dlist_is_empty(procgloballist))
442 : : {
443 : 798 : MyProc = dlist_container(PGPROC, links, dlist_pop_head_node(procgloballist));
444 : 798 : SpinLockRelease(ProcStructLock);
445 : 798 : }
446 : : else
447 : : {
448 : : /*
449 : : * If we reach here, all the PGPROCs are in use. This is one of the
450 : : * possible places to detect "too many backends", so give the standard
451 : : * error message. XXX do we need to give a different failure message
452 : : * in the autovacuum case?
453 : : */
454 : 0 : SpinLockRelease(ProcStructLock);
455 [ # # ]: 0 : if (AmWalSenderProcess())
456 [ # # # # ]: 0 : ereport(FATAL,
457 : : (errcode(ERRCODE_TOO_MANY_CONNECTIONS),
458 : : errmsg("number of requested standby connections exceeds \"max_wal_senders\" (currently %d)",
459 : : max_wal_senders)));
460 [ # # # # ]: 0 : ereport(FATAL,
461 : : (errcode(ERRCODE_TOO_MANY_CONNECTIONS),
462 : : errmsg("sorry, too many clients already")));
463 : : }
464 : 798 : MyProcNumber = GetNumberFromPGProc(MyProc);
465 : :
466 : : /*
467 : : * Cross-check that the PGPROC is of the type we expect; if this were not
468 : : * the case, it would get returned to the wrong list.
469 : : */
470 [ + - ]: 798 : Assert(MyProc->procgloballist == procgloballist);
471 : :
472 : : /*
473 : : * Initialize all fields of MyProc, except for those previously
474 : : * initialized by InitProcGlobal.
475 : : */
476 : 798 : dlist_node_init(&MyProc->links);
477 : 798 : MyProc->waitStatus = PROC_WAIT_STATUS_OK;
478 : 798 : MyProc->fpVXIDLock = false;
479 : 798 : MyProc->fpLocalTransactionId = InvalidLocalTransactionId;
480 : 798 : MyProc->xid = InvalidTransactionId;
481 : 798 : MyProc->xmin = InvalidTransactionId;
482 : 798 : MyProc->pid = MyProcPid;
483 : 798 : MyProc->vxid.procNumber = MyProcNumber;
484 : 798 : MyProc->vxid.lxid = InvalidLocalTransactionId;
485 : : /* databaseId and roleId will be filled in later */
486 : 798 : MyProc->databaseId = InvalidOid;
487 : 798 : MyProc->roleId = InvalidOid;
488 : 798 : MyProc->tempNamespaceId = InvalidOid;
489 : 798 : MyProc->isRegularBackend = AmRegularBackendProcess();
490 : 798 : MyProc->delayChkptFlags = 0;
491 : 798 : MyProc->statusFlags = 0;
492 : : /* NB -- autovac launcher intentionally does not set IS_AUTOVACUUM */
493 [ + + ]: 798 : if (AmAutoVacuumWorkerProcess())
494 : 1 : MyProc->statusFlags |= PROC_IS_AUTOVACUUM;
495 : 798 : MyProc->lwWaiting = LW_WS_NOT_WAITING;
496 : 798 : MyProc->lwWaitMode = 0;
497 : 798 : MyProc->waitLock = NULL;
498 : 798 : MyProc->waitProcLock = NULL;
499 : 798 : pg_atomic_write_u64(&MyProc->waitStart, 0);
500 : : #ifdef USE_ASSERT_CHECKING
501 : : {
502 : 798 : int i;
503 : :
504 : : /* Last process should have released all locks. */
505 [ + + ]: 13566 : for (i = 0; i < NUM_LOCK_PARTITIONS; i++)
506 [ + - ]: 12768 : Assert(dlist_is_empty(&(MyProc->myProcLocks[i])));
507 : 798 : }
508 : : #endif
509 : 798 : MyProc->recoveryConflictPending = false;
510 : :
511 : : /* Initialize fields for sync rep */
512 : 798 : MyProc->waitLSN = 0;
513 : 798 : MyProc->syncRepState = SYNC_REP_NOT_WAITING;
514 : 798 : dlist_node_init(&MyProc->syncRepLinks);
515 : :
516 : : /* Initialize fields for group XID clearing. */
517 : 798 : MyProc->procArrayGroupMember = false;
518 : 798 : MyProc->procArrayGroupMemberXid = InvalidTransactionId;
519 [ + - ]: 798 : Assert(pg_atomic_read_u32(&MyProc->procArrayGroupNext) == INVALID_PROC_NUMBER);
520 : :
521 : : /* Check that group locking fields are in a proper initial state. */
522 [ + - ]: 798 : Assert(MyProc->lockGroupLeader == NULL);
523 [ + - ]: 798 : Assert(dlist_is_empty(&MyProc->lockGroupMembers));
524 : :
525 : : /* Initialize wait event information. */
526 : 798 : MyProc->wait_event_info = 0;
527 : :
528 : : /* Initialize fields for group transaction status update. */
529 : 798 : MyProc->clogGroupMember = false;
530 : 798 : MyProc->clogGroupMemberXid = InvalidTransactionId;
531 : 798 : MyProc->clogGroupMemberXidStatus = TRANSACTION_STATUS_IN_PROGRESS;
532 : 798 : MyProc->clogGroupMemberPage = -1;
533 : 798 : MyProc->clogGroupMemberLsn = InvalidXLogRecPtr;
534 [ + - ]: 798 : Assert(pg_atomic_read_u32(&MyProc->clogGroupNext) == INVALID_PROC_NUMBER);
535 : :
536 : : /*
537 : : * Acquire ownership of the PGPROC's latch, so that we can use WaitLatch
538 : : * on it. That allows us to repoint the process latch, which so far
539 : : * points to process local one, to the shared one.
540 : : */
541 : 798 : OwnLatch(&MyProc->procLatch);
542 : 798 : SwitchToSharedLatch();
543 : :
544 : : /* now that we have a proc, report wait events to shared memory */
545 : 798 : pgstat_set_wait_event_storage(&MyProc->wait_event_info);
546 : :
547 : : /*
548 : : * We might be reusing a semaphore that belonged to a failed process. So
549 : : * be careful and reinitialize its value here. (This is not strictly
550 : : * necessary anymore, but seems like a good idea for cleanliness.)
551 : : */
552 : 798 : PGSemaphoreReset(MyProc->sem);
553 : :
554 : : /*
555 : : * Arrange to clean up at backend exit.
556 : : */
557 : 798 : on_shmem_exit(ProcKill, 0);
558 : :
559 : : /*
560 : : * Now that we have a PGPROC, we could try to acquire locks, so initialize
561 : : * local state needed for LWLocks, and the deadlock checker.
562 : : */
563 : 798 : InitLWLockAccess();
564 : 798 : InitDeadLockChecking();
565 : :
566 : : #ifdef EXEC_BACKEND
567 : :
568 : : /*
569 : : * Initialize backend-local pointers to all the shared data structures.
570 : : * (We couldn't do this until now because it needs LWLocks.)
571 : : */
572 : : if (IsUnderPostmaster)
573 : : AttachSharedMemoryStructs();
574 : : #endif
575 : 798 : }
576 : :
577 : : /*
578 : : * InitProcessPhase2 -- make MyProc visible in the shared ProcArray.
579 : : *
580 : : * This is separate from InitProcess because we can't acquire LWLocks until
581 : : * we've created a PGPROC, but in the EXEC_BACKEND case ProcArrayAdd won't
582 : : * work until after we've done AttachSharedMemoryStructs.
583 : : */
584 : : void
585 : 798 : InitProcessPhase2(void)
586 : : {
587 [ + - ]: 798 : Assert(MyProc != NULL);
588 : :
589 : : /*
590 : : * Add our PGPROC to the PGPROC array in shared memory.
591 : : */
592 : 798 : ProcArrayAdd(MyProc);
593 : :
594 : : /*
595 : : * Arrange to clean that up at backend exit.
596 : : */
597 : 798 : on_shmem_exit(RemoveProcFromArray, 0);
598 : 798 : }
599 : :
600 : : /*
601 : : * InitAuxiliaryProcess -- create a PGPROC entry for an auxiliary process
602 : : *
603 : : * This is called by bgwriter and similar processes so that they will have a
604 : : * MyProc value that's real enough to let them wait for LWLocks. The PGPROC
605 : : * and sema that are assigned are one of the extra ones created during
606 : : * InitProcGlobal.
607 : : *
608 : : * Auxiliary processes are presently not expected to wait for real (lockmgr)
609 : : * locks, so we need not set up the deadlock checker. They are never added
610 : : * to the ProcArray or the sinval messaging mechanism, either. They also
611 : : * don't get a VXID assigned, since this is only useful when we actually
612 : : * hold lockmgr locks.
613 : : *
614 : : * Startup process however uses locks but never waits for them in the
615 : : * normal backend sense. Startup process also takes part in sinval messaging
616 : : * as a sendOnly process, so never reads messages from sinval queue. So
617 : : * Startup process does have a VXID and does show up in pg_locks.
618 : : */
619 : : void
620 : 8 : InitAuxiliaryProcess(void)
621 : : {
622 : 8 : PGPROC *auxproc;
623 : 8 : int proctype;
624 : :
625 : : /*
626 : : * ProcGlobal should be set up already (if we are a backend, we inherit
627 : : * this by fork() or EXEC_BACKEND mechanism from the postmaster).
628 : : */
629 [ + - ]: 8 : if (ProcGlobal == NULL || AuxiliaryProcs == NULL)
630 [ # # # # ]: 0 : elog(PANIC, "proc header uninitialized");
631 : :
632 [ + - ]: 8 : if (MyProc != NULL)
633 [ # # # # ]: 0 : elog(ERROR, "you already exist");
634 : :
635 [ - + ]: 8 : if (IsUnderPostmaster)
636 : 8 : RegisterPostmasterChildActive();
637 : :
638 : : /*
639 : : * We use the ProcStructLock to protect assignment and releasing of
640 : : * AuxiliaryProcs entries.
641 : : *
642 : : * While we are holding the ProcStructLock, also copy the current shared
643 : : * estimate of spins_per_delay to local storage.
644 : : */
645 [ + + ]: 8 : SpinLockAcquire(ProcStructLock);
646 : :
647 : 8 : set_spins_per_delay(ProcGlobal->spins_per_delay);
648 : :
649 : : /*
650 : : * Find a free auxproc ... *big* trouble if there isn't one ...
651 : : */
652 [ - + ]: 33 : for (proctype = 0; proctype < NUM_AUXILIARY_PROCS; proctype++)
653 : : {
654 : 33 : auxproc = &AuxiliaryProcs[proctype];
655 [ + + ]: 33 : if (auxproc->pid == 0)
656 : 8 : break;
657 : 25 : }
658 [ + - ]: 8 : if (proctype >= NUM_AUXILIARY_PROCS)
659 : : {
660 : 0 : SpinLockRelease(ProcStructLock);
661 [ # # # # ]: 0 : elog(FATAL, "all AuxiliaryProcs are in use");
662 : 0 : }
663 : :
664 : : /* Mark auxiliary proc as in use by me */
665 : : /* use volatile pointer to prevent code rearrangement */
666 : 8 : ((volatile PGPROC *) auxproc)->pid = MyProcPid;
667 : :
668 : 8 : SpinLockRelease(ProcStructLock);
669 : :
670 : 8 : MyProc = auxproc;
671 : 8 : MyProcNumber = GetNumberFromPGProc(MyProc);
672 : :
673 : : /*
674 : : * Initialize all fields of MyProc, except for those previously
675 : : * initialized by InitProcGlobal.
676 : : */
677 : 8 : dlist_node_init(&MyProc->links);
678 : 8 : MyProc->waitStatus = PROC_WAIT_STATUS_OK;
679 : 8 : MyProc->fpVXIDLock = false;
680 : 8 : MyProc->fpLocalTransactionId = InvalidLocalTransactionId;
681 : 8 : MyProc->xid = InvalidTransactionId;
682 : 8 : MyProc->xmin = InvalidTransactionId;
683 : 8 : MyProc->vxid.procNumber = INVALID_PROC_NUMBER;
684 : 8 : MyProc->vxid.lxid = InvalidLocalTransactionId;
685 : 8 : MyProc->databaseId = InvalidOid;
686 : 8 : MyProc->roleId = InvalidOid;
687 : 8 : MyProc->tempNamespaceId = InvalidOid;
688 : 8 : MyProc->isRegularBackend = false;
689 : 8 : MyProc->delayChkptFlags = 0;
690 : 8 : MyProc->statusFlags = 0;
691 : 8 : MyProc->lwWaiting = LW_WS_NOT_WAITING;
692 : 8 : MyProc->lwWaitMode = 0;
693 : 8 : MyProc->waitLock = NULL;
694 : 8 : MyProc->waitProcLock = NULL;
695 : 8 : pg_atomic_write_u64(&MyProc->waitStart, 0);
696 : : #ifdef USE_ASSERT_CHECKING
697 : : {
698 : 8 : int i;
699 : :
700 : : /* Last process should have released all locks. */
701 [ + + ]: 136 : for (i = 0; i < NUM_LOCK_PARTITIONS; i++)
702 [ + - ]: 128 : Assert(dlist_is_empty(&(MyProc->myProcLocks[i])));
703 : 8 : }
704 : : #endif
705 : :
706 : : /*
707 : : * Acquire ownership of the PGPROC's latch, so that we can use WaitLatch
708 : : * on it. That allows us to repoint the process latch, which so far
709 : : * points to process local one, to the shared one.
710 : : */
711 : 8 : OwnLatch(&MyProc->procLatch);
712 : 8 : SwitchToSharedLatch();
713 : :
714 : : /* now that we have a proc, report wait events to shared memory */
715 : 8 : pgstat_set_wait_event_storage(&MyProc->wait_event_info);
716 : :
717 : : /* Check that group locking fields are in a proper initial state. */
718 [ + - ]: 8 : Assert(MyProc->lockGroupLeader == NULL);
719 [ + - ]: 8 : Assert(dlist_is_empty(&MyProc->lockGroupMembers));
720 : :
721 : : /*
722 : : * We might be reusing a semaphore that belonged to a failed process. So
723 : : * be careful and reinitialize its value here. (This is not strictly
724 : : * necessary anymore, but seems like a good idea for cleanliness.)
725 : : */
726 : 8 : PGSemaphoreReset(MyProc->sem);
727 : :
728 : : /*
729 : : * Arrange to clean up at process exit.
730 : : */
731 : 8 : on_shmem_exit(AuxiliaryProcKill, Int32GetDatum(proctype));
732 : :
733 : : /*
734 : : * Now that we have a PGPROC, we could try to acquire lightweight locks.
735 : : * Initialize local state needed for them. (Heavyweight locks cannot be
736 : : * acquired in aux processes.)
737 : : */
738 : 8 : InitLWLockAccess();
739 : :
740 : : #ifdef EXEC_BACKEND
741 : :
742 : : /*
743 : : * Initialize backend-local pointers to all the shared data structures.
744 : : * (We couldn't do this until now because it needs LWLocks.)
745 : : */
746 : : if (IsUnderPostmaster)
747 : : AttachSharedMemoryStructs();
748 : : #endif
749 : 8 : }
750 : :
751 : : /*
752 : : * Used from bufmgr to share the value of the buffer that Startup waits on,
753 : : * or to reset the value to "not waiting" (-1). This allows processing
754 : : * of recovery conflicts for buffer pins. Set is made before backends look
755 : : * at this value, so locking not required, especially since the set is
756 : : * an atomic integer set operation.
757 : : */
758 : : void
759 : 0 : SetStartupBufferPinWaitBufId(int bufid)
760 : : {
761 : : /* use volatile pointer to prevent code rearrangement */
762 : 0 : volatile PROC_HDR *procglobal = ProcGlobal;
763 : :
764 : 0 : procglobal->startupBufferPinWaitBufId = bufid;
765 : 0 : }
766 : :
767 : : /*
768 : : * Used by backends when they receive a request to check for buffer pin waits.
769 : : */
770 : : int
771 : 0 : GetStartupBufferPinWaitBufId(void)
772 : : {
773 : : /* use volatile pointer to prevent code rearrangement */
774 : 0 : volatile PROC_HDR *procglobal = ProcGlobal;
775 : :
776 : 0 : return procglobal->startupBufferPinWaitBufId;
777 : 0 : }
778 : :
779 : : /*
780 : : * Check whether there are at least N free PGPROC objects. If false is
781 : : * returned, *nfree will be set to the number of free PGPROC objects.
782 : : * Otherwise, *nfree will be set to n.
783 : : *
784 : : * Note: this is designed on the assumption that N will generally be small.
785 : : */
786 : : bool
787 : 0 : HaveNFreeProcs(int n, int *nfree)
788 : : {
789 : 0 : dlist_iter iter;
790 : :
791 [ # # ]: 0 : Assert(n > 0);
792 [ # # ]: 0 : Assert(nfree);
793 : :
794 [ # # ]: 0 : SpinLockAcquire(ProcStructLock);
795 : :
796 : 0 : *nfree = 0;
797 [ # # # # ]: 0 : dlist_foreach(iter, &ProcGlobal->freeProcs)
798 : : {
799 : 0 : (*nfree)++;
800 [ # # ]: 0 : if (*nfree == n)
801 : 0 : break;
802 : 0 : }
803 : :
804 : 0 : SpinLockRelease(ProcStructLock);
805 : :
806 : 0 : return (*nfree == n);
807 : 0 : }
808 : :
809 : : /*
810 : : * Cancel any pending wait for lock, when aborting a transaction, and revert
811 : : * any strong lock count acquisition for a lock being acquired.
812 : : *
813 : : * (Normally, this would only happen if we accept a cancel/die
814 : : * interrupt while waiting; but an ereport(ERROR) before or during the lock
815 : : * wait is within the realm of possibility, too.)
816 : : */
817 : : void
818 : 66115 : LockErrorCleanup(void)
819 : : {
820 : 66115 : LOCALLOCK *lockAwaited;
821 : 66115 : LWLock *partitionLock;
822 : 66115 : DisableTimeoutParams timeouts[2];
823 : :
824 : 66115 : HOLD_INTERRUPTS();
825 : :
826 : 66115 : AbortStrongLockAcquire();
827 : :
828 : : /* Nothing to do if we weren't waiting for a lock */
829 : 66115 : lockAwaited = GetAwaitedLock();
830 [ + + ]: 66115 : if (lockAwaited == NULL)
831 : : {
832 [ + - ]: 66114 : RESUME_INTERRUPTS();
833 : 66114 : return;
834 : : }
835 : :
836 : : /*
837 : : * Turn off the deadlock and lock timeout timers, if they are still
838 : : * running (see ProcSleep). Note we must preserve the LOCK_TIMEOUT
839 : : * indicator flag, since this function is executed before
840 : : * ProcessInterrupts when responding to SIGINT; else we'd lose the
841 : : * knowledge that the SIGINT came from a lock timeout and not an external
842 : : * source.
843 : : */
844 : 1 : timeouts[0].id = DEADLOCK_TIMEOUT;
845 : 1 : timeouts[0].keep_indicator = false;
846 : 1 : timeouts[1].id = LOCK_TIMEOUT;
847 : 1 : timeouts[1].keep_indicator = true;
848 : 1 : disable_timeouts(timeouts, 2);
849 : :
850 : : /* Unlink myself from the wait queue, if on it (might not be anymore!) */
851 : 1 : partitionLock = LockHashPartitionLock(lockAwaited->hashcode);
852 : 1 : LWLockAcquire(partitionLock, LW_EXCLUSIVE);
853 : :
854 [ - + ]: 1 : if (!dlist_node_is_detached(&MyProc->links))
855 : : {
856 : : /* We could not have been granted the lock yet */
857 : 1 : RemoveFromWaitQueue(MyProc, lockAwaited->hashcode);
858 : 1 : }
859 : : else
860 : : {
861 : : /*
862 : : * Somebody kicked us off the lock queue already. Perhaps they
863 : : * granted us the lock, or perhaps they detected a deadlock. If they
864 : : * did grant us the lock, we'd better remember it in our local lock
865 : : * table.
866 : : */
867 [ # # ]: 0 : if (MyProc->waitStatus == PROC_WAIT_STATUS_OK)
868 : 0 : GrantAwaitedLock();
869 : : }
870 : :
871 : 1 : ResetAwaitedLock();
872 : :
873 : 1 : LWLockRelease(partitionLock);
874 : :
875 [ + - ]: 1 : RESUME_INTERRUPTS();
876 [ - + ]: 66115 : }
877 : :
878 : :
879 : : /*
880 : : * ProcReleaseLocks() -- release locks associated with current transaction
881 : : * at main transaction commit or abort
882 : : *
883 : : * At main transaction commit, we release standard locks except session locks.
884 : : * At main transaction abort, we release all locks including session locks.
885 : : *
886 : : * Advisory locks are released only if they are transaction-level;
887 : : * session-level holds remain, whether this is a commit or not.
888 : : *
889 : : * At subtransaction commit, we don't release any locks (so this func is not
890 : : * needed at all); we will defer the releasing to the parent transaction.
891 : : * At subtransaction abort, we release all locks held by the subtransaction;
892 : : * this is implemented by retail releasing of the locks under control of
893 : : * the ResourceOwner mechanism.
894 : : */
895 : : void
896 : 57914 : ProcReleaseLocks(bool isCommit)
897 : : {
898 [ + - ]: 57914 : if (!MyProc)
899 : 0 : return;
900 : : /* If waiting, get off wait queue (should only be needed after error) */
901 : 57914 : LockErrorCleanup();
902 : : /* Release standard locks, including session-level if aborting */
903 : 57914 : LockReleaseAll(DEFAULT_LOCKMETHOD, !isCommit);
904 : : /* Release transaction-level advisory locks */
905 : 57914 : LockReleaseAll(USER_LOCKMETHOD, false);
906 : 57914 : }
907 : :
908 : :
909 : : /*
910 : : * RemoveProcFromArray() -- Remove this process from the shared ProcArray.
911 : : */
912 : : static void
913 : 798 : RemoveProcFromArray(int code, Datum arg)
914 : : {
915 [ + - ]: 798 : Assert(MyProc != NULL);
916 : 798 : ProcArrayRemove(MyProc, InvalidTransactionId);
917 : 798 : }
918 : :
919 : : /*
920 : : * ProcKill() -- Destroy the per-proc data structure for
921 : : * this process. Release any of its held LW locks.
922 : : */
923 : : static void
924 : 798 : ProcKill(int code, Datum arg)
925 : : {
926 : 798 : PGPROC *proc;
927 : 798 : dlist_head *procgloballist;
928 : :
929 [ + - ]: 798 : Assert(MyProc != NULL);
930 : :
931 : : /* not safe if forked by system(), etc. */
932 [ + - ]: 798 : if (MyProc->pid != (int) getpid())
933 [ # # # # ]: 0 : elog(PANIC, "ProcKill() called in child process");
934 : :
935 : : /* Make sure we're out of the sync rep lists */
936 : 798 : SyncRepCleanupAtProcExit();
937 : :
938 : : #ifdef USE_ASSERT_CHECKING
939 : : {
940 : 798 : int i;
941 : :
942 : : /* Last process should have released all locks. */
943 [ + + ]: 13566 : for (i = 0; i < NUM_LOCK_PARTITIONS; i++)
944 [ + - ]: 12768 : Assert(dlist_is_empty(&(MyProc->myProcLocks[i])));
945 : 798 : }
946 : : #endif
947 : :
948 : : /*
949 : : * Release any LW locks I am holding. There really shouldn't be any, but
950 : : * it's cheap to check again before we cut the knees off the LWLock
951 : : * facility by releasing our PGPROC ...
952 : : */
953 : 798 : LWLockReleaseAll();
954 : :
955 : : /*
956 : : * Cleanup waiting for LSN if any.
957 : : */
958 : 798 : WaitLSNCleanup();
959 : :
960 : : /* Cancel any pending condition variable sleep, too */
961 : 798 : ConditionVariableCancelSleep();
962 : :
963 : : /*
964 : : * Detach from any lock group of which we are a member. If the leader
965 : : * exits before all other group members, its PGPROC will remain allocated
966 : : * until the last group process exits; that process must return the
967 : : * leader's PGPROC to the appropriate list.
968 : : */
969 [ + + ]: 798 : if (MyProc->lockGroupLeader != NULL)
970 : : {
971 : 499 : PGPROC *leader = MyProc->lockGroupLeader;
972 : 499 : LWLock *leader_lwlock = LockHashPartitionLockByProc(leader);
973 : :
974 : 499 : LWLockAcquire(leader_lwlock, LW_EXCLUSIVE);
975 [ + - ]: 499 : Assert(!dlist_is_empty(&leader->lockGroupMembers));
976 : 499 : dlist_delete(&MyProc->lockGroupLink);
977 [ + + ]: 499 : if (dlist_is_empty(&leader->lockGroupMembers))
978 : : {
979 : 22 : leader->lockGroupLeader = NULL;
980 [ + - ]: 22 : if (leader != MyProc)
981 : : {
982 : 0 : procgloballist = leader->procgloballist;
983 : :
984 : : /* Leader exited first; return its PGPROC. */
985 [ # # ]: 0 : SpinLockAcquire(ProcStructLock);
986 : 0 : dlist_push_head(procgloballist, &leader->links);
987 : 0 : SpinLockRelease(ProcStructLock);
988 : 0 : }
989 : 22 : }
990 [ + - ]: 477 : else if (leader != MyProc)
991 : 477 : MyProc->lockGroupLeader = NULL;
992 : 499 : LWLockRelease(leader_lwlock);
993 : 499 : }
994 : :
995 : : /*
996 : : * Reset MyLatch to the process local one. This is so that signal
997 : : * handlers et al can continue using the latch after the shared latch
998 : : * isn't ours anymore.
999 : : *
1000 : : * Similarly, stop reporting wait events to MyProc->wait_event_info.
1001 : : *
1002 : : * After that clear MyProc and disown the shared latch.
1003 : : */
1004 : 798 : SwitchBackToLocalLatch();
1005 : 798 : pgstat_reset_wait_event_storage();
1006 : :
1007 : 798 : proc = MyProc;
1008 : 798 : MyProc = NULL;
1009 : 798 : MyProcNumber = INVALID_PROC_NUMBER;
1010 : 798 : DisownLatch(&proc->procLatch);
1011 : :
1012 : : /* Mark the proc no longer in use */
1013 : 798 : proc->pid = 0;
1014 : 798 : proc->vxid.procNumber = INVALID_PROC_NUMBER;
1015 : 798 : proc->vxid.lxid = InvalidTransactionId;
1016 : :
1017 : 798 : procgloballist = proc->procgloballist;
1018 [ - + ]: 798 : SpinLockAcquire(ProcStructLock);
1019 : :
1020 : : /*
1021 : : * If we're still a member of a locking group, that means we're a leader
1022 : : * which has somehow exited before its children. The last remaining child
1023 : : * will release our PGPROC. Otherwise, release it now.
1024 : : */
1025 [ - + ]: 798 : if (proc->lockGroupLeader == NULL)
1026 : : {
1027 : : /* Since lockGroupLeader is NULL, lockGroupMembers should be empty. */
1028 [ + - ]: 798 : Assert(dlist_is_empty(&proc->lockGroupMembers));
1029 : :
1030 : : /* Return PGPROC structure (and semaphore) to appropriate freelist */
1031 : 798 : dlist_push_tail(procgloballist, &proc->links);
1032 : 798 : }
1033 : :
1034 : : /* Update shared estimate of spins_per_delay */
1035 : 798 : ProcGlobal->spins_per_delay = update_spins_per_delay(ProcGlobal->spins_per_delay);
1036 : :
1037 : 798 : SpinLockRelease(ProcStructLock);
1038 : 798 : }
1039 : :
1040 : : /*
1041 : : * AuxiliaryProcKill() -- Cut-down version of ProcKill for auxiliary
1042 : : * processes (bgwriter, etc). The PGPROC and sema are not released, only
1043 : : * marked as not-in-use.
1044 : : */
1045 : : static void
1046 : 8 : AuxiliaryProcKill(int code, Datum arg)
1047 : : {
1048 : 8 : int proctype = DatumGetInt32(arg);
1049 : 8 : PGPROC *auxproc PG_USED_FOR_ASSERTS_ONLY;
1050 : 8 : PGPROC *proc;
1051 : :
1052 [ + - ]: 8 : Assert(proctype >= 0 && proctype < NUM_AUXILIARY_PROCS);
1053 : :
1054 : : /* not safe if forked by system(), etc. */
1055 [ + - ]: 8 : if (MyProc->pid != (int) getpid())
1056 [ # # # # ]: 0 : elog(PANIC, "AuxiliaryProcKill() called in child process");
1057 : :
1058 : 8 : auxproc = &AuxiliaryProcs[proctype];
1059 : :
1060 [ + - ]: 8 : Assert(MyProc == auxproc);
1061 : :
1062 : : /* Release any LW locks I am holding (see notes above) */
1063 : 8 : LWLockReleaseAll();
1064 : :
1065 : : /* Cancel any pending condition variable sleep, too */
1066 : 8 : ConditionVariableCancelSleep();
1067 : :
1068 : : /* look at the equivalent ProcKill() code for comments */
1069 : 8 : SwitchBackToLocalLatch();
1070 : 8 : pgstat_reset_wait_event_storage();
1071 : :
1072 : 8 : proc = MyProc;
1073 : 8 : MyProc = NULL;
1074 : 8 : MyProcNumber = INVALID_PROC_NUMBER;
1075 : 8 : DisownLatch(&proc->procLatch);
1076 : :
1077 [ - + ]: 8 : SpinLockAcquire(ProcStructLock);
1078 : :
1079 : : /* Mark auxiliary proc no longer in use */
1080 : 8 : proc->pid = 0;
1081 : 8 : proc->vxid.procNumber = INVALID_PROC_NUMBER;
1082 : 8 : proc->vxid.lxid = InvalidTransactionId;
1083 : :
1084 : : /* Update shared estimate of spins_per_delay */
1085 : 8 : ProcGlobal->spins_per_delay = update_spins_per_delay(ProcGlobal->spins_per_delay);
1086 : :
1087 : 8 : SpinLockRelease(ProcStructLock);
1088 : 8 : }
1089 : :
1090 : : /*
1091 : : * AuxiliaryPidGetProc -- get PGPROC for an auxiliary process
1092 : : * given its PID
1093 : : *
1094 : : * Returns NULL if not found.
1095 : : */
1096 : : PGPROC *
1097 : 33 : AuxiliaryPidGetProc(int pid)
1098 : : {
1099 : 33 : PGPROC *result = NULL;
1100 : 33 : int index;
1101 : :
1102 [ + + ]: 33 : if (pid == 0) /* never match dummy PGPROCs */
1103 : 1 : return NULL;
1104 : :
1105 [ - + ]: 109 : for (index = 0; index < NUM_AUXILIARY_PROCS; index++)
1106 : : {
1107 : 109 : PGPROC *proc = &AuxiliaryProcs[index];
1108 : :
1109 [ + + ]: 109 : if (proc->pid == pid)
1110 : : {
1111 : 32 : result = proc;
1112 : 32 : break;
1113 : : }
1114 [ - + + ]: 109 : }
1115 : 32 : return result;
1116 : 33 : }
1117 : :
1118 : :
1119 : : /*
1120 : : * JoinWaitQueue -- join the wait queue on the specified lock
1121 : : *
1122 : : * It's not actually guaranteed that we need to wait when this function is
1123 : : * called, because it could be that when we try to find a position at which
1124 : : * to insert ourself into the wait queue, we discover that we must be inserted
1125 : : * ahead of everyone who wants a lock that conflict with ours. In that case,
1126 : : * we get the lock immediately. Because of this, it's sensible for this function
1127 : : * to have a dontWait argument, despite the name.
1128 : : *
1129 : : * On entry, the caller has already set up LOCK and PROCLOCK entries to
1130 : : * reflect that we have "requested" the lock. The caller is responsible for
1131 : : * cleaning that up, if we end up not joining the queue after all.
1132 : : *
1133 : : * The lock table's partition lock must be held at entry, and is still held
1134 : : * at exit. The caller must release it before calling ProcSleep().
1135 : : *
1136 : : * Result is one of the following:
1137 : : *
1138 : : * PROC_WAIT_STATUS_OK - lock was immediately granted
1139 : : * PROC_WAIT_STATUS_WAITING - joined the wait queue; call ProcSleep()
1140 : : * PROC_WAIT_STATUS_ERROR - immediate deadlock was detected, or would
1141 : : * need to wait and dontWait == true
1142 : : *
1143 : : * NOTES: The process queue is now a priority queue for locking.
1144 : : */
1145 : : ProcWaitStatus
1146 : 57 : JoinWaitQueue(LOCALLOCK *locallock, LockMethod lockMethodTable, bool dontWait)
1147 : : {
1148 : 57 : LOCKMODE lockmode = locallock->tag.mode;
1149 : 57 : LOCK *lock = locallock->lock;
1150 : 57 : PROCLOCK *proclock = locallock->proclock;
1151 : 57 : uint32 hashcode = locallock->hashcode;
1152 : 57 : LWLock *partitionLock PG_USED_FOR_ASSERTS_ONLY = LockHashPartitionLock(hashcode);
1153 : 57 : dclist_head *waitQueue = &lock->waitProcs;
1154 : 57 : PGPROC *insert_before = NULL;
1155 : 57 : LOCKMASK myProcHeldLocks;
1156 : 57 : LOCKMASK myHeldLocks;
1157 : 57 : bool early_deadlock = false;
1158 : 57 : PGPROC *leader = MyProc->lockGroupLeader;
1159 : :
1160 [ + - ]: 57 : Assert(LWLockHeldByMeInMode(partitionLock, LW_EXCLUSIVE));
1161 : :
1162 : : /*
1163 : : * Set bitmask of locks this process already holds on this object.
1164 : : */
1165 : 57 : myHeldLocks = MyProc->heldLocks = proclock->holdMask;
1166 : :
1167 : : /*
1168 : : * Determine which locks we're already holding.
1169 : : *
1170 : : * If group locking is in use, locks held by members of my locking group
1171 : : * need to be included in myHeldLocks. This is not required for relation
1172 : : * extension lock which conflict among group members. However, including
1173 : : * them in myHeldLocks will give group members the priority to get those
1174 : : * locks as compared to other backends which are also trying to acquire
1175 : : * those locks. OTOH, we can avoid giving priority to group members for
1176 : : * that kind of locks, but there doesn't appear to be a clear advantage of
1177 : : * the same.
1178 : : */
1179 : 57 : myProcHeldLocks = proclock->holdMask;
1180 : 57 : myHeldLocks = myProcHeldLocks;
1181 [ + + ]: 57 : if (leader != NULL)
1182 : : {
1183 : 1 : dlist_iter iter;
1184 : :
1185 [ + - + + ]: 3 : dlist_foreach(iter, &lock->procLocks)
1186 : : {
1187 : 2 : PROCLOCK *otherproclock;
1188 : :
1189 : 2 : otherproclock = dlist_container(PROCLOCK, lockLink, iter.cur);
1190 : :
1191 [ + + ]: 2 : if (otherproclock->groupLeader == leader)
1192 : 1 : myHeldLocks |= otherproclock->holdMask;
1193 : 2 : }
1194 : 1 : }
1195 : :
1196 : : /*
1197 : : * Determine where to add myself in the wait queue.
1198 : : *
1199 : : * Normally I should go at the end of the queue. However, if I already
1200 : : * hold locks that conflict with the request of any previous waiter, put
1201 : : * myself in the queue just in front of the first such waiter. This is not
1202 : : * a necessary step, since deadlock detection would move me to before that
1203 : : * waiter anyway; but it's relatively cheap to detect such a conflict
1204 : : * immediately, and avoid delaying till deadlock timeout.
1205 : : *
1206 : : * Special case: if I find I should go in front of some waiter, check to
1207 : : * see if I conflict with already-held locks or the requests before that
1208 : : * waiter. If not, then just grant myself the requested lock immediately.
1209 : : * This is the same as the test for immediate grant in LockAcquire, except
1210 : : * we are only considering the part of the wait queue before my insertion
1211 : : * point.
1212 : : */
1213 [ + + - + ]: 57 : if (myHeldLocks != 0 && !dclist_is_empty(waitQueue))
1214 : : {
1215 : 14 : LOCKMASK aheadRequests = 0;
1216 : 14 : dlist_iter iter;
1217 : :
1218 [ + - - + ]: 14 : dclist_foreach(iter, waitQueue)
1219 : : {
1220 : 14 : PGPROC *proc = dlist_container(PGPROC, links, iter.cur);
1221 : :
1222 : : /*
1223 : : * If we're part of the same locking group as this waiter, its
1224 : : * locks neither conflict with ours nor contribute to
1225 : : * aheadRequests.
1226 : : */
1227 [ - + # # ]: 14 : if (leader != NULL && leader == proc->lockGroupLeader)
1228 : 0 : continue;
1229 : :
1230 : : /* Must he wait for me? */
1231 [ + - ]: 14 : if (lockMethodTable->conflictTab[proc->waitLockMode] & myHeldLocks)
1232 : : {
1233 : : /* Must I wait for him ? */
1234 [ - + ]: 14 : if (lockMethodTable->conflictTab[lockmode] & proc->heldLocks)
1235 : : {
1236 : : /*
1237 : : * Yes, so we have a deadlock. Easiest way to clean up
1238 : : * correctly is to call RemoveFromWaitQueue(), but we
1239 : : * can't do that until we are *on* the wait queue. So, set
1240 : : * a flag to check below, and break out of loop. Also,
1241 : : * record deadlock info for later message.
1242 : : */
1243 : 0 : RememberSimpleDeadLock(MyProc, lockmode, lock, proc);
1244 : 0 : early_deadlock = true;
1245 : 0 : break;
1246 : : }
1247 : : /* I must go before this waiter. Check special case. */
1248 [ + - - + ]: 14 : if ((lockMethodTable->conflictTab[lockmode] & aheadRequests) == 0 &&
1249 : 28 : !LockCheckConflicts(lockMethodTable, lockmode, lock,
1250 : 14 : proclock))
1251 : : {
1252 : : /* Skip the wait and just grant myself the lock. */
1253 : 14 : GrantLock(lock, proclock, lockmode);
1254 : 14 : return PROC_WAIT_STATUS_OK;
1255 : : }
1256 : :
1257 : : /* Put myself into wait queue before conflicting process */
1258 : 0 : insert_before = proc;
1259 : 0 : break;
1260 : : }
1261 : : /* Nope, so advance to next waiter */
1262 : 0 : aheadRequests |= LOCKBIT_ON(proc->waitLockMode);
1263 [ - - + - ]: 14 : }
1264 [ + - ]: 14 : }
1265 : :
1266 : : /*
1267 : : * If we detected deadlock, give up without waiting. This must agree with
1268 : : * CheckDeadLock's recovery code.
1269 : : */
1270 [ - + ]: 43 : if (early_deadlock)
1271 : 0 : return PROC_WAIT_STATUS_ERROR;
1272 : :
1273 : : /*
1274 : : * At this point we know that we'd really need to sleep. If we've been
1275 : : * commanded not to do that, bail out.
1276 : : */
1277 [ - + ]: 43 : if (dontWait)
1278 : 0 : return PROC_WAIT_STATUS_ERROR;
1279 : :
1280 : : /*
1281 : : * Insert self into queue, at the position determined above.
1282 : : */
1283 [ - + ]: 43 : if (insert_before)
1284 : 0 : dclist_insert_before(waitQueue, &insert_before->links, &MyProc->links);
1285 : : else
1286 : 43 : dclist_push_tail(waitQueue, &MyProc->links);
1287 : :
1288 : 43 : lock->waitMask |= LOCKBIT_ON(lockmode);
1289 : :
1290 : : /* Set up wait information in PGPROC object, too */
1291 : 43 : MyProc->heldLocks = myProcHeldLocks;
1292 : 43 : MyProc->waitLock = lock;
1293 : 43 : MyProc->waitProcLock = proclock;
1294 : 43 : MyProc->waitLockMode = lockmode;
1295 : :
1296 : 43 : MyProc->waitStatus = PROC_WAIT_STATUS_WAITING;
1297 : :
1298 : 43 : return PROC_WAIT_STATUS_WAITING;
1299 : 57 : }
1300 : :
1301 : : /*
1302 : : * ProcSleep -- put process to sleep waiting on lock
1303 : : *
1304 : : * This must be called when JoinWaitQueue() returns PROC_WAIT_STATUS_WAITING.
1305 : : * Returns after the lock has been granted, or if a deadlock is detected. Can
1306 : : * also bail out with ereport(ERROR), if some other error condition, or a
1307 : : * timeout or cancellation is triggered.
1308 : : *
1309 : : * Result is one of the following:
1310 : : *
1311 : : * PROC_WAIT_STATUS_OK - lock was granted
1312 : : * PROC_WAIT_STATUS_ERROR - a deadlock was detected
1313 : : */
1314 : : ProcWaitStatus
1315 : 43 : ProcSleep(LOCALLOCK *locallock)
1316 : : {
1317 : 43 : LOCKMODE lockmode = locallock->tag.mode;
1318 : 43 : LOCK *lock = locallock->lock;
1319 : 43 : uint32 hashcode = locallock->hashcode;
1320 : 43 : LWLock *partitionLock = LockHashPartitionLock(hashcode);
1321 : 43 : TimestampTz standbyWaitStart = 0;
1322 : 43 : bool allow_autovacuum_cancel = true;
1323 : 43 : bool logged_recovery_conflict = false;
1324 : 43 : ProcWaitStatus myWaitStatus;
1325 : :
1326 : : /* The caller must've armed the on-error cleanup mechanism */
1327 [ + - ]: 43 : Assert(GetAwaitedLock() == locallock);
1328 [ + - ]: 43 : Assert(!LWLockHeldByMe(partitionLock));
1329 : :
1330 : : /*
1331 : : * Now that we will successfully clean up after an ereport, it's safe to
1332 : : * check to see if there's a buffer pin deadlock against the Startup
1333 : : * process. Of course, that's only necessary if we're doing Hot Standby
1334 : : * and are not the Startup process ourselves.
1335 : : */
1336 [ - + # # ]: 43 : if (RecoveryInProgress() && !InRecovery)
1337 : 0 : CheckRecoveryConflictDeadlock();
1338 : :
1339 : : /* Reset deadlock_state before enabling the timeout handler */
1340 : 43 : deadlock_state = DS_NOT_YET_CHECKED;
1341 : 43 : got_deadlock_timeout = false;
1342 : :
1343 : : /*
1344 : : * Set timer so we can wake up after awhile and check for a deadlock. If a
1345 : : * deadlock is detected, the handler sets MyProc->waitStatus =
1346 : : * PROC_WAIT_STATUS_ERROR, allowing us to know that we must report failure
1347 : : * rather than success.
1348 : : *
1349 : : * By delaying the check until we've waited for a bit, we can avoid
1350 : : * running the rather expensive deadlock-check code in most cases.
1351 : : *
1352 : : * If LockTimeout is set, also enable the timeout for that. We can save a
1353 : : * few cycles by enabling both timeout sources in one call.
1354 : : *
1355 : : * If InHotStandby we set lock waits slightly later for clarity with other
1356 : : * code.
1357 : : */
1358 [ - + ]: 43 : if (!InHotStandby)
1359 : : {
1360 [ - + ]: 43 : if (LockTimeout > 0)
1361 : : {
1362 : 0 : EnableTimeoutParams timeouts[2];
1363 : :
1364 : 0 : timeouts[0].id = DEADLOCK_TIMEOUT;
1365 : 0 : timeouts[0].type = TMPARAM_AFTER;
1366 : 0 : timeouts[0].delay_ms = DeadlockTimeout;
1367 : 0 : timeouts[1].id = LOCK_TIMEOUT;
1368 : 0 : timeouts[1].type = TMPARAM_AFTER;
1369 : 0 : timeouts[1].delay_ms = LockTimeout;
1370 : 0 : enable_timeouts(timeouts, 2);
1371 : 0 : }
1372 : : else
1373 : 43 : enable_timeout_after(DEADLOCK_TIMEOUT, DeadlockTimeout);
1374 : :
1375 : : /*
1376 : : * Use the current time obtained for the deadlock timeout timer as
1377 : : * waitStart (i.e., the time when this process started waiting for the
1378 : : * lock). Since getting the current time newly can cause overhead, we
1379 : : * reuse the already-obtained time to avoid that overhead.
1380 : : *
1381 : : * Note that waitStart is updated without holding the lock table's
1382 : : * partition lock, to avoid the overhead by additional lock
1383 : : * acquisition. This can cause "waitstart" in pg_locks to become NULL
1384 : : * for a very short period of time after the wait started even though
1385 : : * "granted" is false. This is OK in practice because we can assume
1386 : : * that users are likely to look at "waitstart" when waiting for the
1387 : : * lock for a long time.
1388 : : */
1389 : 86 : pg_atomic_write_u64(&MyProc->waitStart,
1390 : 43 : get_timeout_start_time(DEADLOCK_TIMEOUT));
1391 : 43 : }
1392 [ # # ]: 0 : else if (log_recovery_conflict_waits)
1393 : : {
1394 : : /*
1395 : : * Set the wait start timestamp if logging is enabled and in hot
1396 : : * standby.
1397 : : */
1398 : 0 : standbyWaitStart = GetCurrentTimestamp();
1399 : 0 : }
1400 : :
1401 : : /*
1402 : : * If somebody wakes us between LWLockRelease and WaitLatch, the latch
1403 : : * will not wait. But a set latch does not necessarily mean that the lock
1404 : : * is free now, as there are many other sources for latch sets than
1405 : : * somebody releasing the lock.
1406 : : *
1407 : : * We process interrupts whenever the latch has been set, so cancel/die
1408 : : * interrupts are processed quickly. This means we must not mind losing
1409 : : * control to a cancel/die interrupt here. We don't, because we have no
1410 : : * shared-state-change work to do after being granted the lock (the
1411 : : * grantor did it all). We do have to worry about canceling the deadlock
1412 : : * timeout and updating the locallock table, but if we lose control to an
1413 : : * error, LockErrorCleanup will fix that up.
1414 : : */
1415 : 43 : do
1416 : : {
1417 [ - + ]: 49 : if (InHotStandby)
1418 : : {
1419 : 0 : bool maybe_log_conflict =
1420 [ # # ]: 0 : (standbyWaitStart != 0 && !logged_recovery_conflict);
1421 : :
1422 : : /* Set a timer and wait for that or for the lock to be granted */
1423 : 0 : ResolveRecoveryConflictWithLock(locallock->tag.lock,
1424 : 0 : maybe_log_conflict);
1425 : :
1426 : : /*
1427 : : * Emit the log message if the startup process is waiting longer
1428 : : * than deadlock_timeout for recovery conflict on lock.
1429 : : */
1430 [ # # ]: 0 : if (maybe_log_conflict)
1431 : : {
1432 : 0 : TimestampTz now = GetCurrentTimestamp();
1433 : :
1434 [ # # # # ]: 0 : if (TimestampDifferenceExceeds(standbyWaitStart, now,
1435 : 0 : DeadlockTimeout))
1436 : : {
1437 : 0 : VirtualTransactionId *vxids;
1438 : 0 : int cnt;
1439 : :
1440 : 0 : vxids = GetLockConflicts(&locallock->tag.lock,
1441 : : AccessExclusiveLock, &cnt);
1442 : :
1443 : : /*
1444 : : * Log the recovery conflict and the list of PIDs of
1445 : : * backends holding the conflicting lock. Note that we do
1446 : : * logging even if there are no such backends right now
1447 : : * because the startup process here has already waited
1448 : : * longer than deadlock_timeout.
1449 : : */
1450 : 0 : LogRecoveryConflict(PROCSIG_RECOVERY_CONFLICT_LOCK,
1451 : 0 : standbyWaitStart, now,
1452 [ # # ]: 0 : cnt > 0 ? vxids : NULL, true);
1453 : 0 : logged_recovery_conflict = true;
1454 : 0 : }
1455 : 0 : }
1456 : 0 : }
1457 : : else
1458 : : {
1459 : 98 : (void) WaitLatch(MyLatch, WL_LATCH_SET | WL_EXIT_ON_PM_DEATH, 0,
1460 : 49 : PG_WAIT_LOCK | locallock->tag.lock.locktag_type);
1461 : 49 : ResetLatch(MyLatch);
1462 : : /* check for deadlocks first, as that's probably log-worthy */
1463 [ + + ]: 49 : if (got_deadlock_timeout)
1464 : : {
1465 : 2 : CheckDeadLock();
1466 : 2 : got_deadlock_timeout = false;
1467 : 2 : }
1468 [ + + ]: 49 : CHECK_FOR_INTERRUPTS();
1469 : : }
1470 : :
1471 : : /*
1472 : : * waitStatus could change from PROC_WAIT_STATUS_WAITING to something
1473 : : * else asynchronously. Read it just once per loop to prevent
1474 : : * surprising behavior (such as missing log messages).
1475 : : */
1476 : 49 : myWaitStatus = *((volatile ProcWaitStatus *) &MyProc->waitStatus);
1477 : :
1478 : : /*
1479 : : * If we are not deadlocked, but are waiting on an autovacuum-induced
1480 : : * task, send a signal to interrupt it.
1481 : : */
1482 [ - + # # ]: 49 : if (deadlock_state == DS_BLOCKED_BY_AUTOVACUUM && allow_autovacuum_cancel)
1483 : : {
1484 : 0 : PGPROC *autovac = GetBlockingAutoVacuumPgproc();
1485 : 0 : uint8 statusFlags;
1486 : 0 : uint8 lockmethod_copy;
1487 : 0 : LOCKTAG locktag_copy;
1488 : :
1489 : : /*
1490 : : * Grab info we need, then release lock immediately. Note this
1491 : : * coding means that there is a tiny chance that the process
1492 : : * terminates its current transaction and starts a different one
1493 : : * before we have a change to send the signal; the worst possible
1494 : : * consequence is that a for-wraparound vacuum is canceled. But
1495 : : * that could happen in any case unless we were to do kill() with
1496 : : * the lock held, which is much more undesirable.
1497 : : */
1498 : 0 : LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
1499 : 0 : statusFlags = ProcGlobal->statusFlags[autovac->pgxactoff];
1500 : 0 : lockmethod_copy = lock->tag.locktag_lockmethodid;
1501 : 0 : locktag_copy = lock->tag;
1502 : 0 : LWLockRelease(ProcArrayLock);
1503 : :
1504 : : /*
1505 : : * Only do it if the worker is not working to protect against Xid
1506 : : * wraparound.
1507 : : */
1508 [ # # # # ]: 0 : if ((statusFlags & PROC_IS_AUTOVACUUM) &&
1509 : 0 : !(statusFlags & PROC_VACUUM_FOR_WRAPAROUND))
1510 : : {
1511 : 0 : int pid = autovac->pid;
1512 : :
1513 : : /* report the case, if configured to do so */
1514 [ # # ]: 0 : if (message_level_is_interesting(DEBUG1))
1515 : : {
1516 : 0 : StringInfoData locktagbuf;
1517 : 0 : StringInfoData logbuf; /* errdetail for server log */
1518 : :
1519 : 0 : initStringInfo(&locktagbuf);
1520 : 0 : initStringInfo(&logbuf);
1521 : 0 : DescribeLockTag(&locktagbuf, &locktag_copy);
1522 : 0 : appendStringInfo(&logbuf,
1523 : : "Process %d waits for %s on %s.",
1524 : 0 : MyProcPid,
1525 : 0 : GetLockmodeName(lockmethod_copy, lockmode),
1526 : 0 : locktagbuf.data);
1527 : :
1528 [ # # # # ]: 0 : ereport(DEBUG1,
1529 : : (errmsg_internal("sending cancel to blocking autovacuum PID %d",
1530 : : pid),
1531 : : errdetail_log("%s", logbuf.data)));
1532 : :
1533 : 0 : pfree(locktagbuf.data);
1534 : 0 : pfree(logbuf.data);
1535 : 0 : }
1536 : :
1537 : : /* send the autovacuum worker Back to Old Kent Road */
1538 [ # # ]: 0 : if (kill(pid, SIGINT) < 0)
1539 : : {
1540 : : /*
1541 : : * There's a race condition here: once we release the
1542 : : * ProcArrayLock, it's possible for the autovac worker to
1543 : : * close up shop and exit before we can do the kill().
1544 : : * Therefore, we do not whinge about no-such-process.
1545 : : * Other errors such as EPERM could conceivably happen if
1546 : : * the kernel recycles the PID fast enough, but such cases
1547 : : * seem improbable enough that it's probably best to issue
1548 : : * a warning if we see some other errno.
1549 : : */
1550 [ # # ]: 0 : if (errno != ESRCH)
1551 [ # # # # ]: 0 : ereport(WARNING,
1552 : : (errmsg("could not send signal to process %d: %m",
1553 : : pid)));
1554 : 0 : }
1555 : 0 : }
1556 : :
1557 : : /* prevent signal from being sent again more than once */
1558 : 0 : allow_autovacuum_cancel = false;
1559 : 0 : }
1560 : :
1561 : : /*
1562 : : * If awoken after the deadlock check interrupt has run, and
1563 : : * log_lock_waits is on, then report about the wait.
1564 : : */
1565 [ + - + + ]: 49 : if (log_lock_waits && deadlock_state != DS_NOT_YET_CHECKED)
1566 : : {
1567 : 4 : StringInfoData buf,
1568 : : lock_waiters_sbuf,
1569 : : lock_holders_sbuf;
1570 : 4 : const char *modename;
1571 : 4 : long secs;
1572 : 4 : int usecs;
1573 : 4 : long msecs;
1574 : 4 : int lockHoldersNum = 0;
1575 : :
1576 : 4 : initStringInfo(&buf);
1577 : 4 : initStringInfo(&lock_waiters_sbuf);
1578 : 4 : initStringInfo(&lock_holders_sbuf);
1579 : :
1580 : 4 : DescribeLockTag(&buf, &locallock->tag.lock);
1581 : 8 : modename = GetLockmodeName(locallock->tag.lock.locktag_lockmethodid,
1582 : 4 : lockmode);
1583 : 8 : TimestampDifference(get_timeout_start_time(DEADLOCK_TIMEOUT),
1584 : 4 : GetCurrentTimestamp(),
1585 : : &secs, &usecs);
1586 : 4 : msecs = secs * 1000 + usecs / 1000;
1587 : 4 : usecs = usecs % 1000;
1588 : :
1589 : : /* Gather a list of all lock holders and waiters */
1590 : 4 : LWLockAcquire(partitionLock, LW_SHARED);
1591 : 4 : GetLockHoldersAndWaiters(locallock, &lock_holders_sbuf,
1592 : : &lock_waiters_sbuf, &lockHoldersNum);
1593 : 4 : LWLockRelease(partitionLock);
1594 : :
1595 [ - + ]: 4 : if (deadlock_state == DS_SOFT_DEADLOCK)
1596 [ # # # # ]: 0 : ereport(LOG,
1597 : : (errmsg("process %d avoided deadlock for %s on %s by rearranging queue order after %ld.%03d ms",
1598 : : MyProcPid, modename, buf.data, msecs, usecs),
1599 : : (errdetail_log_plural("Process holding the lock: %s. Wait queue: %s.",
1600 : : "Processes holding the lock: %s. Wait queue: %s.",
1601 : : lockHoldersNum, lock_holders_sbuf.data, lock_waiters_sbuf.data))));
1602 [ + - ]: 4 : else if (deadlock_state == DS_HARD_DEADLOCK)
1603 : : {
1604 : : /*
1605 : : * This message is a bit redundant with the error that will be
1606 : : * reported subsequently, but in some cases the error report
1607 : : * might not make it to the log (eg, if it's caught by an
1608 : : * exception handler), and we want to ensure all long-wait
1609 : : * events get logged.
1610 : : */
1611 [ # # # # ]: 0 : ereport(LOG,
1612 : : (errmsg("process %d detected deadlock while waiting for %s on %s after %ld.%03d ms",
1613 : : MyProcPid, modename, buf.data, msecs, usecs),
1614 : : (errdetail_log_plural("Process holding the lock: %s. Wait queue: %s.",
1615 : : "Processes holding the lock: %s. Wait queue: %s.",
1616 : : lockHoldersNum, lock_holders_sbuf.data, lock_waiters_sbuf.data))));
1617 : 0 : }
1618 : :
1619 [ + + ]: 4 : if (myWaitStatus == PROC_WAIT_STATUS_WAITING)
1620 [ - + + - ]: 2 : ereport(LOG,
1621 : : (errmsg("process %d still waiting for %s on %s after %ld.%03d ms",
1622 : : MyProcPid, modename, buf.data, msecs, usecs),
1623 : : (errdetail_log_plural("Process holding the lock: %s. Wait queue: %s.",
1624 : : "Processes holding the lock: %s. Wait queue: %s.",
1625 : : lockHoldersNum, lock_holders_sbuf.data, lock_waiters_sbuf.data))));
1626 [ - + ]: 2 : else if (myWaitStatus == PROC_WAIT_STATUS_OK)
1627 [ - + + - ]: 2 : ereport(LOG,
1628 : : (errmsg("process %d acquired %s on %s after %ld.%03d ms",
1629 : : MyProcPid, modename, buf.data, msecs, usecs)));
1630 : : else
1631 : : {
1632 [ # # ]: 0 : Assert(myWaitStatus == PROC_WAIT_STATUS_ERROR);
1633 : :
1634 : : /*
1635 : : * Currently, the deadlock checker always kicks its own
1636 : : * process, which means that we'll only see
1637 : : * PROC_WAIT_STATUS_ERROR when deadlock_state ==
1638 : : * DS_HARD_DEADLOCK, and there's no need to print redundant
1639 : : * messages. But for completeness and future-proofing, print
1640 : : * a message if it looks like someone else kicked us off the
1641 : : * lock.
1642 : : */
1643 [ # # ]: 0 : if (deadlock_state != DS_HARD_DEADLOCK)
1644 [ # # # # ]: 0 : ereport(LOG,
1645 : : (errmsg("process %d failed to acquire %s on %s after %ld.%03d ms",
1646 : : MyProcPid, modename, buf.data, msecs, usecs),
1647 : : (errdetail_log_plural("Process holding the lock: %s. Wait queue: %s.",
1648 : : "Processes holding the lock: %s. Wait queue: %s.",
1649 : : lockHoldersNum, lock_holders_sbuf.data, lock_waiters_sbuf.data))));
1650 : : }
1651 : :
1652 : : /*
1653 : : * At this point we might still need to wait for the lock. Reset
1654 : : * state so we don't print the above messages again.
1655 : : */
1656 : 4 : deadlock_state = DS_NO_DEADLOCK;
1657 : :
1658 : 4 : pfree(buf.data);
1659 : 4 : pfree(lock_holders_sbuf.data);
1660 : 4 : pfree(lock_waiters_sbuf.data);
1661 : 4 : }
1662 [ + + ]: 49 : } while (myWaitStatus == PROC_WAIT_STATUS_WAITING);
1663 : :
1664 : : /*
1665 : : * Disable the timers, if they are still running. As in LockErrorCleanup,
1666 : : * we must preserve the LOCK_TIMEOUT indicator flag: if a lock timeout has
1667 : : * already caused QueryCancelPending to become set, we want the cancel to
1668 : : * be reported as a lock timeout, not a user cancel.
1669 : : */
1670 [ + + ]: 43 : if (!InHotStandby)
1671 : : {
1672 [ - + ]: 42 : if (LockTimeout > 0)
1673 : : {
1674 : 0 : DisableTimeoutParams timeouts[2];
1675 : :
1676 : 0 : timeouts[0].id = DEADLOCK_TIMEOUT;
1677 : 0 : timeouts[0].keep_indicator = false;
1678 : 0 : timeouts[1].id = LOCK_TIMEOUT;
1679 : 0 : timeouts[1].keep_indicator = true;
1680 : 0 : disable_timeouts(timeouts, 2);
1681 : 0 : }
1682 : : else
1683 : 42 : disable_timeout(DEADLOCK_TIMEOUT, false);
1684 : 42 : }
1685 : :
1686 : : /*
1687 : : * Emit the log message if recovery conflict on lock was resolved but the
1688 : : * startup process waited longer than deadlock_timeout for it.
1689 : : */
1690 [ - + # # ]: 43 : if (InHotStandby && logged_recovery_conflict)
1691 : 0 : LogRecoveryConflict(PROCSIG_RECOVERY_CONFLICT_LOCK,
1692 : 0 : standbyWaitStart, GetCurrentTimestamp(),
1693 : : NULL, false);
1694 : :
1695 : : /*
1696 : : * We don't have to do anything else, because the awaker did all the
1697 : : * necessary updates of the lock table and MyProc. (The caller is
1698 : : * responsible for updating the local lock table.)
1699 : : */
1700 : 86 : return myWaitStatus;
1701 : 43 : }
1702 : :
1703 : :
1704 : : /*
1705 : : * ProcWakeup -- wake up a process by setting its latch.
1706 : : *
1707 : : * Also remove the process from the wait queue and set its links invalid.
1708 : : *
1709 : : * The appropriate lock partition lock must be held by caller.
1710 : : *
1711 : : * XXX: presently, this code is only used for the "success" case, and only
1712 : : * works correctly for that case. To clean up in failure case, would need
1713 : : * to twiddle the lock's request counts too --- see RemoveFromWaitQueue.
1714 : : * Hence, in practice the waitStatus parameter must be PROC_WAIT_STATUS_OK.
1715 : : */
1716 : : void
1717 : 42 : ProcWakeup(PGPROC *proc, ProcWaitStatus waitStatus)
1718 : : {
1719 [ - + ]: 42 : if (dlist_node_is_detached(&proc->links))
1720 : 0 : return;
1721 : :
1722 [ + - ]: 42 : Assert(proc->waitStatus == PROC_WAIT_STATUS_WAITING);
1723 : :
1724 : : /* Remove process from wait queue */
1725 : 42 : dclist_delete_from_thoroughly(&proc->waitLock->waitProcs, &proc->links);
1726 : :
1727 : : /* Clean up process' state and pass it the ok/fail signal */
1728 : 42 : proc->waitLock = NULL;
1729 : 42 : proc->waitProcLock = NULL;
1730 : 42 : proc->waitStatus = waitStatus;
1731 : 42 : pg_atomic_write_u64(&MyProc->waitStart, 0);
1732 : :
1733 : : /* And awaken it */
1734 : 42 : SetLatch(&proc->procLatch);
1735 : 42 : }
1736 : :
1737 : : /*
1738 : : * ProcLockWakeup -- routine for waking up processes when a lock is
1739 : : * released (or a prior waiter is aborted). Scan all waiters
1740 : : * for lock, waken any that are no longer blocked.
1741 : : *
1742 : : * The appropriate lock partition lock must be held by caller.
1743 : : */
1744 : : void
1745 : 49 : ProcLockWakeup(LockMethod lockMethodTable, LOCK *lock)
1746 : : {
1747 : 49 : dclist_head *waitQueue = &lock->waitProcs;
1748 : 49 : LOCKMASK aheadRequests = 0;
1749 : 49 : dlist_mutable_iter miter;
1750 : :
1751 [ + + ]: 49 : if (dclist_is_empty(waitQueue))
1752 : 1 : return;
1753 : :
1754 [ + - + + ]: 203 : dclist_foreach_modify(miter, waitQueue)
1755 : : {
1756 : 155 : PGPROC *proc = dlist_container(PGPROC, links, miter.cur);
1757 : 155 : LOCKMODE lockmode = proc->waitLockMode;
1758 : :
1759 : : /*
1760 : : * Waken if (a) doesn't conflict with requests of earlier waiters, and
1761 : : * (b) doesn't conflict with already-held locks.
1762 : : */
1763 [ + + + + ]: 155 : if ((lockMethodTable->conflictTab[lockmode] & aheadRequests) == 0 &&
1764 : 140 : !LockCheckConflicts(lockMethodTable, lockmode, lock,
1765 : 70 : proc->waitProcLock))
1766 : : {
1767 : : /* OK to waken */
1768 : 42 : GrantLock(lock, proc->waitProcLock, lockmode);
1769 : : /* removes proc from the lock's waiting process queue */
1770 : 42 : ProcWakeup(proc, PROC_WAIT_STATUS_OK);
1771 : 42 : }
1772 : : else
1773 : : {
1774 : : /*
1775 : : * Lock conflicts: Don't wake, but remember requested mode for
1776 : : * later checks.
1777 : : */
1778 : 113 : aheadRequests |= LOCKBIT_ON(lockmode);
1779 : : }
1780 : 155 : }
1781 [ - + ]: 49 : }
1782 : :
1783 : : /*
1784 : : * CheckDeadLock
1785 : : *
1786 : : * We only get to this routine, if DEADLOCK_TIMEOUT fired while waiting for a
1787 : : * lock to be released by some other process. Check if there's a deadlock; if
1788 : : * not, just return. (But signal ProcSleep to log a message, if
1789 : : * log_lock_waits is true.) If we have a real deadlock, remove ourselves from
1790 : : * the lock's wait queue and signal an error to ProcSleep.
1791 : : */
1792 : : static void
1793 : 2 : CheckDeadLock(void)
1794 : : {
1795 : 2 : int i;
1796 : :
1797 : : /*
1798 : : * Acquire exclusive lock on the entire shared lock data structures. Must
1799 : : * grab LWLocks in partition-number order to avoid LWLock deadlock.
1800 : : *
1801 : : * Note that the deadlock check interrupt had better not be enabled
1802 : : * anywhere that this process itself holds lock partition locks, else this
1803 : : * will wait forever. Also note that LWLockAcquire creates a critical
1804 : : * section, so that this routine cannot be interrupted by cancel/die
1805 : : * interrupts.
1806 : : */
1807 [ + + ]: 34 : for (i = 0; i < NUM_LOCK_PARTITIONS; i++)
1808 : 32 : LWLockAcquire(LockHashPartitionLockByIndex(i), LW_EXCLUSIVE);
1809 : :
1810 : : /*
1811 : : * Check to see if we've been awoken by anyone in the interim.
1812 : : *
1813 : : * If we have, we can return and resume our transaction -- happy day.
1814 : : * Before we are awoken the process releasing the lock grants it to us so
1815 : : * we know that we don't have to wait anymore.
1816 : : *
1817 : : * We check by looking to see if we've been unlinked from the wait queue.
1818 : : * This is safe because we hold the lock partition lock.
1819 : : */
1820 [ + - - + ]: 2 : if (MyProc->links.prev == NULL ||
1821 : 2 : MyProc->links.next == NULL)
1822 : 0 : goto check_done;
1823 : :
1824 : : #ifdef LOCK_DEBUG
1825 : : if (Debug_deadlocks)
1826 : : DumpAllLocks();
1827 : : #endif
1828 : :
1829 : : /* Run the deadlock check, and set deadlock_state for use by ProcSleep */
1830 : 2 : deadlock_state = DeadLockCheck(MyProc);
1831 : :
1832 [ + - ]: 2 : if (deadlock_state == DS_HARD_DEADLOCK)
1833 : : {
1834 : : /*
1835 : : * Oops. We have a deadlock.
1836 : : *
1837 : : * Get this process out of wait state. (Note: we could do this more
1838 : : * efficiently by relying on lockAwaited, but use this coding to
1839 : : * preserve the flexibility to kill some other transaction than the
1840 : : * one detecting the deadlock.)
1841 : : *
1842 : : * RemoveFromWaitQueue sets MyProc->waitStatus to
1843 : : * PROC_WAIT_STATUS_ERROR, so ProcSleep will report an error after we
1844 : : * return from the signal handler.
1845 : : */
1846 [ # # ]: 0 : Assert(MyProc->waitLock != NULL);
1847 : 0 : RemoveFromWaitQueue(MyProc, LockTagHashCode(&(MyProc->waitLock->tag)));
1848 : :
1849 : : /*
1850 : : * We're done here. Transaction abort caused by the error that
1851 : : * ProcSleep will raise will cause any other locks we hold to be
1852 : : * released, thus allowing other processes to wake up; we don't need
1853 : : * to do that here. NOTE: an exception is that releasing locks we
1854 : : * hold doesn't consider the possibility of waiters that were blocked
1855 : : * behind us on the lock we just failed to get, and might now be
1856 : : * wakable because we're not in front of them anymore. However,
1857 : : * RemoveFromWaitQueue took care of waking up any such processes.
1858 : : */
1859 : 0 : }
1860 : :
1861 : : /*
1862 : : * And release locks. We do this in reverse order for two reasons: (1)
1863 : : * Anyone else who needs more than one of the locks will be trying to lock
1864 : : * them in increasing order; we don't want to release the other process
1865 : : * until it can get all the locks it needs. (2) This avoids O(N^2)
1866 : : * behavior inside LWLockRelease.
1867 : : */
1868 : : check_done:
1869 [ + + ]: 34 : for (i = NUM_LOCK_PARTITIONS; --i >= 0;)
1870 : 32 : LWLockRelease(LockHashPartitionLockByIndex(i));
1871 : 2 : }
1872 : :
1873 : : /*
1874 : : * CheckDeadLockAlert - Handle the expiry of deadlock_timeout.
1875 : : *
1876 : : * NB: Runs inside a signal handler, be careful.
1877 : : */
1878 : : void
1879 : 2 : CheckDeadLockAlert(void)
1880 : : {
1881 : 2 : int save_errno = errno;
1882 : :
1883 : 2 : got_deadlock_timeout = true;
1884 : :
1885 : : /*
1886 : : * Have to set the latch again, even if handle_sig_alarm already did. Back
1887 : : * then got_deadlock_timeout wasn't yet set... It's unlikely that this
1888 : : * ever would be a problem, but setting a set latch again is cheap.
1889 : : *
1890 : : * Note that, when this function runs inside procsignal_sigusr1_handler(),
1891 : : * the handler function sets the latch again after the latch is set here.
1892 : : */
1893 : 2 : SetLatch(MyLatch);
1894 : 2 : errno = save_errno;
1895 : 2 : }
1896 : :
1897 : : /*
1898 : : * GetLockHoldersAndWaiters - get lock holders and waiters for a lock
1899 : : *
1900 : : * Fill lock_holders_sbuf and lock_waiters_sbuf with the PIDs of processes holding
1901 : : * and waiting for the lock, and set lockHoldersNum to the number of lock holders.
1902 : : *
1903 : : * The lock table's partition lock must be held on entry and remains held on exit.
1904 : : */
1905 : : void
1906 : 4 : GetLockHoldersAndWaiters(LOCALLOCK *locallock, StringInfo lock_holders_sbuf,
1907 : : StringInfo lock_waiters_sbuf, int *lockHoldersNum)
1908 : : {
1909 : 4 : dlist_iter proc_iter;
1910 : 4 : PROCLOCK *curproclock;
1911 : 4 : LOCK *lock = locallock->lock;
1912 : 4 : bool first_holder = true,
1913 : 4 : first_waiter = true;
1914 : :
1915 : : #ifdef USE_ASSERT_CHECKING
1916 : : {
1917 : 4 : uint32 hashcode = locallock->hashcode;
1918 : 4 : LWLock *partitionLock = LockHashPartitionLock(hashcode);
1919 : :
1920 [ + - ]: 4 : Assert(LWLockHeldByMe(partitionLock));
1921 : 4 : }
1922 : : #endif
1923 : :
1924 : 4 : *lockHoldersNum = 0;
1925 : :
1926 : : /*
1927 : : * Loop over the lock's procLocks to gather a list of all holders and
1928 : : * waiters. Thus we will be able to provide more detailed information for
1929 : : * lock debugging purposes.
1930 : : *
1931 : : * lock->procLocks contains all processes which hold or wait for this
1932 : : * lock.
1933 : : */
1934 [ + - + + ]: 14 : dlist_foreach(proc_iter, &lock->procLocks)
1935 : : {
1936 : 10 : curproclock =
1937 : 10 : dlist_container(PROCLOCK, lockLink, proc_iter.cur);
1938 : :
1939 : : /*
1940 : : * We are a waiter if myProc->waitProcLock == curproclock; we are a
1941 : : * holder if it is NULL or something different.
1942 : : */
1943 [ + + ]: 10 : if (curproclock->tag.myProc->waitProcLock == curproclock)
1944 : : {
1945 [ + + ]: 4 : if (first_waiter)
1946 : : {
1947 : 4 : appendStringInfo(lock_waiters_sbuf, "%d",
1948 : 2 : curproclock->tag.myProc->pid);
1949 : 2 : first_waiter = false;
1950 : 2 : }
1951 : : else
1952 : 4 : appendStringInfo(lock_waiters_sbuf, ", %d",
1953 : 2 : curproclock->tag.myProc->pid);
1954 : 4 : }
1955 : : else
1956 : : {
1957 [ + + ]: 6 : if (first_holder)
1958 : : {
1959 : 8 : appendStringInfo(lock_holders_sbuf, "%d",
1960 : 4 : curproclock->tag.myProc->pid);
1961 : 4 : first_holder = false;
1962 : 4 : }
1963 : : else
1964 : 4 : appendStringInfo(lock_holders_sbuf, ", %d",
1965 : 2 : curproclock->tag.myProc->pid);
1966 : :
1967 : 6 : (*lockHoldersNum)++;
1968 : : }
1969 : 10 : }
1970 : 4 : }
1971 : :
1972 : : /*
1973 : : * ProcWaitForSignal - wait for a signal from another backend.
1974 : : *
1975 : : * As this uses the generic process latch the caller has to be robust against
1976 : : * unrelated wakeups: Always check that the desired state has occurred, and
1977 : : * wait again if not.
1978 : : */
1979 : : void
1980 : 0 : ProcWaitForSignal(uint32 wait_event_info)
1981 : : {
1982 : 0 : (void) WaitLatch(MyLatch, WL_LATCH_SET | WL_EXIT_ON_PM_DEATH, 0,
1983 : 0 : wait_event_info);
1984 : 0 : ResetLatch(MyLatch);
1985 [ # # ]: 0 : CHECK_FOR_INTERRUPTS();
1986 : 0 : }
1987 : :
1988 : : /*
1989 : : * ProcSendSignal - set the latch of a backend identified by ProcNumber
1990 : : */
1991 : : void
1992 : 0 : ProcSendSignal(ProcNumber procNumber)
1993 : : {
1994 [ # # ]: 0 : if (procNumber < 0 || procNumber >= ProcGlobal->allProcCount)
1995 [ # # # # ]: 0 : elog(ERROR, "procNumber out of range");
1996 : :
1997 : 0 : SetLatch(&GetPGProcByNumber(procNumber)->procLatch);
1998 : 0 : }
1999 : :
2000 : : /*
2001 : : * BecomeLockGroupLeader - designate process as lock group leader
2002 : : *
2003 : : * Once this function has returned, other processes can join the lock group
2004 : : * by calling BecomeLockGroupMember.
2005 : : */
2006 : : void
2007 : 203 : BecomeLockGroupLeader(void)
2008 : : {
2009 : 203 : LWLock *leader_lwlock;
2010 : :
2011 : : /* If we already did it, we don't need to do it again. */
2012 [ + + ]: 203 : if (MyProc->lockGroupLeader == MyProc)
2013 : 181 : return;
2014 : :
2015 : : /* We had better not be a follower. */
2016 [ + - ]: 22 : Assert(MyProc->lockGroupLeader == NULL);
2017 : :
2018 : : /* Create single-member group, containing only ourselves. */
2019 : 22 : leader_lwlock = LockHashPartitionLockByProc(MyProc);
2020 : 22 : LWLockAcquire(leader_lwlock, LW_EXCLUSIVE);
2021 : 22 : MyProc->lockGroupLeader = MyProc;
2022 : 22 : dlist_push_head(&MyProc->lockGroupMembers, &MyProc->lockGroupLink);
2023 : 22 : LWLockRelease(leader_lwlock);
2024 [ - + ]: 203 : }
2025 : :
2026 : : /*
2027 : : * BecomeLockGroupMember - designate process as lock group member
2028 : : *
2029 : : * This is pretty straightforward except for the possibility that the leader
2030 : : * whose group we're trying to join might exit before we manage to do so;
2031 : : * and the PGPROC might get recycled for an unrelated process. To avoid
2032 : : * that, we require the caller to pass the PID of the intended PGPROC as
2033 : : * an interlock. Returns true if we successfully join the intended lock
2034 : : * group, and false if not.
2035 : : */
2036 : : bool
2037 : 477 : BecomeLockGroupMember(PGPROC *leader, int pid)
2038 : : {
2039 : 477 : LWLock *leader_lwlock;
2040 : 477 : bool ok = false;
2041 : :
2042 : : /* Group leader can't become member of group */
2043 [ + - ]: 477 : Assert(MyProc != leader);
2044 : :
2045 : : /* Can't already be a member of a group */
2046 [ + - ]: 477 : Assert(MyProc->lockGroupLeader == NULL);
2047 : :
2048 : : /* PID must be valid. */
2049 [ + - ]: 477 : Assert(pid != 0);
2050 : :
2051 : : /*
2052 : : * Get lock protecting the group fields. Note LockHashPartitionLockByProc
2053 : : * calculates the proc number based on the PGPROC slot without looking at
2054 : : * its contents, so we will acquire the correct lock even if the leader
2055 : : * PGPROC is in process of being recycled.
2056 : : */
2057 : 477 : leader_lwlock = LockHashPartitionLockByProc(leader);
2058 : 477 : LWLockAcquire(leader_lwlock, LW_EXCLUSIVE);
2059 : :
2060 : : /* Is this the leader we're looking for? */
2061 [ + - - + ]: 477 : if (leader->pid == pid && leader->lockGroupLeader == leader)
2062 : : {
2063 : : /* OK, join the group */
2064 : 477 : ok = true;
2065 : 477 : MyProc->lockGroupLeader = leader;
2066 : 477 : dlist_push_tail(&leader->lockGroupMembers, &MyProc->lockGroupLink);
2067 : 477 : }
2068 : 477 : LWLockRelease(leader_lwlock);
2069 : :
2070 : 954 : return ok;
2071 : 477 : }
|
