PostgreSQL Source Code  git master
deadlock.c File Reference
#include "postgres.h"
#include "miscadmin.h"
#include "pg_trace.h"
#include "pgstat.h"
#include "storage/lmgr.h"
#include "storage/proc.h"
#include "utils/memutils.h"
Include dependency graph for deadlock.c:

Go to the source code of this file.

Data Structures

struct  EDGE
 
struct  WAIT_ORDER
 
struct  DEADLOCK_INFO
 

Functions

static bool DeadLockCheckRecurse (PGPROC *proc)
 
static int TestConfiguration (PGPROC *startProc)
 
static bool FindLockCycle (PGPROC *checkProc, EDGE *softEdges, int *nSoftEdges)
 
static bool FindLockCycleRecurse (PGPROC *checkProc, int depth, EDGE *softEdges, int *nSoftEdges)
 
static bool FindLockCycleRecurseMember (PGPROC *checkProc, PGPROC *checkProcLeader, int depth, EDGE *softEdges, int *nSoftEdges)
 
static bool ExpandConstraints (EDGE *constraints, int nConstraints)
 
static bool TopoSort (LOCK *lock, EDGE *constraints, int nConstraints, PGPROC **ordering)
 
void InitDeadLockChecking (void)
 
DeadLockState DeadLockCheck (PGPROC *proc)
 
PGPROCGetBlockingAutoVacuumPgproc (void)
 
void DeadLockReport (void)
 
void RememberSimpleDeadLock (PGPROC *proc1, LOCKMODE lockmode, LOCK *lock, PGPROC *proc2)
 

Variables

static PGPROC ** visitedProcs
 
static int nVisitedProcs
 
static PGPROC ** topoProcs
 
static int * beforeConstraints
 
static int * afterConstraints
 
static WAIT_ORDERwaitOrders
 
static int nWaitOrders
 
static PGPROC ** waitOrderProcs
 
static EDGEcurConstraints
 
static int nCurConstraints
 
static int maxCurConstraints
 
static EDGEpossibleConstraints
 
static int nPossibleConstraints
 
static int maxPossibleConstraints
 
static DEADLOCK_INFOdeadlockDetails
 
static int nDeadlockDetails
 
static PGPROCblocking_autovacuum_proc = NULL
 

Function Documentation

◆ DeadLockCheck()

DeadLockState DeadLockCheck ( PGPROC proc)

Definition at line 217 of file deadlock.c.

References Assert, DeadLockCheckRecurse(), DS_BLOCKED_BY_AUTOVACUUM, DS_HARD_DEADLOCK, DS_NO_DEADLOCK, DS_SOFT_DEADLOCK, elog, FATAL, FindLockCycle(), GetLocksMethodTable(), i, PROC_QUEUE::links, PGPROC::links, WAIT_ORDER::lock, nCurConstraints, nPossibleConstraints, WAIT_ORDER::nProcs, nWaitOrders, ProcLockWakeup(), ProcQueueInit(), WAIT_ORDER::procs, SHMQueueInsertBefore(), PROC_QUEUE::size, and LOCK::waitProcs.

Referenced by CheckDeadLock().

218 {
219  int i,
220  j;
221 
222  /* Initialize to "no constraints" */
223  nCurConstraints = 0;
225  nWaitOrders = 0;
226 
227  /* Initialize to not blocked by an autovacuum worker */
229 
230  /* Search for deadlocks and possible fixes */
231  if (DeadLockCheckRecurse(proc))
232  {
233  /*
234  * Call FindLockCycle one more time, to record the correct
235  * deadlockDetails[] for the basic state with no rearrangements.
236  */
237  int nSoftEdges;
238 
239  TRACE_POSTGRESQL_DEADLOCK_FOUND();
240 
241  nWaitOrders = 0;
242  if (!FindLockCycle(proc, possibleConstraints, &nSoftEdges))
243  elog(FATAL, "deadlock seems to have disappeared");
244 
245  return DS_HARD_DEADLOCK; /* cannot find a non-deadlocked state */
246  }
247 
248  /* Apply any needed rearrangements of wait queues */
249  for (i = 0; i < nWaitOrders; i++)
250  {
251  LOCK *lock = waitOrders[i].lock;
252  PGPROC **procs = waitOrders[i].procs;
253  int nProcs = waitOrders[i].nProcs;
254  PROC_QUEUE *waitQueue = &(lock->waitProcs);
255 
256  Assert(nProcs == waitQueue->size);
257 
258 #ifdef DEBUG_DEADLOCK
259  PrintLockQueue(lock, "DeadLockCheck:");
260 #endif
261 
262  /* Reset the queue and re-add procs in the desired order */
263  ProcQueueInit(waitQueue);
264  for (j = 0; j < nProcs; j++)
265  {
266  SHMQueueInsertBefore(&(waitQueue->links), &(procs[j]->links));
267  waitQueue->size++;
268  }
269 
270 #ifdef DEBUG_DEADLOCK
271  PrintLockQueue(lock, "rearranged to:");
272 #endif
273 
274  /* See if any waiters for the lock can be woken up now */
275  ProcLockWakeup(GetLocksMethodTable(lock), lock);
276  }
277 
278  /* Return code tells caller if we had to escape a deadlock or not */
279  if (nWaitOrders > 0)
280  return DS_SOFT_DEADLOCK;
281  else if (blocking_autovacuum_proc != NULL)
283  else
284  return DS_NO_DEADLOCK;
285 }
static WAIT_ORDER * waitOrders
Definition: deadlock.c:111
SHM_QUEUE links
Definition: lock.h:31
SHM_QUEUE links
Definition: proc.h:115
static PGPROC * blocking_autovacuum_proc
Definition: deadlock.c:128
void SHMQueueInsertBefore(SHM_QUEUE *queue, SHM_QUEUE *elem)
Definition: shmqueue.c:89
static int nCurConstraints
Definition: deadlock.c:117
static int nPossibleConstraints
Definition: deadlock.c:122
int nProcs
Definition: deadlock.c:60
PROC_QUEUE waitProcs
Definition: lock.h:306
LOCK * lock
Definition: deadlock.c:58
static bool FindLockCycle(PGPROC *checkProc, EDGE *softEdges, int *nSoftEdges)
Definition: deadlock.c:449
PGPROC ** procs
Definition: deadlock.c:59
#define FATAL
Definition: elog.h:52
void ProcQueueInit(PROC_QUEUE *queue)
Definition: proc.c:1033
Definition: lock.h:297
void ProcLockWakeup(LockMethod lockMethodTable, LOCK *lock)
Definition: proc.c:1628
#define Assert(condition)
Definition: c.h:746
static EDGE * possibleConstraints
Definition: deadlock.c:121
static bool DeadLockCheckRecurse(PGPROC *proc)
Definition: deadlock.c:315
#define elog(elevel,...)
Definition: elog.h:214
int i
int size
Definition: lock.h:32
static int nWaitOrders
Definition: deadlock.c:112
Definition: proc.h:112
LockMethod GetLocksMethodTable(const LOCK *lock)
Definition: lock.c:487

◆ DeadLockCheckRecurse()

static bool DeadLockCheckRecurse ( PGPROC proc)
static

Definition at line 315 of file deadlock.c.

References elog, FATAL, i, MaxBackends, maxCurConstraints, maxPossibleConstraints, nCurConstraints, nPossibleConstraints, and TestConfiguration().

Referenced by DeadLockCheck().

316 {
317  int nEdges;
318  int oldPossibleConstraints;
319  bool savedList;
320  int i;
321 
322  nEdges = TestConfiguration(proc);
323  if (nEdges < 0)
324  return true; /* hard deadlock --- no solution */
325  if (nEdges == 0)
326  return false; /* good configuration found */
328  return true; /* out of room for active constraints? */
329  oldPossibleConstraints = nPossibleConstraints;
331  {
332  /* We can save the edge list in possibleConstraints[] */
333  nPossibleConstraints += nEdges;
334  savedList = true;
335  }
336  else
337  {
338  /* Not room; will need to regenerate the edges on-the-fly */
339  savedList = false;
340  }
341 
342  /*
343  * Try each available soft edge as an addition to the configuration.
344  */
345  for (i = 0; i < nEdges; i++)
346  {
347  if (!savedList && i > 0)
348  {
349  /* Regenerate the list of possible added constraints */
350  if (nEdges != TestConfiguration(proc))
351  elog(FATAL, "inconsistent results during deadlock check");
352  }
354  possibleConstraints[oldPossibleConstraints + i];
355  nCurConstraints++;
356  if (!DeadLockCheckRecurse(proc))
357  return false; /* found a valid solution! */
358  /* give up on that added constraint, try again */
359  nCurConstraints--;
360  }
361  nPossibleConstraints = oldPossibleConstraints;
362  return true; /* no solution found */
363 }
static int maxCurConstraints
Definition: deadlock.c:118
static int nCurConstraints
Definition: deadlock.c:117
static int nPossibleConstraints
Definition: deadlock.c:122
#define FATAL
Definition: elog.h:52
int MaxBackends
Definition: globals.c:136
static int TestConfiguration(PGPROC *startProc)
Definition: deadlock.c:381
static EDGE * curConstraints
Definition: deadlock.c:116
static EDGE * possibleConstraints
Definition: deadlock.c:121
static bool DeadLockCheckRecurse(PGPROC *proc)
Definition: deadlock.c:315
#define elog(elevel,...)
Definition: elog.h:214
int i
static int maxPossibleConstraints
Definition: deadlock.c:123

◆ DeadLockReport()

void DeadLockReport ( void  )

Definition at line 1090 of file deadlock.c.

References _, appendBinaryStringInfo(), appendStringInfo(), appendStringInfoChar(), StringInfoData::data, DescribeLockTag(), ereport, errcode(), errdetail_internal(), errdetail_log(), errhint(), errmsg(), ERROR, GetLockmodeName(), i, initStringInfo(), StringInfoData::len, DEADLOCK_INFO::lockmode, DEADLOCK_INFO::locktag, LOCKTAG::locktag_lockmethodid, nDeadlockDetails, pgstat_get_backend_current_activity(), pgstat_report_deadlock(), DEADLOCK_INFO::pid, and resetStringInfo().

Referenced by WaitOnLock().

1091 {
1092  StringInfoData clientbuf; /* errdetail for client */
1093  StringInfoData logbuf; /* errdetail for server log */
1094  StringInfoData locktagbuf;
1095  int i;
1096 
1097  initStringInfo(&clientbuf);
1098  initStringInfo(&logbuf);
1099  initStringInfo(&locktagbuf);
1100 
1101  /* Generate the "waits for" lines sent to the client */
1102  for (i = 0; i < nDeadlockDetails; i++)
1103  {
1104  DEADLOCK_INFO *info = &deadlockDetails[i];
1105  int nextpid;
1106 
1107  /* The last proc waits for the first one... */
1108  if (i < nDeadlockDetails - 1)
1109  nextpid = info[1].pid;
1110  else
1111  nextpid = deadlockDetails[0].pid;
1112 
1113  /* reset locktagbuf to hold next object description */
1114  resetStringInfo(&locktagbuf);
1115 
1116  DescribeLockTag(&locktagbuf, &info->locktag);
1117 
1118  if (i > 0)
1119  appendStringInfoChar(&clientbuf, '\n');
1120 
1121  appendStringInfo(&clientbuf,
1122  _("Process %d waits for %s on %s; blocked by process %d."),
1123  info->pid,
1125  info->lockmode),
1126  locktagbuf.data,
1127  nextpid);
1128  }
1129 
1130  /* Duplicate all the above for the server ... */
1131  appendBinaryStringInfo(&logbuf, clientbuf.data, clientbuf.len);
1132 
1133  /* ... and add info about query strings */
1134  for (i = 0; i < nDeadlockDetails; i++)
1135  {
1136  DEADLOCK_INFO *info = &deadlockDetails[i];
1137 
1138  appendStringInfoChar(&logbuf, '\n');
1139 
1140  appendStringInfo(&logbuf,
1141  _("Process %d: %s"),
1142  info->pid,
1144  }
1145 
1147 
1148  ereport(ERROR,
1149  (errcode(ERRCODE_T_R_DEADLOCK_DETECTED),
1150  errmsg("deadlock detected"),
1151  errdetail_internal("%s", clientbuf.data),
1152  errdetail_log("%s", logbuf.data),
1153  errhint("See server log for query details.")));
1154 }
void pgstat_report_deadlock(void)
Definition: pgstat.c:1635
int errhint(const char *fmt,...)
Definition: elog.c:1068
const char * GetLockmodeName(LOCKMETHODID lockmethodid, LOCKMODE mode)
Definition: lock.c:4015
LOCKMODE lockmode
Definition: deadlock.c:74
int errcode(int sqlerrcode)
Definition: elog.c:610
int errdetail_internal(const char *fmt,...)
Definition: elog.c:981
void appendStringInfo(StringInfo str, const char *fmt,...)
Definition: stringinfo.c:91
#define ERROR
Definition: elog.h:43
void DescribeLockTag(StringInfo buf, const LOCKTAG *tag)
Definition: lmgr.c:1100
static int nDeadlockDetails
Definition: deadlock.c:125
void resetStringInfo(StringInfo str)
Definition: stringinfo.c:75
int errdetail_log(const char *fmt,...)
Definition: elog.c:1002
const char * pgstat_get_backend_current_activity(int pid, bool checkUser)
Definition: pgstat.c:4327
void appendStringInfoChar(StringInfo str, char ch)
Definition: stringinfo.c:188
void initStringInfo(StringInfo str)
Definition: stringinfo.c:59
#define ereport(elevel,...)
Definition: elog.h:144
static DEADLOCK_INFO * deadlockDetails
Definition: deadlock.c:124
uint8 locktag_lockmethodid
Definition: lock.h:171
int errmsg(const char *fmt,...)
Definition: elog.c:821
int i
LOCKTAG locktag
Definition: deadlock.c:73
#define _(x)
Definition: elog.c:88
void appendBinaryStringInfo(StringInfo str, const char *data, int datalen)
Definition: stringinfo.c:227

◆ ExpandConstraints()

static bool ExpandConstraints ( EDGE constraints,
int  nConstraints 
)
static

Definition at line 806 of file deadlock.c.

References Assert, i, EDGE::lock, WAIT_ORDER::lock, MaxBackends, WAIT_ORDER::nProcs, nWaitOrders, WAIT_ORDER::procs, PROC_QUEUE::size, TopoSort(), and LOCK::waitProcs.

Referenced by TestConfiguration().

808 {
809  int nWaitOrderProcs = 0;
810  int i,
811  j;
812 
813  nWaitOrders = 0;
814 
815  /*
816  * Scan constraint list backwards. This is because the last-added
817  * constraint is the only one that could fail, and so we want to test it
818  * for inconsistency first.
819  */
820  for (i = nConstraints; --i >= 0;)
821  {
822  LOCK *lock = constraints[i].lock;
823 
824  /* Did we already make a list for this lock? */
825  for (j = nWaitOrders; --j >= 0;)
826  {
827  if (waitOrders[j].lock == lock)
828  break;
829  }
830  if (j >= 0)
831  continue;
832  /* No, so allocate a new list */
833  waitOrders[nWaitOrders].lock = lock;
834  waitOrders[nWaitOrders].procs = waitOrderProcs + nWaitOrderProcs;
836  nWaitOrderProcs += lock->waitProcs.size;
837  Assert(nWaitOrderProcs <= MaxBackends);
838 
839  /*
840  * Do the topo sort. TopoSort need not examine constraints after this
841  * one, since they must be for different locks.
842  */
843  if (!TopoSort(lock, constraints, i + 1,
844  waitOrders[nWaitOrders].procs))
845  return false;
846  nWaitOrders++;
847  }
848  return true;
849 }
LOCK * lock
Definition: deadlock.c:50
static WAIT_ORDER * waitOrders
Definition: deadlock.c:111
int nProcs
Definition: deadlock.c:60
static PGPROC ** waitOrderProcs
Definition: deadlock.c:113
PROC_QUEUE waitProcs
Definition: lock.h:306
LOCK * lock
Definition: deadlock.c:58
PGPROC ** procs
Definition: deadlock.c:59
int MaxBackends
Definition: globals.c:136
Definition: lock.h:297
static bool TopoSort(LOCK *lock, EDGE *constraints, int nConstraints, PGPROC **ordering)
Definition: deadlock.c:878
#define Assert(condition)
Definition: c.h:746
int i
int size
Definition: lock.h:32
static int nWaitOrders
Definition: deadlock.c:112

◆ FindLockCycle()

static bool FindLockCycle ( PGPROC checkProc,
EDGE softEdges,
int *  nSoftEdges 
)
static

Definition at line 449 of file deadlock.c.

References FindLockCycleRecurse(), nDeadlockDetails, and nVisitedProcs.

Referenced by DeadLockCheck(), and TestConfiguration().

452 {
453  nVisitedProcs = 0;
454  nDeadlockDetails = 0;
455  *nSoftEdges = 0;
456  return FindLockCycleRecurse(checkProc, 0, softEdges, nSoftEdges);
457 }
static int nDeadlockDetails
Definition: deadlock.c:125
static bool FindLockCycleRecurse(PGPROC *checkProc, int depth, EDGE *softEdges, int *nSoftEdges)
Definition: deadlock.c:460
static int nVisitedProcs
Definition: deadlock.c:103

◆ FindLockCycleRecurse()

static bool FindLockCycleRecurse ( PGPROC checkProc,
int  depth,
EDGE softEdges,
int *  nSoftEdges 
)
static

Definition at line 460 of file deadlock.c.

References Assert, dlist_iter::cur, dlist_container, dlist_foreach, FindLockCycleRecurseMember(), i, PGPROC::links, PGPROC::lockGroupLeader, PGPROC::lockGroupMembers, MaxBackends, nDeadlockDetails, SHM_QUEUE::next, nVisitedProcs, and PGPROC::waitLock.

Referenced by FindLockCycle(), and FindLockCycleRecurseMember().

464 {
465  int i;
466  dlist_iter iter;
467 
468  /*
469  * If this process is a lock group member, check the leader instead. (Note
470  * that we might be the leader, in which case this is a no-op.)
471  */
472  if (checkProc->lockGroupLeader != NULL)
473  checkProc = checkProc->lockGroupLeader;
474 
475  /*
476  * Have we already seen this proc?
477  */
478  for (i = 0; i < nVisitedProcs; i++)
479  {
480  if (visitedProcs[i] == checkProc)
481  {
482  /* If we return to starting point, we have a deadlock cycle */
483  if (i == 0)
484  {
485  /*
486  * record total length of cycle --- outer levels will now fill
487  * deadlockDetails[]
488  */
489  Assert(depth <= MaxBackends);
490  nDeadlockDetails = depth;
491 
492  return true;
493  }
494 
495  /*
496  * Otherwise, we have a cycle but it does not include the start
497  * point, so say "no deadlock".
498  */
499  return false;
500  }
501  }
502  /* Mark proc as seen */
503  Assert(nVisitedProcs < MaxBackends);
504  visitedProcs[nVisitedProcs++] = checkProc;
505 
506  /*
507  * If the process is waiting, there is an outgoing waits-for edge to each
508  * process that blocks it.
509  */
510  if (checkProc->links.next != NULL && checkProc->waitLock != NULL &&
511  FindLockCycleRecurseMember(checkProc, checkProc, depth, softEdges,
512  nSoftEdges))
513  return true;
514 
515  /*
516  * If the process is not waiting, there could still be outgoing waits-for
517  * edges if it is part of a lock group, because other members of the lock
518  * group might be waiting even though this process is not. (Given lock
519  * groups {A1, A2} and {B1, B2}, if A1 waits for B1 and B2 waits for A2,
520  * that is a deadlock even neither of B1 and A2 are waiting for anything.)
521  */
522  dlist_foreach(iter, &checkProc->lockGroupMembers)
523  {
524  PGPROC *memberProc;
525 
526  memberProc = dlist_container(PGPROC, lockGroupLink, iter.cur);
527 
528  if (memberProc->links.next != NULL && memberProc->waitLock != NULL &&
529  memberProc != checkProc &&
530  FindLockCycleRecurseMember(memberProc, checkProc, depth, softEdges,
531  nSoftEdges))
532  return true;
533  }
534 
535  return false;
536 }
dlist_head lockGroupMembers
Definition: proc.h:240
SHM_QUEUE links
Definition: proc.h:115
#define dlist_foreach(iter, lhead)
Definition: ilist.h:507
struct SHM_QUEUE * next
Definition: shmem.h:31
#define dlist_container(type, membername, ptr)
Definition: ilist.h:477
int MaxBackends
Definition: globals.c:136
static int nDeadlockDetails
Definition: deadlock.c:125
LOCK * waitLock
Definition: proc.h:170
static bool FindLockCycleRecurseMember(PGPROC *checkProc, PGPROC *checkProcLeader, int depth, EDGE *softEdges, int *nSoftEdges)
Definition: deadlock.c:539
dlist_node * cur
Definition: ilist.h:161
#define Assert(condition)
Definition: c.h:746
static PGPROC ** visitedProcs
Definition: deadlock.c:102
int i
static int nVisitedProcs
Definition: deadlock.c:103
Definition: proc.h:112
PGPROC * lockGroupLeader
Definition: proc.h:239

◆ FindLockCycleRecurseMember()

static bool FindLockCycleRecurseMember ( PGPROC checkProc,
PGPROC checkProcLeader,
int  depth,
EDGE softEdges,
int *  nSoftEdges 
)
static

Definition at line 539 of file deadlock.c.

References Assert, EDGE::blocker, LockMethodData::conflictTab, FindLockCycleRecurse(), GetLocksMethodTable(), PROCLOCK::holdMask, i, PROC_QUEUE::links, PGPROC::links, EDGE::lock, LOCK_LOCKTAG, LOCKBIT_ON, PGPROC::lockGroupLeader, PROCLOCK::lockLink, DEADLOCK_INFO::lockmode, DEADLOCK_INFO::locktag, LOCKTAG_PAGE, LOCKTAG_RELATION_EXTEND, MaxBackends, MyProc, PROCLOCKTAG::myProc, SHM_QUEUE::next, WAIT_ORDER::nProcs, LockMethodData::numLockModes, nWaitOrders, offsetof, DEADLOCK_INFO::pid, PGPROC::pid, PROC_IS_AUTOVACUUM, LOCK::procLocks, WAIT_ORDER::procs, SHMQueueNext(), PROC_QUEUE::size, LOCK::tag, PROCLOCK::tag, PGPROC::vacuumFlags, EDGE::waiter, PGPROC::waitLock, PGPROC::waitLockMode, and LOCK::waitProcs.

Referenced by FindLockCycleRecurse().

544 {
545  PGPROC *proc;
546  LOCK *lock = checkProc->waitLock;
547  PROCLOCK *proclock;
548  SHM_QUEUE *procLocks;
549  LockMethod lockMethodTable;
550  PROC_QUEUE *waitQueue;
551  int queue_size;
552  int conflictMask;
553  int i;
554  int numLockModes,
555  lm;
556 
557  /*
558  * The relation extension or page lock can never participate in actual
559  * deadlock cycle. See Asserts in LockAcquireExtended. So, there is no
560  * advantage in checking wait edges from them.
561  */
562  if (LOCK_LOCKTAG(*lock) == LOCKTAG_RELATION_EXTEND ||
563  (LOCK_LOCKTAG(*lock) == LOCKTAG_PAGE))
564  return false;
565 
566  lockMethodTable = GetLocksMethodTable(lock);
567  numLockModes = lockMethodTable->numLockModes;
568  conflictMask = lockMethodTable->conflictTab[checkProc->waitLockMode];
569 
570  /*
571  * Scan for procs that already hold conflicting locks. These are "hard"
572  * edges in the waits-for graph.
573  */
574  procLocks = &(lock->procLocks);
575 
576  proclock = (PROCLOCK *) SHMQueueNext(procLocks, procLocks,
577  offsetof(PROCLOCK, lockLink));
578 
579  while (proclock)
580  {
581  PGPROC *leader;
582 
583  proc = proclock->tag.myProc;
584  leader = proc->lockGroupLeader == NULL ? proc : proc->lockGroupLeader;
585 
586  /* A proc never blocks itself or any other lock group member */
587  if (leader != checkProcLeader)
588  {
589  for (lm = 1; lm <= numLockModes; lm++)
590  {
591  if ((proclock->holdMask & LOCKBIT_ON(lm)) &&
592  (conflictMask & LOCKBIT_ON(lm)))
593  {
594  /* This proc hard-blocks checkProc */
595  if (FindLockCycleRecurse(proc, depth + 1,
596  softEdges, nSoftEdges))
597  {
598  /* fill deadlockDetails[] */
599  DEADLOCK_INFO *info = &deadlockDetails[depth];
600 
601  info->locktag = lock->tag;
602  info->lockmode = checkProc->waitLockMode;
603  info->pid = checkProc->pid;
604 
605  return true;
606  }
607 
608  /*
609  * No deadlock here, but see if this proc is an autovacuum
610  * that is directly hard-blocking our own proc. If so,
611  * report it so that the caller can send a cancel signal
612  * to it, if appropriate. If there's more than one such
613  * proc, it's indeterminate which one will be reported.
614  *
615  * We don't touch autovacuums that are indirectly blocking
616  * us; it's up to the direct blockee to take action. This
617  * rule simplifies understanding the behavior and ensures
618  * that an autovacuum won't be canceled with less than
619  * deadlock_timeout grace period.
620  *
621  * Note we read vacuumFlags without any locking. This is
622  * OK only for checking the PROC_IS_AUTOVACUUM flag,
623  * because that flag is set at process start and never
624  * reset. There is logic elsewhere to avoid canceling an
625  * autovacuum that is working to prevent XID wraparound
626  * problems (which needs to read a different vacuumFlag
627  * bit), but we don't do that here to avoid grabbing
628  * ProcArrayLock.
629  */
630  if (checkProc == MyProc &&
633 
634  /* We're done looking at this proclock */
635  break;
636  }
637  }
638  }
639 
640  proclock = (PROCLOCK *) SHMQueueNext(procLocks, &proclock->lockLink,
641  offsetof(PROCLOCK, lockLink));
642  }
643 
644  /*
645  * Scan for procs that are ahead of this one in the lock's wait queue.
646  * Those that have conflicting requests soft-block this one. This must be
647  * done after the hard-block search, since if another proc both hard- and
648  * soft-blocks this one, we want to call it a hard edge.
649  *
650  * If there is a proposed re-ordering of the lock's wait order, use that
651  * rather than the current wait order.
652  */
653  for (i = 0; i < nWaitOrders; i++)
654  {
655  if (waitOrders[i].lock == lock)
656  break;
657  }
658 
659  if (i < nWaitOrders)
660  {
661  /* Use the given hypothetical wait queue order */
662  PGPROC **procs = waitOrders[i].procs;
663 
664  queue_size = waitOrders[i].nProcs;
665 
666  for (i = 0; i < queue_size; i++)
667  {
668  PGPROC *leader;
669 
670  proc = procs[i];
671  leader = proc->lockGroupLeader == NULL ? proc :
672  proc->lockGroupLeader;
673 
674  /*
675  * TopoSort will always return an ordering with group members
676  * adjacent to each other in the wait queue (see comments
677  * therein). So, as soon as we reach a process in the same lock
678  * group as checkProc, we know we've found all the conflicts that
679  * precede any member of the lock group lead by checkProcLeader.
680  */
681  if (leader == checkProcLeader)
682  break;
683 
684  /* Is there a conflict with this guy's request? */
685  if ((LOCKBIT_ON(proc->waitLockMode) & conflictMask) != 0)
686  {
687  /* This proc soft-blocks checkProc */
688  if (FindLockCycleRecurse(proc, depth + 1,
689  softEdges, nSoftEdges))
690  {
691  /* fill deadlockDetails[] */
692  DEADLOCK_INFO *info = &deadlockDetails[depth];
693 
694  info->locktag = lock->tag;
695  info->lockmode = checkProc->waitLockMode;
696  info->pid = checkProc->pid;
697 
698  /*
699  * Add this edge to the list of soft edges in the cycle
700  */
701  Assert(*nSoftEdges < MaxBackends);
702  softEdges[*nSoftEdges].waiter = checkProcLeader;
703  softEdges[*nSoftEdges].blocker = leader;
704  softEdges[*nSoftEdges].lock = lock;
705  (*nSoftEdges)++;
706  return true;
707  }
708  }
709  }
710  }
711  else
712  {
713  PGPROC *lastGroupMember = NULL;
714 
715  /* Use the true lock wait queue order */
716  waitQueue = &(lock->waitProcs);
717 
718  /*
719  * Find the last member of the lock group that is present in the wait
720  * queue. Anything after this is not a soft lock conflict. If group
721  * locking is not in use, then we know immediately which process we're
722  * looking for, but otherwise we've got to search the wait queue to
723  * find the last process actually present.
724  */
725  if (checkProc->lockGroupLeader == NULL)
726  lastGroupMember = checkProc;
727  else
728  {
729  proc = (PGPROC *) waitQueue->links.next;
730  queue_size = waitQueue->size;
731  while (queue_size-- > 0)
732  {
733  if (proc->lockGroupLeader == checkProcLeader)
734  lastGroupMember = proc;
735  proc = (PGPROC *) proc->links.next;
736  }
737  Assert(lastGroupMember != NULL);
738  }
739 
740  /*
741  * OK, now rescan (or scan) the queue to identify the soft conflicts.
742  */
743  queue_size = waitQueue->size;
744  proc = (PGPROC *) waitQueue->links.next;
745  while (queue_size-- > 0)
746  {
747  PGPROC *leader;
748 
749  leader = proc->lockGroupLeader == NULL ? proc :
750  proc->lockGroupLeader;
751 
752  /* Done when we reach the target proc */
753  if (proc == lastGroupMember)
754  break;
755 
756  /* Is there a conflict with this guy's request? */
757  if ((LOCKBIT_ON(proc->waitLockMode) & conflictMask) != 0 &&
758  leader != checkProcLeader)
759  {
760  /* This proc soft-blocks checkProc */
761  if (FindLockCycleRecurse(proc, depth + 1,
762  softEdges, nSoftEdges))
763  {
764  /* fill deadlockDetails[] */
765  DEADLOCK_INFO *info = &deadlockDetails[depth];
766 
767  info->locktag = lock->tag;
768  info->lockmode = checkProc->waitLockMode;
769  info->pid = checkProc->pid;
770 
771  /*
772  * Add this edge to the list of soft edges in the cycle
773  */
774  Assert(*nSoftEdges < MaxBackends);
775  softEdges[*nSoftEdges].waiter = checkProcLeader;
776  softEdges[*nSoftEdges].blocker = leader;
777  softEdges[*nSoftEdges].lock = lock;
778  (*nSoftEdges)++;
779  return true;
780  }
781  }
782 
783  proc = (PGPROC *) proc->links.next;
784  }
785  }
786 
787  /*
788  * No conflict detected here.
789  */
790  return false;
791 }
PROCLOCKTAG tag
Definition: lock.h:361
LOCK * lock
Definition: deadlock.c:50
LOCKMODE lockmode
Definition: deadlock.c:74
static WAIT_ORDER * waitOrders
Definition: deadlock.c:111
SHM_QUEUE links
Definition: lock.h:31
PGPROC * MyProc
Definition: proc.c:67
LOCKMASK holdMask
Definition: lock.h:365
SHM_QUEUE links
Definition: proc.h:115
static PGPROC * blocking_autovacuum_proc
Definition: deadlock.c:128
struct SHM_QUEUE * next
Definition: shmem.h:31
PGPROC * waiter
Definition: deadlock.c:48
LOCKMODE waitLockMode
Definition: proc.h:172
LOCKTAG tag
Definition: lock.h:300
const LOCKMASK * conflictTab
Definition: lock.h:113
SHM_QUEUE lockLink
Definition: lock.h:367
int nProcs
Definition: deadlock.c:60
PROC_QUEUE waitProcs
Definition: lock.h:306
PGPROC * blocker
Definition: deadlock.c:49
#define LOCK_LOCKTAG(lock)
Definition: lock.h:314
PGPROC ** procs
Definition: deadlock.c:59
int MaxBackends
Definition: globals.c:136
Definition: lock.h:297
LOCK * waitLock
Definition: proc.h:170
SHM_QUEUE procLocks
Definition: lock.h:305
Pointer SHMQueueNext(const SHM_QUEUE *queue, const SHM_QUEUE *curElem, Size linkOffset)
Definition: shmqueue.c:145
#define Assert(condition)
Definition: c.h:746
static DEADLOCK_INFO * deadlockDetails
Definition: deadlock.c:124
static bool FindLockCycleRecurse(PGPROC *checkProc, int depth, EDGE *softEdges, int *nSoftEdges)
Definition: deadlock.c:460
PGPROC * myProc
Definition: lock.h:355
#define LOCKBIT_ON(lockmode)
Definition: lock.h:86
Definition: lock.h:358
int i
int size
Definition: lock.h:32
static int nWaitOrders
Definition: deadlock.c:112
LOCKTAG locktag
Definition: deadlock.c:73
uint8 vacuumFlags
Definition: proc.h:178
Definition: proc.h:112
int pid
Definition: proc.h:137
LockMethod GetLocksMethodTable(const LOCK *lock)
Definition: lock.c:487
PGPROC * lockGroupLeader
Definition: proc.h:239
#define PROC_IS_AUTOVACUUM
Definition: proc.h:54
#define offsetof(type, field)
Definition: c.h:669
int numLockModes
Definition: lock.h:112

◆ GetBlockingAutoVacuumPgproc()

PGPROC* GetBlockingAutoVacuumPgproc ( void  )

Definition at line 293 of file deadlock.c.

References blocking_autovacuum_proc.

Referenced by ProcSleep().

294 {
295  PGPROC *ptr;
296 
299 
300  return ptr;
301 }
static PGPROC * blocking_autovacuum_proc
Definition: deadlock.c:128
Definition: proc.h:112

◆ InitDeadLockChecking()

void InitDeadLockChecking ( void  )

Definition at line 143 of file deadlock.c.

References afterConstraints, beforeConstraints, MaxBackends, maxCurConstraints, maxPossibleConstraints, MemoryContextSwitchTo(), palloc(), TopMemoryContext, and visitedProcs.

Referenced by InitProcess().

144 {
145  MemoryContext oldcxt;
146 
147  /* Make sure allocations are permanent */
149 
150  /*
151  * FindLockCycle needs at most MaxBackends entries in visitedProcs[] and
152  * deadlockDetails[].
153  */
154  visitedProcs = (PGPROC **) palloc(MaxBackends * sizeof(PGPROC *));
156 
157  /*
158  * TopoSort needs to consider at most MaxBackends wait-queue entries, and
159  * it needn't run concurrently with FindLockCycle.
160  */
161  topoProcs = visitedProcs; /* re-use this space */
162  beforeConstraints = (int *) palloc(MaxBackends * sizeof(int));
163  afterConstraints = (int *) palloc(MaxBackends * sizeof(int));
164 
165  /*
166  * We need to consider rearranging at most MaxBackends/2 wait queues
167  * (since it takes at least two waiters in a queue to create a soft edge),
168  * and the expanded form of the wait queues can't involve more than
169  * MaxBackends total waiters.
170  */
171  waitOrders = (WAIT_ORDER *)
172  palloc((MaxBackends / 2) * sizeof(WAIT_ORDER));
173  waitOrderProcs = (PGPROC **) palloc(MaxBackends * sizeof(PGPROC *));
174 
175  /*
176  * Allow at most MaxBackends distinct constraints in a configuration. (Is
177  * this enough? In practice it seems it should be, but I don't quite see
178  * how to prove it. If we run out, we might fail to find a workable wait
179  * queue rearrangement even though one exists.) NOTE that this number
180  * limits the maximum recursion depth of DeadLockCheckRecurse. Making it
181  * really big might potentially allow a stack-overflow problem.
182  */
185 
186  /*
187  * Allow up to 3*MaxBackends constraints to be saved without having to
188  * re-run TestConfiguration. (This is probably more than enough, but we
189  * can survive if we run low on space by doing excess runs of
190  * TestConfiguration to re-compute constraint lists each time needed.) The
191  * last MaxBackends entries in possibleConstraints[] are reserved as
192  * output workspace for FindLockCycle.
193  */
196  (EDGE *) palloc(maxPossibleConstraints * sizeof(EDGE));
197 
198  MemoryContextSwitchTo(oldcxt);
199 }
static int maxCurConstraints
Definition: deadlock.c:118
static WAIT_ORDER * waitOrders
Definition: deadlock.c:111
Definition: deadlock.c:46
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
static PGPROC ** waitOrderProcs
Definition: deadlock.c:113
static PGPROC ** topoProcs
Definition: deadlock.c:106
int MaxBackends
Definition: globals.c:136
static EDGE * curConstraints
Definition: deadlock.c:116
MemoryContext TopMemoryContext
Definition: mcxt.c:44
static int * afterConstraints
Definition: deadlock.c:108
static DEADLOCK_INFO * deadlockDetails
Definition: deadlock.c:124
static PGPROC ** visitedProcs
Definition: deadlock.c:102
static EDGE * possibleConstraints
Definition: deadlock.c:121
void * palloc(Size size)
Definition: mcxt.c:950
static int maxPossibleConstraints
Definition: deadlock.c:123
static int * beforeConstraints
Definition: deadlock.c:107
Definition: proc.h:112

◆ RememberSimpleDeadLock()

void RememberSimpleDeadLock ( PGPROC proc1,
LOCKMODE  lockmode,
LOCK lock,
PGPROC proc2 
)

Definition at line 1162 of file deadlock.c.

References DEADLOCK_INFO::lockmode, DEADLOCK_INFO::locktag, nDeadlockDetails, DEADLOCK_INFO::pid, PGPROC::pid, LOCK::tag, PGPROC::waitLock, and PGPROC::waitLockMode.

Referenced by ProcSleep().

1166 {
1167  DEADLOCK_INFO *info = &deadlockDetails[0];
1168 
1169  info->locktag = lock->tag;
1170  info->lockmode = lockmode;
1171  info->pid = proc1->pid;
1172  info++;
1173  info->locktag = proc2->waitLock->tag;
1174  info->lockmode = proc2->waitLockMode;
1175  info->pid = proc2->pid;
1176  nDeadlockDetails = 2;
1177 }
LOCKMODE lockmode
Definition: deadlock.c:74
LOCKMODE waitLockMode
Definition: proc.h:172
LOCKTAG tag
Definition: lock.h:300
static int nDeadlockDetails
Definition: deadlock.c:125
LOCK * waitLock
Definition: proc.h:170
static DEADLOCK_INFO * deadlockDetails
Definition: deadlock.c:124
LOCKTAG locktag
Definition: deadlock.c:73
int pid
Definition: proc.h:137

◆ TestConfiguration()

static int TestConfiguration ( PGPROC startProc)
static

Definition at line 381 of file deadlock.c.

References ExpandConstraints(), FindLockCycle(), i, MaxBackends, maxPossibleConstraints, nCurConstraints, and nPossibleConstraints.

Referenced by DeadLockCheckRecurse().

382 {
383  int softFound = 0;
385  int nSoftEdges;
386  int i;
387 
388  /*
389  * Make sure we have room for FindLockCycle's output.
390  */
391  if (nPossibleConstraints + MaxBackends > maxPossibleConstraints)
392  return -1;
393 
394  /*
395  * Expand current constraint set into wait orderings. Fail if the
396  * constraint set is not self-consistent.
397  */
399  return -1;
400 
401  /*
402  * Check for cycles involving startProc or any of the procs mentioned in
403  * constraints. We check startProc last because if it has a soft cycle
404  * still to be dealt with, we want to deal with that first.
405  */
406  for (i = 0; i < nCurConstraints; i++)
407  {
408  if (FindLockCycle(curConstraints[i].waiter, softEdges, &nSoftEdges))
409  {
410  if (nSoftEdges == 0)
411  return -1; /* hard deadlock detected */
412  softFound = nSoftEdges;
413  }
414  if (FindLockCycle(curConstraints[i].blocker, softEdges, &nSoftEdges))
415  {
416  if (nSoftEdges == 0)
417  return -1; /* hard deadlock detected */
418  softFound = nSoftEdges;
419  }
420  }
421  if (FindLockCycle(startProc, softEdges, &nSoftEdges))
422  {
423  if (nSoftEdges == 0)
424  return -1; /* hard deadlock detected */
425  softFound = nSoftEdges;
426  }
427  return softFound;
428 }
Definition: deadlock.c:46
static int nCurConstraints
Definition: deadlock.c:117
static int nPossibleConstraints
Definition: deadlock.c:122
static bool ExpandConstraints(EDGE *constraints, int nConstraints)
Definition: deadlock.c:806
static bool FindLockCycle(PGPROC *checkProc, EDGE *softEdges, int *nSoftEdges)
Definition: deadlock.c:449
int MaxBackends
Definition: globals.c:136
static EDGE * curConstraints
Definition: deadlock.c:116
static EDGE * possibleConstraints
Definition: deadlock.c:121
int i
static int maxPossibleConstraints
Definition: deadlock.c:123

◆ TopoSort()

static bool TopoSort ( LOCK lock,
EDGE constraints,
int  nConstraints,
PGPROC **  ordering 
)
static

Definition at line 878 of file deadlock.c.

References afterConstraints, Assert, beforeConstraints, EDGE::blocker, i, EDGE::link, PROC_QUEUE::links, PGPROC::links, PGPROC::lockGroupLeader, MemSet, SHM_QUEUE::next, PGPROC::pid, EDGE::pred, printf, PROC_QUEUE::size, generate_unaccent_rules::stdout, EDGE::waiter, PGPROC::waitLock, and LOCK::waitProcs.

Referenced by ExpandConstraints().

882 {
883  PROC_QUEUE *waitQueue = &(lock->waitProcs);
884  int queue_size = waitQueue->size;
885  PGPROC *proc;
886  int i,
887  j,
888  jj,
889  k,
890  kk,
891  last;
892 
893  /* First, fill topoProcs[] array with the procs in their current order */
894  proc = (PGPROC *) waitQueue->links.next;
895  for (i = 0; i < queue_size; i++)
896  {
897  topoProcs[i] = proc;
898  proc = (PGPROC *) proc->links.next;
899  }
900 
901  /*
902  * Scan the constraints, and for each proc in the array, generate a count
903  * of the number of constraints that say it must be before something else,
904  * plus a list of the constraints that say it must be after something
905  * else. The count for the j'th proc is stored in beforeConstraints[j],
906  * and the head of its list in afterConstraints[j]. Each constraint
907  * stores its list link in constraints[i].link (note any constraint will
908  * be in just one list). The array index for the before-proc of the i'th
909  * constraint is remembered in constraints[i].pred.
910  *
911  * Note that it's not necessarily the case that every constraint affects
912  * this particular wait queue. Prior to group locking, a process could be
913  * waiting for at most one lock. But a lock group can be waiting for
914  * zero, one, or multiple locks. Since topoProcs[] is an array of the
915  * processes actually waiting, while constraints[] is an array of group
916  * leaders, we've got to scan through topoProcs[] for each constraint,
917  * checking whether both a waiter and a blocker for that group are
918  * present. If so, the constraint is relevant to this wait queue; if not,
919  * it isn't.
920  */
921  MemSet(beforeConstraints, 0, queue_size * sizeof(int));
922  MemSet(afterConstraints, 0, queue_size * sizeof(int));
923  for (i = 0; i < nConstraints; i++)
924  {
925  /*
926  * Find a representative process that is on the lock queue and part of
927  * the waiting lock group. This may or may not be the leader, which
928  * may or may not be waiting at all. If there are any other processes
929  * in the same lock group on the queue, set their number of
930  * beforeConstraints to -1 to indicate that they should be emitted
931  * with their groupmates rather than considered separately.
932  *
933  * In this loop and the similar one just below, it's critical that we
934  * consistently select the same representative member of any one lock
935  * group, so that all the constraints are associated with the same
936  * proc, and the -1's are only associated with not-representative
937  * members. We select the last one in the topoProcs array.
938  */
939  proc = constraints[i].waiter;
940  Assert(proc != NULL);
941  jj = -1;
942  for (j = queue_size; --j >= 0;)
943  {
944  PGPROC *waiter = topoProcs[j];
945 
946  if (waiter == proc || waiter->lockGroupLeader == proc)
947  {
948  Assert(waiter->waitLock == lock);
949  if (jj == -1)
950  jj = j;
951  else
952  {
953  Assert(beforeConstraints[j] <= 0);
954  beforeConstraints[j] = -1;
955  }
956  }
957  }
958 
959  /* If no matching waiter, constraint is not relevant to this lock. */
960  if (jj < 0)
961  continue;
962 
963  /*
964  * Similarly, find a representative process that is on the lock queue
965  * and waiting for the blocking lock group. Again, this could be the
966  * leader but does not need to be.
967  */
968  proc = constraints[i].blocker;
969  Assert(proc != NULL);
970  kk = -1;
971  for (k = queue_size; --k >= 0;)
972  {
973  PGPROC *blocker = topoProcs[k];
974 
975  if (blocker == proc || blocker->lockGroupLeader == proc)
976  {
977  Assert(blocker->waitLock == lock);
978  if (kk == -1)
979  kk = k;
980  else
981  {
982  Assert(beforeConstraints[k] <= 0);
983  beforeConstraints[k] = -1;
984  }
985  }
986  }
987 
988  /* If no matching blocker, constraint is not relevant to this lock. */
989  if (kk < 0)
990  continue;
991 
992  Assert(beforeConstraints[jj] >= 0);
993  beforeConstraints[jj]++; /* waiter must come before */
994  /* add this constraint to list of after-constraints for blocker */
995  constraints[i].pred = jj;
996  constraints[i].link = afterConstraints[kk];
997  afterConstraints[kk] = i + 1;
998  }
999 
1000  /*--------------------
1001  * Now scan the topoProcs array backwards. At each step, output the
1002  * last proc that has no remaining before-constraints plus any other
1003  * members of the same lock group; then decrease the beforeConstraints
1004  * count of each of the procs it was constrained against.
1005  * i = index of ordering[] entry we want to output this time
1006  * j = search index for topoProcs[]
1007  * k = temp for scanning constraint list for proc j
1008  * last = last non-null index in topoProcs (avoid redundant searches)
1009  *--------------------
1010  */
1011  last = queue_size - 1;
1012  for (i = queue_size - 1; i >= 0;)
1013  {
1014  int c;
1015  int nmatches = 0;
1016 
1017  /* Find next candidate to output */
1018  while (topoProcs[last] == NULL)
1019  last--;
1020  for (j = last; j >= 0; j--)
1021  {
1022  if (topoProcs[j] != NULL && beforeConstraints[j] == 0)
1023  break;
1024  }
1025 
1026  /* If no available candidate, topological sort fails */
1027  if (j < 0)
1028  return false;
1029 
1030  /*
1031  * Output everything in the lock group. There's no point in
1032  * outputting an ordering where members of the same lock group are not
1033  * consecutive on the wait queue: if some other waiter is between two
1034  * requests that belong to the same group, then either it conflicts
1035  * with both of them and is certainly not a solution; or it conflicts
1036  * with at most one of them and is thus isomorphic to an ordering
1037  * where the group members are consecutive.
1038  */
1039  proc = topoProcs[j];
1040  if (proc->lockGroupLeader != NULL)
1041  proc = proc->lockGroupLeader;
1042  Assert(proc != NULL);
1043  for (c = 0; c <= last; ++c)
1044  {
1045  if (topoProcs[c] == proc || (topoProcs[c] != NULL &&
1046  topoProcs[c]->lockGroupLeader == proc))
1047  {
1048  ordering[i - nmatches] = topoProcs[c];
1049  topoProcs[c] = NULL;
1050  ++nmatches;
1051  }
1052  }
1053  Assert(nmatches > 0);
1054  i -= nmatches;
1055 
1056  /* Update beforeConstraints counts of its predecessors */
1057  for (k = afterConstraints[j]; k > 0; k = constraints[k - 1].link)
1058  beforeConstraints[constraints[k - 1].pred]--;
1059  }
1060 
1061  /* Done */
1062  return true;
1063 }
int link
Definition: deadlock.c:52
SHM_QUEUE links
Definition: lock.h:31
SHM_QUEUE links
Definition: proc.h:115
struct SHM_QUEUE * next
Definition: shmem.h:31
PGPROC * waiter
Definition: deadlock.c:48
#define MemSet(start, val, len)
Definition: c.h:950
PROC_QUEUE waitProcs
Definition: lock.h:306
int pred
Definition: deadlock.c:51
PGPROC * blocker
Definition: deadlock.c:49
static PGPROC ** topoProcs
Definition: deadlock.c:106
char * c
LOCK * waitLock
Definition: proc.h:170
static int * afterConstraints
Definition: deadlock.c:108
#define Assert(condition)
Definition: c.h:746
int i
int size
Definition: lock.h:32
static int * beforeConstraints
Definition: deadlock.c:107
Definition: proc.h:112
PGPROC * lockGroupLeader
Definition: proc.h:239

Variable Documentation

◆ afterConstraints

int* afterConstraints
static

Definition at line 108 of file deadlock.c.

Referenced by InitDeadLockChecking(), and TopoSort().

◆ beforeConstraints

int* beforeConstraints
static

Definition at line 107 of file deadlock.c.

Referenced by InitDeadLockChecking(), and TopoSort().

◆ blocking_autovacuum_proc

PGPROC* blocking_autovacuum_proc = NULL
static

Definition at line 128 of file deadlock.c.

Referenced by GetBlockingAutoVacuumPgproc().

◆ curConstraints

EDGE* curConstraints
static

Definition at line 116 of file deadlock.c.

◆ deadlockDetails

DEADLOCK_INFO* deadlockDetails
static

Definition at line 124 of file deadlock.c.

◆ maxCurConstraints

int maxCurConstraints
static

Definition at line 118 of file deadlock.c.

Referenced by DeadLockCheckRecurse(), and InitDeadLockChecking().

◆ maxPossibleConstraints

int maxPossibleConstraints
static

Definition at line 123 of file deadlock.c.

Referenced by DeadLockCheckRecurse(), InitDeadLockChecking(), and TestConfiguration().

◆ nCurConstraints

int nCurConstraints
static

Definition at line 117 of file deadlock.c.

Referenced by DeadLockCheck(), DeadLockCheckRecurse(), and TestConfiguration().

◆ nDeadlockDetails

int nDeadlockDetails
static

◆ nPossibleConstraints

int nPossibleConstraints
static

Definition at line 122 of file deadlock.c.

Referenced by DeadLockCheck(), DeadLockCheckRecurse(), and TestConfiguration().

◆ nVisitedProcs

int nVisitedProcs
static

Definition at line 103 of file deadlock.c.

Referenced by FindLockCycle(), and FindLockCycleRecurse().

◆ nWaitOrders

int nWaitOrders
static

Definition at line 112 of file deadlock.c.

Referenced by DeadLockCheck(), ExpandConstraints(), and FindLockCycleRecurseMember().

◆ possibleConstraints

EDGE* possibleConstraints
static

Definition at line 121 of file deadlock.c.

◆ topoProcs

PGPROC** topoProcs
static

Definition at line 106 of file deadlock.c.

◆ visitedProcs

PGPROC** visitedProcs
static

Definition at line 102 of file deadlock.c.

Referenced by InitDeadLockChecking().

◆ waitOrderProcs

PGPROC** waitOrderProcs
static

Definition at line 113 of file deadlock.c.

◆ waitOrders

WAIT_ORDER* waitOrders
static

Definition at line 111 of file deadlock.c.