Header And Logo
|
#include "postgres.h"#include <signal.h>#include <unistd.h>#include <sys/time.h>#include "access/transam.h"#include "access/twophase.h"#include "access/xact.h"#include "miscadmin.h"#include "postmaster/autovacuum.h"#include "replication/syncrep.h"#include "storage/ipc.h"#include "storage/lmgr.h"#include "storage/pmsignal.h"#include "storage/proc.h"#include "storage/procarray.h"#include "storage/procsignal.h"#include "storage/spin.h"#include "utils/timeout.h"#include "utils/timestamp.h"
Go to the source code of this file.
| static void AuxiliaryProcKill | ( | int | code, | |
| Datum | arg | |||
| ) | [static] |
Definition at line 850 of file proc.c.
References Assert, AuxiliaryProcs, DatumGetInt32, DisownLatch(), LWLockReleaseAll(), NUM_AUXILIARY_PROCS, PGPROC::pid, PGPROC::procLatch, ProcStructLock, SpinLockAcquire, SpinLockRelease, PROC_HDR::spins_per_delay, and update_spins_per_delay().
Referenced by InitAuxiliaryProcess().
{
int proctype = DatumGetInt32(arg);
PGPROC *auxproc PG_USED_FOR_ASSERTS_ONLY;
Assert(proctype >= 0 && proctype < NUM_AUXILIARY_PROCS);
auxproc = &AuxiliaryProcs[proctype];
Assert(MyProc == auxproc);
/* Release any LW locks I am holding (see notes above) */
LWLockReleaseAll();
/* Release ownership of the process's latch, too */
DisownLatch(&MyProc->procLatch);
SpinLockAcquire(ProcStructLock);
/* Mark auxiliary proc no longer in use */
MyProc->pid = 0;
/* PGPROC struct isn't mine anymore */
MyProc = NULL;
/* Update shared estimate of spins_per_delay */
ProcGlobal->spins_per_delay = update_spins_per_delay(ProcGlobal->spins_per_delay);
SpinLockRelease(ProcStructLock);
}
| void CheckDeadLock | ( | void | ) |
Definition at line 1429 of file proc.c.
References Assert, deadlock_state, DeadLockCheck(), DS_BLOCKED_BY_AUTOVACUUM, DS_HARD_DEADLOCK, FirstLockMgrLock, i, PGPROC::links, LockTagHashCode(), log_lock_waits, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), SHM_QUEUE::next, NULL, PGSemaphoreUnlock(), SHM_QUEUE::prev, RemoveFromWaitQueue(), PGPROC::sem, LOCK::tag, and PGPROC::waitLock.
Referenced by InitPostgres().
{
int i;
/*
* Acquire exclusive lock on the entire shared lock data structures. Must
* grab LWLocks in partition-number order to avoid LWLock deadlock.
*
* Note that the deadlock check interrupt had better not be enabled
* anywhere that this process itself holds lock partition locks, else this
* will wait forever. Also note that LWLockAcquire creates a critical
* section, so that this routine cannot be interrupted by cancel/die
* interrupts.
*/
for (i = 0; i < NUM_LOCK_PARTITIONS; i++)
LWLockAcquire(FirstLockMgrLock + i, LW_EXCLUSIVE);
/*
* Check to see if we've been awoken by anyone in the interim.
*
* If we have, we can return and resume our transaction -- happy day.
* Before we are awoken the process releasing the lock grants it to us so
* we know that we don't have to wait anymore.
*
* We check by looking to see if we've been unlinked from the wait queue.
* This is quicker than checking our semaphore's state, since no kernel
* call is needed, and it is safe because we hold the lock partition lock.
*/
if (MyProc->links.prev == NULL ||
MyProc->links.next == NULL)
goto check_done;
#ifdef LOCK_DEBUG
if (Debug_deadlocks)
DumpAllLocks();
#endif
/* Run the deadlock check, and set deadlock_state for use by ProcSleep */
deadlock_state = DeadLockCheck(MyProc);
if (deadlock_state == DS_HARD_DEADLOCK)
{
/*
* Oops. We have a deadlock.
*
* Get this process out of wait state. (Note: we could do this more
* efficiently by relying on lockAwaited, but use this coding to
* preserve the flexibility to kill some other transaction than the
* one detecting the deadlock.)
*
* RemoveFromWaitQueue sets MyProc->waitStatus to STATUS_ERROR, so
* ProcSleep will report an error after we return from the signal
* handler.
*/
Assert(MyProc->waitLock != NULL);
RemoveFromWaitQueue(MyProc, LockTagHashCode(&(MyProc->waitLock->tag)));
/*
* Unlock my semaphore so that the interrupted ProcSleep() call can
* finish.
*/
PGSemaphoreUnlock(&MyProc->sem);
/*
* We're done here. Transaction abort caused by the error that
* ProcSleep will raise will cause any other locks we hold to be
* released, thus allowing other processes to wake up; we don't need
* to do that here. NOTE: an exception is that releasing locks we
* hold doesn't consider the possibility of waiters that were blocked
* behind us on the lock we just failed to get, and might now be
* wakable because we're not in front of them anymore. However,
* RemoveFromWaitQueue took care of waking up any such processes.
*/
}
else if (log_lock_waits || deadlock_state == DS_BLOCKED_BY_AUTOVACUUM)
{
/*
* Unlock my semaphore so that the interrupted ProcSleep() call can
* print the log message (we daren't do it here because we are inside
* a signal handler). It will then sleep again until someone releases
* the lock.
*
* If blocked by autovacuum, this wakeup will enable ProcSleep to send
* the canceling signal to the autovacuum worker.
*/
PGSemaphoreUnlock(&MyProc->sem);
}
/*
* And release locks. We do this in reverse order for two reasons: (1)
* Anyone else who needs more than one of the locks will be trying to lock
* them in increasing order; we don't want to release the other process
* until it can get all the locks it needs. (2) This avoids O(N^2)
* behavior inside LWLockRelease.
*/
check_done:
for (i = NUM_LOCK_PARTITIONS; --i >= 0;)
LWLockRelease(FirstLockMgrLock + i);
}
| int GetStartupBufferPinWaitBufId | ( | void | ) |
Definition at line 609 of file proc.c.
References PROC_HDR::startupBufferPinWaitBufId.
Referenced by HoldingBufferPinThatDelaysRecovery().
{
/* use volatile pointer to prevent code rearrangement */
volatile PROC_HDR *procglobal = ProcGlobal;
return procglobal->startupBufferPinWaitBufId;
}
| bool HaveNFreeProcs | ( | int | n | ) |
Definition at line 623 of file proc.c.
References PROC_HDR::freeProcs, PGPROC::links, SHM_QUEUE::next, NULL, ProcStructLock, SpinLockAcquire, and SpinLockRelease.
Referenced by InitPostgres().
{
PGPROC *proc;
/* use volatile pointer to prevent code rearrangement */
volatile PROC_HDR *procglobal = ProcGlobal;
SpinLockAcquire(ProcStructLock);
proc = procglobal->freeProcs;
while (n > 0 && proc != NULL)
{
proc = (PGPROC *) proc->links.next;
n--;
}
SpinLockRelease(ProcStructLock);
return (n <= 0);
}
| void InitAuxiliaryProcess | ( | void | ) |
Definition at line 463 of file proc.c.
References PROC_HDR::allPgXact, Assert, assert_enabled, AuxiliaryProcKill(), AuxiliaryProcs, PGPROC::backendId, PGPROC::databaseId, PGXACT::delayChkpt, elog, ERROR, FATAL, PGPROC::fpLocalTransactionId, PGPROC::fpVXIDLock, i, InitializeLatchSupport(), Int32GetDatum, PGPROC::links, PGPROC::lwWaiting, PGPROC::lwWaitLink, PGPROC::lwWaitMode, PGPROC::lxid, PGPROC::myProcLocks, MyProcPid, NULL, on_shmem_exit(), OwnLatch(), PANIC, PGPROC::pgprocno, PGSemaphoreReset(), PGPROC::pid, PGPROC::procLatch, ProcStructLock, PGPROC::roleId, PGPROC::sem, set_spins_per_delay(), SHMQueueElemInit(), SHMQueueEmpty(), SpinLockAcquire, SpinLockRelease, PROC_HDR::spins_per_delay, PGXACT::vacuumFlags, PGPROC::waitLock, PGPROC::waitProcLock, PGPROC::waitStatus, PGXACT::xid, and PGXACT::xmin.
Referenced by AuxiliaryProcessMain().
{
PGPROC *auxproc;
int proctype;
/*
* ProcGlobal should be set up already (if we are a backend, we inherit
* this by fork() or EXEC_BACKEND mechanism from the postmaster).
*/
if (ProcGlobal == NULL || AuxiliaryProcs == NULL)
elog(PANIC, "proc header uninitialized");
if (MyProc != NULL)
elog(ERROR, "you already exist");
/*
* Initialize process-local latch support. This could fail if the kernel
* is low on resources, and if so we want to exit cleanly before acquiring
* any shared-memory resources.
*/
InitializeLatchSupport();
/*
* We use the ProcStructLock to protect assignment and releasing of
* AuxiliaryProcs entries.
*
* While we are holding the ProcStructLock, also copy the current shared
* estimate of spins_per_delay to local storage.
*/
SpinLockAcquire(ProcStructLock);
set_spins_per_delay(ProcGlobal->spins_per_delay);
/*
* Find a free auxproc ... *big* trouble if there isn't one ...
*/
for (proctype = 0; proctype < NUM_AUXILIARY_PROCS; proctype++)
{
auxproc = &AuxiliaryProcs[proctype];
if (auxproc->pid == 0)
break;
}
if (proctype >= NUM_AUXILIARY_PROCS)
{
SpinLockRelease(ProcStructLock);
elog(FATAL, "all AuxiliaryProcs are in use");
}
/* Mark auxiliary proc as in use by me */
/* use volatile pointer to prevent code rearrangement */
((volatile PGPROC *) auxproc)->pid = MyProcPid;
MyProc = auxproc;
MyPgXact = &ProcGlobal->allPgXact[auxproc->pgprocno];
SpinLockRelease(ProcStructLock);
/*
* Initialize all fields of MyProc, except for those previously
* initialized by InitProcGlobal.
*/
SHMQueueElemInit(&(MyProc->links));
MyProc->waitStatus = STATUS_OK;
MyProc->lxid = InvalidLocalTransactionId;
MyProc->fpVXIDLock = false;
MyProc->fpLocalTransactionId = InvalidLocalTransactionId;
MyPgXact->xid = InvalidTransactionId;
MyPgXact->xmin = InvalidTransactionId;
MyProc->backendId = InvalidBackendId;
MyProc->databaseId = InvalidOid;
MyProc->roleId = InvalidOid;
MyPgXact->delayChkpt = false;
MyPgXact->vacuumFlags = 0;
MyProc->lwWaiting = false;
MyProc->lwWaitMode = 0;
MyProc->lwWaitLink = NULL;
MyProc->waitLock = NULL;
MyProc->waitProcLock = NULL;
#ifdef USE_ASSERT_CHECKING
if (assert_enabled)
{
int i;
/* Last process should have released all locks. */
for (i = 0; i < NUM_LOCK_PARTITIONS; i++)
Assert(SHMQueueEmpty(&(MyProc->myProcLocks[i])));
}
#endif
/*
* Acquire ownership of the PGPROC's latch, so that we can use WaitLatch.
* Note that there's no particular need to do ResetLatch here.
*/
OwnLatch(&MyProc->procLatch);
/*
* We might be reusing a semaphore that belonged to a failed process. So
* be careful and reinitialize its value here. (This is not strictly
* necessary anymore, but seems like a good idea for cleanliness.)
*/
PGSemaphoreReset(&MyProc->sem);
/*
* Arrange to clean up at process exit.
*/
on_shmem_exit(AuxiliaryProcKill, Int32GetDatum(proctype));
}
| void InitProcess | ( | void | ) |
Definition at line 278 of file proc.c.
References PROC_HDR::allPgXact, Assert, assert_enabled, PROC_HDR::autovacFreeProcs, PGPROC::backendId, PROC_HDR::bgworkerFreeProcs, PGPROC::databaseId, PGXACT::delayChkpt, elog, ereport, errcode(), errmsg(), ERROR, FATAL, PGPROC::fpLocalTransactionId, PGPROC::fpVXIDLock, PROC_HDR::freeProcs, i, InitDeadLockChecking(), InitializeLatchSupport(), IsAnyAutoVacuumProcess, IsAutoVacuumLauncherProcess(), IsAutoVacuumWorkerProcess(), IsBackgroundWorker, IsUnderPostmaster, PGPROC::links, PGPROC::lwWaiting, PGPROC::lwWaitLink, PGPROC::lwWaitMode, PGPROC::lxid, MarkPostmasterChildActive(), PGPROC::myProcLocks, MyProcPid, SHM_QUEUE::next, NULL, on_shmem_exit(), OwnLatch(), PANIC, PGPROC::pgprocno, PGSemaphoreReset(), PGPROC::pid, ProcKill(), PGPROC::procLatch, ProcStructLock, PGPROC::recoveryConflictPending, PGPROC::roleId, PGPROC::sem, set_spins_per_delay(), SHMQueueElemInit(), SHMQueueEmpty(), SpinLockAcquire, SpinLockRelease, PROC_HDR::spins_per_delay, PGPROC::syncRepLinks, PGPROC::syncRepState, PGXACT::vacuumFlags, PGPROC::waitLock, PGPROC::waitLSN, PGPROC::waitProcLock, PGPROC::waitStatus, PGXACT::xid, and PGXACT::xmin.
Referenced by AutoVacLauncherMain(), AutoVacWorkerMain(), BootstrapModeMain(), do_start_bgworker(), and PostgresMain().
{
/* use volatile pointer to prevent code rearrangement */
volatile PROC_HDR *procglobal = ProcGlobal;
/*
* ProcGlobal should be set up already (if we are a backend, we inherit
* this by fork() or EXEC_BACKEND mechanism from the postmaster).
*/
if (procglobal == NULL)
elog(PANIC, "proc header uninitialized");
if (MyProc != NULL)
elog(ERROR, "you already exist");
/*
* Initialize process-local latch support. This could fail if the kernel
* is low on resources, and if so we want to exit cleanly before acquiring
* any shared-memory resources.
*/
InitializeLatchSupport();
/*
* Try to get a proc struct from the free list. If this fails, we must be
* out of PGPROC structures (not to mention semaphores).
*
* While we are holding the ProcStructLock, also copy the current shared
* estimate of spins_per_delay to local storage.
*/
SpinLockAcquire(ProcStructLock);
set_spins_per_delay(procglobal->spins_per_delay);
if (IsAnyAutoVacuumProcess())
MyProc = procglobal->autovacFreeProcs;
else if (IsBackgroundWorker)
MyProc = procglobal->bgworkerFreeProcs;
else
MyProc = procglobal->freeProcs;
if (MyProc != NULL)
{
if (IsAnyAutoVacuumProcess())
procglobal->autovacFreeProcs = (PGPROC *) MyProc->links.next;
else if (IsBackgroundWorker)
procglobal->bgworkerFreeProcs = (PGPROC *) MyProc->links.next;
else
procglobal->freeProcs = (PGPROC *) MyProc->links.next;
SpinLockRelease(ProcStructLock);
}
else
{
/*
* If we reach here, all the PGPROCs are in use. This is one of the
* possible places to detect "too many backends", so give the standard
* error message. XXX do we need to give a different failure message
* in the autovacuum case?
*/
SpinLockRelease(ProcStructLock);
ereport(FATAL,
(errcode(ERRCODE_TOO_MANY_CONNECTIONS),
errmsg("sorry, too many clients already")));
}
MyPgXact = &ProcGlobal->allPgXact[MyProc->pgprocno];
/*
* Now that we have a PGPROC, mark ourselves as an active postmaster
* child; this is so that the postmaster can detect it if we exit without
* cleaning up. (XXX autovac launcher currently doesn't participate in
* this; it probably should.)
*/
if (IsUnderPostmaster && !IsAutoVacuumLauncherProcess())
MarkPostmasterChildActive();
/*
* Initialize all fields of MyProc, except for those previously
* initialized by InitProcGlobal.
*/
SHMQueueElemInit(&(MyProc->links));
MyProc->waitStatus = STATUS_OK;
MyProc->lxid = InvalidLocalTransactionId;
MyProc->fpVXIDLock = false;
MyProc->fpLocalTransactionId = InvalidLocalTransactionId;
MyPgXact->xid = InvalidTransactionId;
MyPgXact->xmin = InvalidTransactionId;
MyProc->pid = MyProcPid;
/* backendId, databaseId and roleId will be filled in later */
MyProc->backendId = InvalidBackendId;
MyProc->databaseId = InvalidOid;
MyProc->roleId = InvalidOid;
MyPgXact->delayChkpt = false;
MyPgXact->vacuumFlags = 0;
/* NB -- autovac launcher intentionally does not set IS_AUTOVACUUM */
if (IsAutoVacuumWorkerProcess())
MyPgXact->vacuumFlags |= PROC_IS_AUTOVACUUM;
MyProc->lwWaiting = false;
MyProc->lwWaitMode = 0;
MyProc->lwWaitLink = NULL;
MyProc->waitLock = NULL;
MyProc->waitProcLock = NULL;
#ifdef USE_ASSERT_CHECKING
if (assert_enabled)
{
int i;
/* Last process should have released all locks. */
for (i = 0; i < NUM_LOCK_PARTITIONS; i++)
Assert(SHMQueueEmpty(&(MyProc->myProcLocks[i])));
}
#endif
MyProc->recoveryConflictPending = false;
/* Initialize fields for sync rep */
MyProc->waitLSN = 0;
MyProc->syncRepState = SYNC_REP_NOT_WAITING;
SHMQueueElemInit(&(MyProc->syncRepLinks));
/*
* Acquire ownership of the PGPROC's latch, so that we can use WaitLatch.
* Note that there's no particular need to do ResetLatch here.
*/
OwnLatch(&MyProc->procLatch);
/*
* We might be reusing a semaphore that belonged to a failed process. So
* be careful and reinitialize its value here. (This is not strictly
* necessary anymore, but seems like a good idea for cleanliness.)
*/
PGSemaphoreReset(&MyProc->sem);
/*
* Arrange to clean up at backend exit.
*/
on_shmem_exit(ProcKill, 0);
/*
* Now that we have a PGPROC, we could try to acquire locks, so initialize
* the deadlock checker.
*/
InitDeadLockChecking();
}
| void InitProcessPhase2 | ( | void | ) |
Definition at line 428 of file proc.c.
References Assert, NULL, on_shmem_exit(), ProcArrayAdd(), and RemoveProcFromArray().
Referenced by InitPostgres().
{
Assert(MyProc != NULL);
/*
* Add our PGPROC to the PGPROC array in shared memory.
*/
ProcArrayAdd(MyProc);
/*
* Arrange to clean that up at backend exit.
*/
on_shmem_exit(RemoveProcFromArray, 0);
}
| void InitProcGlobal | ( | void | ) |
Definition at line 157 of file proc.c.
References PROC_HDR::allPgXact, PROC_HDR::allProcCount, PROC_HDR::allProcs, Assert, PROC_HDR::autovacFreeProcs, autovacuum_max_workers, AuxiliaryProcs, PGPROC::backendLock, PROC_HDR::bgworkerFreeProcs, PROC_HDR::checkpointerLatch, ereport, errcode(), errmsg(), FATAL, PROC_HDR::freeProcs, i, InitSharedLatch(), PGPROC::links, LWLockAssign(), max_prepared_xacts, MaxBackends, MaxConnections, MemSet, SHM_QUEUE::next, NUM_AUXILIARY_PROCS, PGPROC::pgprocno, PGSemaphoreCreate(), ProcStructLock, ShmemAlloc(), ShmemInitStruct(), SHMQueueInit(), SpinLockInit, PROC_HDR::spins_per_delay, PROC_HDR::startupBufferPinWaitBufId, PROC_HDR::startupProc, PROC_HDR::startupProcPid, and PROC_HDR::walwriterLatch.
Referenced by CreateSharedMemoryAndSemaphores().
{
PGPROC *procs;
PGXACT *pgxacts;
int i,
j;
bool found;
uint32 TotalProcs = MaxBackends + NUM_AUXILIARY_PROCS + max_prepared_xacts;
/* Create the ProcGlobal shared structure */
ProcGlobal = (PROC_HDR *)
ShmemInitStruct("Proc Header", sizeof(PROC_HDR), &found);
Assert(!found);
/*
* Initialize the data structures.
*/
ProcGlobal->spins_per_delay = DEFAULT_SPINS_PER_DELAY;
ProcGlobal->freeProcs = NULL;
ProcGlobal->autovacFreeProcs = NULL;
ProcGlobal->bgworkerFreeProcs = NULL;
ProcGlobal->startupProc = NULL;
ProcGlobal->startupProcPid = 0;
ProcGlobal->startupBufferPinWaitBufId = -1;
ProcGlobal->walwriterLatch = NULL;
ProcGlobal->checkpointerLatch = NULL;
/*
* Create and initialize all the PGPROC structures we'll need. There are
* five separate consumers: (1) normal backends, (2) autovacuum workers
* and the autovacuum launcher, (3) background workers, (4) auxiliary
* processes, and (5) prepared transactions. Each PGPROC structure is
* dedicated to exactly one of these purposes, and they do not move between
* groups.
*/
procs = (PGPROC *) ShmemAlloc(TotalProcs * sizeof(PGPROC));
ProcGlobal->allProcs = procs;
ProcGlobal->allProcCount = TotalProcs;
if (!procs)
ereport(FATAL,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of shared memory")));
MemSet(procs, 0, TotalProcs * sizeof(PGPROC));
/*
* Also allocate a separate array of PGXACT structures. This is separate
* from the main PGPROC array so that the most heavily accessed data is
* stored contiguously in memory in as few cache lines as possible. This
* provides significant performance benefits, especially on a
* multiprocessor system. There is one PGXACT structure for every PGPROC
* structure.
*/
pgxacts = (PGXACT *) ShmemAlloc(TotalProcs * sizeof(PGXACT));
MemSet(pgxacts, 0, TotalProcs * sizeof(PGXACT));
ProcGlobal->allPgXact = pgxacts;
for (i = 0; i < TotalProcs; i++)
{
/* Common initialization for all PGPROCs, regardless of type. */
/*
* Set up per-PGPROC semaphore, latch, and backendLock. Prepared xact
* dummy PGPROCs don't need these though - they're never associated
* with a real process
*/
if (i < MaxBackends + NUM_AUXILIARY_PROCS)
{
PGSemaphoreCreate(&(procs[i].sem));
InitSharedLatch(&(procs[i].procLatch));
procs[i].backendLock = LWLockAssign();
}
procs[i].pgprocno = i;
/*
* Newly created PGPROCs for normal backends, autovacuum and bgworkers
* must be queued up on the appropriate free list. Because there can
* only ever be a small, fixed number of auxiliary processes, no free
* list is used in that case; InitAuxiliaryProcess() instead uses a
* linear search. PGPROCs for prepared transactions are added to a
* free list by TwoPhaseShmemInit().
*/
if (i < MaxConnections)
{
/* PGPROC for normal backend, add to freeProcs list */
procs[i].links.next = (SHM_QUEUE *) ProcGlobal->freeProcs;
ProcGlobal->freeProcs = &procs[i];
}
else if (i < MaxConnections + autovacuum_max_workers + 1)
{
/* PGPROC for AV launcher/worker, add to autovacFreeProcs list */
procs[i].links.next = (SHM_QUEUE *) ProcGlobal->autovacFreeProcs;
ProcGlobal->autovacFreeProcs = &procs[i];
}
else if (i < MaxBackends)
{
/* PGPROC for bgworker, add to bgworkerFreeProcs list */
procs[i].links.next = (SHM_QUEUE *) ProcGlobal->bgworkerFreeProcs;
ProcGlobal->bgworkerFreeProcs = &procs[i];
}
/* Initialize myProcLocks[] shared memory queues. */
for (j = 0; j < NUM_LOCK_PARTITIONS; j++)
SHMQueueInit(&(procs[i].myProcLocks[j]));
}
/*
* Save pointers to the blocks of PGPROC structures reserved for auxiliary
* processes and prepared transactions.
*/
AuxiliaryProcs = &procs[MaxBackends];
PreparedXactProcs = &procs[MaxBackends + NUM_AUXILIARY_PROCS];
/* Create ProcStructLock spinlock, too */
ProcStructLock = (slock_t *) ShmemAlloc(sizeof(slock_t));
SpinLockInit(ProcStructLock);
}
| bool IsWaitingForLock | ( | void | ) |
Definition at line 649 of file proc.c.
References NULL.
Referenced by RecoveryConflictInterrupt().
{
if (lockAwaited == NULL)
return false;
return true;
}
| void LockErrorCleanup | ( | void | ) |
Definition at line 666 of file proc.c.
References AbortStrongLockAcquire(), disable_timeouts(), GrantAwaitedLock(), LOCALLOCK::hashcode, DisableTimeoutParams::id, DisableTimeoutParams::keep_indicator, PGPROC::links, LockHashPartitionLock, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), SHM_QUEUE::next, NULL, RemoveFromWaitQueue(), STATUS_OK, and PGPROC::waitStatus.
Referenced by AbortSubTransaction(), AbortTransaction(), die(), ProcReleaseLocks(), RecoveryConflictInterrupt(), and StatementCancelHandler().
{
LWLockId partitionLock;
DisableTimeoutParams timeouts[2];
AbortStrongLockAcquire();
/* Nothing to do if we weren't waiting for a lock */
if (lockAwaited == NULL)
return;
/*
* Turn off the deadlock and lock timeout timers, if they are still
* running (see ProcSleep). Note we must preserve the LOCK_TIMEOUT
* indicator flag, since this function is executed before
* ProcessInterrupts when responding to SIGINT; else we'd lose the
* knowledge that the SIGINT came from a lock timeout and not an external
* source.
*/
timeouts[0].id = DEADLOCK_TIMEOUT;
timeouts[0].keep_indicator = false;
timeouts[1].id = LOCK_TIMEOUT;
timeouts[1].keep_indicator = true;
disable_timeouts(timeouts, 2);
/* Unlink myself from the wait queue, if on it (might not be anymore!) */
partitionLock = LockHashPartitionLock(lockAwaited->hashcode);
LWLockAcquire(partitionLock, LW_EXCLUSIVE);
if (MyProc->links.next != NULL)
{
/* We could not have been granted the lock yet */
RemoveFromWaitQueue(MyProc, lockAwaited->hashcode);
}
else
{
/*
* Somebody kicked us off the lock queue already. Perhaps they
* granted us the lock, or perhaps they detected a deadlock. If they
* did grant us the lock, we'd better remember it in our local lock
* table.
*/
if (MyProc->waitStatus == STATUS_OK)
GrantAwaitedLock();
}
lockAwaited = NULL;
LWLockRelease(partitionLock);
/*
* We used to do PGSemaphoreReset() here to ensure that our proc's wait
* semaphore is reset to zero. This prevented a leftover wakeup signal
* from remaining in the semaphore if someone else had granted us the lock
* we wanted before we were able to remove ourselves from the wait-list.
* However, now that ProcSleep loops until waitStatus changes, a leftover
* wakeup signal isn't harmful, and it seems not worth expending cycles to
* get rid of a signal that most likely isn't there.
*/
}
| int ProcGlobalSemas | ( | void | ) |
Definition at line 121 of file proc.c.
References MaxBackends.
Referenced by CreateSharedMemoryAndSemaphores().
{
/*
* We need a sema per backend (including autovacuum), plus one for each
* auxiliary process.
*/
return MaxBackends + NUM_AUXILIARY_PROCS;
}
| Size ProcGlobalShmemSize | ( | void | ) |
Definition at line 95 of file proc.c.
References add_size(), max_prepared_xacts, MaxBackends, mul_size(), and NUM_AUXILIARY_PROCS.
Referenced by CreateSharedMemoryAndSemaphores().
{
Size size = 0;
/* ProcGlobal */
size = add_size(size, sizeof(PROC_HDR));
/* MyProcs, including autovacuum workers and launcher */
size = add_size(size, mul_size(MaxBackends, sizeof(PGPROC)));
/* AuxiliaryProcs */
size = add_size(size, mul_size(NUM_AUXILIARY_PROCS, sizeof(PGPROC)));
/* Prepared xacts */
size = add_size(size, mul_size(max_prepared_xacts, sizeof(PGPROC)));
/* ProcStructLock */
size = add_size(size, sizeof(slock_t));
size = add_size(size, mul_size(MaxBackends, sizeof(PGXACT)));
size = add_size(size, mul_size(NUM_AUXILIARY_PROCS, sizeof(PGXACT)));
size = add_size(size, mul_size(max_prepared_xacts, sizeof(PGXACT)));
return size;
}
| static void ProcKill | ( | int | code, | |
| Datum | arg | |||
| ) | [static] |
Definition at line 773 of file proc.c.
References Assert, assert_enabled, PROC_HDR::autovacFreeProcs, AutovacuumLauncherPid, PROC_HDR::bgworkerFreeProcs, DisownLatch(), PROC_HDR::freeProcs, i, IsAnyAutoVacuumProcess, IsAutoVacuumLauncherProcess(), IsBackgroundWorker, IsUnderPostmaster, PGPROC::links, LWLockReleaseAll(), MarkPostmasterChildInactive(), PGPROC::myProcLocks, SHM_QUEUE::next, NULL, PGPROC::procLatch, ProcStructLock, SHMQueueEmpty(), SIGUSR2, SpinLockAcquire, SpinLockRelease, PROC_HDR::spins_per_delay, SyncRepCleanupAtProcExit(), and update_spins_per_delay().
Referenced by InitProcess().
{
/* use volatile pointer to prevent code rearrangement */
volatile PROC_HDR *procglobal = ProcGlobal;
Assert(MyProc != NULL);
/* Make sure we're out of the sync rep lists */
SyncRepCleanupAtProcExit();
#ifdef USE_ASSERT_CHECKING
if (assert_enabled)
{
int i;
/* Last process should have released all locks. */
for (i = 0; i < NUM_LOCK_PARTITIONS; i++)
Assert(SHMQueueEmpty(&(MyProc->myProcLocks[i])));
}
#endif
/*
* Release any LW locks I am holding. There really shouldn't be any, but
* it's cheap to check again before we cut the knees off the LWLock
* facility by releasing our PGPROC ...
*/
LWLockReleaseAll();
/* Release ownership of the process's latch, too */
DisownLatch(&MyProc->procLatch);
SpinLockAcquire(ProcStructLock);
/* Return PGPROC structure (and semaphore) to appropriate freelist */
if (IsAnyAutoVacuumProcess())
{
MyProc->links.next = (SHM_QUEUE *) procglobal->autovacFreeProcs;
procglobal->autovacFreeProcs = MyProc;
}
else if (IsBackgroundWorker)
{
MyProc->links.next = (SHM_QUEUE *) procglobal->bgworkerFreeProcs;
procglobal->bgworkerFreeProcs = MyProc;
}
else
{
MyProc->links.next = (SHM_QUEUE *) procglobal->freeProcs;
procglobal->freeProcs = MyProc;
}
/* PGPROC struct isn't mine anymore */
MyProc = NULL;
/* Update shared estimate of spins_per_delay */
procglobal->spins_per_delay = update_spins_per_delay(procglobal->spins_per_delay);
SpinLockRelease(ProcStructLock);
/*
* This process is no longer present in shared memory in any meaningful
* way, so tell the postmaster we've cleaned up acceptably well. (XXX
* autovac launcher should be included here someday)
*/
if (IsUnderPostmaster && !IsAutoVacuumLauncherProcess())
MarkPostmasterChildInactive();
/* wake autovac launcher if needed -- see comments in FreeWorkerInfo */
if (AutovacuumLauncherPid != 0)
kill(AutovacuumLauncherPid, SIGUSR2);
}
| void ProcLockWakeup | ( | LockMethod | lockMethodTable, | |
| LOCK * | lock | |||
| ) |
Definition at line 1363 of file proc.c.
References Assert, LockMethodData::conflictTab, GrantLock(), PGPROC::links, PROC_QUEUE::links, LOCKBIT_ON, LockCheckConflicts(), SHM_QUEUE::next, ProcWakeup(), PROC_QUEUE::size, STATUS_OK, PGPROC::waitLockMode, PGPROC::waitProcLock, and LOCK::waitProcs.
Referenced by CleanUpLock(), and DeadLockCheck().
{
PROC_QUEUE *waitQueue = &(lock->waitProcs);
int queue_size = waitQueue->size;
PGPROC *proc;
LOCKMASK aheadRequests = 0;
Assert(queue_size >= 0);
if (queue_size == 0)
return;
proc = (PGPROC *) waitQueue->links.next;
while (queue_size-- > 0)
{
LOCKMODE lockmode = proc->waitLockMode;
/*
* Waken if (a) doesn't conflict with requests of earlier waiters, and
* (b) doesn't conflict with already-held locks.
*/
if ((lockMethodTable->conflictTab[lockmode] & aheadRequests) == 0 &&
LockCheckConflicts(lockMethodTable,
lockmode,
lock,
proc->waitProcLock,
proc) == STATUS_OK)
{
/* OK to waken */
GrantLock(lock, proc->waitProcLock, lockmode);
proc = ProcWakeup(proc, STATUS_OK);
/*
* ProcWakeup removes proc from the lock's waiting process queue
* and returns the next proc in chain; don't use proc's next-link,
* because it's been cleared.
*/
}
else
{
/*
* Cannot wake this guy. Remember his request for later checks.
*/
aheadRequests |= LOCKBIT_ON(lockmode);
proc = (PGPROC *) proc->links.next;
}
}
Assert(waitQueue->size >= 0);
}
| void ProcQueueInit | ( | PROC_QUEUE * | queue | ) |
Definition at line 914 of file proc.c.
References PROC_QUEUE::links, SHMQueueInit(), and PROC_QUEUE::size.
Referenced by DeadLockCheck(), lock_twophase_recover(), and SetupLockInTable().
{
SHMQueueInit(&(queue->links));
queue->size = 0;
}
| void ProcReleaseLocks | ( | bool | isCommit | ) |
Definition at line 745 of file proc.c.
References DEFAULT_LOCKMETHOD, LockErrorCleanup(), LockReleaseAll(), and USER_LOCKMETHOD.
Referenced by ResourceOwnerReleaseInternal().
{
if (!MyProc)
return;
/* If waiting, get off wait queue (should only be needed after error) */
LockErrorCleanup();
/* Release standard locks, including session-level if aborting */
LockReleaseAll(DEFAULT_LOCKMETHOD, !isCommit);
/* Release transaction-level advisory locks */
LockReleaseAll(USER_LOCKMETHOD, false);
}
| void ProcSendSignal | ( | int | pid | ) |
Definition at line 1551 of file proc.c.
References BackendPidGetProc(), NULL, PGSemaphoreUnlock(), ProcStructLock, RecoveryInProgress(), PGPROC::sem, SpinLockAcquire, SpinLockRelease, PROC_HDR::startupProc, and PROC_HDR::startupProcPid.
Referenced by ReleasePredicateLocks(), and UnpinBuffer().
{
PGPROC *proc = NULL;
if (RecoveryInProgress())
{
/* use volatile pointer to prevent code rearrangement */
volatile PROC_HDR *procglobal = ProcGlobal;
SpinLockAcquire(ProcStructLock);
/*
* Check to see whether it is the Startup process we wish to signal.
* This call is made by the buffer manager when it wishes to wake up a
* process that has been waiting for a pin in so it can obtain a
* cleanup lock using LockBufferForCleanup(). Startup is not a normal
* backend, so BackendPidGetProc() will not return any pid at all. So
* we remember the information for this special case.
*/
if (pid == procglobal->startupProcPid)
proc = procglobal->startupProc;
SpinLockRelease(ProcStructLock);
}
if (proc == NULL)
proc = BackendPidGetProc(pid);
if (proc != NULL)
PGSemaphoreUnlock(&proc->sem);
}
| int ProcSleep | ( | LOCALLOCK * | locallock, | |
| LockMethod | lockMethodTable | |||
| ) |
Definition at line 941 of file proc.c.
References _, PROC_HDR::allPgXact, appendStringInfo(), Assert, buf, CheckRecoveryConflictDeadlock(), LockMethodData::conflictTab, StringInfoData::data, deadlock_state, DEADLOCK_TIMEOUT, DeadlockTimeout, EnableTimeoutParams::delay_ms, DescribeLockTag(), disable_timeout(), disable_timeouts(), DS_BLOCKED_BY_AUTOVACUUM, DS_HARD_DEADLOCK, DS_NOT_YET_CHECKED, DS_SOFT_DEADLOCK, enable_timeout_after(), enable_timeouts(), ereport, errdetail_log(), errmsg(), get_timeout_start_time(), GetBlockingAutoVacuumPgproc(), GetCurrentTimestamp(), GetLockmodeName(), GrantAwaitedLock(), GrantLock(), LOCALLOCK::hashcode, PGPROC::heldLocks, i, DisableTimeoutParams::id, EnableTimeoutParams::id, initStringInfo(), InRecovery, DisableTimeoutParams::keep_indicator, PGPROC::links, PROC_QUEUE::links, LOCALLOCKTAG::lock, LOCALLOCK::lock, LOCKBIT_ON, LockCheckConflicts(), LockHashPartitionLock, LOCKTAG::locktag_lockmethodid, LockTimeout, LOG, log_lock_waits, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), LOCALLOCKTAG::mode, MyProcPid, SHM_QUEUE::next, NULL, pfree(), PGPROC::pgprocno, PGSemaphoreLock(), PGPROC::pid, PROC_IS_AUTOVACUUM, PROC_VACUUM_FOR_WRAPAROUND, ProcArrayLock, LOCALLOCK::proclock, RecoveryInProgress(), RememberSimpleDeadLock(), RemoveFromWaitQueue(), PGPROC::sem, SHMQueueInsertBefore(), PROC_QUEUE::size, STATUS_ERROR, STATUS_OK, STATUS_WAITING, LOCK::tag, LOCALLOCK::tag, TimestampDifference(), EnableTimeoutParams::type, PGXACT::vacuumFlags, PGPROC::waitLock, PGPROC::waitLockMode, LOCK::waitMask, PGPROC::waitProcLock, LOCK::waitProcs, PGPROC::waitStatus, and WARNING.
Referenced by WaitOnLock().
{
LOCKMODE lockmode = locallock->tag.mode;
LOCK *lock = locallock->lock;
PROCLOCK *proclock = locallock->proclock;
uint32 hashcode = locallock->hashcode;
LWLockId partitionLock = LockHashPartitionLock(hashcode);
PROC_QUEUE *waitQueue = &(lock->waitProcs);
LOCKMASK myHeldLocks = MyProc->heldLocks;
bool early_deadlock = false;
bool allow_autovacuum_cancel = true;
int myWaitStatus;
PGPROC *proc;
int i;
/*
* Determine where to add myself in the wait queue.
*
* Normally I should go at the end of the queue. However, if I already
* hold locks that conflict with the request of any previous waiter, put
* myself in the queue just in front of the first such waiter. This is not
* a necessary step, since deadlock detection would move me to before that
* waiter anyway; but it's relatively cheap to detect such a conflict
* immediately, and avoid delaying till deadlock timeout.
*
* Special case: if I find I should go in front of some waiter, check to
* see if I conflict with already-held locks or the requests before that
* waiter. If not, then just grant myself the requested lock immediately.
* This is the same as the test for immediate grant in LockAcquire, except
* we are only considering the part of the wait queue before my insertion
* point.
*/
if (myHeldLocks != 0)
{
LOCKMASK aheadRequests = 0;
proc = (PGPROC *) waitQueue->links.next;
for (i = 0; i < waitQueue->size; i++)
{
/* Must he wait for me? */
if (lockMethodTable->conflictTab[proc->waitLockMode] & myHeldLocks)
{
/* Must I wait for him ? */
if (lockMethodTable->conflictTab[lockmode] & proc->heldLocks)
{
/*
* Yes, so we have a deadlock. Easiest way to clean up
* correctly is to call RemoveFromWaitQueue(), but we
* can't do that until we are *on* the wait queue. So, set
* a flag to check below, and break out of loop. Also,
* record deadlock info for later message.
*/
RememberSimpleDeadLock(MyProc, lockmode, lock, proc);
early_deadlock = true;
break;
}
/* I must go before this waiter. Check special case. */
if ((lockMethodTable->conflictTab[lockmode] & aheadRequests) == 0 &&
LockCheckConflicts(lockMethodTable,
lockmode,
lock,
proclock,
MyProc) == STATUS_OK)
{
/* Skip the wait and just grant myself the lock. */
GrantLock(lock, proclock, lockmode);
GrantAwaitedLock();
return STATUS_OK;
}
/* Break out of loop to put myself before him */
break;
}
/* Nope, so advance to next waiter */
aheadRequests |= LOCKBIT_ON(proc->waitLockMode);
proc = (PGPROC *) proc->links.next;
}
/*
* If we fall out of loop normally, proc points to waitQueue head, so
* we will insert at tail of queue as desired.
*/
}
else
{
/* I hold no locks, so I can't push in front of anyone. */
proc = (PGPROC *) &(waitQueue->links);
}
/*
* Insert self into queue, ahead of the given proc (or at tail of queue).
*/
SHMQueueInsertBefore(&(proc->links), &(MyProc->links));
waitQueue->size++;
lock->waitMask |= LOCKBIT_ON(lockmode);
/* Set up wait information in PGPROC object, too */
MyProc->waitLock = lock;
MyProc->waitProcLock = proclock;
MyProc->waitLockMode = lockmode;
MyProc->waitStatus = STATUS_WAITING;
/*
* If we detected deadlock, give up without waiting. This must agree with
* CheckDeadLock's recovery code, except that we shouldn't release the
* semaphore since we haven't tried to lock it yet.
*/
if (early_deadlock)
{
RemoveFromWaitQueue(MyProc, hashcode);
return STATUS_ERROR;
}
/* mark that we are waiting for a lock */
lockAwaited = locallock;
/*
* Release the lock table's partition lock.
*
* NOTE: this may also cause us to exit critical-section state, possibly
* allowing a cancel/die interrupt to be accepted. This is OK because we
* have recorded the fact that we are waiting for a lock, and so
* LockErrorCleanup will clean up if cancel/die happens.
*/
LWLockRelease(partitionLock);
/*
* Also, now that we will successfully clean up after an ereport, it's
* safe to check to see if there's a buffer pin deadlock against the
* Startup process. Of course, that's only necessary if we're doing Hot
* Standby and are not the Startup process ourselves.
*/
if (RecoveryInProgress() && !InRecovery)
CheckRecoveryConflictDeadlock();
/* Reset deadlock_state before enabling the timeout handler */
deadlock_state = DS_NOT_YET_CHECKED;
/*
* Set timer so we can wake up after awhile and check for a deadlock. If a
* deadlock is detected, the handler releases the process's semaphore and
* sets MyProc->waitStatus = STATUS_ERROR, allowing us to know that we
* must report failure rather than success.
*
* By delaying the check until we've waited for a bit, we can avoid
* running the rather expensive deadlock-check code in most cases.
*
* If LockTimeout is set, also enable the timeout for that. We can save a
* few cycles by enabling both timeout sources in one call.
*/
if (LockTimeout > 0)
{
EnableTimeoutParams timeouts[2];
timeouts[0].id = DEADLOCK_TIMEOUT;
timeouts[0].type = TMPARAM_AFTER;
timeouts[0].delay_ms = DeadlockTimeout;
timeouts[1].id = LOCK_TIMEOUT;
timeouts[1].type = TMPARAM_AFTER;
timeouts[1].delay_ms = LockTimeout;
enable_timeouts(timeouts, 2);
}
else
enable_timeout_after(DEADLOCK_TIMEOUT, DeadlockTimeout);
/*
* If someone wakes us between LWLockRelease and PGSemaphoreLock,
* PGSemaphoreLock will not block. The wakeup is "saved" by the semaphore
* implementation. While this is normally good, there are cases where a
* saved wakeup might be leftover from a previous operation (for example,
* we aborted ProcWaitForSignal just before someone did ProcSendSignal).
* So, loop to wait again if the waitStatus shows we haven't been granted
* nor denied the lock yet.
*
* We pass interruptOK = true, which eliminates a window in which
* cancel/die interrupts would be held off undesirably. This is a promise
* that we don't mind losing control to a cancel/die interrupt here. We
* don't, because we have no shared-state-change work to do after being
* granted the lock (the grantor did it all). We do have to worry about
* canceling the deadlock timeout and updating the locallock table, but if
* we lose control to an error, LockErrorCleanup will fix that up.
*/
do
{
PGSemaphoreLock(&MyProc->sem, true);
/*
* waitStatus could change from STATUS_WAITING to something else
* asynchronously. Read it just once per loop to prevent surprising
* behavior (such as missing log messages).
*/
myWaitStatus = MyProc->waitStatus;
/*
* If we are not deadlocked, but are waiting on an autovacuum-induced
* task, send a signal to interrupt it.
*/
if (deadlock_state == DS_BLOCKED_BY_AUTOVACUUM && allow_autovacuum_cancel)
{
PGPROC *autovac = GetBlockingAutoVacuumPgproc();
PGXACT *autovac_pgxact = &ProcGlobal->allPgXact[autovac->pgprocno];
LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
/*
* Only do it if the worker is not working to protect against Xid
* wraparound.
*/
if ((autovac != NULL) &&
(autovac_pgxact->vacuumFlags & PROC_IS_AUTOVACUUM) &&
!(autovac_pgxact->vacuumFlags & PROC_VACUUM_FOR_WRAPAROUND))
{
int pid = autovac->pid;
StringInfoData locktagbuf;
StringInfoData logbuf; /* errdetail for server log */
initStringInfo(&locktagbuf);
initStringInfo(&logbuf);
DescribeLockTag(&locktagbuf, &lock->tag);
appendStringInfo(&logbuf,
_("Process %d waits for %s on %s."),
MyProcPid,
GetLockmodeName(lock->tag.locktag_lockmethodid,
lockmode),
locktagbuf.data);
/* release lock as quickly as possible */
LWLockRelease(ProcArrayLock);
ereport(LOG,
(errmsg("sending cancel to blocking autovacuum PID %d",
pid),
errdetail_log("%s", logbuf.data)));
pfree(logbuf.data);
pfree(locktagbuf.data);
/* send the autovacuum worker Back to Old Kent Road */
if (kill(pid, SIGINT) < 0)
{
/* Just a warning to allow multiple callers */
ereport(WARNING,
(errmsg("could not send signal to process %d: %m",
pid)));
}
}
else
LWLockRelease(ProcArrayLock);
/* prevent signal from being resent more than once */
allow_autovacuum_cancel = false;
}
/*
* If awoken after the deadlock check interrupt has run, and
* log_lock_waits is on, then report about the wait.
*/
if (log_lock_waits && deadlock_state != DS_NOT_YET_CHECKED)
{
StringInfoData buf;
const char *modename;
long secs;
int usecs;
long msecs;
initStringInfo(&buf);
DescribeLockTag(&buf, &locallock->tag.lock);
modename = GetLockmodeName(locallock->tag.lock.locktag_lockmethodid,
lockmode);
TimestampDifference(get_timeout_start_time(DEADLOCK_TIMEOUT),
GetCurrentTimestamp(),
&secs, &usecs);
msecs = secs * 1000 + usecs / 1000;
usecs = usecs % 1000;
if (deadlock_state == DS_SOFT_DEADLOCK)
ereport(LOG,
(errmsg("process %d avoided deadlock for %s on %s by rearranging queue order after %ld.%03d ms",
MyProcPid, modename, buf.data, msecs, usecs)));
else if (deadlock_state == DS_HARD_DEADLOCK)
{
/*
* This message is a bit redundant with the error that will be
* reported subsequently, but in some cases the error report
* might not make it to the log (eg, if it's caught by an
* exception handler), and we want to ensure all long-wait
* events get logged.
*/
ereport(LOG,
(errmsg("process %d detected deadlock while waiting for %s on %s after %ld.%03d ms",
MyProcPid, modename, buf.data, msecs, usecs)));
}
if (myWaitStatus == STATUS_WAITING)
ereport(LOG,
(errmsg("process %d still waiting for %s on %s after %ld.%03d ms",
MyProcPid, modename, buf.data, msecs, usecs)));
else if (myWaitStatus == STATUS_OK)
ereport(LOG,
(errmsg("process %d acquired %s on %s after %ld.%03d ms",
MyProcPid, modename, buf.data, msecs, usecs)));
else
{
Assert(myWaitStatus == STATUS_ERROR);
/*
* Currently, the deadlock checker always kicks its own
* process, which means that we'll only see STATUS_ERROR when
* deadlock_state == DS_HARD_DEADLOCK, and there's no need to
* print redundant messages. But for completeness and
* future-proofing, print a message if it looks like someone
* else kicked us off the lock.
*/
if (deadlock_state != DS_HARD_DEADLOCK)
ereport(LOG,
(errmsg("process %d failed to acquire %s on %s after %ld.%03d ms",
MyProcPid, modename, buf.data, msecs, usecs)));
}
/*
* At this point we might still need to wait for the lock. Reset
* state so we don't print the above messages again.
*/
deadlock_state = DS_NO_DEADLOCK;
pfree(buf.data);
}
} while (myWaitStatus == STATUS_WAITING);
/*
* Disable the timers, if they are still running
*/
if (LockTimeout > 0)
{
DisableTimeoutParams timeouts[2];
timeouts[0].id = DEADLOCK_TIMEOUT;
timeouts[0].keep_indicator = false;
timeouts[1].id = LOCK_TIMEOUT;
timeouts[1].keep_indicator = false;
disable_timeouts(timeouts, 2);
}
else
disable_timeout(DEADLOCK_TIMEOUT, false);
/*
* Re-acquire the lock table's partition lock. We have to do this to hold
* off cancel/die interrupts before we can mess with lockAwaited (else we
* might have a missed or duplicated locallock update).
*/
LWLockAcquire(partitionLock, LW_EXCLUSIVE);
/*
* We no longer want LockErrorCleanup to do anything.
*/
lockAwaited = NULL;
/*
* If we got the lock, be sure to remember it in the locallock table.
*/
if (MyProc->waitStatus == STATUS_OK)
GrantAwaitedLock();
/*
* We don't have to do anything else, because the awaker did all the
* necessary update of the lock table and MyProc.
*/
return MyProc->waitStatus;
}
| void ProcWaitForSignal | ( | void | ) |
Definition at line 1542 of file proc.c.
References PGSemaphoreLock(), and PGPROC::sem.
Referenced by GetSafeSnapshot(), LockBufferForCleanup(), and ResolveRecoveryConflictWithBufferPin().
{
PGSemaphoreLock(&MyProc->sem, true);
}
Definition at line 1327 of file proc.c.
References Assert, PGPROC::links, SHM_QUEUE::next, NULL, PGSemaphoreUnlock(), SHM_QUEUE::prev, PGPROC::sem, SHMQueueDelete(), PROC_QUEUE::size, STATUS_WAITING, PGPROC::waitLock, PGPROC::waitProcLock, LOCK::waitProcs, and PGPROC::waitStatus.
Referenced by ProcLockWakeup().
{
PGPROC *retProc;
/* Proc should be sleeping ... */
if (proc->links.prev == NULL ||
proc->links.next == NULL)
return NULL;
Assert(proc->waitStatus == STATUS_WAITING);
/* Save next process before we zap the list link */
retProc = (PGPROC *) proc->links.next;
/* Remove process from wait queue */
SHMQueueDelete(&(proc->links));
(proc->waitLock->waitProcs.size)--;
/* Clean up process' state and pass it the ok/fail signal */
proc->waitLock = NULL;
proc->waitProcLock = NULL;
proc->waitStatus = waitStatus;
/* And awaken it */
PGSemaphoreUnlock(&proc->sem);
return retProc;
}
| void PublishStartupProcessInformation | ( | void | ) |
Definition at line 576 of file proc.c.
References MyProcPid, ProcStructLock, SpinLockAcquire, SpinLockRelease, PROC_HDR::startupProc, and PROC_HDR::startupProcPid.
Referenced by StartupXLOG().
{
/* use volatile pointer to prevent code rearrangement */
volatile PROC_HDR *procglobal = ProcGlobal;
SpinLockAcquire(ProcStructLock);
procglobal->startupProc = MyProc;
procglobal->startupProcPid = MyProcPid;
SpinLockRelease(ProcStructLock);
}
| static void RemoveProcFromArray | ( | int | code, | |
| Datum | arg | |||
| ) | [static] |
Definition at line 762 of file proc.c.
References Assert, InvalidTransactionId, NULL, and ProcArrayRemove().
Referenced by InitProcessPhase2().
{
Assert(MyProc != NULL);
ProcArrayRemove(MyProc, InvalidTransactionId);
}
| void SetStartupBufferPinWaitBufId | ( | int | bufid | ) |
Definition at line 597 of file proc.c.
References PROC_HDR::startupBufferPinWaitBufId.
Referenced by LockBufferForCleanup().
{
/* use volatile pointer to prevent code rearrangement */
volatile PROC_HDR *procglobal = ProcGlobal;
procglobal->startupBufferPinWaitBufId = bufid;
}
| NON_EXEC_STATIC PGPROC* AuxiliaryProcs = NULL |
Definition at line 76 of file proc.c.
Referenced by AuxiliaryProcKill(), InitAuxiliaryProcess(), and InitProcGlobal().
volatile DeadLockState deadlock_state = DS_NOT_YET_CHECKED [static] |
Definition at line 83 of file proc.c.
Referenced by CheckDeadLock(), and ProcSleep().
| int DeadlockTimeout = 1000 |
Definition at line 56 of file proc.c.
Referenced by ProcSleep(), and ResolveRecoveryConflictWithBufferPin().
LOCALLOCK* lockAwaited = NULL [static] |
| int LockTimeout = 0 |
Definition at line 58 of file proc.c.
Referenced by ProcSleep().
| bool log_lock_waits = false |
Definition at line 59 of file proc.c.
Referenced by CheckDeadLock(), and ProcSleep().
Definition at line 63 of file proc.c.
Referenced by analyze_rel(), EndPrepare(), GetNewTransactionId(), GetSnapshotData(), MarkBufferDirtyHint(), ProcArrayInstallImportedXmin(), ProcessStandbyHSFeedbackMessage(), RecordTransactionCommit(), RecordTransactionCommitPrepared(), SnapshotResetXmin(), vacuum_rel(), XidCacheRemoveRunningXids(), and XLogSaveBufferForHint().
Definition at line 62 of file proc.c.
Referenced by AbortTransaction(), AutoVacLauncherMain(), AutoVacWorkerMain(), avl_sighup_handler(), avl_sigterm_handler(), avl_sigusr2_handler(), BackgroundWriterMain(), BgSigHupHandler(), CheckpointerMain(), ChkptSigHupHandler(), CommitTransaction(), CountOtherDBBackends(), die(), errdetail_abort(), exec_eval_simple_expr(), FastPathGetRelationLockEntry(), FastPathGrantRelationLock(), FastPathUnGrantRelationLock(), FindLockCycleRecurse(), fmgr_sql(), GetCurrentVirtualXIDs(), GetLockConflicts(), GetNewTransactionId(), GetSerializableTransactionSnapshotInt(), GetStableLatestTransactionId(), handle_sig_alarm(), init_sql_fcache(), InitializeSessionUserId(), InitPostgres(), LockAcquireExtended(), LockRelease(), LockReleaseAll(), log_line_prefix(), LWLockAcquire(), LWLockAcquireOrWait(), MinimumActiveBackends(), open_share_lock(), PostPrepare_Locks(), PrepareTransaction(), RecoveryConflictInterrupt(), ReqCheckpointHandler(), ReqShutdownHandler(), SharedInvalBackendInit(), SigHupHandler(), StartTransaction(), StatementCancelHandler(), SyncRepCancelWait(), SyncRepCleanupAtProcExit(), SyncRepQueueInsert(), SyncRepWaitForLSN(), TransactionIdIsInProgress(), VirtualXactLockTableCleanup(), VirtualXactLockTableInsert(), WalShutdownHandler(), WalSigHupHandler(), WalWriterMain(), worker_spi_main(), worker_spi_sighup(), worker_spi_sigterm(), write_csvlog(), and XidCacheRemoveRunningXids().
| PGPROC* PreparedXactProcs = NULL |
Definition at line 77 of file proc.c.
Referenced by TwoPhaseShmemInit().
| PROC_HDR* ProcGlobal = NULL |
Definition at line 75 of file proc.c.
Referenced by CheckpointerMain(), CheckPointTwoPhase(), CreateSharedProcArray(), EndPrepare(), FastPathTransferRelationLocks(), FindLockCycleRecurse(), FinishPreparedTransaction(), ForwardFsyncRequest(), GetLockConflicts(), GetLockStatusData(), GetRunningTransactionLocks(), GXactLoadSubxactData(), LockGXact(), MarkAsPrepared(), MarkAsPreparing(), pg_prepared_xact(), StartPrepare(), TransactionIdIsPrepared(), TwoPhaseGetDummyProc(), TwoPhaseGetGXact(), WalWriterMain(), and XLogSetAsyncXactLSN().
| NON_EXEC_STATIC slock_t* ProcStructLock = NULL |
Definition at line 72 of file proc.c.
Referenced by AuxiliaryProcKill(), HaveNFreeProcs(), InitAuxiliaryProcess(), InitProcess(), InitProcGlobal(), ProcKill(), ProcSendSignal(), and PublishStartupProcessInformation().
| int StatementTimeout = 0 |
Definition at line 57 of file proc.c.
Referenced by start_xact_command().
1.7.1