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-rw-r--r--src/backend/storage/ipc/procarray.c133
1 files changed, 78 insertions, 55 deletions
diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index 42a89fc5dc9..085bd1e4077 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -446,6 +446,7 @@ ProcArrayAdd(PGPROC *proc)
{
ProcArrayStruct *arrayP = procArray;
int index;
+ int movecount;
/* See ProcGlobal comment explaining why both locks are held */
LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
@@ -474,33 +475,48 @@ ProcArrayAdd(PGPROC *proc)
*/
for (index = 0; index < arrayP->numProcs; index++)
{
- /*
- * If we are the first PGPROC or if we have found our right position
- * in the array, break
- */
- if ((arrayP->pgprocnos[index] == -1) || (arrayP->pgprocnos[index] > proc->pgprocno))
+ int procno PG_USED_FOR_ASSERTS_ONLY = arrayP->pgprocnos[index];
+
+ Assert(procno >= 0 && procno < (arrayP->maxProcs + NUM_AUXILIARY_PROCS));
+ Assert(allProcs[procno].pgxactoff == index);
+
+ /* If we have found our right position in the array, break */
+ if (arrayP->pgprocnos[index] > proc->pgprocno)
break;
}
- memmove(&arrayP->pgprocnos[index + 1], &arrayP->pgprocnos[index],
- (arrayP->numProcs - index) * sizeof(*arrayP->pgprocnos));
- memmove(&ProcGlobal->xids[index + 1], &ProcGlobal->xids[index],
- (arrayP->numProcs - index) * sizeof(*ProcGlobal->xids));
- memmove(&ProcGlobal->subxidStates[index + 1], &ProcGlobal->subxidStates[index],
- (arrayP->numProcs - index) * sizeof(*ProcGlobal->subxidStates));
- memmove(&ProcGlobal->statusFlags[index + 1], &ProcGlobal->statusFlags[index],
- (arrayP->numProcs - index) * sizeof(*ProcGlobal->statusFlags));
+ movecount = arrayP->numProcs - index;
+ memmove(&arrayP->pgprocnos[index + 1],
+ &arrayP->pgprocnos[index],
+ movecount * sizeof(*arrayP->pgprocnos));
+ memmove(&ProcGlobal->xids[index + 1],
+ &ProcGlobal->xids[index],
+ movecount * sizeof(*ProcGlobal->xids));
+ memmove(&ProcGlobal->subxidStates[index + 1],
+ &ProcGlobal->subxidStates[index],
+ movecount * sizeof(*ProcGlobal->subxidStates));
+ memmove(&ProcGlobal->statusFlags[index + 1],
+ &ProcGlobal->statusFlags[index],
+ movecount * sizeof(*ProcGlobal->statusFlags));
arrayP->pgprocnos[index] = proc->pgprocno;
+ proc->pgxactoff = index;
ProcGlobal->xids[index] = proc->xid;
ProcGlobal->subxidStates[index] = proc->subxidStatus;
ProcGlobal->statusFlags[index] = proc->statusFlags;
arrayP->numProcs++;
+ /* adjust pgxactoff for all following PGPROCs */
+ index++;
for (; index < arrayP->numProcs; index++)
{
- allProcs[arrayP->pgprocnos[index]].pgxactoff = index;
+ int procno = arrayP->pgprocnos[index];
+
+ Assert(procno >= 0 && procno < (arrayP->maxProcs + NUM_AUXILIARY_PROCS));
+ Assert(allProcs[procno].pgxactoff == index - 1);
+
+ allProcs[procno].pgxactoff = index;
}
/*
@@ -525,7 +541,8 @@ void
ProcArrayRemove(PGPROC *proc, TransactionId latestXid)
{
ProcArrayStruct *arrayP = procArray;
- int index;
+ int myoff;
+ int movecount;
#ifdef XIDCACHE_DEBUG
/* dump stats at backend shutdown, but not prepared-xact end */
@@ -537,11 +554,14 @@ ProcArrayRemove(PGPROC *proc, TransactionId latestXid)
LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
LWLockAcquire(XidGenLock, LW_EXCLUSIVE);
- Assert(ProcGlobal->allProcs[arrayP->pgprocnos[proc->pgxactoff]].pgxactoff == proc->pgxactoff);
+ myoff = proc->pgxactoff;
+
+ Assert(myoff >= 0 && myoff < arrayP->numProcs);
+ Assert(ProcGlobal->allProcs[arrayP->pgprocnos[myoff]].pgxactoff == myoff);
if (TransactionIdIsValid(latestXid))
{
- Assert(TransactionIdIsValid(ProcGlobal->xids[proc->pgxactoff]));
+ Assert(TransactionIdIsValid(ProcGlobal->xids[myoff]));
/* Advance global latestCompletedXid while holding the lock */
MaintainLatestCompletedXid(latestXid);
@@ -549,57 +569,60 @@ ProcArrayRemove(PGPROC *proc, TransactionId latestXid)
/* Same with xactCompletionCount */
ShmemVariableCache->xactCompletionCount++;
- ProcGlobal->xids[proc->pgxactoff] = 0;
- ProcGlobal->subxidStates[proc->pgxactoff].overflowed = false;
- ProcGlobal->subxidStates[proc->pgxactoff].count = 0;
+ ProcGlobal->xids[myoff] = InvalidTransactionId;
+ ProcGlobal->subxidStates[myoff].overflowed = false;
+ ProcGlobal->subxidStates[myoff].count = 0;
}
else
{
/* Shouldn't be trying to remove a live transaction here */
- Assert(!TransactionIdIsValid(ProcGlobal->xids[proc->pgxactoff]));
+ Assert(!TransactionIdIsValid(ProcGlobal->xids[myoff]));
}
- Assert(TransactionIdIsValid(ProcGlobal->xids[proc->pgxactoff] == 0));
- Assert(TransactionIdIsValid(ProcGlobal->subxidStates[proc->pgxactoff].count == 0));
- Assert(TransactionIdIsValid(ProcGlobal->subxidStates[proc->pgxactoff].overflowed == false));
- ProcGlobal->statusFlags[proc->pgxactoff] = 0;
+ Assert(!TransactionIdIsValid(ProcGlobal->xids[myoff]));
+ Assert(ProcGlobal->subxidStates[myoff].count == 0);
+ Assert(ProcGlobal->subxidStates[myoff].overflowed == false);
+
+ ProcGlobal->statusFlags[myoff] = 0;
+
+ /* Keep the PGPROC array sorted. See notes above */
+ movecount = arrayP->numProcs - myoff - 1;
+ memmove(&arrayP->pgprocnos[myoff],
+ &arrayP->pgprocnos[myoff + 1],
+ movecount * sizeof(*arrayP->pgprocnos));
+ memmove(&ProcGlobal->xids[myoff],
+ &ProcGlobal->xids[myoff + 1],
+ movecount * sizeof(*ProcGlobal->xids));
+ memmove(&ProcGlobal->subxidStates[myoff],
+ &ProcGlobal->subxidStates[myoff + 1],
+ movecount * sizeof(*ProcGlobal->subxidStates));
+ memmove(&ProcGlobal->statusFlags[myoff],
+ &ProcGlobal->statusFlags[myoff + 1],
+ movecount * sizeof(*ProcGlobal->statusFlags));
+
+ arrayP->pgprocnos[arrayP->numProcs - 1] = -1; /* for debugging */
+ arrayP->numProcs--;
- for (index = 0; index < arrayP->numProcs; index++)
+ /*
+ * Adjust pgxactoff of following procs for removed PGPROC (note that
+ * numProcs already has been decremented).
+ */
+ for (int index = myoff; index < arrayP->numProcs; index++)
{
- if (arrayP->pgprocnos[index] == proc->pgprocno)
- {
- /* Keep the PGPROC array sorted. See notes above */
- memmove(&arrayP->pgprocnos[index], &arrayP->pgprocnos[index + 1],
- (arrayP->numProcs - index - 1) * sizeof(*arrayP->pgprocnos));
- memmove(&ProcGlobal->xids[index], &ProcGlobal->xids[index + 1],
- (arrayP->numProcs - index - 1) * sizeof(*ProcGlobal->xids));
- memmove(&ProcGlobal->subxidStates[index], &ProcGlobal->subxidStates[index + 1],
- (arrayP->numProcs - index - 1) * sizeof(*ProcGlobal->subxidStates));
- memmove(&ProcGlobal->statusFlags[index], &ProcGlobal->statusFlags[index + 1],
- (arrayP->numProcs - index - 1) * sizeof(*ProcGlobal->statusFlags));
-
- arrayP->pgprocnos[arrayP->numProcs - 1] = -1; /* for debugging */
- arrayP->numProcs--;
-
- /* adjust for removed PGPROC */
- for (; index < arrayP->numProcs; index++)
- allProcs[arrayP->pgprocnos[index]].pgxactoff--;
+ int procno = arrayP->pgprocnos[index];
- /*
- * Release in reversed acquisition order, to reduce frequency of
- * having to wait for XidGenLock while holding ProcArrayLock.
- */
- LWLockRelease(XidGenLock);
- LWLockRelease(ProcArrayLock);
- return;
- }
+ Assert(procno >= 0 && procno < (arrayP->maxProcs + NUM_AUXILIARY_PROCS));
+ Assert(allProcs[procno].pgxactoff - 1 == index);
+
+ allProcs[procno].pgxactoff = index;
}
- /* Oops */
+ /*
+ * Release in reversed acquisition order, to reduce frequency of having to
+ * wait for XidGenLock while holding ProcArrayLock.
+ */
LWLockRelease(XidGenLock);
LWLockRelease(ProcArrayLock);
-
- elog(LOG, "failed to find proc %p in ProcArray", proc);
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-28 18:40:01 +0000