Volatile-qualify the ProcArray PGPROC pointer in a bunch of routines

that examine fields that could change under them.  This is just to make
really sure that when we are fetching a value 'only once', that's what
actually happens.  Possibly this is a bug that should be back-patched,
but in the absence of solid evidence that it's needed, I won't bother.
This commit is contained in:
Tom Lane 2007-09-05 21:11:19 +00:00
parent 4bf2dfb9a2
commit 0ecb4ea773
1 changed files with 14 additions and 14 deletions

View File

@ -23,7 +23,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/storage/ipc/procarray.c,v 1.29 2007/09/05 18:10:47 tgl Exp $
* $PostgreSQL: pgsql/src/backend/storage/ipc/procarray.c,v 1.30 2007/09/05 21:11:19 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -233,7 +233,7 @@ TransactionIdIsInProgress(TransactionId xid)
for (i = 0; i < arrayP->numProcs; i++)
{
PGPROC *proc = arrayP->procs[i];
volatile PGPROC *proc = arrayP->procs[i];
/* Fetch xid just once - see GetNewTransactionId */
TransactionId pxid = proc->xid;
@ -361,7 +361,7 @@ TransactionIdIsActive(TransactionId xid)
for (i = 0; i < arrayP->numProcs; i++)
{
PGPROC *proc = arrayP->procs[i];
volatile PGPROC *proc = arrayP->procs[i];
/* Fetch xid just once - see GetNewTransactionId */
TransactionId pxid = proc->xid;
@ -434,7 +434,7 @@ GetOldestXmin(bool allDbs, bool ignoreVacuum)
for (index = 0; index < arrayP->numProcs; index++)
{
PGPROC *proc = arrayP->procs[index];
volatile PGPROC *proc = arrayP->procs[index];
if (ignoreVacuum && proc->inVacuum)
continue;
@ -613,7 +613,7 @@ GetSnapshotData(Snapshot snapshot, bool serializable)
*/
for (index = 0; index < arrayP->numProcs; index++)
{
PGPROC *proc = arrayP->procs[index];
volatile PGPROC *proc = arrayP->procs[index];
TransactionId xid;
/* Ignore procs running LAZY VACUUM */
@ -672,7 +672,7 @@ GetSnapshotData(Snapshot snapshot, bool serializable)
if (nxids > 0)
{
memcpy(snapshot->subxip + subcount,
proc->subxids.xids,
(void *) proc->subxids.xids,
nxids * sizeof(TransactionId));
subcount += nxids;
}
@ -739,7 +739,7 @@ GetTransactionsInCommit(TransactionId **xids_p)
for (index = 0; index < arrayP->numProcs; index++)
{
PGPROC *proc = arrayP->procs[index];
volatile PGPROC *proc = arrayP->procs[index];
/* Fetch xid just once - see GetNewTransactionId */
TransactionId pxid = proc->xid;
@ -773,7 +773,7 @@ HaveTransactionsInCommit(TransactionId *xids, int nxids)
for (index = 0; index < arrayP->numProcs; index++)
{
PGPROC *proc = arrayP->procs[index];
volatile PGPROC *proc = arrayP->procs[index];
/* Fetch xid just once - see GetNewTransactionId */
TransactionId pxid = proc->xid;
@ -861,7 +861,7 @@ BackendXidGetPid(TransactionId xid)
for (index = 0; index < arrayP->numProcs; index++)
{
PGPROC *proc = arrayP->procs[index];
volatile PGPROC *proc = arrayP->procs[index];
if (proc->xid == xid)
{
@ -909,7 +909,7 @@ GetCurrentVirtualXIDs(TransactionId limitXmin)
for (index = 0; index < arrayP->numProcs; index++)
{
PGPROC *proc = arrayP->procs[index];
volatile PGPROC *proc = arrayP->procs[index];
/* Fetch xmin just once - might change on us? */
TransactionId pxmin = proc->xmin;
@ -963,7 +963,7 @@ CountActiveBackends(void)
*/
for (index = 0; index < arrayP->numProcs; index++)
{
PGPROC *proc = arrayP->procs[index];
volatile PGPROC *proc = arrayP->procs[index];
if (proc == MyProc)
continue; /* do not count myself */
@ -993,7 +993,7 @@ CountDBBackends(Oid databaseid)
for (index = 0; index < arrayP->numProcs; index++)
{
PGPROC *proc = arrayP->procs[index];
volatile PGPROC *proc = arrayP->procs[index];
if (proc->pid == 0)
continue; /* do not count prepared xacts */
@ -1020,7 +1020,7 @@ CountUserBackends(Oid roleid)
for (index = 0; index < arrayP->numProcs; index++)
{
PGPROC *proc = arrayP->procs[index];
volatile PGPROC *proc = arrayP->procs[index];
if (proc->pid == 0)
continue; /* do not count prepared xacts */
@ -1072,7 +1072,7 @@ CheckOtherDBBackends(Oid databaseId)
for (index = 0; index < arrayP->numProcs; index++)
{
PGPROC *proc = arrayP->procs[index];
volatile PGPROC *proc = arrayP->procs[index];
if (proc->databaseId != databaseId)
continue;