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Remove volatile qualifiers from proc.c and procarray.c

Browse Source 
Prior to commit 0709b7ee72, access to
variables within a spinlock-protected critical section had to be done
through a volatile pointer, but that should no longer be necessary.

Michael Paquier
This commit is contained in:
Robert Haas
2015-10-16 14:20:36 -04:00
parent 430008b5a7
commit d53e3d5fe0
2 changed files with 19 additions and 36 deletions
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20
src/backend/storage/ipc/procarray.c
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@@ -3718,8 +3718,6 @@ static int
KnownAssignedXidsGetAndSetXmin(TransactionId *xarray, TransactionId *xmin,
TransactionId xmax)
{
/* use volatile pointer to prevent code rearrangement */
volatile ProcArrayStruct *pArray = procArray;
int count = 0;
int head,
tail;
@@ -3734,10 +3732,10 @@ KnownAssignedXidsGetAndSetXmin(TransactionId *xarray, TransactionId *xmin,
*
* Must take spinlock to ensure we see up-to-date array contents.
*/
SpinLockAcquire(&pArray->known_assigned_xids_lck);
tail = pArray->tailKnownAssignedXids;
head = pArray->headKnownAssignedXids;
SpinLockRelease(&pArray->known_assigned_xids_lck);
SpinLockAcquire(&procArray->known_assigned_xids_lck);
tail = procArray->tailKnownAssignedXids;
head = procArray->headKnownAssignedXids;
SpinLockRelease(&procArray->known_assigned_xids_lck);
for (i = tail; i < head; i++)
{
@@ -3777,8 +3775,6 @@ KnownAssignedXidsGetAndSetXmin(TransactionId *xarray, TransactionId *xmin,
static TransactionId
KnownAssignedXidsGetOldestXmin(void)
{
/* use volatile pointer to prevent code rearrangement */
volatile ProcArrayStruct *pArray = procArray;
int head,
tail;
int i;
@@ -3786,10 +3782,10 @@ KnownAssignedXidsGetOldestXmin(void)
/*
* Fetch head just once, since it may change while we loop.
*/
SpinLockAcquire(&pArray->known_assigned_xids_lck);
tail = pArray->tailKnownAssignedXids;
head = pArray->headKnownAssignedXids;
SpinLockRelease(&pArray->known_assigned_xids_lck);
SpinLockAcquire(&procArray->known_assigned_xids_lck);
tail = procArray->tailKnownAssignedXids;
head = procArray->headKnownAssignedXids;
SpinLockRelease(&procArray->known_assigned_xids_lck);
for (i = tail; i < head; i++)
{