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Diffstat (limited to 'src/backend/access/transam/multixact.c')
-rw-r--r--src/backend/access/transam/multixact.c64
1 files changed, 31 insertions, 33 deletions
diff --git a/src/backend/access/transam/multixact.c b/src/backend/access/transam/multixact.c
index 9b815061452..9dc7aa9c2f4 100644
--- a/src/backend/access/transam/multixact.c
+++ b/src/backend/access/transam/multixact.c
@@ -237,11 +237,11 @@ typedef struct MultiXactStateData
/*
* Per-backend data starts here. We have two arrays stored in the area
* immediately following the MultiXactStateData struct. Each is indexed by
- * BackendId.
+ * ProcNumber.
*
- * In both arrays, there's a slot for all normal backends (1..MaxBackends)
- * followed by a slot for max_prepared_xacts prepared transactions. Valid
- * BackendIds start from 1; element zero of each array is never used.
+ * In both arrays, there's a slot for all normal backends
+ * (0..MaxBackends-1) followed by a slot for max_prepared_xacts prepared
+ * transactions.
*
* OldestMemberMXactId[k] is the oldest MultiXactId each backend's current
* transaction(s) could possibly be a member of, or InvalidMultiXactId
@@ -285,8 +285,7 @@ typedef struct MultiXactStateData
} MultiXactStateData;
/*
- * Last element of OldestMemberMXactId and OldestVisibleMXactId arrays.
- * Valid elements are (1..MaxOldestSlot); element 0 is never used.
+ * Size of OldestMemberMXactId and OldestVisibleMXactId arrays.
*/
#define MaxOldestSlot (MaxBackends + max_prepared_xacts)
@@ -397,7 +396,7 @@ MultiXactIdCreate(TransactionId xid1, MultiXactStatus status1,
Assert(!TransactionIdEquals(xid1, xid2) || (status1 != status2));
/* MultiXactIdSetOldestMember() must have been called already. */
- Assert(MultiXactIdIsValid(OldestMemberMXactId[MyBackendId]));
+ Assert(MultiXactIdIsValid(OldestMemberMXactId[MyProcNumber]));
/*
* Note: unlike MultiXactIdExpand, we don't bother to check that both XIDs
@@ -451,7 +450,7 @@ MultiXactIdExpand(MultiXactId multi, TransactionId xid, MultiXactStatus status)
Assert(TransactionIdIsValid(xid));
/* MultiXactIdSetOldestMember() must have been called already. */
- Assert(MultiXactIdIsValid(OldestMemberMXactId[MyBackendId]));
+ Assert(MultiXactIdIsValid(OldestMemberMXactId[MyProcNumber]));
debug_elog5(DEBUG2, "Expand: received multi %u, xid %u status %s",
multi, xid, mxstatus_to_string(status));
@@ -626,7 +625,7 @@ MultiXactIdIsRunning(MultiXactId multi, bool isLockOnly)
void
MultiXactIdSetOldestMember(void)
{
- if (!MultiXactIdIsValid(OldestMemberMXactId[MyBackendId]))
+ if (!MultiXactIdIsValid(OldestMemberMXactId[MyProcNumber]))
{
MultiXactId nextMXact;
@@ -655,12 +654,12 @@ MultiXactIdSetOldestMember(void)
if (nextMXact < FirstMultiXactId)
nextMXact = FirstMultiXactId;
- OldestMemberMXactId[MyBackendId] = nextMXact;
+ OldestMemberMXactId[MyProcNumber] = nextMXact;
LWLockRelease(MultiXactGenLock);
debug_elog4(DEBUG2, "MultiXact: setting OldestMember[%d] = %u",
- MyBackendId, nextMXact);
+ MyProcNumber, nextMXact);
}
}
@@ -683,7 +682,7 @@ MultiXactIdSetOldestMember(void)
static void
MultiXactIdSetOldestVisible(void)
{
- if (!MultiXactIdIsValid(OldestVisibleMXactId[MyBackendId]))
+ if (!MultiXactIdIsValid(OldestVisibleMXactId[MyProcNumber]))
{
MultiXactId oldestMXact;
int i;
@@ -699,7 +698,7 @@ MultiXactIdSetOldestVisible(void)
if (oldestMXact < FirstMultiXactId)
oldestMXact = FirstMultiXactId;
- for (i = 1; i <= MaxOldestSlot; i++)
+ for (i = 0; i < MaxOldestSlot; i++)
{
MultiXactId thisoldest = OldestMemberMXactId[i];
@@ -708,12 +707,12 @@ MultiXactIdSetOldestVisible(void)
oldestMXact = thisoldest;
}
- OldestVisibleMXactId[MyBackendId] = oldestMXact;
+ OldestVisibleMXactId[MyProcNumber] = oldestMXact;
LWLockRelease(MultiXactGenLock);
debug_elog4(DEBUG2, "MultiXact: setting OldestVisible[%d] = %u",
- MyBackendId, oldestMXact);
+ MyProcNumber, oldestMXact);
}
}
@@ -1285,7 +1284,7 @@ GetMultiXactIdMembers(MultiXactId multi, MultiXactMember **members,
* multi. It cannot possibly still be running.
*/
if (isLockOnly &&
- MultiXactIdPrecedes(multi, OldestVisibleMXactId[MyBackendId]))
+ MultiXactIdPrecedes(multi, OldestVisibleMXactId[MyProcNumber]))
{
debug_elog2(DEBUG2, "GetMembers: a locker-only multi is too old");
*members = NULL;
@@ -1752,8 +1751,8 @@ AtEOXact_MultiXact(void)
* We assume that storing a MultiXactId is atomic and so we need not take
* MultiXactGenLock to do this.
*/
- OldestMemberMXactId[MyBackendId] = InvalidMultiXactId;
- OldestVisibleMXactId[MyBackendId] = InvalidMultiXactId;
+ OldestMemberMXactId[MyProcNumber] = InvalidMultiXactId;
+ OldestVisibleMXactId[MyProcNumber] = InvalidMultiXactId;
/*
* Discard the local MultiXactId cache. Since MXactContext was created as
@@ -1773,7 +1772,7 @@ AtEOXact_MultiXact(void)
void
AtPrepare_MultiXact(void)
{
- MultiXactId myOldestMember = OldestMemberMXactId[MyBackendId];
+ MultiXactId myOldestMember = OldestMemberMXactId[MyProcNumber];
if (MultiXactIdIsValid(myOldestMember))
RegisterTwoPhaseRecord(TWOPHASE_RM_MULTIXACT_ID, 0,
@@ -1793,10 +1792,10 @@ PostPrepare_MultiXact(TransactionId xid)
* Transfer our OldestMemberMXactId value to the slot reserved for the
* prepared transaction.
*/
- myOldestMember = OldestMemberMXactId[MyBackendId];
+ myOldestMember = OldestMemberMXactId[MyProcNumber];
if (MultiXactIdIsValid(myOldestMember))
{
- BackendId dummyBackendId = TwoPhaseGetDummyBackendId(xid, false);
+ ProcNumber dummyProcNumber = TwoPhaseGetDummyProcNumber(xid, false);
/*
* Even though storing MultiXactId is atomic, acquire lock to make
@@ -1806,8 +1805,8 @@ PostPrepare_MultiXact(TransactionId xid)
*/
LWLockAcquire(MultiXactGenLock, LW_EXCLUSIVE);
- OldestMemberMXactId[dummyBackendId] = myOldestMember;
- OldestMemberMXactId[MyBackendId] = InvalidMultiXactId;
+ OldestMemberMXactId[dummyProcNumber] = myOldestMember;
+ OldestMemberMXactId[MyProcNumber] = InvalidMultiXactId;
LWLockRelease(MultiXactGenLock);
}
@@ -1820,7 +1819,7 @@ PostPrepare_MultiXact(TransactionId xid)
* We assume that storing a MultiXactId is atomic and so we need not take
* MultiXactGenLock to do this.
*/
- OldestVisibleMXactId[MyBackendId] = InvalidMultiXactId;
+ OldestVisibleMXactId[MyProcNumber] = InvalidMultiXactId;
/*
* Discard the local MultiXactId cache like in AtEOXact_MultiXact.
@@ -1837,7 +1836,7 @@ void
multixact_twophase_recover(TransactionId xid, uint16 info,
void *recdata, uint32 len)
{
- BackendId dummyBackendId = TwoPhaseGetDummyBackendId(xid, false);
+ ProcNumber dummyProcNumber = TwoPhaseGetDummyProcNumber(xid, false);
MultiXactId oldestMember;
/*
@@ -1847,7 +1846,7 @@ multixact_twophase_recover(TransactionId xid, uint16 info,
Assert(len == sizeof(MultiXactId));
oldestMember = *((MultiXactId *) recdata);
- OldestMemberMXactId[dummyBackendId] = oldestMember;
+ OldestMemberMXactId[dummyProcNumber] = oldestMember;
}
/*
@@ -1858,11 +1857,11 @@ void
multixact_twophase_postcommit(TransactionId xid, uint16 info,
void *recdata, uint32 len)
{
- BackendId dummyBackendId = TwoPhaseGetDummyBackendId(xid, true);
+ ProcNumber dummyProcNumber = TwoPhaseGetDummyProcNumber(xid, true);
Assert(len == sizeof(MultiXactId));
- OldestMemberMXactId[dummyBackendId] = InvalidMultiXactId;
+ OldestMemberMXactId[dummyProcNumber] = InvalidMultiXactId;
}
/*
@@ -1886,9 +1885,9 @@ MultiXactShmemSize(void)
{
Size size;
- /* We need 2*MaxOldestSlot + 1 perBackendXactIds[] entries */
+ /* We need 2*MaxOldestSlot perBackendXactIds[] entries */
#define SHARED_MULTIXACT_STATE_SIZE \
- add_size(offsetof(MultiXactStateData, perBackendXactIds) + sizeof(MultiXactId), \
+ add_size(offsetof(MultiXactStateData, perBackendXactIds), \
mul_size(sizeof(MultiXactId) * 2, MaxOldestSlot))
size = SHARED_MULTIXACT_STATE_SIZE;
@@ -1938,8 +1937,7 @@ MultiXactShmemInit(void)
Assert(found);
/*
- * Set up array pointers. Note that perBackendXactIds[0] is wasted space
- * since we only use indexes 1..MaxOldestSlot in each array.
+ * Set up array pointers.
*/
OldestMemberMXactId = MultiXactState->perBackendXactIds;
OldestVisibleMXactId = OldestMemberMXactId + MaxOldestSlot;
@@ -2617,7 +2615,7 @@ GetOldestMultiXactId(void)
nextMXact = FirstMultiXactId;
oldestMXact = nextMXact;
- for (i = 1; i <= MaxOldestSlot; i++)
+ for (i = 0; i < MaxOldestSlot; i++)
{
MultiXactId thisoldest;
generated by cgit v1.2.3 (git 2.46.0) at 2025-10-01 09:08:44 +0000