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Pgindent run for 8.0.

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This commit is contained in:
Bruce Momjian
2004-08-29 05:07:03 +00:00
parent 90cb9c3051
commit b6b71b85bc
527 changed files with 20550 additions and 18283 deletions
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41
src/backend/access/transam/varsup.c
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@ -6,7 +6,7 @@
* Copyright (c) 2000-2004, PostgreSQL Global Development Group
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/access/transam/varsup.c,v 1.58 2004/08/29 04:12:23 momjian Exp $
* $PostgreSQL: pgsql/src/backend/access/transam/varsup.c,v 1.59 2004/08/29 05:06:40 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -47,9 +47,9 @@ GetNewTransactionId(bool isSubXact)
xid = ShmemVariableCache->nextXid;
/*
* If we are allocating the first XID of a new page of the commit
* log, zero out that commit-log page before returning. We must do
* this while holding XidGenLock, else another xact could acquire and
* If we are allocating the first XID of a new page of the commit log,
* zero out that commit-log page before returning. We must do this
* while holding XidGenLock, else another xact could acquire and
* commit a later XID before we zero the page. Fortunately, a page of
* the commit log holds 32K or more transactions, so we don't have to
* do this very often.
@ -61,17 +61,18 @@ GetNewTransactionId(bool isSubXact)
/*
* Now advance the nextXid counter. This must not happen until after
* we have successfully completed ExtendCLOG() --- if that routine fails,
* we want the next incoming transaction to try it again. We cannot
* assign more XIDs until there is CLOG space for them.
* we have successfully completed ExtendCLOG() --- if that routine
* fails, we want the next incoming transaction to try it again. We
* cannot assign more XIDs until there is CLOG space for them.
*/
TransactionIdAdvance(ShmemVariableCache->nextXid);
/*
* We must store the new XID into the shared PGPROC array before releasing
* XidGenLock. This ensures that when GetSnapshotData calls
* We must store the new XID into the shared PGPROC array before
* releasing XidGenLock. This ensures that when GetSnapshotData calls
* ReadNewTransactionId, all active XIDs before the returned value of
* nextXid are already present in PGPROC. Else we have a race condition.
* nextXid are already present in PGPROC. Else we have a race
* condition.
*
* XXX by storing xid into MyProc without acquiring SInvalLock, we are
* relying on fetch/store of an xid to be atomic, else other backends
@ -86,19 +87,19 @@ GetNewTransactionId(bool isSubXact)
*
* A solution to the atomic-store problem would be to give each PGPROC
* its own spinlock used only for fetching/storing that PGPROC's xid
* and related fields. (SInvalLock would then mean primarily that
* and related fields. (SInvalLock would then mean primarily that
* PGPROCs couldn't be added/removed while holding the lock.)
*
* If there's no room to fit a subtransaction XID into PGPROC, set the
* cache-overflowed flag instead. This forces readers to look in
* pg_subtrans to map subtransaction XIDs up to top-level XIDs.
* There is a race-condition window, in that the new XID will not
* appear as running until its parent link has been placed into
* pg_subtrans. However, that will happen before anyone could possibly
* have a reason to inquire about the status of the XID, so it seems
* OK. (Snapshots taken during this window *will* include the parent
* XID, so they will deliver the correct answer later on when someone
* does have a reason to inquire.)
* pg_subtrans to map subtransaction XIDs up to top-level XIDs. There
* is a race-condition window, in that the new XID will not appear as
* running until its parent link has been placed into pg_subtrans.
* However, that will happen before anyone could possibly have a
* reason to inquire about the status of the XID, so it seems OK.
* (Snapshots taken during this window *will* include the parent XID,
* so they will deliver the correct answer later on when someone does
* have a reason to inquire.)
*/
if (MyProc != NULL)
{
@ -112,9 +113,7 @@ GetNewTransactionId(bool isSubXact)
MyProc->subxids.nxids++;
}
else
{
MyProc->subxids.overflowed = true;
}
}
}