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Make ascii-art in comments pgindent-safe, and some other formatting changes.

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Kevin Grittner
This commit is contained in:
Heikki Linnakangas 2011-06-07 09:54:24 +03:00
parent fc1286d3cb
commit a31ff707a2
1 changed files with 17 additions and 13 deletions
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16
src/backend/storage/lmgr/predicate.c
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@ -3814,7 +3814,7 @@ FlagRWConflict(SERIALIZABLEXACT *reader, SERIALIZABLEXACT *writer)
SetRWConflict(reader, writer);
}
/*
/*----------------------------------------------------------------------------
* We are about to add a RW-edge to the dependency graph - check that we don't
* introduce a dangerous structure by doing so, and abort one of the
* transactions if so.
@ -3830,6 +3830,7 @@ FlagRWConflict(SERIALIZABLEXACT *reader, SERIALIZABLEXACT *writer)
* One more optimization is that if Tin is declared READ ONLY (or commits
* without writing), we can only have a problem if Tout committed before Tin
* acquired its snapshot.
*----------------------------------------------------------------------------
*/
static void
OnConflict_CheckForSerializationFailure(const SERIALIZABLEXACT *reader,
@ -3842,7 +3843,7 @@ OnConflict_CheckForSerializationFailure(const SERIALIZABLEXACT *reader,
failure = false;
/*
/*------------------------------------------------------------------------
* Check for already-committed writer with rw-conflict out flagged
* (conflict-flag on W means that T2 committed before W):
*
@ -3851,12 +3852,13 @@ OnConflict_CheckForSerializationFailure(const SERIALIZABLEXACT *reader,
*
* That is a dangerous structure, so we must abort. (Since the writer
* has already committed, we must be the reader)
*------------------------------------------------------------------------
*/
if (SxactIsCommitted(writer)
&& (SxactHasConflictOut(writer) || SxactHasSummaryConflictOut(writer)))
failure = true;
/*
/*------------------------------------------------------------------------
* Check whether the writer has become a pivot with an out-conflict
* committed transaction (T2), and T2 committed first:
*
@ -3868,6 +3870,7 @@ OnConflict_CheckForSerializationFailure(const SERIALIZABLEXACT *reader,
* - the writer committed before T2
* - the reader is a READ ONLY transaction and the reader was concurrent
* with T2 (= reader acquired its snapshot before T2 committed)
*------------------------------------------------------------------------
*/
if (!failure)
{
@ -3903,7 +3906,7 @@ OnConflict_CheckForSerializationFailure(const SERIALIZABLEXACT *reader,
}
}
/*
/*------------------------------------------------------------------------
* Check whether the reader has become a pivot with a committed writer:
*
* T0 ------> R ------> W
@ -3913,6 +3916,7 @@ OnConflict_CheckForSerializationFailure(const SERIALIZABLEXACT *reader,
* anomaly if:
* - T0 committed before the writer
* - T0 is READ ONLY, and overlaps the writer
*------------------------------------------------------------------------
*/
if (!failure && SxactIsCommitted(writer) && !SxactIsReadOnly(reader))
{
@ -3950,8 +3954,8 @@ OnConflict_CheckForSerializationFailure(const SERIALIZABLEXACT *reader,
{
/*
* We have to kill a transaction to avoid a possible anomaly from
* occurring. If the writer is us, we can just ereport() to cause
* a transaction abort. Otherwise we flag the writer for termination,
* occurring. If the writer is us, we can just ereport() to cause a
* transaction abort. Otherwise we flag the writer for termination,
* causing it to abort when it tries to commit. However, if the writer
* is a prepared transaction, already prepared, we can't abort it
* anymore, so we have to kill the reader instead.