Move call to GetTopTransactionId() earlier in LockAcquire(),
removing an infrequently occurring race condition in Hot Standby.
An xid must be assigned before a lock appears in shared memory,
rather than immediately after, else GetRunningTransactionLocks()
may see InvalidTransactionId, causing assertion failures during
lock processing on standby.
Bug report and diagnosis by Fujii Masao, fix by me.
Branch
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REL9_0_STABLE
Details
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http://git.postgresql.org/gitweb?p=postgresql.git;a=commitdiff;h=09425f89e764beabbdd30cc877b3de96f5d3d2b9
Modified Files
--------------
src/backend/storage/ipc/standby.c | 29 +++++++++++++++++++++--------
src/backend/storage/lmgr/lock.c | 29 +++++++++++++++++++++--------
src/include/storage/standby.h | 1 +
3 files changed, 43 insertions(+), 16 deletions(-)