BUG#45749 - Race condition in SET GLOBAL innodb_commit_concurrency=DEFAULT
Detailed revision comments:
r5419 | marko | 2009-06-25 16:11:57 +0300 (Thu, 25 Jun 2009) | 18 lines
branches/5.1: Merge r5418 from branches/zip:
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r5418 | marko | 2009-06-25 15:55:52 +0300 (Thu, 25 Jun 2009) | 5 lines
Changed paths:
M /branches/zip/ChangeLog
M /branches/zip/handler/ha_innodb.cc
M /branches/zip/mysql-test/innodb_bug42101-nonzero.result
M /branches/zip/mysql-test/innodb_bug42101-nonzero.test
M /branches/zip/mysql-test/innodb_bug42101.result
M /branches/zip/mysql-test/innodb_bug42101.test
branches/zip: Fix a race condition caused by
SET GLOBAL innodb_commit_concurrency=DEFAULT. (Bug #45749)
When innodb_commit_concurrency is initially set nonzero,
DEFAULT would change it back to 0, triggering Bug #42101.
rb://139 approved by Heikki Tuuri.
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BUG#42101 - Race condition in innodb_commit_concurrency
Detailed revision comments:
r4994 | marko | 2009-05-14 15:04:55 +0300 (Thu, 14 May 2009) | 18 lines
branches/5.1: Prevent a race condition in innobase_commit() by ensuring
that innodb_commit_concurrency>0 remains constant at run time. (Bug #42101)
srv_commit_concurrency: Make this a static variable in ha_innodb.cc.
innobase_commit_concurrency_validate(): Check that innodb_commit_concurrency
is not changed from or to 0 at run time. This is needed, because
innobase_commit() assumes that innodb_commit_concurrency>0 remains constant.
Without this limitation, the checks for innodb_commit_concurrency>0
in innobase_commit() should be removed and that function would have to
acquire and release commit_cond_m at least twice per invocation.
Normally, innodb_commit_concurrency=0, and introducing the mutex operations
would mean significant overhead.
innodb_bug42101.test, innodb_bug42101-nonzero.test: Test cases.
rb://123 approved by Heikki Tuuri
