#At file:///home/satya/WORK/mysql/mysql-5.1-bugteam-innodb/ based on revid:satya.bn@stripped
2891 Satya B 2009-05-19
Applying InnoDB snashot 5.1-ss5024,part 3. Fixes BUG#42101
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
added:
mysql-test/r/innodb_bug42101-nonzero.result
mysql-test/r/innodb_bug42101.result
mysql-test/t/innodb_bug42101-nonzero-master.opt
mysql-test/t/innodb_bug42101-nonzero.test
mysql-test/t/innodb_bug42101.test
modified:
storage/innobase/handler/ha_innodb.cc
storage/innobase/include/srv0srv.h
storage/innobase/srv/srv0srv.c
=== added file 'mysql-test/r/innodb_bug42101-nonzero.result'
--- a/mysql-test/r/innodb_bug42101-nonzero.result 1970-01-01 00:00:00 +0000
+++ b/mysql-test/r/innodb_bug42101-nonzero.result 2009-05-19 08:20:28 +0000
@@ -0,0 +1,22 @@
+set global innodb_commit_concurrency=0;
+ERROR HY000: Incorrect arguments to SET
+select @@innodb_commit_concurrency;
+@@innodb_commit_concurrency
+1
+set global innodb_commit_concurrency=1;
+select @@innodb_commit_concurrency;
+@@innodb_commit_concurrency
+1
+set global innodb_commit_concurrency=42;
+select @@innodb_commit_concurrency;
+@@innodb_commit_concurrency
+42
+set global innodb_commit_concurrency=0;
+ERROR HY000: Incorrect arguments to SET
+select @@innodb_commit_concurrency;
+@@innodb_commit_concurrency
+42
+set global innodb_commit_concurrency=1;
+select @@innodb_commit_concurrency;
+@@innodb_commit_concurrency
+1
=== added file 'mysql-test/r/innodb_bug42101.result'
--- a/mysql-test/r/innodb_bug42101.result 1970-01-01 00:00:00 +0000
+++ b/mysql-test/r/innodb_bug42101.result 2009-05-19 08:20:28 +0000
@@ -0,0 +1,18 @@
+set global innodb_commit_concurrency=0;
+select @@innodb_commit_concurrency;
+@@innodb_commit_concurrency
+0
+set global innodb_commit_concurrency=1;
+ERROR HY000: Incorrect arguments to SET
+select @@innodb_commit_concurrency;
+@@innodb_commit_concurrency
+0
+set global innodb_commit_concurrency=42;
+ERROR HY000: Incorrect arguments to SET
+select @@innodb_commit_concurrency;
+@@innodb_commit_concurrency
+0
+set global innodb_commit_concurrency=0;
+select @@innodb_commit_concurrency;
+@@innodb_commit_concurrency
+0
=== added file 'mysql-test/t/innodb_bug42101-nonzero-master.opt'
--- a/mysql-test/t/innodb_bug42101-nonzero-master.opt 1970-01-01 00:00:00 +0000
+++ b/mysql-test/t/innodb_bug42101-nonzero-master.opt 2009-05-19 08:20:28 +0000
@@ -0,0 +1 @@
+--innodb_commit_concurrency=1
=== added file 'mysql-test/t/innodb_bug42101-nonzero.test'
--- a/mysql-test/t/innodb_bug42101-nonzero.test 1970-01-01 00:00:00 +0000
+++ b/mysql-test/t/innodb_bug42101-nonzero.test 2009-05-19 08:20:28 +0000
@@ -0,0 +1,19 @@
+#
+# Bug#42101 Race condition in innodb_commit_concurrency
+# http://bugs.mysql.com/42101
+#
+
+-- source include/have_innodb.inc
+
+--error ER_WRONG_ARGUMENTS
+set global innodb_commit_concurrency=0;
+select @@innodb_commit_concurrency;
+set global innodb_commit_concurrency=1;
+select @@innodb_commit_concurrency;
+set global innodb_commit_concurrency=42;
+select @@innodb_commit_concurrency;
+--error ER_WRONG_ARGUMENTS
+set global innodb_commit_concurrency=0;
+select @@innodb_commit_concurrency;
+set global innodb_commit_concurrency=1;
+select @@innodb_commit_concurrency;
=== added file 'mysql-test/t/innodb_bug42101.test'
--- a/mysql-test/t/innodb_bug42101.test 1970-01-01 00:00:00 +0000
+++ b/mysql-test/t/innodb_bug42101.test 2009-05-19 08:20:28 +0000
@@ -0,0 +1,17 @@
+#
+# Bug#42101 Race condition in innodb_commit_concurrency
+# http://bugs.mysql.com/42101
+#
+
+-- source include/have_innodb.inc
+
+set global innodb_commit_concurrency=0;
+select @@innodb_commit_concurrency;
+--error ER_WRONG_ARGUMENTS
+set global innodb_commit_concurrency=1;
+select @@innodb_commit_concurrency;
+--error ER_WRONG_ARGUMENTS
+set global innodb_commit_concurrency=42;
+select @@innodb_commit_concurrency;
+set global innodb_commit_concurrency=0;
+select @@innodb_commit_concurrency;
=== modified file 'storage/innobase/handler/ha_innodb.cc'
--- a/storage/innobase/handler/ha_innodb.cc 2009-05-13 10:11:24 +0000
+++ b/storage/innobase/handler/ha_innodb.cc 2009-05-19 08:20:28 +0000
@@ -101,6 +101,7 @@ static long innobase_mirrored_log_groups
innobase_additional_mem_pool_size, innobase_file_io_threads,
innobase_lock_wait_timeout, innobase_force_recovery,
innobase_open_files, innobase_autoinc_lock_mode;
+static ulong innobase_commit_concurrency = 0;
static long long innobase_buffer_pool_size, innobase_log_file_size;
@@ -165,6 +166,38 @@ static handler *innobase_create_handler(
static const char innobase_hton_name[]= "InnoDB";
+/*****************************************************************
+Check for a valid value of innobase_commit_concurrency. */
+static
+int
+innobase_commit_concurrency_validate(
+/*=================================*/
+ /* out: 0 for valid
+ innodb_commit_concurrency */
+ THD* thd, /* in: thread handle */
+ struct st_mysql_sys_var* var, /* in: pointer to system
+ variable */
+ void* save, /* out: immediate result
+ for update function */
+ struct st_mysql_value* value) /* in: incoming string */
+{
+ long long intbuf;
+ ulong commit_concurrency;
+
+ DBUG_ENTER("innobase_commit_concurrency_validate");
+
+ if (value->val_int(value, &intbuf)) {
+ /* The value is NULL. That is invalid. */
+ DBUG_RETURN(1);
+ }
+
+ *reinterpret_cast<ulong*>(save) = commit_concurrency
+ = static_cast<ulong>(intbuf);
+
+ /* Allow the value to be updated, as long as it remains zero
+ or nonzero. */
+ DBUG_RETURN(!(!commit_concurrency == !innobase_commit_concurrency));
+}
static MYSQL_THDVAR_BOOL(support_xa, PLUGIN_VAR_OPCMDARG,
"Enable InnoDB support for the XA two-phase commit",
@@ -1951,11 +1984,11 @@ innobase_commit(
Note, the position is current because of
prepare_commit_mutex */
retry:
- if (srv_commit_concurrency > 0) {
+ if (innobase_commit_concurrency > 0) {
pthread_mutex_lock(&commit_cond_m);
commit_threads++;
- if (commit_threads > srv_commit_concurrency) {
+ if (commit_threads > innobase_commit_concurrency) {
commit_threads--;
pthread_cond_wait(&commit_cond,
&commit_cond_m);
@@ -1972,7 +2005,7 @@ retry:
innobase_commit_low(trx);
- if (srv_commit_concurrency > 0) {
+ if (innobase_commit_concurrency > 0) {
pthread_mutex_lock(&commit_cond_m);
commit_threads--;
pthread_cond_signal(&commit_cond);
@@ -8289,10 +8322,10 @@ static MYSQL_SYSVAR_LONGLONG(buffer_pool
"The size of the memory buffer InnoDB uses to cache data and indexes of its tables.",
NULL, NULL, 8*1024*1024L, 1024*1024L, LONGLONG_MAX, 1024*1024L);
-static MYSQL_SYSVAR_ULONG(commit_concurrency, srv_commit_concurrency,
+static MYSQL_SYSVAR_ULONG(commit_concurrency, innobase_commit_concurrency,
PLUGIN_VAR_RQCMDARG,
"Helps in performance tuning in heavily concurrent environments.",
- NULL, NULL, 0, 0, 1000, 0);
+ innobase_commit_concurrency_validate, NULL, 0, 0, 1000, 0);
static MYSQL_SYSVAR_ULONG(concurrency_tickets, srv_n_free_tickets_to_enter,
PLUGIN_VAR_RQCMDARG,
=== modified file 'storage/innobase/include/srv0srv.h'
--- a/storage/innobase/include/srv0srv.h 2009-04-24 11:28:46 +0000
+++ b/storage/innobase/include/srv0srv.h 2009-05-19 08:20:28 +0000
@@ -109,7 +109,6 @@ extern ulint srv_max_dirty_pages_pct;
extern ulint srv_force_recovery;
extern ulong srv_thread_concurrency;
-extern ulong srv_commit_concurrency;
extern ulint srv_max_n_threads;
=== modified file 'storage/innobase/srv/srv0srv.c'
--- a/storage/innobase/srv/srv0srv.c 2009-04-24 11:28:46 +0000
+++ b/storage/innobase/srv/srv0srv.c 2009-05-19 08:20:28 +0000
@@ -285,7 +285,6 @@ computer. Bigger computers need bigger v
concurrency check. */
ulong srv_thread_concurrency = 0;
-ulong srv_commit_concurrency = 0;
os_fast_mutex_t srv_conc_mutex; /* this mutex protects srv_conc data
structures */
| Thread |
|---|
| • bzr commit into mysql-5.1-bugteam branch (satya.bn:2891) Bug#42101 | Satya B | 19 May |
