bzr push into mysql-trunk branch (Dmitry.Lenev:3893 to 3894) WL#5772

[Dmitry Lenev]

 3894 Dmitry Lenev	2012-05-15
      WL#5772 "Add partitioned Table Definition Cache to avoid
      using LOCK_open and its derivatives in DML queries".
      
      Review change #6:
        Update description of --table-open-cache option to
        better reflect its "new" meaning.

    modified:
      mysql-test/r/mysqld--help-notwin.result
      mysql-test/r/mysqld--help-win.result
      sql/sys_vars.cc
 3893 Dmitry Lenev	2012-05-12
      WL#5772 "Add partitioned Table Definition Cache to avoid
      using LOCK_open and its derivatives in DML queries".
      
      Review changes #5:
      - Made status variables for table cache visible in SHOW STATUS.
      - Added test coverage for them.
      - Fixed setting of @@table_open_cache size at runtime.

    modified:
      mysql-test/r/status.result
      mysql-test/t/status.test
      sql/mysqld.cc
      sql/sys_vars.cc
=== modified file 'mysql-test/r/mysqld--help-notwin.result'
--- a/mysql-test/r/mysqld--help-notwin.result	2012-05-03 10:22:18 +0000
+++ b/mysql-test/r/mysqld--help-notwin.result	2012-05-14 20:05:23 +0000
@@ -852,7 +852,8 @@ The following options may be given as th
  --table-definition-cache=# 
  The number of cached table definitions
  --table-open-cache=# 
- The number of cached open tables
+ The number of cached open tables (total for all table
+ cache instances)
  --table-open-cache-instances=# 
  The number of table cache instances
  --tc-heuristic-recover=name 

=== modified file 'mysql-test/r/mysqld--help-win.result'
--- a/mysql-test/r/mysqld--help-win.result	2012-05-03 10:22:18 +0000
+++ b/mysql-test/r/mysqld--help-win.result	2012-05-14 20:05:23 +0000
@@ -860,7 +860,8 @@ The following options may be given as th
  --table-definition-cache=# 
  The number of cached table definitions
  --table-open-cache=# 
- The number of cached open tables
+ The number of cached open tables (total for all table
+ cache instances)
  --table-open-cache-instances=# 
  The number of table cache instances
  --tc-heuristic-recover=name 

=== modified file 'sql/sys_vars.cc'
--- a/sql/sys_vars.cc	2012-05-12 14:54:12 +0000
+++ b/sql/sys_vars.cc	2012-05-14 20:05:23 +0000
@@ -2715,12 +2715,18 @@ static Sys_var_ulong Sys_table_def_size(
 
 static bool fix_table_cache_size(sys_var *self, THD *thd, enum_var_type type)
 {
+  /*
+    table_open_cache parameter is a soft limit for total number of objects
+    in all table cache instances. Once this value is updated we need to
+    update value of a per-instance soft limit on table cache size.
+  */
   table_cache_size_per_instance= table_cache_size / table_cache_instances;
   return false;
 }
 
 static Sys_var_ulong Sys_table_cache_size(
-       "table_open_cache", "The number of cached open tables",
+       "table_open_cache", "The number of cached open tables "
+       "(total for all table cache instances)",
        GLOBAL_VAR(table_cache_size), CMD_LINE(REQUIRED_ARG),
        VALID_RANGE(1, 512*1024), DEFAULT(TABLE_OPEN_CACHE_DEFAULT),
        BLOCK_SIZE(1), NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(NULL),

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