bk commit into 5.0 tree (davi:1.2583) BUG#17954

[Davi Arnaut]

Below is the list of changes that have just been committed into a local
5.0 repository of davi. When davi does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
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ChangeSet@stripped, 2008-01-14 09:28:42-02:00, davi@stripped +5 -0
  Bug#17954 Threads_connected > Threads_created
  
  The problem is that insert delayed threads are counted as connected
  but not as created, leading to a Threads_connected value greater then
  the Threads_created value.
  
  The solution is to increment the Threads_created variable when insert
  delayed threads are created. Nevertheless, the Threads_connected may
  still be greater then Threads_created because in reality it reflects
  the number of open connections (or open thread states) that also might
  not be associated with created threads.

  mysql-test/r/status.result@stripped, 2008-01-14 09:28:39-02:00, davi@stripped +12 -0
    Add test case result for Bug#17954

  mysql-test/t/status.test@stripped, 2008-01-14 09:28:39-02:00, davi@stripped +27 -0
    Add test case for Bug#17954

  sql/mysql_priv.h@stripped, 2008-01-14 09:28:40-02:00, davi@stripped +1 -0
    Export the thread_created variable.

  sql/mysqld.cc@stripped, 2008-01-14 09:28:40-02:00, davi@stripped +2 -1
    thread_create is now used outside this compilation unit.

  sql/sql_insert.cc@stripped, 2008-01-14 09:28:40-02:00, davi@stripped +2 -3
    Increment the thread_count value after the thread has been
    created. Also, increment the thread_created value since
    the thread has been successfully created.

diff -Nrup a/mysql-test/r/status.result b/mysql-test/r/status.result
--- a/mysql-test/r/status.result	2007-08-28 12:51:02 -03:00
+++ b/mysql-test/r/status.result	2008-01-14 09:28:39 -02:00
@@ -91,3 +91,15 @@ SHOW SESSION STATUS LIKE 'Last_query_cos
 Variable_name	Value
 Last_query_cost	4.805836
 DROP TABLE t1;
+DROP TABLE IF EXISTS t1;
+CREATE TABLE t1 (a int);
+FLUSH STATUS;
+SELECT @dit < @tcr;
+@dit < @tcr
+1
+SET GLOBAL delayed_insert_limit= 10;
+INSERT DELAYED INTO t1 VALUES (0);
+DROP TABLE t1;
+SELECT @dit < @ditp, @tcr < @tcrp, @ditp < @tcrp;
+@dit < @ditp	@tcr < @tcrp	@ditp < @tcrp
+1	1	1
diff -Nrup a/mysql-test/t/status.test b/mysql-test/t/status.test
--- a/mysql-test/t/status.test	2007-08-28 12:51:02 -03:00
+++ b/mysql-test/t/status.test	2008-01-14 09:28:39 -02:00
@@ -170,5 +170,32 @@ SHOW SESSION STATUS LIKE 'Last_query_cos
 
 DROP TABLE t1;
 
+#
+# Bug #17954: Threads_connected > Threads_created
+#
+
+--disable_warnings
+DROP TABLE IF EXISTS t1;
+--enable_warnings
+
+CREATE TABLE t1 (a int);
+FLUSH STATUS;
+let $dit= `SHOW STATUS LIKE 'delayed_insert_threads'`;
+let $tcr= `SHOW STATUS LIKE 'threads_created'`;
+--disable_query_log
+eval SET @dit= SUBSTRING_INDEX('$dit', '	', -1);
+eval SET @tcr= SUBSTRING_INDEX('$tcr', '	', -1);
+--enable_query_log
+SELECT @dit < @tcr;
+SET GLOBAL delayed_insert_limit= 10;
+INSERT DELAYED INTO t1 VALUES (0);
+let $dit= `SHOW STATUS LIKE 'delayed_insert_threads'`;
+let $tcr= `SHOW STATUS LIKE 'threads_created'`;
+DROP TABLE t1;
+--disable_query_log
+eval SET @ditp= SUBSTRING_INDEX('$dit', '	', -1);
+eval SET @tcrp= SUBSTRING_INDEX('$tcr', '	', -1);
+--enable_query_log
+SELECT @dit < @ditp, @tcr < @tcrp, @ditp < @tcrp;
 
 # End of 5.0 tests
diff -Nrup a/sql/mysql_priv.h b/sql/mysql_priv.h
--- a/sql/mysql_priv.h	2007-12-13 08:49:12 -02:00
+++ b/sql/mysql_priv.h	2008-01-14 09:28:40 -02:00
@@ -1291,6 +1291,7 @@ extern ulong table_cache_size;
 extern ulong max_connections,max_connect_errors, connect_timeout;
 extern ulong slave_net_timeout, slave_trans_retries;
 extern uint max_user_connections;
+extern ulong thread_created;
 extern ulong what_to_log,flush_time;
 extern ulong query_buff_size, thread_stack;
 extern ulong max_prepared_stmt_count, prepared_stmt_count;
diff -Nrup a/sql/mysqld.cc b/sql/mysqld.cc
--- a/sql/mysqld.cc	2007-12-14 03:53:52 -02:00
+++ b/sql/mysqld.cc	2008-01-14 09:28:40 -02:00
@@ -323,7 +323,7 @@ static my_bool opt_debugging= 0, opt_ext
 static my_bool opt_bdb, opt_isam, opt_ndbcluster, opt_merge;
 static my_bool opt_short_log_format= 0;
 static uint kill_cached_threads, wake_thread;
-static ulong killed_threads, thread_created;
+static ulong killed_threads;
 static ulong max_used_connections;
 static ulong my_bind_addr;			/* the address we bind to */
 static volatile ulong cached_thread_count= 0;
@@ -438,6 +438,7 @@ ulong specialflag=0;
 ulong binlog_cache_use= 0, binlog_cache_disk_use= 0;
 ulong max_connections, max_connect_errors;
 uint  max_user_connections= 0;
+ulong thread_created;
 /*
   Limit of the total number of prepared statements in the server.
   Is necessary to protect the server against out-of-memory attacks.
diff -Nrup a/sql/sql_insert.cc b/sql/sql_insert.cc
--- a/sql/sql_insert.cc	2007-12-13 08:52:47 -02:00
+++ b/sql/sql_insert.cc	2008-01-14 09:28:40 -02:00
@@ -1804,9 +1804,6 @@ bool delayed_get_table(THD *thd, TABLE_L
         thd->fatal_error();
         goto end_create;
       }
-      pthread_mutex_lock(&LOCK_thread_count);
-      thread_count++;
-      pthread_mutex_unlock(&LOCK_thread_count);
       di->thd.set_db(table_list->db, strlen(table_list->db));
       di->thd.query= my_strdup(table_list->table_name, MYF(MY_WME));
       if (di->thd.db == NULL || di->thd.query == NULL)
@@ -2149,6 +2146,8 @@ pthread_handler_t handle_delayed_insert(
   pthread_detach_this_thread();
   /* Add thread to THD list so that's it's visible in 'show processlist' */
   pthread_mutex_lock(&LOCK_thread_count);
+  thread_created++;
+  thread_count++;
   thd->thread_id=thread_id++;
   thd->end_time();
   threads.append(thd);