bzr commit into mysql-6.0-perf branch (marc.alff:2868)

[Marc Alff]

#At file:///home/malff/BZR-TREE/mysql-6.0-perf/ based on revid:marc.alff@stripped

 2868 Marc Alff	2009-04-15
      Fixed race conditions in the --pool-of-threads instrumentation
      Fixed broken unit test
modified:
  sql/scheduler.cc
  storage/perfschema/unittest/pfs-t.cc

=== modified file 'sql/scheduler.cc'
--- a/sql/scheduler.cc	2009-04-14 21:37:16 +0000
+++ b/sql/scheduler.cc	2009-04-15 09:35:58 +0000
@@ -24,6 +24,9 @@
 #include <mysql_priv.h>
 #include "sql_audit.h"
 
+#ifdef HAVE_PSI_INTERFACE
+pthread_key(PSI_thread*, THR_PSI_backup);
+#endif
 
 /*
   'Dummy' functions to be used when we don't need any handling for a scheduler
@@ -196,6 +199,19 @@ bool thd_scheduler::init(THD *parent_thd
 bool thd_scheduler::thread_attach()
 {
   DBUG_ASSERT(!thread_attached);
+
+#ifdef HAVE_PSI_INTERFACE
+  {
+    /*
+      Until now, this thread is running under the libevent instrumentation.
+      Save this instrumentation before binding to the job instrumentation,
+      THD::m_psi, in setup_connection_thread_globals().
+    */
+    PSI_thread *psi= (PSI_server ? PSI_server->get_thread() : NULL);
+    my_pthread_setspecific_ptr(THR_PSI_backup, psi);
+  }
+#endif
+
   THD* thd = (THD*)list.data;
   if (libevent_should_close_connection(thd) ||
       setup_connection_thread_globals(thd))
@@ -226,6 +242,21 @@ void thd_scheduler::thread_detach()
 {
   if (thread_attached)
   {
+#ifdef HAVE_PSI_INTERFACE
+    {
+      /*
+        Until now, this thread is running under the job instrumentation.
+        Restore the libevent instrumentation before giving up the job,
+        so that from now on:
+        - waits are properly counted against libevent,
+        - race conditions are not generated in the job THD::m_psi,
+        which might be picked up by another thread.
+      */
+      PSI_thread *psi= my_pthread_getspecific_ptr(PSI_thread*, THR_PSI_backup);
+      if (PSI_server)
+        PSI_server->set_thread(psi);
+    }
+#endif
     THD* thd = (THD*)list.data;
     MYSQL_MUTEX_LOCK(&thd->LOCK_delete);
     thd->mysys_var= NULL;
@@ -274,6 +305,14 @@ static bool libevent_init(void)
   killed_threads= 0;
   kill_pool_threads= FALSE;
 
+#ifdef HAVE_PSI_INTERFACE
+  if (pthread_key_create(&THR_PSI_backup, NULL))
+  {
+    sql_print_error("Can't create thread key THR_PSI_backup");
+    DBUG_RETURN(1);
+  }
+#endif
+
   MYSQL_MUTEX_INIT(key_LOCK_event_loop, &LOCK_event_loop, NULL);
   MYSQL_MUTEX_INIT(key_LOCK_thd_add, &LOCK_thd_add, NULL);
 
@@ -732,6 +771,11 @@ static void libevent_end()
 
   (void) MYSQL_MUTEX_DESTROY(&LOCK_event_loop);
   (void) MYSQL_MUTEX_DESTROY(&LOCK_thd_add);
+
+#ifdef HAVE_PSI_INTERFACE
+  pthread_key_delete(THR_PSI_backup);
+#endif
+
   DBUG_VOID_RETURN;
 }
 

=== modified file 'storage/perfschema/unittest/pfs-t.cc'
--- a/storage/perfschema/unittest/pfs-t.cc	2009-03-31 22:26:14 +0000
+++ b/storage/perfschema/unittest/pfs-t.cc	2009-04-15 09:35:58 +0000
@@ -671,7 +671,7 @@ void test_init_disabled()
   /* enabled F-A + out-of-descriptors + enabled T-1: no instrumentation */
 
   file_info_A->m_instr.m_enabled= true;
-  psi->create_file(file_key_A, "foo", (File) 1024);
+  psi->create_file(file_key_A, "foo", (File) 65000);
   file_A1= lookup_file_by_name("foo");
   ok(file_A1 == NULL, "not instrumented");
   ok(file_lost == 1, "lost a file");