bk commit into 5.0 tree (tnurnberg:1.2161) BUG#18235

[Tatjana A Nuernberg]

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ChangeSet
  1.2161 06/05/31 14:27:31 tnurnberg@stripped +1 -0
  Bug#18235: assertion/crash when windows mysqld is ended with ctrl-c
  
  Two threads both try a shutdown sequence which creates a race to the
  de-init/free of certain resources.
  
  This exists in similar form in the client as 17926: "mysql.exe crashes
  when ctrl-c is pressed in windows."

  sql/mysqld.cc
    1.554 06/05/31 14:27:23 tnurnberg@stripped +5 -1
    We have three potential ways of hitting the iceberg:
    - unireg_end()   has basic de-init
    - unireg_abort() has extended de-init
    - main() has a de-init sequence similar to unireg_abort()
    
    In the Windows version of the server, Control-C is handled
    in a different thread from the one main() is in.  The main
    loop is told to end, then unireg_abort() is called.  Its
    de-init and that of main() will then race each other for
    mutex- and cond-var-destroys, free(), and finally exit().
    
    This patch introduces a special case for Windows that will eliminate
    the race by ending the signal-handler via unireg_end() instead if
    SIGINT is signalled.  This seems the least intrusive fix that still
    fixes user-visible behaviour.

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	tnurnberg
# Host:	salvation.intern.azundris.com
# Root:	/home/mysql-5.0-maint-18235

--- 1.553/sql/mysqld.cc	2006-05-29 15:06:30 +02:00
+++ 1.554/sql/mysqld.cc	2006-05-31 14:27:23 +02:00
@@ -991,7 +991,11 @@
   my_thread_init();				// If this is a new thread
 #endif
   close_connections();
-  if (sig != MYSQL_KILL_SIGNAL && sig != 0)
+  if (sig != MYSQL_KILL_SIGNAL &&
+#ifdef __WIN__
+      sig != SIGINT &&				/* Bug#18235 */
+#endif
+      sig != 0)
     unireg_abort(1);				/* purecov: inspected */
   else
     unireg_end();