[Emacs-diffs] /srv/bzr/emacs/emacs-24 r110867: Clean up w32 timer thread code in the hope of solving bug #12832.

[Eli Zaretskii]

------------------------------------------------------------
revno: 110867
fixes bug: http://debbugs.gnu.org/12832
committer: Eli Zaretskii <address@hidden>
branch nick: emacs-24
timestamp: Wed 2012-11-14 18:41:43 +0200
message:
  Clean up w32 timer thread code in the hope of solving bug #12832.
  
   src/w32proc.c (timer_loop): Make sure SuspendThread and ResumeThread
   use the same value of thread handle.
   (start_timer_thread): If the timer thread exited (due to error),
   clean up by closing the two handles it used.  Duplicate the caller
   thread's handle here, so it gets duplicated only once, when
   launching the timer thread.  Set priority of the timer thread, not
   the caller thread.
   (getitimer): Don't duplicate the caller thread's handle here.
modified:
  src/ChangeLog
  src/w32proc.c

=== modified file 'src/ChangeLog'
--- a/src/ChangeLog     2012-11-13 07:56:15 +0000
+++ b/src/ChangeLog     2012-11-14 16:41:43 +0000
@@ -1,3 +1,15 @@
+2012-11-14  Eli Zaretskii  <address@hidden>
+
+       * w32proc.c (timer_loop): Make sure SuspendThread and ResumeThread
+       use the same value of thread handle.
+       (start_timer_thread): If the timer thread exited (due to error),
+       clean up by closing the two handles it used.  Duplicate the caller
+       thread's handle here, so it gets duplicated only once, when
+       launching the timer thread.  Set priority of the timer thread, not
+       the caller thread.
+       (getitimer): Don't duplicate the caller thread's handle here.
+       (Bug#12832)
+
 2012-11-13  Jan Djärv  <address@hidden>
 
        * nsterm.m (hold_event): Send SIGIO to make sure ns_read_socket is

=== modified file 'src/w32proc.c'
--- a/src/w32proc.c     2012-11-01 14:21:45 +0000
+++ b/src/w32proc.c     2012-11-14 16:41:43 +0000
@@ -425,13 +425,14 @@
          /* Simulate a signal delivered to the thread which installed
             the timer, by suspending that thread while the handler
             runs.  */
-         DWORD result = SuspendThread (itimer->caller_thread);
+         HANDLE th = itimer->caller_thread;
+         DWORD result = SuspendThread (th);
 
          if (result == (DWORD)-1)
            return 2;
 
          handler (sig);
-         ResumeThread (itimer->caller_thread);
+         ResumeThread (th);
        }
 
       /* Update expiration time and loop.  */
@@ -556,6 +557,7 @@
 start_timer_thread (int which)
 {
   DWORD exit_code;
+  HANDLE th;
   struct itimer_data *itimer =
     (which == ITIMER_REAL) ? &real_itimer : &prof_itimer;
 
@@ -564,9 +566,29 @@
       && exit_code == STILL_ACTIVE)
     return 0;
 
+  /* Clean up after possibly exited thread.  */
+  if (itimer->timer_thread)
+    {
+      CloseHandle (itimer->timer_thread);
+      itimer->timer_thread = NULL;
+    }
+  if (itimer->caller_thread)
+    {
+      CloseHandle (itimer->caller_thread);
+      itimer->caller_thread = NULL;
+    }
+
   /* Start a new thread.  */
+  if (!DuplicateHandle (GetCurrentProcess (), GetCurrentThread (),
+                       GetCurrentProcess (), &th, 0, FALSE,
+                       DUPLICATE_SAME_ACCESS))
+    {
+      errno = ESRCH;
+      return -1;
+    }
   itimer->terminate = 0;
   itimer->type = which;
+  itimer->caller_thread = th;
   /* Request that no more than 64KB of stack be reserved for this
      thread, to avoid reserving too much memory, which would get in
      the way of threads we start to wait for subprocesses.  See also
@@ -585,7 +607,7 @@
   /* This is needed to make sure that the timer thread running for
      profiling gets CPU as soon as the Sleep call terminates. */
   if (which == ITIMER_PROF)
-    SetThreadPriority (itimer->caller_thread, THREAD_PRIORITY_TIME_CRITICAL);
+    SetThreadPriority (itimer->timer_thread, THREAD_PRIORITY_TIME_CRITICAL);
 
   return 0;
 }
@@ -620,17 +642,9 @@
 
   itimer = (which == ITIMER_REAL) ? &real_itimer : &prof_itimer;
 
-  if (!DuplicateHandle (GetCurrentProcess (), GetCurrentThread (),
-                       GetCurrentProcess (), &itimer->caller_thread, 0,
-                       FALSE, DUPLICATE_SAME_ACCESS))
-    {
-      errno = ESRCH;
-      return -1;
-    }
-
   ticks_now = w32_get_timer_time ((which == ITIMER_REAL)
                                  ? NULL
-                                 : itimer->caller_thread);
+                                 : GetCurrentThread ());
 
   t_expire = &itimer->expire;
   t_reload = &itimer->reload;