Subject: Re: bug#12832: 24.3.50; Emacs lockup when idle

From: Andy Moreton <[email-masked]>
Date: Wed, 14 Nov 2012 16:29:53 +0000

On 14/11/2012 12:44, Andy Moreton wrote:
> On 13/11/2012 17:04, Eli Zaretskii wrote:
>> Can you please try the patch below and see if it prevents the
>> lock-ups?
>>
>> === modified file 'src/w32proc.c'
>> --- src/w32proc.c	2012-11-05 03:18:32 +0000
>> +++ src/w32proc.c	2012-11-13 16:59:53 +0000
>> @@ -431,13 +431,24 @@ timer_loop (LPVOID arg)
>>   	  /* 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);
>> +	  DWORD result;
>> +
>> +	  if (dwMainThreadId)
>> +	    enter_crit ();
>> +	  result = SuspendThread (itimer->caller_thread);
>>
>>   	  if (result == (DWORD)-1)
>> -	    return 2;
>> +	    {
>> +	      if (dwMainThreadId)
>> +		leave_crit ();
>> +	      return 2;
>> +	    }
>>
>>   	  handler (sig);
>>   	  ResumeThread (itimer->caller_thread);
>> +
>> +	  if (dwMainThreadId)
>> +	    leave_crit ();
>>   	}
>>
>>         /* Update expiration time and loop.  */
>>
>
> I applied this to emacs-24 branch (r110866) this morning. So far I've not seen
> a lockup, but I'll to run it for a day or two to be sure.

After longer uptime, it seems this patch is not successful. I haven't had a 
complete lockup, but I have seen a couple of glitches where it froze but then 
recovered a short while later.

The unfreeze may have been due to capturing a stack trace with Process 
Explorer (I have upgraded to the latest version which is less buggy).

The patched emacs-24 does seem to leak handles: at the moment Process Explorer 
report that emacs has 50805 handles in all, most of which are thread handles. 
The number of handles seems to increase at a rate of 2 to 4 per second.

     AndyM