SYSTEM WARNING: Creating default object from empty value

SYSTEM WARNING: Creating default object from empty value

SYSTEM WARNING: Creating default object from empty value

Mantis - Squeak
Viewing Issue Advanced Details
6588 Kernel block random 08-02-07 11:36 12-01-08 23:03
al  
 
high  
closed 3.10  
fixed  
none    
none 3.10  
0006588: Broken Semaphore>>critical: leads to frozen processes in Delay
David Shaffer: VNC doesn't respond to UI events, 0% cpu usage, several processes frozen in Delay although our Seaside server still responds.

Andreas Raab: You're missing another batch of fixes that we have long applied to our servers. In this case it's the handling of Semaphore>>critical: (which is broken in all Squeak versions).
See mail http://lists.squeakfoundation.org/pipermail/squeak-dev/2007-July/119082.html [^] and answers to it.
has duplicate 0006587closed  Broken Semaphore>>critical: leads to frozen processes in Delay 
has duplicate 0006582closed  Semaphore fix 
related to 0004882closed  VM lockup 
related to 0006576closed  Delay is not thread-safe 
 SemaTests-ar.cs [^] (1,413 bytes) 10-06-07 01:22
 SemaCritical-ar.cs [^] (4,050 bytes) 10-06-07 01:35

Notes
(0011237)
GazzaGuru   
10-05-07 22:16   
Though the fixes help somewhat there is still a problem with termination of processes leading to over/under signaling of semaphores.

In particular Seaside will terminate a process on timeout...
(0011239)
andreas   
10-06-07 01:26   
I think the attached two change sets should do it. The first one (SemaTests-ar) provides tests for the "one too many" and "one too few" behavior as I understand it so far. The second one (SemaCritical-ar) tries to address the issues by cooperating between Process>>terminate and Semaphore>>critical:. Note that it is critically important (pun intended) to use Semaphore>>critical: from all of the other critical: variants.
(0011241)
Keith_Hodges   
10-06-07 10:48   
"fix begin"
Installer mantis bug: 6588 fix: 'SemaCritical-ar.cs'.
"fix test"
Installer mantis bug: 6588 fix: 'SemaTests-ar.cs'.
"fix end"
(0011437)
edgardec   
11-15-07 18:04   
This is 7153SemaCritical-ar.cs in the 3.10.1 updates.

Thanks all
(0012820)
KenCausey   
12-01-08 23:03   
Harvested as update 7153 and released with Squeak 3.10.