Opened 8 years ago

Closed 7 weeks ago

#109 closed defect (migrated)

Parallel CBC Bug

Reported by: unxusr Owned by:
Priority: major Component: Cbc
Version: 2.7 Keywords: parallel cbc bug
Cc:

Description

I found this bug in previous versions of CBC but only now I had time to properly discover how to replicate it.

It occurs when CBC runs in parallel and creates many nodes in the search tree.

Versions compiled with "-O2 -g" are more likely to show this bug earlier in the search tree (could not replicate with -O0 -g).

To replicate it I suggest to run cbc in problem markshare1, from miplib2003.

To speed up node creation, I used this command line: cbc markshare1.mps dualS preprocess=off cuts=off heur=off passF=0 threads=6 strong=0 trust=0 log=3 solve

Follows the message printed while running cbc in gdb: Program received signal SIGSEGV, Segmentation fault. [Switching to Thread 0x7ffff493f700 (LWP 7875)] doNodesThread (voidInfo=<value optimized out>) at CbcThread?.cpp:1088 1088 assert (node->nodeInfo()); (gdb) backtrace #0 doNodesThread (voidInfo=<value optimized out>) at CbcThread?.cpp:1088 #1 0x00007ffff75e29ca in start_thread (arg=<value optimized out>) at pthread_create.c:300 #2 0x00007ffff522770d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112 #3 0x0000000000000000 in ?? () (gdb) #0 doNodesThread (voidInfo=<value optimized out>) at CbcThread?.cpp:1088 #1 0x00007ffff75e29ca in start_thread (arg=<value optimized out>) at pthread_create.c:300 #2 0x00007ffff522770d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112 #3 0x0000000000000000 in ?? ()

Change History (1)

comment:1 Changed 7 weeks ago by stefan

  • Component set to Cbc
  • Resolution set to migrated
  • Status changed from new to closed

This ticket has been migrated to GitHub and will be resolved there: https://github.com/coin-or/Cbc/issues/109

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