[Cbc-tickets] [COIN-OR Branch-and-Cut MIP Solver] #109: Parallel CBC Bug

[COIN-OR Branch-and-Cut MIP Solver]

#109: Parallel CBC Bug
-------------------+--------------------------------------------------------
Reporter:  unxusr  |       Type:  defect          
  Status:  new     |   Priority:  major           
 Version:  2.7     |   Keywords:  parallel cbc bug
-------------------+--------------------------------------------------------
 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 ?? ()

-- 
Ticket URL: <https://projects.coin-or.org/Cbc/ticket/109>
COIN-OR Branch-and-Cut MIP Solver <http://projects.coin-or.org/Cbc>
An LP-based branch-and-cut MIP solver.