Forum Discussion
__lll_lock_wait allowing only one thread to work
I am calling the XPRESS optimizer from a multithreaded Pascal application and having performance issues with the solver. While the program is multithreaded, all but one of the threads are sleeping a...
See the following GDB output:
(gdb) thread 50
[Switching to thread 50 (Thread 0x7fff2bbfe700 (LWP 2011467))]
#0 0x00007ffff7bc175d in __lll_lock_wait () from /lib64/libpthread.so.0
(gdb) frame 5
#5 0x00000000004c0d0a in RESOLVER (this=0x7fff205890b8) at ../../rchlib/mat/umipsimplex_xprs.pas:829
829 XPRSdestroyprob(pxprs);
(gdb) print @pxprs
warning: can't find linker symbol for virtual table for `TMIPSIMPLEX_XPRS' value
$6 = (^XPRSPROB) 0x7fff205891c0
(gdb) thread 49
[Switching to thread 49 (Thread 0x7fff2bfff700 (LWP 2011466))]
#0 0x00007ffff7bc175d in __lll_lock_wait () from /lib64/libpthread.so.0
(gdb) frame 5
#5 0x00000000004c0d0a in RESOLVER (this=0x7fff1c5640e8) at ../../rchlib/mat/umipsimplex_xprs.pas:829
829 XPRSdestroyprob(pxprs);
(gdb) print @pxprs
warning: can't find linker symbol for virtual table for `TMIPSIMPLEX_XPRS' value
$7 = (^XPRSPROB) 0x7fff1c5641f0Both threads are waiting on XPRSdestroyprob and I understand that both problems appear to be in different memory positions (which is to be expected, but this is a confirmation).