OpenMP C programs deadlock immediately after starting when OMP_NUM_THREADS is >
1.
For example, the following simple code just hangs:
#include <stdio.h>
main() {
int i;
#pragma omp parallel for private(i)
for (i = 0; i < 100; i++)
printf("Thread = %d.\n", omp_get_thread_num());
}
This occurs on MacOS X 10.4.5 with gcc version:
Using built-in specs.
Target: powerpc-apple-darwin8.4.0
Configured with:
/opt/local/var/db/dports/build/_opt_local_var_db_dports_sources_rsync.rsync.darwinports.org_dpupdate_dports_lang_gcc42/work/gcc-4.2-20060204/configure
--prefix=/opt/local --enable-languages=c,c++,java,objc,fortran
--libdir=/opt/local/lib/gcc42 --includedir=/opt/local/include/gcc42
--infodir=/opt/local/share/info --mandir=/opt/local/share/man
--with-local-prefix=/opt/local --with-system-zlib --disable-nls
--program-suffix=-dp-4.2 --with-gxx-include-dir=/opt/local/include/gcc42/c++/
--with-gmp=/opt/local --with-mpfr=/opt/local --disable-multilib
Thread model: posix
gcc version 4.2.0 20060204 (experimental)
Also it appears that when -fopenmp switch is used, gcc does not automatically
include -lgomp but
this has to be done by hand.
--
Summary: OpenMP program deadlocks when executed
Product: gcc
Version: 4.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: eloranta at jyu dot fi
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26456
