http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55561
--- Comment #27 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch>
2012-12-30 19:57:24 UTC ---
(In reply to comment #24)
> For testing you can comment out first 2 lines of gomp_ptrlock_get(). That
> should fix the race in libgomp. It's not a good fix form performance pov, but
> should be OK for testing.
I found that the routines in config/posix can be used instead of the
config/linux by configuring gcc with '--disable-linux-futex' . With your
suggestion above, I still get warnings (absent in the linux case) from the
following testcase:
[vjoost@nanosim-s03 bugs]$ cat test_23.f90
INTEGER :: i,j,OMP_GET_THREAD_NUM
!$OMP PARALLEL PRIVATE(i,j)
j=OMP_GET_THREAD_NUM()
!$OMP DO
DO i=1,10
!$OMP CRITICAL(xxx)
!$OMP END CRITICAL(xxx)
! !$OMP CRITICAL(yyy)
! !$OMP END CRITICAL(yyy)
END DO
!$OMP END PARALLEL
END
[vjoost@nanosim-s03 bugs]$ gfortran -fsanitize=thread -fopenmp -gdwarf-3 -O1
-fPIE -pie test_23.f90
[vjoost@nanosim-s03 bugs]$ export OMP_NUM_THREADS=4 ; ./a.out
==================
WARNING: ThreadSanitizer: data race (pid=29039)
Read of size 1 at 0x7d020003d050 by thread 1:
#0 pthread_mutex_lock ??:0 (libtsan.so.0+0x00000001a863)
#1 GOMP_critical_name_start
/data/vjoost/gnu/gcc_exp/obj/x86_64-unknown-linux-gnu/libgomp/../../../gcc/libgomp/config/posix/mutex.h:44
(libgomp.so.1+0x000000005e5d)
#2 MAIN__._omp_fn.0 /data/vjoost/gnu/bugs/test_23.f90:6
(exe+0x000000000dcc)
#3 gomp_thread_start
/data/vjoost/gnu/gcc_exp/obj/x86_64-unknown-linux-gnu/libgomp/../../../gcc/libgomp/team.c:116
(libgomp.so.1+0x00000000c6b2)
Previous write of size 8 at 0x7d020003d050 by main thread:
#0 gomp_barrier_wait_end
/data/vjoost/gnu/gcc_exp/obj/x86_64-unknown-linux-gnu/libgomp/../../../gcc/libgomp/config/posix/bar.c:93
(libgomp.so.1+0x00000000e691)
#1 gomp_malloc
/data/vjoost/gnu/gcc_exp/obj/x86_64-unknown-linux-gnu/libgomp/../../../gcc/libgomp/alloc.c:36
(libgomp.so.1+0x000000005cba)
#2 GOMP_critical_name_start
/data/vjoost/gnu/gcc_exp/obj/x86_64-unknown-linux-gnu/libgomp/../../../gcc/libgomp/critical.c:71
(libgomp.so.1+0x000000005e79)
#3 MAIN__._omp_fn.0 /data/vjoost/gnu/bugs/test_23.f90:6
(exe+0x000000000dcc)
#4 MAIN__ /data/vjoost/gnu/bugs/test_23.f90:2 (exe+0x000000000e43)
#5 __libc_start_main ??:0 (libc.so.6+0x0037a121ecdc)
Location is heap block of size 40 at 0x7d020003d050 allocated by main thread:
#0 malloc ??:0 (libtsan.so.0+0x00000001839e)
#1 gomp_malloc
/data/vjoost/gnu/gcc_exp/obj/x86_64-unknown-linux-gnu/libgomp/../../../gcc/libgomp/alloc.c:36
(libgomp.so.1+0x000000005cba)
#2 GOMP_critical_name_start
/data/vjoost/gnu/gcc_exp/obj/x86_64-unknown-linux-gnu/libgomp/../../../gcc/libgomp/critical.c:71
(libgomp.so.1+0x000000005e79)
#3 MAIN__._omp_fn.0 /data/vjoost/gnu/bugs/test_23.f90:6
(exe+0x000000000dcc)
#4 MAIN__ /data/vjoost/gnu/bugs/test_23.f90:2 (exe+0x000000000e43)
#5 __libc_start_main ??:0 (libc.so.6+0x0037a121ecdc)
Thread 1 (tid=29040, running) created at:
#0 pthread_create ??:0 (libtsan.so.0+0x00000001a298)
#1 gomp_team_start
/data/vjoost/gnu/gcc_exp/obj/x86_64-unknown-linux-gnu/libgomp/../../../gcc/libgomp/team.c:440
(libgomp.so.1+0x00000000d000)
#2 GOMP_parallel_start
/data/vjoost/gnu/gcc_exp/obj/x86_64-unknown-linux-gnu/libgomp/../../../gcc/libgomp/parallel.c:108
(libgomp.so.1+0x00000000abb7)
#3 MAIN__ /data/vjoost/gnu/bugs/test_23.f90:2 (exe+0x000000000e39)
#4 __libc_start_main ??:0 (libc.so.6+0x0037a121ecdc)
==================
ThreadSanitizer: reported 1 warnings
