Fix the race in gdb.threads/staticthreads.exp

The code in gdb.threads/staticthreads.exp about checking the value of
tlsvar in main thread is racy, because when child thread hits
breakpoint, the main thread may not go into pthread_join yet, and
may not be unwind to main.

This patch is to move the line setting breakpoint on after sem_wait,
so that the child thread will hit breakpoint after main thread calls
sem_post.  IOW, when child thread hits breakpoint, the main thread is
in either sem_post or pthread_join.  "up 10" can unwind main thread to
main.

gdb/testsuite:

2014-06-06  Yao Qi  <yao@codesourcery.com>

	* gdb.threads/staticthreads.c (thread_function): Move the line
	setting breakpoint on forward.
	* gdb.threads/staticthreads.exp: Update comments.
This commit is contained in:
Yao Qi 2014-06-05 15:07:47 +08:00
parent 872a9dd881
commit b8b91e982e
3 changed files with 8 additions and 2 deletions

View File

@ -1,3 +1,9 @@
2014-06-06 Yao Qi <yao@codesourcery.com>
* gdb.threads/staticthreads.c (thread_function): Move the line
setting breakpoint on forward.
* gdb.threads/staticthreads.exp: Update comments.
2014-06-05 Ludovic Courtès <ludo@gnu.org>
* gdb.guile/scm-value.exp (test_value_in_inferior): Add test

View File

@ -38,7 +38,6 @@ thread_function (void *arg)
#ifdef HAVE_TLS
tlsvar = 2;
#endif
printf ("Thread executing\n"); /* tlsvar-is-set */
while (sem_wait (&semaphore) != 0)
{
if (errno != EINTR)
@ -47,6 +46,7 @@ thread_function (void *arg)
return NULL;
}
}
printf ("Thread executing\n"); /* tlsvar-is-set */
return NULL;
}

View File

@ -105,7 +105,7 @@ if { "$have_tls" != "" } {
gdb_continue_to_breakpoint "tlsvar-is-set" ".* tlsvar-is-set .*"
gdb_test "p tlsvar" " = 2" "tlsvar in thread"
gdb_test "thread 1" ".*"
# Unwind from pthread_join.
# Unwind to main.
gdb_test "up 10" " in main .*"
gdb_test "p tlsvar" " = 1" "tlsvar in main"
}