From b8b91e982ec3235a24ce052cbd8bb0e4fe1464e0 Mon Sep 17 00:00:00 2001 From: Yao Qi Date: Thu, 5 Jun 2014 15:07:47 +0800 Subject: [PATCH] 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 * gdb.threads/staticthreads.c (thread_function): Move the line setting breakpoint on forward. * gdb.threads/staticthreads.exp: Update comments. --- gdb/testsuite/ChangeLog | 6 ++++++ gdb/testsuite/gdb.threads/staticthreads.c | 2 +- gdb/testsuite/gdb.threads/staticthreads.exp | 2 +- 3 files changed, 8 insertions(+), 2 deletions(-) diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index 83c57e0b7f..51686d19ad 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,9 @@ +2014-06-06 Yao Qi + + * gdb.threads/staticthreads.c (thread_function): Move the line + setting breakpoint on forward. + * gdb.threads/staticthreads.exp: Update comments. + 2014-06-05 Ludovic Courtès * gdb.guile/scm-value.exp (test_value_in_inferior): Add test diff --git a/gdb/testsuite/gdb.threads/staticthreads.c b/gdb/testsuite/gdb.threads/staticthreads.c index 5c8eabea47..db78063cec 100644 --- a/gdb/testsuite/gdb.threads/staticthreads.c +++ b/gdb/testsuite/gdb.threads/staticthreads.c @@ -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; } diff --git a/gdb/testsuite/gdb.threads/staticthreads.exp b/gdb/testsuite/gdb.threads/staticthreads.exp index 9fa625a83c..bdc03d4316 100644 --- a/gdb/testsuite/gdb.threads/staticthreads.exp +++ b/gdb/testsuite/gdb.threads/staticthreads.exp @@ -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" } -- 2.34.1