merges r30272 from trunk into ruby_1_9_2.

--
        * thread.c (thread_cleanup_func): Don't touch native threading
          resource at fork. Sadly this is purely bandaid. We need to
          implement proper fix later. [Bug #4169] [ruby-core:33767]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@32375 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 12 insertions, 3 deletions

diff --git a/thread.c b/thread.c
index 76f4cb6763..0c8c6ea463 100644
--- a/thread.c
+++ b/thread.c
@@ -389,12 +389,21 @@ thread_cleanup_func_before_exec(void *th_ptr)
 }
 
 static void
-thread_cleanup_func(void *th_ptr)
+thread_cleanup_func(void *th_ptr, int atfork)
 {
     rb_thread_t *th = th_ptr;
 
     th->locking_mutex = Qfalse;
     thread_cleanup_func_before_exec(th_ptr);
+
+    /*
+     * Unfortunately, we can't release native threading resource at fork
+     * because libc may have unstable locking state therefore touching
+     * a threading resource may cause a deadlock.
+     */
+    if (atfork)
+	return;
+
     native_thread_destroy(th);
 }
 
@@ -524,7 +533,7 @@ thread_start_func_2(rb_thread_t *th, VALUE *stack_start, VALUE *register_stack_s
 	ruby_cleanup(state);
     }
     else {
-	thread_cleanup_func(th);
+	thread_cleanup_func(th, FALSE);
 	native_mutex_unlock(&th->vm->global_vm_lock);
     }
 
@@ -2776,7 +2785,7 @@ terminate_atfork_i(st_data_t key, st_data_t val, st_data_t current_th)
 	    rb_mutex_abandon_all(th->keeping_mutexes);
 	}
 	th->keeping_mutexes = NULL;
-	thread_cleanup_func(th);
+	thread_cleanup_func(th, TRUE);
     }
     return ST_CONTINUE;
 }