Revision

1938

Author

lsansonetti@apple.com

Date

2009-06-26 15:10:11 -0700 (Fri, 26 Jun 2009)

Log Message

fixed potential 'signal-before-wait' deadlocks

Modified Paths

• MacRuby/branches/experimental/thread.c
• MacRuby/branches/experimental/vm.cpp

Diff

--- MacRuby/branches/experimental/thread.c	2009-06-26 19:13:14 UTC (rev 1937)
+++ MacRuby/branches/experimental/thread.c	2009-06-26 22:10:11 UTC (rev 1938)
@@ -83,8 +83,6 @@
 	rb_sys_fail("pthread_create() failed");
     }
 
-    //assert(pthread_detach(t->thread) == 0);
-
     return thread;
 }
 

--- MacRuby/branches/experimental/vm.cpp	2009-06-26 19:13:14 UTC (rev 1937)
+++ MacRuby/branches/experimental/vm.cpp	2009-06-26 22:10:11 UTC (rev 1938)
@@ -4538,15 +4538,23 @@
     post_wait(t);
 }
 
+static inline void
+signal_thread(rb_vm_thread_t *t)
+{
+    assert(pthread_mutex_lock(&t->sleep_mutex) == 0);
+    assert(pthread_cond_signal(&t->sleep_cond) == 0);
+    assert(pthread_mutex_unlock(&t->sleep_mutex) == 0);
+}
+
 extern "C"
 void
 rb_vm_thread_wakeup(rb_vm_thread_t *t)
 {
     if (t->status == THREAD_DEAD) {
-	rb_raise(rb_eThreadError, "can't wake up thread from the dead");
+	rb_raise(rb_eThreadError, "can't wake up thread from the death");
     }
-    if (t->status == THREAD_SLEEP) {
-	assert(pthread_cond_signal(&t->sleep_cond) == 0);
+    if (t->status == THREAD_SLEEP && t->in_cond_wait) {
+	signal_thread(t);
     }
 }
 
@@ -4566,7 +4574,7 @@
 	    // will autodestroy itself, to work around a stack unwinding bug
 	    // in the Mac OS X pthread implementation that messes our C++
 	    // exception handlers.
-	    assert(pthread_cond_signal(&t->sleep_cond) == 0);
+	    signal_thread(t);
 	}
 	else {
 	    assert(pthread_cancel(t->thread) == 0);