Iterate in JNI thread exit check.
The Dalvik VM includes a helpful check that kicks and screams if a thread
exits without detaching from the VM first. It manages this with a pthread
TLS destructor. This is handy, but it will interfere with anyone who
wants to use a TLS destructor to initiate the thread detach.
With this change, we now iterate a couple of times to allow other
destructors a chance to detach the thread before we get snippy.
For 2319072.
diff --git a/vm/Thread.c b/vm/Thread.c
index 2ea7bb5..2bd540d 100644
--- a/vm/Thread.c
+++ b/vm/Thread.c
@@ -1124,7 +1124,7 @@
* This is associated with the pthreadKeySelf key. It's called by the
* pthread library when a thread is exiting and the "self" pointer in TLS
* is non-NULL, meaning the VM hasn't had a chance to clean up. In normal
- * operation this should never be called.
+ * operation this will not be called.
*
* This is mainly of use to ensure that we don't leak resources if, for
* example, a thread attaches itself to us with AttachCurrentThread and
@@ -1135,16 +1135,43 @@
* will simply be unaware that the thread has exited, leading to resource
* leaks (and, if this is a non-daemon thread, an infinite hang when the
* VM tries to shut down).
+ *
+ * Because some implementations may want to use the pthread destructor
+ * to initiate the detach, and the ordering of destructors is not defined,
+ * we want to iterate a couple of times to give those a chance to run.
*/
static void threadExitCheck(void* arg)
{
- Thread* thread = (Thread*) arg;
+ const int kMaxCount = 2;
- LOGI("In threadExitCheck %p\n", arg);
- assert(thread != NULL);
+ Thread* self = (Thread*) arg;
+ assert(self != NULL);
- if (thread->status != THREAD_ZOMBIE) {
- LOGE("Native thread exited without telling us\n");
+ LOGV("threadid=%d: threadExitCheck(%p) count=%d\n",
+ self->threadId, arg, self->threadExitCheckCount);
+
+ if (self->status == THREAD_ZOMBIE) {
+ LOGW("threadid=%d: Weird -- shouldn't be in threadExitCheck\n",
+ self->threadId);
+ return;
+ }
+
+ if (self->threadExitCheckCount < kMaxCount) {
+ /*
+ * Spin a couple of times to let other destructors fire.
+ */
+ LOGD("threadid=%d: thread exiting, not yet detached (count=%d)\n",
+ self->threadId, self->threadExitCheckCount);
+ self->threadExitCheckCount++;
+ int cc = pthread_setspecific(gDvm.pthreadKeySelf, self);
+ if (cc != 0) {
+ LOGE("threadid=%d: unable to re-add thread to TLS\n",
+ self->threadId);
+ dvmAbort();
+ }
+ } else {
+ LOGE("threadid=%d: native thread exited without detaching\n",
+ self->threadId);
dvmAbort();
}
}