Make pthread join_state not protected by g_thread_list_lock.
1. Move the representation of thread join_state from pthread.attr.flag
to pthread.join_state. This clarifies thread state change.
2. Use atomic operations for pthread.join_state. So we don't need to
protect it by g_thread_list_lock. g_thread_list_lock will be reduced
to only protect g_thread_list or even removed in further changes.
Bug: 19636317
Change-Id: I31fb143a7c69508c7287307dd3b0776993ec0f43
diff --git a/libc/bionic/pthread_create.cpp b/libc/bionic/pthread_create.cpp
index 2bca43f..a4bd054 100644
--- a/libc/bionic/pthread_create.cpp
+++ b/libc/bionic/pthread_create.cpp
@@ -86,6 +86,12 @@
int __init_thread(pthread_internal_t* thread, bool add_to_thread_list) {
int error = 0;
+ if (__predict_true((thread->attr.flags & PTHREAD_ATTR_FLAG_DETACHED) == 0)) {
+ atomic_init(&thread->join_state, THREAD_NOT_JOINED);
+ } else {
+ atomic_init(&thread->join_state, THREAD_DETACHED);
+ }
+
// Set the scheduling policy/priority of the thread.
if (thread->attr.sched_policy != SCHED_NORMAL) {
sched_param param;
@@ -263,7 +269,7 @@
if (init_errno != 0) {
// Mark the thread detached and replace its start_routine with a no-op.
// Letting the thread run is the easiest way to clean up its resources.
- thread->attr.flags |= PTHREAD_ATTR_FLAG_DETACHED;
+ atomic_store(&thread->join_state, THREAD_DETACHED);
thread->start_routine = __do_nothing;
pthread_mutex_unlock(&thread->startup_handshake_mutex);
return init_errno;