diff options
| -rw-r--r-- | runtime/thread-inl.h | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/runtime/thread-inl.h b/runtime/thread-inl.h index 6f3c117..b87a8ec 100644 --- a/runtime/thread-inl.h +++ b/runtime/thread-inl.h @@ -87,18 +87,22 @@ inline void Thread::TransitionFromRunnableToSuspended(ThreadState new_state) { DCHECK_EQ(GetState(), kRunnable); union StateAndFlags old_state_and_flags; union StateAndFlags new_state_and_flags; - do { + while (true) { old_state_and_flags.as_int = state_and_flags_.as_int; if (UNLIKELY((old_state_and_flags.as_struct.flags & kCheckpointRequest) != 0)) { RunCheckpointFunction(); continue; } - // Copy over flags and try to clear the checkpoint bit if it is set. - new_state_and_flags.as_struct.flags = old_state_and_flags.as_struct.flags & ~kCheckpointRequest; + // Change the state but keep the current flags (kCheckpointRequest is clear). + DCHECK_EQ((old_state_and_flags.as_struct.flags & kCheckpointRequest), 0); + new_state_and_flags.as_struct.flags = old_state_and_flags.as_struct.flags; new_state_and_flags.as_struct.state = new_state; - // CAS the value without a memory barrier, that will occur in the unlock below. - } while (UNLIKELY(android_atomic_cas(old_state_and_flags.as_int, new_state_and_flags.as_int, - &state_and_flags_.as_int) != 0)); + int status = android_atomic_cas(old_state_and_flags.as_int, new_state_and_flags.as_int, + &state_and_flags_.as_int); + if (LIKELY(status == 0)) { + break; + } + } // Release share on mutator_lock_. Locks::mutator_lock_->SharedUnlock(this); } |