Implement pthread spin.
In order to run tsan unit tests, we need to support pthread spin APIs.
Bug: 18623621
Bug: 25392375
Change-Id: Icbb4a74e72e467824b3715982a01600031868e29
diff --git a/libc/private/bionic_lock.h b/libc/private/bionic_lock.h
index a36d1ed..238ace4 100644
--- a/libc/private/bionic_lock.h
+++ b/libc/private/bionic_lock.h
@@ -30,6 +30,7 @@
#include <stdatomic.h>
#include "private/bionic_futex.h"
+#include "private/bionic_macros.h"
// Lock is used in places like pthread_rwlock_t, which can be initialized without calling
// an initialization function. So make sure Lock can be initialized by setting its memory to 0.
@@ -49,6 +50,12 @@
this->process_shared = process_shared;
}
+ bool trylock() {
+ LockState old_state = Unlocked;
+ return __predict_true(atomic_compare_exchange_strong_explicit(&state, &old_state,
+ LockedWithoutWaiter, memory_order_acquire, memory_order_relaxed));
+ }
+
void lock() {
LockState old_state = Unlocked;
if (__predict_true(atomic_compare_exchange_strong_explicit(&state, &old_state,