diff options
Diffstat (limited to 'absl/base/internal/spinlock.h')
| -rw-r--r-- | absl/base/internal/spinlock.h | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/absl/base/internal/spinlock.h b/absl/base/internal/spinlock.h index 2929cd6f..1bb260f4 100644 --- a/absl/base/internal/spinlock.h +++ b/absl/base/internal/spinlock.h @@ -53,7 +53,7 @@ namespace absl { ABSL_NAMESPACE_BEGIN namespace base_internal { -class ABSL_LOCKABLE SpinLock { +class ABSL_LOCKABLE ABSL_ATTRIBUTE_WARN_UNUSED SpinLock { public: SpinLock() : lockword_(kSpinLockCooperative) { ABSL_TSAN_MUTEX_CREATE(this, __tsan_mutex_not_static); @@ -89,7 +89,8 @@ class ABSL_LOCKABLE SpinLock { // acquisition was successful. If the lock was not acquired, false is // returned. If this SpinLock is free at the time of the call, TryLock // will return true with high probability. - inline bool TryLock() ABSL_EXCLUSIVE_TRYLOCK_FUNCTION(true) { + ABSL_MUST_USE_RESULT inline bool TryLock() + ABSL_EXCLUSIVE_TRYLOCK_FUNCTION(true) { ABSL_TSAN_MUTEX_PRE_LOCK(this, __tsan_mutex_try_lock); bool res = TryLockImpl(); ABSL_TSAN_MUTEX_POST_LOCK( @@ -120,7 +121,7 @@ class ABSL_LOCKABLE SpinLock { // Determine if the lock is held. When the lock is held by the invoking // thread, true will always be returned. Intended to be used as // CHECK(lock.IsHeld()). - inline bool IsHeld() const { + ABSL_MUST_USE_RESULT inline bool IsHeld() const { return (lockword_.load(std::memory_order_relaxed) & kSpinLockHeld) != 0; } @@ -202,6 +203,15 @@ class ABSL_LOCKABLE SpinLock { // Corresponding locker object that arranges to acquire a spinlock for // the duration of a C++ scope. +// +// TODO(b/176172494): Use only [[nodiscard]] when baseline is raised. +// TODO(b/6695610): Remove forward declaration when #ifdef is no longer needed. +#if ABSL_HAVE_CPP_ATTRIBUTE(nodiscard) +class [[nodiscard]] SpinLockHolder; +#else +class ABSL_MUST_USE_RESULT ABSL_ATTRIBUTE_TRIVIAL_ABI SpinLockHolder; +#endif + class ABSL_SCOPED_LOCKABLE SpinLockHolder { public: inline explicit SpinLockHolder(SpinLock* l) ABSL_EXCLUSIVE_LOCK_FUNCTION(l) |