| //===-- sanitizer_mutex.cpp -----------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file is shared between AddressSanitizer and ThreadSanitizer |
| // run-time libraries. |
| //===----------------------------------------------------------------------===// |
| |
| #include "sanitizer_mutex.h" |
| |
| #include "sanitizer_common.h" |
| |
| namespace __sanitizer { |
| |
| void Semaphore::Wait() { |
| u32 count = atomic_load(&state_, memory_order_relaxed); |
| for (;;) { |
| if (count == 0) { |
| FutexWait(&state_, 0); |
| count = atomic_load(&state_, memory_order_relaxed); |
| continue; |
| } |
| if (atomic_compare_exchange_weak(&state_, &count, count - 1, |
| memory_order_acquire)) |
| break; |
| } |
| } |
| |
| void Semaphore::Post(u32 count) { |
| CHECK_NE(count, 0); |
| atomic_fetch_add(&state_, count, memory_order_release); |
| FutexWake(&state_, count); |
| } |
| |
| } // namespace __sanitizer |
