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Diffstat (limited to 'libsanitizer/sanitizer_common/sanitizer_mutex.h')
-rw-r--r-- | libsanitizer/sanitizer_common/sanitizer_mutex.h | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/libsanitizer/sanitizer_common/sanitizer_mutex.h b/libsanitizer/sanitizer_common/sanitizer_mutex.h new file mode 100644 index 00000000000..a38a49ae242 --- /dev/null +++ b/libsanitizer/sanitizer_common/sanitizer_mutex.h @@ -0,0 +1,106 @@ +//===-- sanitizer_mutex.h ---------------------------------------*- C++ -*-===// +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file is a part of ThreadSanitizer/AddressSanitizer runtime. +// +//===----------------------------------------------------------------------===// + +#ifndef SANITIZER_MUTEX_H +#define SANITIZER_MUTEX_H + +#include "sanitizer_atomic.h" +#include "sanitizer_internal_defs.h" +#include "sanitizer_libc.h" + +namespace __sanitizer { + +class StaticSpinMutex { + public: + void Init() { + atomic_store(&state_, 0, memory_order_relaxed); + } + + void Lock() { + if (atomic_exchange(&state_, 1, memory_order_acquire) == 0) + return; + LockSlow(); + } + + void Unlock() { + atomic_store(&state_, 0, memory_order_release); + } + + private: + atomic_uint8_t state_; + + void NOINLINE LockSlow() { + for (int i = 0;; i++) { + if (i < 10) + proc_yield(10); + else + internal_sched_yield(); + if (atomic_load(&state_, memory_order_relaxed) == 0 + && atomic_exchange(&state_, 1, memory_order_acquire) == 0) + return; + } + } +}; + +class SpinMutex : public StaticSpinMutex { + public: + SpinMutex() { + Init(); + } + + private: + SpinMutex(const SpinMutex&); + void operator=(const SpinMutex&); +}; + +template<typename MutexType> +class GenericScopedLock { + public: + explicit GenericScopedLock(MutexType *mu) + : mu_(mu) { + mu_->Lock(); + } + + ~GenericScopedLock() { + mu_->Unlock(); + } + + private: + MutexType *mu_; + + GenericScopedLock(const GenericScopedLock&); + void operator=(const GenericScopedLock&); +}; + +template<typename MutexType> +class GenericScopedReadLock { + public: + explicit GenericScopedReadLock(MutexType *mu) + : mu_(mu) { + mu_->ReadLock(); + } + + ~GenericScopedReadLock() { + mu_->ReadUnlock(); + } + + private: + MutexType *mu_; + + GenericScopedReadLock(const GenericScopedReadLock&); + void operator=(const GenericScopedReadLock&); +}; + +typedef GenericScopedLock<StaticSpinMutex> SpinMutexLock; + +} // namespace __sanitizer + +#endif // SANITIZER_MUTEX_H |