1 //===-- asan_lock.h ---------------------------------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file is a part of AddressSanitizer, an address sanity checker. 11 // 12 // A wrapper for a simple lock. 13 //===----------------------------------------------------------------------===// 14 #ifndef ASAN_LOCK_H 15 #define ASAN_LOCK_H 16 17 #include "asan_internal.h" 18 19 // The locks in ASan are global objects and they are never destroyed to avoid 20 // at-exit races (that is, a lock is being used by other threads while the main 21 // thread is doing atexit destructors). 22 // We define the class using opaque storage to avoid including system headers. 23 24 namespace __asan { 25 26 class AsanLock { 27 public: 28 explicit AsanLock(LinkerInitialized); 29 void Lock(); 30 void Unlock(); 31 bool IsLocked() { return owner_ != 0; } 32 private: 33 uintptr_t opaque_storage_[10]; 34 uintptr_t owner_; // for debugging and for malloc_introspection_t interface 35 }; 36 37 class ScopedLock { 38 public: 39 explicit ScopedLock(AsanLock *mu) : mu_(mu) { 40 mu_->Lock(); 41 } 42 ~ScopedLock() { 43 mu_->Unlock(); 44 } 45 private: 46 AsanLock *mu_; 47 }; 48 49 } // namespace __asan 50 51 #endif // ASAN_LOCK_H 52
