1 //===- llvm/Support/ThreadLocal.h - Thread Local Data ------------*- 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 declares the llvm::sys::ThreadLocal class. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_SUPPORT_THREADLOCAL_H 15 #define LLVM_SUPPORT_THREADLOCAL_H 16 17 #include "llvm/Support/DataTypes.h" 18 #include "llvm/Support/Threading.h" 19 #include <cassert> 20 21 namespace llvm { 22 namespace sys { 23 // ThreadLocalImpl - Common base class of all ThreadLocal instantiations. 24 // YOU SHOULD NEVER USE THIS DIRECTLY. 25 class ThreadLocalImpl { 26 typedef uint64_t ThreadLocalDataTy; 27 /// \brief Platform-specific thread local data. 28 /// 29 /// This is embedded in the class and we avoid malloc'ing/free'ing it, 30 /// to make this class more safe for use along with CrashRecoveryContext. 31 union { 32 char data[sizeof(ThreadLocalDataTy)]; 33 ThreadLocalDataTy align_data; 34 }; 35 public: 36 ThreadLocalImpl(); 37 virtual ~ThreadLocalImpl(); 38 void setInstance(const void* d); 39 void *getInstance(); 40 void removeInstance(); 41 }; 42 43 /// ThreadLocal - A class used to abstract thread-local storage. It holds, 44 /// for each thread, a pointer a single object of type T. 45 template<class T> 46 class ThreadLocal : public ThreadLocalImpl { 47 public: 48 ThreadLocal() : ThreadLocalImpl() { } 49 50 /// get - Fetches a pointer to the object associated with the current 51 /// thread. If no object has yet been associated, it returns NULL; 52 T* get() { return static_cast<T*>(getInstance()); } 53 54 // set - Associates a pointer to an object with the current thread. 55 void set(T* d) { setInstance(d); } 56 57 // erase - Removes the pointer associated with the current thread. 58 void erase() { removeInstance(); } 59 }; 60 } 61 } 62 63 #endif 64
