chromium之ThreadLocalStorage

看看头文件怎么用

// Wrapper for thread local storage.  This class doesn't do much except provide
// an API for portability.
class ThreadLocalStorage {
 public:

  // Prototype for the TLS destructor function, which can be optionally used to
  // cleanup thread local storage on thread exit.  'value' is the data that is
  // stored in thread local storage.
  typedef void (*TLSDestructorFunc)(void* value);

  // A key representing one value stored in TLS.
  class Slot {
   public:
    Slot(TLSDestructorFunc destructor = NULL);

    // This constructor should be used for statics.
    // It returns an uninitialized Slot.
    explicit Slot(base::LinkerInitialized x) {}

    // Set up the TLS slot.  Called by the constructor.
    // 'destructor' is a pointer to a function to perform per-thread cleanup of
    // this object.  If set to NULL, no cleanup is done for this TLS slot.
    // Returns false on error.
    bool Initialize(TLSDestructorFunc destructor);

    // Free a previously allocated TLS 'slot'.
    // If a destructor was set for this slot, removes
    // the destructor so that remaining threads exiting
    // will not free data.
    void Free();

    // Get the thread-local value stored in slot 'slot'.
    // Values are guaranteed to initially be zero.
    void* Get() const;

    // Set the thread-local value stored in slot 'slot' to
    // value 'value'.
    void Set(void* value);

    bool initialized() const { return initialized_; }

   private:
    // The internals of this struct should be considered private.
    bool initialized_;
#if defined(OS_WIN)
    int slot_;
#elif defined(OS_POSIX)
    pthread_key_t key_;
#endif

    DISALLOW_COPY_AND_ASSIGN(Slot);
  };

#if defined(OS_WIN)
  // Function called when on thread exit to call TLS
  // destructor functions.  This function is used internally.
  static void ThreadExit();

ThreadLocalStorage::Slot slot = new ThreadLocalStorage::Slot(..)

slot->Initialize

slot->Set

slot->Get

有个测试用例，蛮看一看

TEST(ThreadLocalStorageTest, Basics) {
  ThreadLocalStorage::Slot slot;
  slot.Set(reinterpret_cast<void*>(123));
  int value = reinterpret_cast<intptr_t>(slot.Get());
  EXPECT_EQ(value, 123);
}