[源码] 用C++封装自旋锁 利用C++11及其以上标准封装自旋锁

[i]/************************************************************************
[/i][i]SpinLockTAS<> sp_lock;
[/i][i]std::unique_lock<SpinLockTAS<>> lk(sp_lock);
[/i][i]功  能：[/i][i] TAS[/i][i]自旋锁[/i][i]
[/i][i]返回值：[/i][i]void
[/i][i]************************************************************************/
[/i]template<::std::size_t sleepWhenLockFailedInMicroSecond = ::std::size_t(-1)>
class SpinLockTAS
{
public:
    void lock();
    void unlock();
private:
    ::std::atomic_flag locked_flag = ATOMIC_FLAG_INIT;
};
 
[i]/************************************************************************
[/i][i]SpinLockCAS<> sp_lock;
[/i][i]std::unique_lock<SpinLockCAS<>> lk(sp_lock);
[/i][i]功  能：[/i][i] CAS[/i][i]自旋锁[/i][i]
[/i][i]************************************************************************/
[/i]template<::std::size_t sleepWhenLockFailedInMicroSecond = ::std::size_t(-1)>
class SpinLockCAS
{
public:
    void lock();
    void unlock();
 
private:
    ::std::atomic<bool> locked_flag;
};
 
template<::std::size_t sleepWhenLockFailedInMicroSecond>
void SpinLockTAS<sleepWhenLockFailedInMicroSecond>::lock()
{
   while (this->locked_flag.test_and_set())
   {
       if (sleepWhenLockFailedInMicroSecond <= ::std::size_t(0))
           ::std::this_thread::yield();
       else if (sleepWhenLockFailedInMicroSecond > 0)
           ::std::this_thread::sleep_for(::std::chrono::microseconds(sleepWhenLockFailedInMicroSecond));
   }
}
 
template<::std::size_t sleepWhenLockFailedInMicroSecond>
void SpinLockTAS<sleepWhenLockFailedInMicroSecond>::unlock()
{
   this->locked_flag.clear();
}
 
template<::std::size_t sleepWhenLockFailedInMicroSecond>
void SpinLockCAS<sleepWhenLockFailedInMicroSecond>::lock()
{
    bool expect = false;
 
    while (!this->locked_flag.compare_exchange_weak(expect, true))
    {
       expect = false;
       if (sleepWhenLockFailedInMicroSecond <= ::std::size_t(0))
           ::std::this_thread::yield();
       else if (sleepWhenLockFailedInMicroSecond > 0)
           ::std::this_thread::sleep_for(::std::chrono::microseconds(sleepWhenLockFailedInMicroSecond));
    }
}
 
template<::std::size_t sleepWhenLockFailedInMicroSecond>
void SpinLockCAS<sleepWhenLockFailedInMicroSecond>::unlock()
{
    this->locked_flag.store(false);
}

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