OW_MutexLock.hpp

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#ifndef OW_MUTEXLOCK_HPP_INCLUDE_GUARD_
#define OW_MUTEXLOCK_HPP_INCLUDE_GUARD_
#include "OW_config.h"
#include "OW_Mutex.hpp"
#include <cassert>

namespace OW_NAMESPACE
{

class OW_COMMON_API MutexLock
{
public:
   explicit MutexLock(Mutex& mutex, bool initially_locked=true)
      : m_mutex(&mutex), m_locked(false)
   {
      if (initially_locked)
      {
         lock();
      }
   }
   ~MutexLock()
   {
      try
      {
         if (m_locked)
         {
            release();
         }
      }
      catch (...)
      {
         // don't let exceptions escape
      }
   }
   void lock()
   {
      assert(m_locked == false);
      m_mutex->acquire();
      m_locked = true;
   }
   void release()
   {
      assert(m_locked == true);
      m_mutex->release();
      m_locked = false;
   }
   MutexLock(const MutexLock& arg)
      : m_mutex(arg.m_mutex), m_locked(arg.m_locked)
   {
      arg.m_locked = false;
   }
   bool isLocked() const
   {
      return m_locked;
   }
private:
   Mutex* m_mutex;
   mutable bool m_locked;
   friend class Condition;
};

} // end namespace OW_NAMESPACE

#endif

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