monero/contrib/epee/include/syncobj.h

// Copyright (c) 2014, The Monero Project
// 
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
// 
// 1. Redistributions of source code must retain the above copyright notice, this list of
//    conditions and the following disclaimer.
// 
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
//    of conditions and the following disclaimer in the documentation and/or other
//    materials provided with the distribution.
// 
// 3. Neither the name of the copyright holder nor the names of its contributors may be
//    used to endorse or promote products derived from this software without specific
//    prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// 
// Parts of this file are originally copyright (c) 2006-2013, Andrey N. Sabelnikov

#ifndef __WINH_OBJ_H__
#define __WINH_OBJ_H__

#include <condition_variable>
#include <mutex>
#include <boost/thread/locks.hpp>
#include <boost/thread/mutex.hpp>
#include <boost/thread/recursive_mutex.hpp>

namespace epee
{

  struct simple_event
  {
    simple_event() : m_rised(false)
    {
    }

    void raise()
    {
      std::unique_lock<std::mutex> lock(m_mx);
      m_rised = true;
      m_cond_var.notify_one();
    }

    void wait()
    {
      std::unique_lock<std::mutex> lock(m_mx);
      while (!m_rised) 
        m_cond_var.wait(lock);
      m_rised = false;
    }

  private:
    std::mutex m_mx;
    std::condition_variable m_cond_var;
    bool m_rised;
  };

  class critical_region;

  class critical_section
  {
    boost::recursive_mutex m_section;

  public:
    //to make copy fake!
    critical_section(const critical_section& section)
    {
    }

    critical_section()
    {
    }

    ~critical_section()
    {
    }

    void lock()
    {
      m_section.lock();
      //EnterCriticalSection( &m_section );
    }

    void unlock()
    {
      m_section.unlock();
    }

    bool tryLock()
    {
      return m_section.try_lock();
    }

    // to make copy fake
    critical_section& operator=(const critical_section& section)
    {
      return *this;
    }
  };


  template<class t_lock>
  class critical_region_t
  {
    t_lock&	m_locker;
    bool m_unlocked;

    critical_region_t(const critical_region_t&) {}

  public:
    critical_region_t(t_lock& cs): m_locker(cs), m_unlocked(false)
    {
      m_locker.lock();
    }

    ~critical_region_t()
    {
      unlock();
    }

    void unlock()
    {
      if (!m_unlocked)
      {
        m_locker.unlock();
        m_unlocked = true;
      }
    }
  };


#if defined(WINDWOS_PLATFORM)
  class shared_critical_section
  {
  public: 
    shared_critical_section()
    {
      ::InitializeSRWLock(&m_srw_lock);
    }
    ~shared_critical_section()
    {}

    bool lock_shared()
    {
      AcquireSRWLockShared(&m_srw_lock);
      return true;
    }
    bool unlock_shared()
    {
      ReleaseSRWLockShared(&m_srw_lock);
      return true;
    }
    bool lock_exclusive()
    {
      ::AcquireSRWLockExclusive(&m_srw_lock);
      return true;
    }
    bool unlock_exclusive()
    {
      ::ReleaseSRWLockExclusive(&m_srw_lock);
      return true;
    }
  private:
    SRWLOCK m_srw_lock;
  };


  class shared_guard
  {
  public:
    shared_guard(shared_critical_section& ref_sec):m_ref_sec(ref_sec)
    {
      m_ref_sec.lock_shared();
    }

    ~shared_guard()
    {
      m_ref_sec.unlock_shared();
    }

  private:
    shared_critical_section& m_ref_sec;
  };


  class exclusive_guard
  {
  public:
    exclusive_guard(shared_critical_section& ref_sec):m_ref_sec(ref_sec)
    {
      m_ref_sec.lock_exclusive();
    }

    ~exclusive_guard()
    {
      m_ref_sec.unlock_exclusive();
    }

  private:
    shared_critical_section& m_ref_sec;
  };
#endif

#define  SHARED_CRITICAL_REGION_BEGIN(x) { shared_guard   critical_region_var(x)
#define  EXCLUSIVE_CRITICAL_REGION_BEGIN(x) { exclusive_guard   critical_region_var(x)

#define  CRITICAL_REGION_LOCAL(x) epee::critical_region_t<decltype(x)>   critical_region_var(x)
#define  CRITICAL_REGION_BEGIN(x) { epee::critical_region_t<decltype(x)>   critical_region_var(x)
#define  CRITICAL_REGION_LOCAL1(x) epee::critical_region_t<decltype(x)>   critical_region_var1(x)
#define  CRITICAL_REGION_BEGIN1(x) { epee::critical_region_t<decltype(x)>   critical_region_var1(x)

#define  CRITICAL_REGION_END() }


#if defined(WINDWOS_PLATFORM)
  inline const char* get_wait_for_result_as_text(DWORD res)
  {
    switch(res)
    {
    case WAIT_ABANDONED:  return "WAIT_ABANDONED";
    case WAIT_TIMEOUT:    return "WAIT_TIMEOUT";
    case WAIT_OBJECT_0:   return "WAIT_OBJECT_0";
    case WAIT_OBJECT_0+1: return "WAIT_OBJECT_1";
    case WAIT_OBJECT_0+2: return "WAIT_OBJECT_2";
    default:              return "UNKNOWN CODE";
    }
  }
#endif

}

#endif