rwlock.h

Go to the documentation of this file.

/******************************************************************************
 * Copyright 2022 ETC Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *******************************************************************************
 * This file is a part of EtcPal. For more information, go to:
 * https://github.com/ETCLabs/EtcPal
 ******************************************************************************/
 
 
#ifndef ETCPAL_CPP_RWLOCK_H_
#define ETCPAL_CPP_RWLOCK_H_
 
#include <stdexcept>
#include "etcpal/cpp/common.h"
#include "etcpal/rwlock.h"
 
namespace etcpal
{
 
class RwLock
{
public:
  RwLock();
  ~RwLock();
 
  RwLock(const RwLock& other) = delete;
  RwLock& operator=(const RwLock& other) = delete;
  RwLock(RwLock&& other)                 = delete;
  RwLock& operator=(RwLock&& other) = delete;
 
  bool ReadLock();
  bool TryReadLock(int timeout_ms = 0);
  void ReadUnlock();
 
  bool WriteLock();
  bool TryWriteLock(int timeout_ms = 0);
  void WriteUnlock();
 
  etcpal_rwlock_t& get();
 
private:
  etcpal_rwlock_t rwlock_{};
};
 
inline RwLock::RwLock()
{
  (void)etcpal_rwlock_create(&rwlock_);
}
 
inline RwLock::~RwLock()
{
  etcpal_rwlock_destroy(&rwlock_);
}
 
inline bool RwLock::ReadLock()
{
  return etcpal_rwlock_readlock(&rwlock_);
}
 
inline bool RwLock::TryReadLock(int timeout_ms)
{
  return etcpal_rwlock_timed_readlock(&rwlock_, timeout_ms);
}
 
inline void RwLock::ReadUnlock()
{
  etcpal_rwlock_readunlock(&rwlock_);
}
 
inline bool RwLock::WriteLock()
{
  return etcpal_rwlock_writelock(&rwlock_);
}
 
inline bool RwLock::TryWriteLock(int timeout_ms)
{
  return etcpal_rwlock_timed_writelock(&rwlock_, timeout_ms);
}
 
inline void RwLock::WriteUnlock()
{
  etcpal_rwlock_writeunlock(&rwlock_);
}
 
inline etcpal_rwlock_t& RwLock::get()
{
  return rwlock_;
}
 
class ReadGuard
{
public:
  explicit ReadGuard(RwLock& rwlock);
  explicit ReadGuard(etcpal_rwlock_t& rwlock);
  ~ReadGuard();
 
  ReadGuard(const ReadGuard& other) = delete;
  ReadGuard& operator=(const ReadGuard& other) = delete;
  ReadGuard(ReadGuard&& other)                 = delete;
  ReadGuard& operator=(ReadGuard&& other) = delete;
 
private:
  etcpal_rwlock_t& rwlock_;
 
  void GetReadLock();
};
 
inline ReadGuard::ReadGuard(RwLock& rwlock) : rwlock_(rwlock.get())
{
  GetReadLock();
}
 
inline ReadGuard::ReadGuard(etcpal_rwlock_t& rwlock) : rwlock_(rwlock)
{
  GetReadLock();
}
 
inline ReadGuard::~ReadGuard()
{
  etcpal_rwlock_readunlock(&rwlock_);
}
 
inline void ReadGuard::GetReadLock()
{
  if (!etcpal_rwlock_readlock(&rwlock_))
    ETCPAL_THROW(std::runtime_error("etcpal_rwlock_readlock failed."));
}
 
class WriteGuard
{
public:
  explicit WriteGuard(RwLock& rwlock);
  explicit WriteGuard(etcpal_rwlock_t& rwlock);
  ~WriteGuard();
 
  WriteGuard(const WriteGuard& other) = delete;
  WriteGuard& operator=(const WriteGuard& other) = delete;
  WriteGuard(WriteGuard&& other)                 = delete;
  WriteGuard& operator=(WriteGuard&& other) = delete;
 
private:
  etcpal_rwlock_t& rwlock_;
 
  void GetWriteLock();
};
 
inline WriteGuard::WriteGuard(RwLock& rwlock) : rwlock_(rwlock.get())
{
  GetWriteLock();
}
 
inline WriteGuard::WriteGuard(etcpal_rwlock_t& rwlock) : rwlock_(rwlock)
{
  GetWriteLock();
}
 
inline WriteGuard::~WriteGuard()
{
  etcpal_rwlock_writeunlock(&rwlock_);
}
 
inline void WriteGuard::GetWriteLock()
{
  if (!etcpal_rwlock_writelock(&rwlock_))
    ETCPAL_THROW(std::runtime_error("etcpal_rwlock_writelock failed."));
}
 
};  // namespace etcpal
 
#endif  // ETCPAL_CPP_RWLOCK_H_