text: /*
   * Copyright (c) 2013, Ford Motor Company
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * Redistributions of source code must retain the above copyright notice, this
   * list of conditions and the following disclaimer.
   *
   * 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.
   *
   * Neither the name of the Ford Motor Company 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.
   */
  
  #ifndef SRC_COMPONENTS_INCLUDE_UTILS_THREADS_THREAD_DELEGATE_H_
  #define SRC_COMPONENTS_INCLUDE_UTILS_THREADS_THREAD_DELEGATE_H_
  
  #include <pthread.h>
  
  #include "utils/lock.h"
  
  namespace threads {
  
  enum ThreadState {
    kInit = 0,
    kStarted = 1,
    kStopReq = 2
  };
  
  class Thread;
  
  /**
   * Thread procedure interface.
   * Look for "threads/thread.h" for example
   */
  class ThreadDelegate {
   public:
    ThreadDelegate()
        : state_(kInit),
          thread_(NULL) {
    }
    /**
     * \brief Thread procedure.
     */
    virtual void threadMain() = 0;
  
    /**
     * Should be called to free all resources allocated in threadMain
     * and exiting threadMain
     * This function should be blocking and return only when threadMain() will be
     * finished in other case segmantation failes are possible
     */
    virtual void exitThreadMain();
  
    virtual ~ThreadDelegate();
  
    Thread* thread() const {
      return thread_;
    }
  
    void set_thread(Thread *thread);
  
    bool ImproveState(unsigned int to) {
      state_lock_.Lock();
      if ((state_ + 1 == to) || (to == kInit && state_ == kStopReq)) {
        state_ = to;
      }
      state_lock_.Unlock();
      return state_ == to;
    }
  
    unsigned int state() const {
      return state_;
    }
  
   private:
    volatile unsigned int state_;
    sync_primitives::SpinMutex state_lock_;
    Thread* thread_;
  };
  
  }  // namespace threads
  #endif  // SRC_COMPONENTS_INCLUDE_UTILS_THREADS_THREAD_DELEGATE_H_
  