/******************************************************************************
  Copyright (C), 2001-2016, Allwinner Tech. Co., Ltd.
 ******************************************************************************
  File Name     : Thread.h
  Version       : Initial Draft
  Author        : Allwinner BU3-PD2 Team
  Created       : 2016/06/01
  Last Modified :
  Description   : mpi functions implement
  Function List :
  History       :
******************************************************************************/
#ifndef __IPCLINUX_THREAD_H__
#define __IPCLINUX_THREAD_H__

#include <stdint.h>
#include <sys/types.h>
#include <time.h>
#include <pthread.h>
#include <utils/Mutex.h>
#include <utils/Condition.h>

namespace EyeseeLinux {

class Thread
{
public:
    // Create a Thread object, but doesn't create or start the associated
    // thread. See the run() method.
    Thread();
    virtual ~Thread();

    // Start the thread in threadLoop() which needs to be implemented.
    virtual status_t run(const char *name = 0, int priority =0, size_t stack = 0);

    // Ask this object's thread to exit. This function is asynchronous, when the
    // function returns the thread might still be running. Of course, this
    // function can be called from a different thread.
    virtual void requestExit();

    // Good place to do one-time initializations
    virtual status_t readyToRun();
    
    // Call requestExit() and wait until this object's thread exits.
    // BE VERY CAREFUL of deadlocks. In particular, it would be silly to call
    // this function from this object's thread. Will return WOULD_BLOCK in
    // that case.
    status_t requestExitAndWait();

    // Wait until this object's thread exits. Returns immediately if not yet running.
    // Do not call from this object's thread; will return WOULD_BLOCK in that case.
    status_t join();

protected:
    // exitPending() returns true if requestExit() has been called.
    bool exitPending() const;
    
private:
    // Derived class must implement threadLoop(). The thread starts its life
    // here. There are two ways of using the Thread object:
    // 1) loop: if threadLoop() returns true, it will be called again if
    //          requestExit() wasn't called.
    // 2) once: if threadLoop() returns false, the thread will exit upon return.
    virtual bool threadLoop() = 0;

private:
    Thread& operator=(const Thread&);
    static void *_threadLoop(void* user);
    // always hold mLock when reading or writing
    pthread_t mThread;
    mutable Mutex mLock;
    Condition mThreadExitedCondition;
    status_t mStatus;
    // note that all accesses of mExitPending and mRunning need to hold mLock
    volatile bool mExitPending;
    volatile bool mRunning;
    char* mName;
}; /* class Thread */

};  /* namespace EyeseeLinux */

#endif /* __IPCLINUX_THREAD_H__ */