richk@10211: /* $Id$ */
richk@10211: 
richk@10211: /** @file thread_pthread.cpp POSIX pthread implementation of Threads. */
richk@10211: 
richk@10211: #include "stdafx.h"
richk@10211: #include "thread.h"
richk@10211: #include "debug.h"
richk@10211: #include "core/alloc_func.hpp"
richk@10211: #include <stdlib.h>
richk@10211: #include <pthread.h>
richk@10211: #include <semaphore.h>
richk@10211: #include <unistd.h>
richk@10211: 
richk@10211: /**
richk@10211:  * POSIX pthread version for ThreadObject.
richk@10211:  */
richk@10211: class ThreadObject_pthread : public ThreadObject {
richk@10211: private:
richk@10211: 	pthread_t m_thr;             ///< System thread identifier.
richk@10211: 	OTTDThreadFunc m_proc;       ///< External thread procedure.
richk@10211: 	void     *m_param;           ///< Parameter for the external thread procedure.
richk@10211: 	bool      m_attached;        ///< True if the ThreadObject was attached to an existing thread.
richk@10211: 	sem_t     m_sem_start;       ///< Here the new thread waits before it starts.
richk@10211: 	sem_t     m_sem_stop;        ///< Here the other thread can wait for this thread to end.
richk@10211: 
richk@10211: public:
richk@10211: 	/**
richk@10211: 	 * Create a pthread and start it, calling proc(param).
richk@10211: 	 */
richk@10211: 	ThreadObject_pthread(OTTDThreadFunc proc, void *param) :
richk@10211: 		m_thr(0),
richk@10211: 		m_proc(proc),
richk@10211: 		m_param(param),
richk@10211: 		m_attached(false)
richk@10211: 	{
richk@10211: 		sem_init(&m_sem_start, 0, 0);
richk@10211: 		sem_init(&m_sem_stop, 0, 0);
richk@10211: 
richk@10211: 		pthread_create(&m_thr, NULL, &stThreadProc, this);
richk@10211: 		sem_post(&m_sem_start);
richk@10211: 	}
richk@10211: 
richk@10211: 	/**
richk@10211: 	 * Create a pthread and attach current thread to it.
richk@10211: 	 */
richk@10211: 	ThreadObject_pthread() :
richk@10211: 		m_thr(0),
richk@10211: 		m_proc(NULL),
richk@10211: 		m_param(0),
richk@10211: 		m_attached(true)
richk@10211: 	{
richk@10211: 		sem_init(&m_sem_start, 0, 0);
richk@10211: 		sem_init(&m_sem_stop, 0, 0);
richk@10211: 
richk@10211: 		m_thr = pthread_self();
richk@10211: 	}
richk@10211: 
richk@10211: 	/* virtual */ ~ThreadObject_pthread()
richk@10211: 	{
richk@10211: 		sem_destroy(&m_sem_stop);
richk@10211: 		sem_destroy(&m_sem_start);
richk@10211: 	};
richk@10211: 
richk@10211: 	/* virtual */ bool IsRunning()
richk@10211: 	{
richk@10724: 		int sval;
richk@10724: 		sem_getvalue(&m_sem_stop, &sval);
richk@10724: 		return sval == 0;
richk@10211: 	}
richk@10211: 
richk@10211: 	/* virtual */ bool WaitForStop()
richk@10211: 	{
richk@10211: 		/* You can't wait on yourself */
richk@10211: 		assert(!IsCurrent());
richk@10211: 		/* If the thread is not running, waiting is over */
richk@10211: 		if (!IsRunning()) return true;
richk@10211: 
richk@10211: 		int ret = sem_wait(&m_sem_stop);
richk@10211: 		if (ret == 0) {
richk@10211: 			/* We have passed semaphore so increment it again */
richk@10211: 			sem_post(&m_sem_stop);
richk@10211: 			return true;
richk@10211: 		}
richk@10211: 		return false;
richk@10211: 	}
richk@10211: 
richk@10211: 	/* virtual */ bool Exit()
richk@10211: 	{
richk@10211: 		/* You can only exit yourself */
richk@10211: 		assert(IsCurrent());
richk@10211: 		/* If the thread is not running, we are already closed */
richk@10211: 		if (!IsRunning()) return false;
richk@10211: 
richk@10211: 		/* For now we terminate by throwing an error, gives much cleaner cleanup */
richk@10211: 		throw 0;
richk@10211: 	}
richk@10211: 
richk@10991: 	/* virtual */ void Join()
richk@10211: 	{
richk@10211: 		/* You cannot join yourself */
richk@10211: 		assert(!IsCurrent());
richk@10211: 
richk@10991: 		pthread_join(m_thr, NULL);
richk@10211: 		m_thr = 0;
richk@10211: 	}
richk@10211: 
richk@10211: 	/* virtual */ bool IsCurrent()
richk@10211: 	{
richk@10211: 		return pthread_self() == m_thr;
richk@10211: 	}
richk@10211: 
richk@10211: 	/* virtual */ uint GetId()
richk@10211: 	{
richk@10211: 		return (uint)m_thr;
richk@10211: 	}
richk@10211: 
richk@10211: private:
richk@10211: 	/**
richk@10211: 	 * On thread creation, this function is called, which calls the real startup
richk@10211: 	 *  function. This to get back into the correct instance again.
richk@10211: 	 */
richk@10211: 	static void *stThreadProc(void *thr)
richk@10211: 	{
richk@10991: 		((ThreadObject_pthread *)thr)->ThreadProc();
richk@10991: 		pthread_exit(NULL);
richk@10211: 	}
richk@10211: 
richk@10211: 	/**
richk@10211: 	 * A new thread is created, and this function is called. Call the custom
richk@10211: 	 *  function of the creator of the thread.
richk@10211: 	 */
richk@10991: 	void ThreadProc()
richk@10211: 	{
richk@10211: 		/* The new thread stops here so the calling thread can complete pthread_create() call */
richk@10211: 		sem_wait(&m_sem_start);
richk@10211: 
richk@10211: 		/* Call the proc of the creator to continue this thread */
richk@10211: 		try {
richk@10211: 			m_proc(m_param);
richk@10211: 		} catch (...) {
richk@10211: 		}
richk@10211: 
richk@10211: 		/* Notify threads waiting for our completion */
richk@10211: 		sem_post(&m_sem_stop);
richk@10211: 	}
richk@10211: };
richk@10211: 
richk@10211: /* static */ ThreadObject *ThreadObject::New(OTTDThreadFunc proc, void *param)
richk@10211: {
richk@10211: 	return new ThreadObject_pthread(proc, param);
richk@10211: }
richk@10211: 
richk@10211: /* static */ ThreadObject *ThreadObject::AttachCurrent()
richk@10211: {
richk@10211: 	return new ThreadObject_pthread();
richk@10211: }
richk@10211: 
richk@10211: /* static */ uint ThreadObject::CurrentId()
richk@10211: {
richk@10211: 	return (uint)pthread_self();
richk@10211: }
richk@10211: 
richk@10211: 
richk@10211: /**
richk@10211:  * POSIX pthread version of ThreadSemaphore.
richk@10211:  */
richk@10211: class ThreadSemaphore_pthread : public ThreadSemaphore {
richk@10211: private:
richk@10211: 	sem_t m_sem;
richk@10211: 
richk@10211: public:
richk@10211: 	ThreadSemaphore_pthread()
richk@10211: 	{
richk@10211: 		sem_init(&m_sem, 0, 0);
richk@10211: 	}
richk@10211: 
richk@10211: 	/* virtual */ ~ThreadSemaphore_pthread()
richk@10211: 	{
richk@10211: 		sem_destroy(&m_sem);
richk@10211: 	}
richk@10211: 
richk@10211: 	/* virtual */ void Set()
richk@10211: 	{
richk@10211: 		int val = 0;
richk@10211: 		if (sem_getvalue(&m_sem, &val) == 0 && val == 0) sem_post(&m_sem);
richk@10211: 	}
richk@10211: 
richk@10211: 	/* virtual */ void Wait()
richk@10211: 	{
richk@10211: 		sem_wait(&m_sem);
richk@10211: 	}
richk@10211: };
richk@10211: 
richk@10211: /* static */ ThreadSemaphore *ThreadSemaphore::New()
richk@10211: {
richk@10211: 	return new ThreadSemaphore_pthread();
richk@10211: }