/* -*- mode: c++; c-basic-offset: 4; -*-
 *
 * MICO --- a CORBA implementation
 * Copyright (C) 1997-98 Kay Roemer & Arno Puder
 * 
 * OSThread: An abstract Thread class for MICO
 * Copyright (C) 1999 Andy Kersting & Andreas Schultz
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Send comments and/or bug reports to:
 *                mico@informatik.uni-frankfurt.de
 *
 * $Id: pththreads.cc,v 1.5 2000/01/08 00:57:15 aschultz Exp $
 *
 * support for POSIX Draft 10ish Pthreads for Linux as developed by
 * Xavier LeRoy@inria.fr
 *
 */

#define MICO_CONF_IMR

#include <pthread.h>
#include <CORBA-SMALL.h>
#include <mico/impl.h>

//
// Global things (used/defined ONLY when HAVE_THREADS is defined)
//
#ifdef HAVE_THREADS  

static pthread_mutex_t __debug_mutex = PTHREAD_MUTEX_INITIALIZER;

void __mtdebug_init()
{
}

void __mtdebug_lock()
{
    pthread_mutex_lock( &__debug_mutex );
}

void __mtdebug_unlock()
{
    pthread_mutex_unlock( &__debug_mutex );
}

//
// No matter what the actual thread implementation is, _init ()
// takes care of initializing whatever has to be initialized.
//
void MICOMT::_init (MICO_ULong _tpsize, MICO_ULong _tpincr) {
 
    THREAD_DEBUG( MT_TRACE( MICODebug::instance()->printer()
			    << "_init (_tpsize = " << _tpsize << ", _tpincr = "
			    << _tpincr << ")" << endl ));
}

//
// Thread::ThreadWrapper is a static member function that
// pthread_create(...) (or the like) can call as its "thread start routine".
// Any object whose methods are to be invoked as a thread, must derive from
// the class "Thread".  Thread has a method, _run(),
// which starts the Thread (or a derivative) "in motion".
//
void *
MICOMT::Thread::ThreadWrapper( void *arg )
{
    THREAD_DEBUG( MT_TRACE( MICODebug::instance()->printer()
			    << "ThreadWrapper()" << endl ));
    static_cast<Thread *>(arg)->_thr_startup( arg );
    THREAD_DEBUG( MT_TRACE( MICODebug::instance()->printer()
			    << "ThreadWrapper(): after calling _run()" << endl ));
 
    return NULL;          // the "start_routine" must return a void *.
}

/*********************************** Mutex implementation **********************************/
//
//   lock() and unlock() are inlined for optimal speed
//
	
MICO_ULong
MICOMT::Mutex::trylock()
{
    MUTEX_DEBUG( MT_TRACE( MICODebug::instance()->printer()
			   << name () << ": Mutex::trylock ()" << endl ));
    switch ( pth_mutex_acquire(&_mutex, TRUE, NULL) ) {
    case 0:      return MICOMT::Thread::NoError;
    case EINVAL: return MICOMT::Thread::InvalidPriority;
    case EBUSY:  return MICOMT::Thread::MutexAlreadyLocked;
    };
    return MICOMT::Thread::UnknownError;
}

/***************************** condition variable ************************************/

MICO_Boolean
MICOMT::CondVar::timedwait( Mutex &_mutex, MICO_ULong tmout )
{ 
    pth_event_t ev;
    static pth_key_t ev_key = PTH_KEY_INIT;

    COND_DEBUG( MT_TRACE( MICODebug::instance()->printer() << name () << ": CondVar::timedwait ()" << endl ));

    ev = pth_event(PTH_EVENT_TIME|PTH_MODE_STATIC, &ev_key,
		   pth_time( 0, tmout ));
    if (!pth_cond_await( &_cond, &_mutex._mutex, ev))
        return FALSE;
    return TRUE;
}

/*********************** Semaphore implementation/emulation **********************************/

void
MICOMT::Semaphore::wait()
{
    SEMA_DEBUG( MT_TRACE( MICODebug::instance()->printer()
			  << name () << ": Semaphore::wait ()" << endl ));
    _cond.lock();
    pth_cleanup_push( reinterpret_cast<void (*)(void *)>(&&MICOMT::CondVar::unlock, this ));
    while (count <= 0)
	_cond.wait();
    
    --count;
    pth_cleanup_pop( 1 );
}

void
MICOMT::Semaphore::post()
{
    SEMA_DEBUG( MT_TRACE( MICODebug::instance()->printer()
			      << name () << ": Semaphore::post ()" << endl ));
    _cond.lock();
    if (count++ == 0)
	_cond.signal();
    _cond.unlock();
}

/********************* Thread implementation for GNU PthThreads ********************************/

MICOMT::Thread::Thread (MICOMT::Thread::DetachFlag detached) __NAME( :_namedObject () )
{
    name ("<Un-Named Thread>");
    _detached = detached;
 
    THREAD_DEBUG( MT_TRACE( MICODebug::instance()->printer()
			    <<"Thread::Thread (detached = " << (int)(char)detached
			    << ")" << endl ));
#ifdef _THR_CREATE_AND_BLOCK
    create_thread();
#endif
}
 
//
// Start the thread ala JAVA:
//
MICOMT::Thread::ErrorType 
MICOMT::Thread::start (void *arg)
{
    //FIXME: whats that for ?
    _arg = arg;
 
    THREAD_DEBUG( MT_TRACE( MICODebug::instance()->printer()
			    << "Thread::start (void *arg)" << endl ));
#ifdef _THR_CREATE_AND_BLOCK
    _ready.unlock();
    return MICOMT::Thread::NoError;
#else
    return create_thread();
#endif
}
 
//
// see if the thread given by ThreadID `id' is the same as this
// thread:
//
MICO_Boolean
MICOMT::Thread::operator == (const MICOMT::Thread &thread) const
{
    THREAD_DEBUG( MT_TRACE( MICODebug::instance()->printer()
			    << "Thread::operator == ()" << endl ));
    return ( thread.id() == id() );
}

//
// set the priority of this thread to `new_priority'.
// let's avoid using this if at all possible, some pthreads impls don't
// support it fully or at all:
//
void
MICOMT::Thread::priority (MICO_Long new_priority) {
}

//
// destoying the object that runs our thread is not a good idea
// kill it first
//
MICOMT::Thread::~Thread ()
{
    // make sure the thread is really finished, before we remove it data structures 
    wait();
    _ready.unlock();
    THREAD_DEBUG( MT_TRACE( MICODebug::instance()->printer()
			    << "Thread::~Thread()" << endl ));
}


#endif // HAVE_THREADS
