path: root/src/kernel/qthread_unix.cpp

/****************************************************************************
**
** QThread class for Unix
**
** Copyright (C) 1992-2008 Trolltech ASA.  All rights reserved.
**
** This file is part of the kernel module of the Qt GUI Toolkit.
**
** This file may be used under the terms of the GNU General
** Public License versions 2.0 or 3.0 as published by the Free
** Software Foundation and appearing in the files LICENSE.GPL2
** and LICENSE.GPL3 included in the packaging of this file.
** Alternatively you may (at your option) use any later version
** of the GNU General Public License if such license has been
** publicly approved by Trolltech ASA (or its successors, if any)
** and the KDE Free Qt Foundation.
**
** Please review the following information to ensure GNU General
** Public Licensing requirements will be met:
** http://trolltech.com/products/qt/licenses/licensing/opensource/.
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
** or contact the sales department at [email protected].
**
** This file may be used under the terms of the Q Public License as
** defined by Trolltech ASA and appearing in the file LICENSE.QPL
** included in the packaging of this file.  Licensees holding valid Qt
** Commercial licenses may use this file in accordance with the Qt
** Commercial License Agreement provided with the Software.
**
** This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted
** herein.
**
**********************************************************************/

#if defined(QT_THREAD_SUPPORT)

#include "qplatformdefs.h"

typedef pthread_mutex_t Q_MUTEX_T;

#include "qthread.h"
#include <private/qthreadinstance_p.h>
#include <private/qmutex_p.h>
#include <private/qmutexpool_p.h>
#include <qthreadstorage.h>

#include <errno.h>
#include <sched.h>


static QMutexPool *qt_thread_mutexpool = 0;


#if defined(Q_C_CALLBACKS)
extern "C" {
#endif

typedef void*(*QtThreadCallback)(void*);

static pthread_once_t storage_key_once = PTHREAD_ONCE_INIT;
static pthread_key_t storage_key;
static void create_storage_key()
{
    pthread_key_create( &storage_key, NULL );
}

#if defined(Q_C_CALLBACKS)
}
#endif


/**************************************************************************
 ** QThreadInstance
 *************************************************************************/

void QThreadInstance::setCurrentThread(QThread *thread)
{
    pthread_once(&storage_key_once, create_storage_key);
    pthread_setspecific(storage_key, thread);
}

QThreadInstance *QThreadInstance::current()
{
    QThreadInstance *ret = NULL;
    pthread_once( &storage_key_once, create_storage_key );
    QThread *thread = (QThread *) pthread_getspecific( storage_key );
    if (thread) {
        ret = thread->d;
    }
    return ret;
}

void QThreadInstance::init(unsigned int stackSize)
{
    stacksize = stackSize;
    args[0] = args[1] = 0;
    thread_storage = 0;
    finished = FALSE;
    running = FALSE;
    orphan = FALSE;

    pthread_cond_init(&thread_done, NULL);
    thread_id = 0;

    eventLoop = 0;

    // threads have not been initialized yet, do it now
    if (! qt_thread_mutexpool) QThread::initialize();
}

void QThreadInstance::deinit()
{
    pthread_cond_destroy(&thread_done);
}

void *QThreadInstance::start( void *_arg )
{
    void **arg = (void **) _arg;

    setCurrentThread( (QThread *) arg[0] );

    pthread_cleanup_push( QThreadInstance::finish, arg[1] );
    pthread_testcancel();

    ( (QThread *) arg[0] )->run();

    pthread_cleanup_pop( TRUE );
    return 0;
}

void QThreadInstance::finish( void * )
{
    QThreadInstance *d = current();

    if ( ! d ) {
#ifdef QT_CHECK_STATE
	qWarning( "QThread: internal error: zero data for running thread." );
#endif // QT_CHECK_STATE
	return;
    }

    QMutexLocker locker( d->mutex() );
    d->running = FALSE;
    d->finished = TRUE;
    d->args[0] = d->args[1] = 0;


    QThreadStorageData::finish( d->thread_storage );
    d->thread_storage = 0;

    d->thread_id = 0;
    pthread_cond_broadcast(&d->thread_done);

    if (d->orphan) {
        d->deinit();
	delete d;
    }
}

QMutex *QThreadInstance::mutex() const
{
    return qt_thread_mutexpool ? qt_thread_mutexpool->get( (void *) this ) : 0;
}

void QThreadInstance::terminate()
{
    if ( ! thread_id ) return;
    pthread_cancel( thread_id );
}


/**************************************************************************
 ** QThread
 *************************************************************************/

/*!
    This returns the thread handle of the currently executing thread.

    \warning The handle returned by this function is used for internal
    purposes and should \e not be used in any application code. On
    Windows, the returned value is a pseudo handle for the current
    thread, and it cannot be used for numerical comparison.
*/
Qt::HANDLE QThread::currentThread()
{
    return (HANDLE) pthread_self();
}

/*! \internal
  Initializes the QThread system.
*/
void QThread::initialize()
{
    if ( ! qt_global_mutexpool )
	qt_global_mutexpool = new QMutexPool( TRUE, 73 );
    if ( ! qt_thread_mutexpool )
	qt_thread_mutexpool = new QMutexPool( FALSE, 127 );
}

/*! \internal
  Cleans up the QThread system.
*/
void QThread::cleanup()
{
    delete qt_global_mutexpool;
    delete qt_thread_mutexpool;
    qt_global_mutexpool = 0;
    qt_thread_mutexpool = 0;
}

/*!
    Ends the execution of the calling thread and wakes up any threads
    waiting for its termination.
*/
void QThread::exit()
{
    pthread_exit( 0 );
}

/*  \internal
    helper function to do thread sleeps, since usleep()/nanosleep()
    aren't reliable enough (in terms of behavior and availability)
*/
static void thread_sleep( struct timespec *ti )
{
    pthread_mutex_t mtx;
    pthread_cond_t cnd;

    pthread_mutex_init(&mtx, 0);
    pthread_cond_init(&cnd, 0);

    pthread_mutex_lock( &mtx );
    (void) pthread_cond_timedwait( &cnd, &mtx, ti );
    pthread_mutex_unlock( &mtx );

    pthread_cond_destroy( &cnd );
    pthread_mutex_destroy( &mtx );
}

/*!
    System independent sleep. This causes the current thread to sleep
    for \a secs seconds.
*/
void QThread::sleep( unsigned long secs )
{
    struct timeval tv;
    gettimeofday( &tv, 0 );
    struct timespec ti;
    ti.tv_sec = tv.tv_sec + secs;
    ti.tv_nsec = ( tv.tv_usec * 1000 );
    thread_sleep( &ti );
}

/*!
    System independent sleep. This causes the current thread to sleep
    for \a msecs milliseconds
*/
void QThread::msleep( unsigned long msecs )
{
    struct timeval tv;
    gettimeofday( &tv, 0 );
    struct timespec ti;

    ti.tv_nsec = ( tv.tv_usec + ( msecs % 1000 ) * 1000 ) * 1000;
    ti.tv_sec = tv.tv_sec + ( msecs / 1000 ) + ( ti.tv_nsec / 1000000000 );
    ti.tv_nsec %= 1000000000;
    thread_sleep( &ti );
}

/*!
    System independent sleep. This causes the current thread to sleep
    for \a usecs microseconds
*/
void QThread::usleep( unsigned long usecs )
{
    struct timeval tv;
    gettimeofday( &tv, 0 );
    struct timespec ti;

    ti.tv_nsec = ( tv.tv_usec + ( usecs % 1000000 ) ) * 1000;
    ti.tv_sec = tv.tv_sec + ( usecs / 1000000 ) + ( ti.tv_nsec / 1000000000 );
    ti.tv_nsec %= 1000000000;
    thread_sleep( &ti );
}

/*!
    Begins execution of the thread by calling run(), which should be
    reimplemented in a QThread subclass to contain your code.  The
    operating system will schedule the thread according to the \a
    priority argument.

    If you try to start a thread that is already running, this
    function will wait until the the thread has finished and then
    restart the thread.

    \sa Priority
*/
void QThread::start(Priority priority)
{
    QMutexLocker locker( d->mutex() );

    if ( d->running )
        pthread_cond_wait(&d->thread_done, &locker.mutex()->d->handle);
    d->running = TRUE;
    d->finished = FALSE;

    int ret;
    pthread_attr_t attr;
    pthread_attr_init(&attr);
    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);

#if !defined(Q_OS_OPENBSD) && defined(_POSIX_THREAD_PRIORITY_SCHEDULING) && (_POSIX_THREAD_PRIORITY_SCHEDULING-0 >= 0)
    switch (priority) {
    case InheritPriority:
	{
	    pthread_attr_setinheritsched(&attr, PTHREAD_INHERIT_SCHED);
	    break;
	}

    default:
	{
	    int sched_policy;
	    if (pthread_attr_getschedpolicy(&attr, &sched_policy) != 0) {
                // failed to get the scheduling policy, don't bother
                // setting the priority
                qWarning("QThread: cannot determine default scheduler policy");
                break;
	    }

	    int prio_min = sched_get_priority_min(sched_policy);
	    int prio_max = sched_get_priority_max(sched_policy);
            if (prio_min == -1 || prio_max == -1) {
                // failed to get the scheduling parameters, don't
                // bother setting the priority
                qWarning("QThread: cannot determine scheduler priority range");
                break;
            }

	    int prio;
	    switch (priority) {
	    case IdlePriority:
		prio = prio_min;
		break;

	    case HighestPriority:
		prio = prio_max;
		break;

	    default:
		// crudely scale our priority enum values to the prio_min/prio_max
		prio = (((prio_max - prio_min) / TimeCriticalPriority) *
			priority) + prio_min;
		prio = QMAX(prio_min, QMIN(prio_max, prio));
		break;
	    }

	    sched_param sp;
	    sp.sched_priority = prio;

	    pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED);
	    pthread_attr_setschedparam(&attr, &sp);
	    break;
	}
    }
#endif // _POSIX_THREAD_PRIORITY_SCHEDULING

    if ( d->stacksize > 0 ) {
#if defined(_POSIX_THREAD_ATTR_STACKSIZE) && (_POSIX_THREAD_ATTR_STACKSIZE-0 > 0)
	ret = pthread_attr_setstacksize( &attr, d->stacksize );
#else
	ret = ENOSYS; // stack size not supported, automatically fail
#endif // _POSIX_THREAD_ATTR_STACKSIZE

	if ( ret ) {
#ifdef QT_CHECK_STATE
	    qWarning( "QThread::start: thread stack size error: %s", strerror( ret ) ) ;
#endif // QT_CHECK_STATE

	    // we failed to set the stacksize, and as the documentation states,
	    // the thread will fail to run...
	    d->running = FALSE;
	    d->finished = FALSE;
	    return;
	}
    }

    d->args[0] = this;
    d->args[1] = d;
    ret = pthread_create( &d->thread_id, &attr, (QtThreadCallback)QThreadInstance::start, d->args );
#if defined (Q_OS_HPUX)
    if (ret == EPERM) {
        pthread_attr_setinheritsched(&attr, PTHREAD_INHERIT_SCHED);
	ret = pthread_create(&d->thread_id, &attr, (QtThreadCallback)QThreadInstance::start, d->args);
    }
#endif
    pthread_attr_destroy( &attr );

    if ( ret ) {
#ifdef QT_CHECK_STATE
	qWarning( "QThread::start: thread creation error: %s", strerror( ret ) );
#endif // QT_CHECK_STATE

	d->running = FALSE;
	d->finished = FALSE;
	d->args[0] = d->args[1] = 0;
    }
}

void QThread::start()
{
    start(InheritPriority);
}

/*!
    A thread calling this function will block until either of these
    conditions is met:

    \list
    \i The thread associated with this QThread object has finished
       execution (i.e. when it returns from \l{run()}). This function
       will return TRUE if the thread has finished. It also returns
       TRUE if the thread has not been started yet.
    \i \a time milliseconds has elapsed. If \a time is ULONG_MAX (the
    	default), then the wait will never timeout (the thread must
	return from \l{run()}). This function will return FALSE if the
	wait timed out.
    \endlist

    This provides similar functionality to the POSIX \c pthread_join() function.
*/
bool QThread::wait( unsigned long time )
{
    QMutexLocker locker( d->mutex() );

    if ( d->thread_id == pthread_self() ) {
#ifdef QT_CHECK_STATE
	qWarning( "QThread::wait: thread tried to wait on itself" );
#endif // QT_CHECK_STATE

	return FALSE;
    }

    if ( d->finished || ! d->running )
	return TRUE;

    int ret;
    if (time != ULONG_MAX) {
	struct timeval tv;
	gettimeofday(&tv, 0);

	timespec ti;
	ti.tv_nsec = (tv.tv_usec + (time % 1000) * 1000) * 1000;
	ti.tv_sec = tv.tv_sec + (time / 1000) + (ti.tv_nsec / 1000000000);
	ti.tv_nsec %= 1000000000;

	ret = pthread_cond_timedwait(&d->thread_done, &locker.mutex()->d->handle, &ti);
    } else
	ret = pthread_cond_wait(&d->thread_done, &locker.mutex()->d->handle);

#ifdef QT_CHECK_RANGE
    if (ret && ret != ETIMEDOUT)
	qWarning("Wait condition wait failure: %s",strerror(ret));
#endif

    return (ret == 0);
}

/*!
    Returns a pointer to the currently executing QThread.  If the
    current thread was not started using the QThread API, this
    function returns zero.

    Note that QApplication creates a QThread object to represent the
    main thread; calling this function from main() after creating
    QApplication will return a valid pointer.
*/
QThread *QThread::currentThreadObject()
{
    pthread_once(&storage_key_once, create_storage_key);
    return reinterpret_cast<QThread *>(pthread_getspecific(storage_key));
}


#endif // QT_THREAD_SUPPORT