qthread_unix.cpp

奇趣公司比较新的qt/emd版本

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**
** Copyright (C) 1992-2007 Trolltech ASA. All rights reserved.
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** This file is part of the QtCore module of the Qt Toolkit.
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** and appearing in the file LICENSE.GPL included in the packaging of
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#include "qthread.h"

#include "qplatformdefs.h"

#include <private/qcoreapplication_p.h>
#if !defined(QT_NO_GLIB)
#  include "../kernel/qeventdispatcher_glib_p.h"
#endif
#include <private/qeventdispatcher_unix_p.h>

#include "qthreadstorage.h"

#include "qthread_p.h"

#include "qdebug.h"

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

#ifdef Q_OS_BSD4
#include <sys/sysctl.h>
#endif

#if defined(Q_OS_MAC)
# ifdef qDebug
#   define old_qDebug qDebug
#   undef qDebug
# endif
# include <CoreServices/CoreServices.h>
# ifdef old_qDebug
#   undef qDebug
#   define qDebug QT_NO_QDEBUG_MACRO
#   undef old_qDebug
# endif
#endif

#ifndef QT_NO_THREAD

static pthread_once_t current_thread_data_once = PTHREAD_ONCE_INIT;
static pthread_key_t current_thread_data_key;

static void destroy_current_thread_data(void *p)
{
    // POSIX says the value in our key is set to zero before calling
    // this destructor function, so we need to set it back to the
    // right value...
    pthread_setspecific(current_thread_data_key, p);
    reinterpret_cast<QThreadData *>(p)->deref();
    // ... but we must reset it to zero before returning so we aren't
    // called again (POSIX allows implementations to call destructor
    // functions repeatedly until all values are zero)
    pthread_setspecific(current_thread_data_key, 0);
}

static void create_current_thread_data_key()
{
    pthread_key_create(&current_thread_data_key, destroy_current_thread_data);
}

QThreadData *QThreadData::current()
{
    pthread_once(&current_thread_data_once, create_current_thread_data_key);

    QThreadData *data = reinterpret_cast<QThreadData *>(pthread_getspecific(current_thread_data_key));
    if (!data) {
        void *a;
        if (QInternal::activateCallbacks(QInternal::AdoptCurrentThread, &a)) {
            QThread *adopted = static_cast<QThread*>(a);
            Q_ASSERT(adopted);
            data = QThreadData::get2(adopted);
            pthread_setspecific(current_thread_data_key, data);
            adopted->d_func()->running = true;
            adopted->d_func()->finished = false;
            static_cast<QAdoptedThread *>(adopted)->init();
        } else {
            data = new QThreadData;
            pthread_setspecific(current_thread_data_key, data);
            data->thread = new QAdoptedThread(data);
            data->deref();
        }
        (void) q_atomic_test_and_set_ptr(&QCoreApplicationPrivate::theMainThread, 0, data->thread);
    }
    return data;
}


void QAdoptedThread::init()
{
    d_func()->thread_id = pthread_self();
}

/*
   QThreadPrivate
*/

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

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

#if defined(Q_C_CALLBACKS)
}
#endif

#endif // QT_NO_THREAD

void QThreadPrivate::createEventDispatcher(QThreadData *data)
{
#if !defined(QT_NO_GLIB)
    if (qgetenv("QT_NO_GLIB").isEmpty()
        && qgetenv("QT_NO_THREADED_GLIB").isEmpty()
        && QEventDispatcherGlib::versionSupported())
        data->eventDispatcher = new QEventDispatcherGlib;
    else
#endif
        data->eventDispatcher = new QEventDispatcherUNIX;
    data->eventDispatcher->startingUp();
}

#ifndef QT_NO_THREAD

void *QThreadPrivate::start(void *arg)
{
    pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
    pthread_cleanup_push(QThreadPrivate::finish, arg);

    QThread *thr = reinterpret_cast<QThread *>(arg);
    QThreadData *data = QThreadData::get2(thr);

    pthread_once(&current_thread_data_once, create_current_thread_data_key);
    pthread_setspecific(current_thread_data_key, data);

    data->ref();
    data->quitNow = false;

    // ### TODO: allow the user to create a custom event dispatcher
    createEventDispatcher(data);

    emit thr->started();
    pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
    pthread_testcancel();
    thr->run();

    pthread_cleanup_pop(1);
    return 0;
}

void QThreadPrivate::finish(void *arg)
{
    QThread *thr = reinterpret_cast<QThread *>(arg);
    QThreadPrivate *d = thr->d_func();
    QMutexLocker locker(&d->mutex);

    d->priority = QThread::InheritPriority;
    d->running = false;
    d->finished = true;
    if (d->terminated)
        emit thr->terminated();
    d->terminated = false;
    emit thr->finished();

    if (d->data->eventDispatcher) {
        d->data->eventDispatcher->closingDown();
        QAbstractEventDispatcher *eventDispatcher = d->data->eventDispatcher;
        d->data->eventDispatcher = 0;
        delete eventDispatcher;
    }

    void *data = &d->data->tls;
    QThreadStorageData::finish((void **)data);

    d->thread_id = 0;
    d->thread_done.wakeAll();
}




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

/*!
    Returns the thread handle of the currently executing thread.

    \warning The handle returned by this function is used for internal
    purposes and should not be used in any application code. On
    Windows, the returned value is a pseudo-handle for the current
    thread that cannot be used for numerical comparison.
*/
Qt::HANDLE QThread::currentThreadId()
{
    // requires a C cast here otherwise we run into trouble on AIX
    return (Qt::HANDLE)pthread_self();
}

#if defined(QT_LSB) && !defined(_SC_NPROCESSORS_ONLN)
// LSB doesn't define _SC_NPROCESSORS_ONLN.
#  define _SC_NPROCESSORS_ONLN 84
#endif

/*!
    Returns the ideal number of threads that can be run on the system. This is done querying
    the number of processor cores, both real and logical, in the system. This function returns -1
    if the number of processor cores could not be detected.
*/
int QThread::idealThreadCount()
{
    int cores = -1;

#if defined(Q_OS_MAC)
    // Mac OS X
    cores = MPProcessorsScheduled();
#elif defined(Q_OS_HPUX)
    // HP-UX
    struct pst_dynamic psd;
    if (pstat_getdynamic(&psd, sizeof(psd), 1, 0) == -1) {
        perror("pstat_getdynamic");
        cores = -1;
    } else {
        cores = (int)psd.psd_proc_cnt;
    }
#elif defined(Q_OS_BSD4)
    // FreeBSD, OpenBSD, NetBSD, BSD/OS
    size_t len = sizeof(cores);
    int mib[2];
    mib[0] = CTL_HW;
    mib[1] = HW_NCPU;
    if (sysctl(mib, 2, &cores, &len, NULL, 0) != 0) {
        perror("sysctl");
        cores = -1;
    }
#elif defined(Q_OS_IRIX)
    // IRIX
    cores = (int)sysconf(_SC_NPROC_ONLN);
#elif defined(Q_OS_INTEGRITY)
    // ### TODO - how to get the amound of CPUs on INTEGRITY?
#else
    // the rest: Linux, Solaris, AIX, Tru64
    cores = (int)sysconf(_SC_NPROCESSORS_ONLN);
#endif

    return cores;
}

/*  \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);
}

/*!
    Forces the current thread to sleep for \a secs seconds.

    \sa msleep(), usleep()
*/
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);
}

/*!
    Causes the current thread to sleep for \a msecs milliseconds.

    \sa sleep(), usleep()
*/