qthread.cpp

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#include "qthread.h"
#include "qthreadstorage.h"
#include "qmutex.h"
#include "qmutexpool_p.h"
#include "qreadwritelock.h"
#include "qabstracteventdispatcher.h"

#include <qeventloop.h>
#include <qhash.h>

#include "qthread_p.h"
#include "private/qcoreapplication_p.h"

/*
#ifdef Q_OS_WIN32
# include "qt_windows.h"
#else
# include <unistd.h>
# include <netinet/in.h>
# include <sys/utsname.h>
# include <sys/socket.h>
*/
/*
#  elif defined(Q_OS_HPUX)
#   include <sys/pstat.h>
#  elif defined(Q_OS_FREEBSD) || defined(Q_OS_OPENBSD) || defined(Q_OS_MAC)
#   include <sys/sysctl.h>
#  endif
#endif
*/

QT_BEGIN_NAMESPACE

/*
  QThreadData
*/

QThreadData::QThreadData(int initialRefCount)
    : _ref(initialRefCount), thread(0), threadId(0),
      quitNow(false), loopLevel(0), eventDispatcher(0), canWait(true), isAdopted(false)
{
    // fprintf(stderr, "QThreadData %p created\n", this);
}

QThreadData::~QThreadData()
{
    Q_ASSERT(_ref == 0);

    // In the odd case that Qt is running on a secondary thread, the main
    // thread instance will have been dereffed asunder because of the deref in
    // QThreadData::current() and the deref in the pthread_destroy. To avoid
    // crashing during QCoreApplicationData's global static cleanup we need to
    // safeguard the main thread here.. This fix is a bit crude, but it solves
    // the problem...
    if (this->thread == QCoreApplicationPrivate::theMainThread) {
       QCoreApplicationPrivate::theMainThread = 0;
       QThreadData::clearCurrentThreadData();
    }

    QThread *t = thread;
    thread = 0;
    delete t;

    for (int i = 0; i < postEventList.size(); ++i) {
        const QPostEvent &pe = postEventList.at(i);
        if (pe.event) {
            --pe.receiver->d_func()->postedEvents;
            pe.event->posted = false;
            delete pe.event;
        }
    }

    // fprintf(stderr, "QThreadData %p destroyed\n", this);
}

void QThreadData::ref()
{
#ifndef QT_NO_THREAD
    (void) _ref.ref();
    Q_ASSERT(_ref != 0);
#endif
}

void QThreadData::deref()
{
#ifndef QT_NO_THREAD
    if (!_ref.deref())
        delete this;
#endif
}

/*
  QAdoptedThread
*/

QAdoptedThread::QAdoptedThread(QThreadData *data)
    : QThread(*new QThreadPrivate(data))
{
    // thread should be running and not finished for the lifetime
    // of the application (even if QCoreApplication goes away)
#ifndef QT_NO_THREAD
    d_func()->running = true;
    d_func()->finished = false;
    init();
#endif

    // fprintf(stderr, "new QAdoptedThread = %p\n", this);
}

QAdoptedThread::~QAdoptedThread()
{
    // fprintf(stderr, "~QAdoptedThread = %p\n", this);
}

QThread *QAdoptedThread::createThreadForAdoption()
{
    QScopedPointer<QThread> t(new QAdoptedThread(0));
    t->moveToThread(t.data());
    return t.take();
}

void QAdoptedThread::run()
{
    // this function should never be called
    qFatal("QAdoptedThread::run(): Internal error, this implementation should never be called.");
}
#ifndef QT_NO_THREAD
/*
  QThreadPrivate
*/

QThreadPrivate::QThreadPrivate(QThreadData *d)
    : QObjectPrivate(), running(false), finished(false), terminated(false),
      isInFinish(false), exited(false), returnCode(-1),
      stackSize(0), priority(QThread::InheritPriority), data(d)
{
#if defined (Q_OS_UNIX)
    thread_id = 0;
#elif defined (Q_WS_WIN)
    handle = 0;
    id = 0;
    waiters = 0;
#endif
#if defined (Q_WS_WIN) || defined (Q_OS_SYMBIAN)
    terminationEnabled = true;
    terminatePending = false;
#endif

    if (!data)
        data = new QThreadData;
}

QThreadPrivate::~QThreadPrivate()
{
    data->deref();
}

QThread *QThread::currentThread()
{
    QThreadData *data = QThreadData::current();
    Q_ASSERT(data != 0);
    return data->thread;
}

QThread::QThread(QObject *parent)
    : QObject(*(new QThreadPrivate), parent)
{
    Q_D(QThread);
    // fprintf(stderr, "QThreadData %p created for thread %p\n", d->data, this);
    d->data->thread = this;
}

QThread::QThread(QThreadPrivate &dd, QObject *parent)
    : QObject(dd, parent)
{
    Q_D(QThread);
    // fprintf(stderr, "QThreadData %p taken from private data for thread %p\n", d->data, this);
    d->data->thread = this;
}

QThread::~QThread()
{
    Q_D(QThread);
    {
        QMutexLocker locker(&d->mutex);
        if (d->isInFinish) {
            locker.unlock();
            wait();
            locker.relock();
        }
        if (d->running && !d->finished && !d->data->isAdopted)
            qWarning("QThread: Destroyed while thread is still running");

        d->data->thread = 0;
    }
}

bool QThread::isFinished() const
{
    Q_D(const QThread);
    QMutexLocker locker(&d->mutex);
    return d->finished || d->isInFinish;
}

bool QThread::isRunning() const
{
    Q_D(const QThread);
    QMutexLocker locker(&d->mutex);
#ifdef Q_OS_SYMBIAN
    // app shutdown on Symbian can terminate threads and invalidate their stacks without notification,
    // check the thread is still alive.
    if (d->data->symbian_thread_handle.Handle() && d->data->symbian_thread_handle.ExitType() != EExitPending)
        return false;
#endif
    return d->running && !d->isInFinish;
}

void QThread::setStackSize(uint stackSize)
{
    Q_D(QThread);
    QMutexLocker locker(&d->mutex);
    Q_ASSERT_X(!d->running, "QThread::setStackSize",
               "cannot change stack size while the thread is running");
    d->stackSize = stackSize;
}

uint QThread::stackSize() const
{
    Q_D(const QThread);
    QMutexLocker locker(&d->mutex);
    return d->stackSize;
}

int QThread::exec()
{
    Q_D(QThread);
    QMutexLocker locker(&d->mutex);
    d->data->quitNow = false;
    if (d->exited) {
        d->exited = false;
        return d->returnCode;
    }
    locker.unlock();

    QEventLoop eventLoop;
    int returnCode = eventLoop.exec();

    locker.relock();
    d->exited = false;
    d->returnCode = -1;
    return returnCode;
}

void QThread::exit(int returnCode)
{
    Q_D(QThread);
    QMutexLocker locker(&d->mutex);
    d->exited = true;
    d->returnCode = returnCode;
    d->data->quitNow = true;
    for (int i = 0; i < d->data->eventLoops.size(); ++i) {
        QEventLoop *eventLoop = d->data->eventLoops.at(i);
        eventLoop->exit(returnCode);
    }
}

void QThread::quit()
{ exit(); }

void QThread::run()
{
    (void) exec();
}

#if defined (Q_OS_WIN)
void qt_create_tls();
#endif

void QThread::initialize()
{
    if (qt_global_mutexpool)
        return;
    qt_global_mutexpool = QMutexPool::instance();

#if defined (Q_OS_WIN)
    qt_create_tls();
#endif
}


void QThread::cleanup()
{
    qt_global_mutexpool = 0;
}

QThread::Priority QThread::priority() const
{
    Q_D(const QThread);
    QMutexLocker locker(&d->mutex);

    // mask off the high bits that are used for flags
    return Priority(d->priority & 0xffff);
}

#else // QT_NO_THREAD

QThread::QThread(QObject *parent)
    : QObject(*(new QThreadPrivate), (QObject*)0){
    Q_D(QThread);
    d->data->thread = this;
}

QThread *QThread::currentThread()
{
    return QThreadData::current()->thread;
}

QThreadData* QThreadData::current()
{
    static QThreadData *data = 0; // reinterpret_cast<QThreadData *>(pthread_getspecific(current_thread_data_key));
    if (!data) {
        QScopedPointer<QThreadData> newdata(new QThreadData);
        newdata->thread = new QAdoptedThread(newdata.data());
        data = newdata.take();
        data->deref();
    }
    return data;
}

QThread::QThread(QThreadPrivate &dd, QObject *parent)
    : QObject(dd, parent)
{
    Q_D(QThread);
    // fprintf(stderr, "QThreadData %p taken from private data for thread %p\n", d->data, this);
    d->data->thread = this;
}

#endif // QT_NO_THREAD

QT_END_NAMESPACE