1 files changed, 138 insertions, 0 deletions
diff --git a/src/corelib/thread/qmutex_linux.cpp b/src/corelib/thread/qmutex_linux.cpp
new file mode 100644
index 0000000000..17015b8f84
--- /dev/null
+++ b/src/corelib/thread/qmutex_linux.cpp
@@ -0,0 +1,138 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** GNU Lesser General Public License Usage
+** This file may be used under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation and
+** appearing in the file LICENSE.LGPL included in the packaging of this
+** file. Please review the following information to ensure the GNU Lesser
+** General Public License version 2.1 requirements will be met:
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU General
+** Public License version 3.0 as published by the Free Software Foundation
+** and appearing in the file LICENSE.GPL included in the packaging of this
+** file. Please review the following information to ensure the GNU General
+** Public License version 3.0 requirements will be met:
+** http://www.gnu.org/copyleft/gpl.html.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qplatformdefs.h"
+#include "qmutex.h"
+
+#ifndef QT_NO_THREAD
+#include "qatomic.h"
+#include "qmutex_p.h"
+# include "qelapsedtimer.h"
+
+#include <linux/futex.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+#include <errno.h>
+
+QT_BEGIN_NAMESPACE
+
+static inline int _q_futex(QMutexPrivate *volatile *addr, int op, int val, const struct timespec *timeout)
+{
+    volatile int *int_addr = reinterpret_cast<volatile int *>(addr);
+#if Q_BYTE_ORDER == Q_BIG_ENDIAN && QT_POINTER_SIZE == 8
+    int_addr++; //We want a pointer to the 32 least significant bit of QMutex::d
+#endif
+    int *addr2 = 0;
+    int val2 = 0;
+    return syscall(SYS_futex, int_addr, op, val, timeout, addr2, val2);
+}
+
+static inline QMutexPrivate *dummyFutexValue()
+{
+    return reinterpret_cast<QMutexPrivate *>(quintptr(3));
+}
+
+
+QMutexPrivate::~QMutexPrivate() {}
+QMutexPrivate::QMutexPrivate(QMutex::RecursionMode mode)
+    : recursive(mode == QMutex::Recursive) {}
+
+bool QBasicMutex::lockInternal(int timeout)
+{
+    QElapsedTimer elapsedTimer;
+    if (timeout >= 1)
+        elapsedTimer.start();
+
+    while (!fastTryLock()) {
+        QMutexPrivate *d = this->d;
+        if (!d) // if d is 0, the mutex is unlocked
+            continue;
+
+        if (quintptr(d) <= 0x3) { //d == dummyLocked() || d == dummyFutexValue()
+            if (timeout == 0)
+                return false;
+            while (this->d.fetchAndStoreAcquire(dummyFutexValue()) != 0) {
+                struct timespec ts, *pts = 0;
+                if (timeout >= 1) {
+                    // recalculate the timeout
+                    qint64 xtimeout = timeout * 1000 * 1000;
+                    xtimeout -= elapsedTimer.nsecsElapsed();
+                    if (xtimeout <= 0) {
+                        // timer expired after we returned
+                        return false;
+                    }
+                    ts.tv_sec = xtimeout / Q_INT64_C(1000) / 1000 / 1000;
+                    ts.tv_nsec = xtimeout % (Q_INT64_C(1000) * 1000 * 1000);
+                    pts = &ts;
+                }
+                int r = _q_futex(&this->d._q_value, FUTEX_WAIT, quintptr(dummyFutexValue()), pts);
+                if (r != 0 && errno == ETIMEDOUT)
+                    return false;
+            }
+            return true;
+        }
+        Q_ASSERT(d->recursive);
+        return static_cast<QRecursiveMutexPrivate *>(d)->lock(timeout);
+    }
+    Q_ASSERT(this->d);
+    return true;
+}
+
+void QBasicMutex::unlockInternal()
+{
+    QMutexPrivate *d = this->d;
+    Q_ASSERT(d); //we must be locked
+    Q_ASSERT(d != dummyLocked()); // testAndSetRelease(dummyLocked(), 0) failed
+
+    if (d == dummyFutexValue()) {
+        this->d.fetchAndStoreRelease(0);
+        _q_futex(&this->d._q_value, FUTEX_WAKE, 1, 0);
+        return;
+    }
+
+    Q_ASSERT(d->recursive);
+    static_cast<QRecursiveMutexPrivate *>(d)->unlock();
+}
+
+
+QT_END_NAMESPACE
+
+#endif // QT_NO_THREAD