/*

 * Copyright (C) 2007, 2008 Apple Inc. All rights reserved.

 * Copyright (C) 2007 Justin Haygood (jhaygood@reaktix.com)

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1.  Redistributions of source code must retain the above copyright

 *     notice, this list of conditions and the following disclaimer.

 * 2.  Redistributions in binary form must reproduce the above copyright

 *     notice, this list of conditions and the following disclaimer in the

 *     documentation and/or other materials provided with the distribution.

 * 3.  Neither the name of Apple Inc. ("Apple") nor the names of

 *     its contributors may be used to endorse or promote products derived

 *     from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY

 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include "config.h"

#include "Threading.h"

#if !USE(PTHREADS)

#include "CurrentTime.h"

#include "HashMap.h"

#include "MainThread.h"

#include "RandomNumberSeed.h"

#include <wtf/StdLibExtras.h>

#include <glib.h>

#include <limits.h>

namespace WTF {

typedef HashMap<ThreadIdentifier, GThread*> ThreadMap;

static Mutex* atomicallyInitializedStaticMutex;

static Mutex& threadMapMutex()

{

    DEFINE_STATIC_LOCAL(Mutex, mutex, ());

    return mutex;

}

void initializeThreading()

{

    if (!g_thread_supported())

        g_thread_init(NULL);

    ASSERT(g_thread_supported());

    if (!atomicallyInitializedStaticMutex) {

        atomicallyInitializedStaticMutex = new Mutex;

        threadMapMutex();

        initializeRandomNumberGenerator();

    }

}

void lockAtomicallyInitializedStaticMutex()

{

    ASSERT(atomicallyInitializedStaticMutex);

    atomicallyInitializedStaticMutex->lock();

}

void unlockAtomicallyInitializedStaticMutex()

{

    atomicallyInitializedStaticMutex->unlock();

}

static ThreadMap& threadMap()

{

    DEFINE_STATIC_LOCAL(ThreadMap, map, ());

    return map;

}

static ThreadIdentifier identifierByGthreadHandle(GThread*& thread)

{

    MutexLocker locker(threadMapMutex());

    ThreadMap::iterator i = threadMap().begin();

    for (; i != threadMap().end(); ++i) {

        if (i->second == thread)

            return i->first;

    }

    return 0;

}

static ThreadIdentifier establishIdentifierForThread(GThread*& thread)

{

    ASSERT(!identifierByGthreadHandle(thread));

    MutexLocker locker(threadMapMutex());

    static ThreadIdentifier identifierCount = 1;

    threadMap().add(identifierCount, thread);

    return identifierCount++;

}

static GThread* threadForIdentifier(ThreadIdentifier id)

{

    MutexLocker locker(threadMapMutex());

    return threadMap().get(id);

}

static void clearThreadForIdentifier(ThreadIdentifier id)

{

    MutexLocker locker(threadMapMutex());

    ASSERT(threadMap().contains(id));

    threadMap().remove(id);

}

ThreadIdentifier createThreadInternal(ThreadFunction entryPoint, void* data, const char*)

{

    GThread* thread;

    if (!(thread = g_thread_create(entryPoint, data, TRUE, 0))) {

        LOG_ERROR("Failed to create thread at entry point %p with data %p", entryPoint, data);

        return 0;

    }

    ThreadIdentifier threadID = establishIdentifierForThread(thread);

    return threadID;

}

void initializeCurrentThreadInternal(const char*)

{

}

int waitForThreadCompletion(ThreadIdentifier threadID, void** result)

{

    ASSERT(threadID);

    GThread* thread = threadForIdentifier(threadID);

    void* joinResult = g_thread_join(thread);

    if (result)

        *result = joinResult;

    clearThreadForIdentifier(threadID);

    return 0;

}

void detachThread(ThreadIdentifier)

{

}

ThreadIdentifier currentThread()

{

    GThread* currentThread = g_thread_self();

    if (ThreadIdentifier id = identifierByGthreadHandle(currentThread))

        return id;

    return establishIdentifierForThread(currentThread);

}

Mutex::Mutex()

    : m_mutex(g_mutex_new())

{

}

Mutex::~Mutex()

{

}

void Mutex::lock()

{

    g_mutex_lock(m_mutex.get());

}

bool Mutex::tryLock()

{

    return g_mutex_trylock(m_mutex.get());

}

void Mutex::unlock()

{

    g_mutex_unlock(m_mutex.get());

}

ThreadCondition::ThreadCondition()

    : m_condition(g_cond_new())

{

}

ThreadCondition::~ThreadCondition()

{

}

void ThreadCondition::wait(Mutex& mutex)

{

    g_cond_wait(m_condition.get(), mutex.impl().get());

}

bool ThreadCondition::timedWait(Mutex& mutex, double absoluteTime)

{

    // Time is in the past - return right away.

    if (absoluteTime < currentTime())

        return false;

    // Time is too far in the future for g_cond_timed_wait - wait forever.

    if (absoluteTime > INT_MAX) {

        wait(mutex);

        return true;

    }

    int timeSeconds = static_cast<int>(absoluteTime);

    int timeMicroseconds = static_cast<int>((absoluteTime - timeSeconds) * 1000000.0);

    GTimeVal targetTime;

    targetTime.tv_sec = timeSeconds;

    targetTime.tv_usec = timeMicroseconds;

    return g_cond_timed_wait(m_condition.get(), mutex.impl().get(), &targetTime);

}

void ThreadCondition::signal()

{

    g_cond_signal(m_condition.get());

}

void ThreadCondition::broadcast()

{

    g_cond_broadcast(m_condition.get());

}

}

#endif // !USE(PTHREADS)