/*

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

 *

 * 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 Computer, 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.

 */

#import "config.h"

#import "MainThread.h"

#import <CoreFoundation/CoreFoundation.h>

#import <Foundation/NSThread.h>

#import <stdio.h>

#import <wtf/Assertions.h>

#import <wtf/Threading.h>

@interface WTFMainThreadCaller : NSObject {

}

- (void)call;

@end

@implementation WTFMainThreadCaller

- (void)call

{

    WTF::dispatchFunctionsFromMainThread();

}

@end // implementation WTFMainThreadCaller

namespace WTF {

static WTFMainThreadCaller* staticMainThreadCaller;

static bool isTimerPosted; // This is only accessed on the 'main' thread.

static bool mainThreadEstablishedAsPthreadMain;

static pthread_t mainThreadPthread;

static NSThread* mainThreadNSThread;

void initializeMainThreadPlatform()

{

#if !defined(BUILDING_ON_TIGER)

    ASSERT(!staticMainThreadCaller);

    staticMainThreadCaller = [[WTFMainThreadCaller alloc] init];

    mainThreadEstablishedAsPthreadMain = false;

    mainThreadPthread = pthread_self();

    mainThreadNSThread = [[NSThread currentThread] retain];

#else

    ASSERT_NOT_REACHED();

#endif

}

void initializeMainThreadToProcessMainThreadPlatform()

{

    if (!pthread_main_np())

        NSLog(@"WebKit Threading Violation - initial use of WebKit from a secondary thread.");

    ASSERT(!staticMainThreadCaller);

    staticMainThreadCaller = [[WTFMainThreadCaller alloc] init];

    mainThreadEstablishedAsPthreadMain = true;

    mainThreadPthread = 0;

    mainThreadNSThread = nil;

}

static void timerFired(CFRunLoopTimerRef timer, void*)

{

    CFRelease(timer);

    isTimerPosted = false;

    WTF::dispatchFunctionsFromMainThread();

}

static void postTimer()

{

    ASSERT(isMainThread());

    if (isTimerPosted)

        return;

    isTimerPosted = true;

    CFRunLoopAddTimer(CFRunLoopGetCurrent(), CFRunLoopTimerCreate(0, 0, 0, 0, 0, timerFired, 0), kCFRunLoopCommonModes);

}

void scheduleDispatchFunctionsOnMainThread()

{

    ASSERT(staticMainThreadCaller);

    if (isMainThread()) {

        postTimer();

        return;

    }

    if (mainThreadEstablishedAsPthreadMain) {

        ASSERT(!mainThreadNSThread);

        [staticMainThreadCaller performSelectorOnMainThread:@selector(call) withObject:nil waitUntilDone:NO];

        return;

    }

#if !defined(BUILDING_ON_TIGER)

    ASSERT(mainThreadNSThread);

    [staticMainThreadCaller performSelector:@selector(call) onThread:mainThreadNSThread withObject:nil waitUntilDone:NO];

#else

    ASSERT_NOT_REACHED();

#endif

}

bool isMainThread()

{

    if (mainThreadEstablishedAsPthreadMain) {

        ASSERT(!mainThreadPthread);

        return pthread_main_np();

    }

#if !defined(BUILDING_ON_TIGER)

    ASSERT(mainThreadPthread);

    return pthread_equal(pthread_self(), mainThreadPthread);

#else

    ASSERT_NOT_REACHED();

    return false;

#endif

}

} // namespace WTF