WebCore/platform/mac/ThreadCheck.mm

/*
 * Copyright (C) 2007 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.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``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 COMPUTER, INC. OR
 * 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 "ThreadCheck.h"

#import "StringHash.h"
#import <JavaScriptCore/HashSet.h>

namespace WebCore {

static ThreadViolationBehavior defaultThreadViolationBehavior = RaiseExceptionOnThreadViolation;

static bool didReadThreadViolationBehaviorFromUserDefaults = false;
static bool threadViolationBehaviorIsDefault;
static ThreadViolationBehavior threadViolationBehavior;

static void readThreadViolationBehaviorFromUserDefaults()
{
    NSString *threadCheckLevel = [[NSUserDefaults standardUserDefaults] stringForKey:@"WebCoreThreadCheck"];
    if ([threadCheckLevel isEqualToString:@"None"])
        threadViolationBehavior = NoThreadCheck;
    else if ([threadCheckLevel isEqualToString:@"Exception"])
        threadViolationBehavior = RaiseExceptionOnThreadViolation;
    else if ([threadCheckLevel isEqualToString:@"Log"])
        threadViolationBehavior = LogOnThreadViolation;
    else if ([threadCheckLevel isEqualToString:@"LogOnce"])
        threadViolationBehavior = LogOnFirstThreadViolation;
    else {
        threadViolationBehavior = defaultThreadViolationBehavior;
        threadViolationBehaviorIsDefault = true;
    }
    didReadThreadViolationBehaviorFromUserDefaults = true;
}

void setDefaultThreadViolationBehavior(ThreadViolationBehavior behavior)
{
    defaultThreadViolationBehavior = behavior;
    if (threadViolationBehaviorIsDefault)
        threadViolationBehavior = behavior;
}

void reportThreadViolation(const char* function)
{
    if (!didReadThreadViolationBehaviorFromUserDefaults)
        readThreadViolationBehaviorFromUserDefaults();    
    if (threadViolationBehavior == NoThreadCheck)
        return;
    if (pthread_main_np())
        return;
    WebCoreReportThreadViolation(function);
}

} // namespace WebCore

// Split out the actual reporting of the thread violation to make it easier to set a breakpoint
void WebCoreReportThreadViolation(const char* function)
{
    using namespace WebCore;
    static HashSet<String> loggedFunctions;
    switch (threadViolationBehavior) {
        case NoThreadCheck:
            break;
        case LogOnFirstThreadViolation:
            if (loggedFunctions.add(function).second) {
                NSLog(@"WebKit Threading Violation - %s called from secondary thread", function);
                NSLog(@"Additional threading violations for this function will not be logged.");
            }
            break;
        case LogOnThreadViolation:
            NSLog(@"WebKit Threading Violation - %s called from secondary thread", function);
            break;
        case RaiseExceptionOnThreadViolation:
            [NSException raise:@"WebKitThreadingException" format:@"%s was called from a secondary thread", function];
            break;
    }
}