OOJSEngineTimeManagement.m

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/*
 
OOJSEngineTimeManagement.h
 
 
Copyright (C) 2010-2013 Jens Ayton
 
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
 
*/
 
#include <jsdbgapi.h>
#import "OOJSEngineTimeManagement.h"
#import "OOProfilingStopwatch.h"
#import "OOJSScript.h"
#import "OOCollectionExtractors.h"
#import "OOLoggingExtended.h"
 
#if OOLITE_LINUX
// Workaround for clang/glibc incompatibility.
#define __block __glibc_block
#endif
#include <unistd.h>
 
#if OOLITE_LINUX
#undef __block
#endif
 
 
#if OO_DEBUG
#define OOJS_DEBUG_LIMITER  1
#else
#define OOJS_DEBUG_LIMITER  0
#endif
 
 
static unsigned sLimiterStartDepth;
static int sLimiterPauseDepth;
static OOHighResTimeValue sLimiterStart;
static OOHighResTimeValue sLimiterPauseStart;
static double sLimiterTimeLimit;
 
 
#if OOJS_DEBUG_LIMITER
#define OOJS_TIME_LIMIT     (0.2)   // seconds
#else
#define OOJS_TIME_LIMIT     (1) // seconds
#endif
 
static BOOL sStop;
 
#ifndef NDEBUG
static const char *sLastStartedFile;
static unsigned sLastStartedLine;
static const char *sLastStoppedFile;
static unsigned sLastStoppedLine;
#endif
 
 
#if OOJS_PROFILE && defined(MOZ_TRACE_JSCALLS)
static void FunctionCallback(JSFunction *function, JSScript *script, JSContext *context, int entering);
#endif
 
 
#ifndef NDEBUG
void OOJSStartTimeLimiterWithTimeLimit_(OOTimeDelta limit, const char *file, unsigned line)
#else
void OOJSStartTimeLimiterWithTimeLimit(OOTimeDelta limit)
#endif
{
#if OOJS_DEBUG_LIMITER
    OOLog(@"script.javaScript.timeLimit.debug",@"Limiter starting: %u => %u",sLimiterStartDepth,sLimiterStartDepth+1);
#endif
    if (sLimiterStartDepth++ == 0)
    {
        if (limit <= 0.0)  limit = OOJS_TIME_LIMIT;
        sLimiterTimeLimit = limit;
        sLimiterPauseDepth = 0;
        
        OODisposeHighResTime(sLimiterStart);
        sLimiterStart = OOGetHighResTime();
    }
    
#ifndef NDEBUG
    sLastStartedFile = file;
    sLastStartedLine = line;
#endif
}
 
 
#ifndef NDEBUG
void OOJSStopTimeLimiter_(const char *file, unsigned line)
#else
void OOJSStopTimeLimiter(void)
#endif
{
#ifndef NDEBUG
    if (sLimiterStartDepth == 0)
    {
        OOLog(@"bug.javaScript.limiterDepth", @"Attempt to stop JavaScript time limiter while it is already fully stopped. This is an internal bug, please report it. (Last start: %@:%u, last valid stop: %@:%u, this stop attempt: %@:%u.)", OOLogAbbreviatedFileName(sLastStartedFile), sLastStartedLine, OOLogAbbreviatedFileName(sLastStoppedFile), sLastStoppedLine, OOLogAbbreviatedFileName(file), line);
        return;
    }
    
    sLastStoppedFile = file;
    sLastStoppedLine = line;
 
#if OOJS_DEBUG_LIMITER
    OOLog(@"script.javaScript.timeLimit.debug",@"Limiter ending: %u <= %u",sLimiterStartDepth-1,sLimiterStartDepth);
#endif
 
#endif
    
    if (--sLimiterStartDepth == 0)  sLimiterTimeLimit = 0.0;
}
 
 
void OOJSPauseTimeLimiter(void)
{
    if (sLimiterPauseDepth++ == 0)
    {
        OODisposeHighResTime(sLimiterPauseStart);
        sLimiterPauseStart = OOGetHighResTime();
    }
}
 
 
void OOJSResumeTimeLimiter(void)
{
    if (--sLimiterPauseDepth == 0)
        
    {
        OOHighResTimeValue now = OOGetHighResTime();
        OOTimeDelta elapsed = OOHighResTimeDeltaInSeconds(sLimiterPauseStart, now);
        OODisposeHighResTime(now);
        
        sLimiterTimeLimit += elapsed;
    }
}
 
 
#ifndef NDEBUG
OOHighResTimeValue OOJSCopyTimeLimiterNominalStartTime(void)
{
    return sLimiterStart;
}
 
 
void OOJSResetTimeLimiter(void)
{
    OODisposeHighResTime(sLimiterStart);
    sLimiterStart = OOGetHighResTime();
    
    sStop = NO;
}
 
 
OOTimeDelta OOJSGetTimeLimiterLimit(void)
{
    return sLimiterTimeLimit;
}
 
 
void OOJSSetTimeLimiterLimit(OOTimeDelta limit)
{
    sLimiterTimeLimit = limit;
}
#endif
 
 
@implementation OOJavaScriptEngine (WatchdogTimer)
 
- (void) watchdogTimerThread
{
    for (;;)
    {
#if OOLITE_WINDOWS
        Sleep(OOJS_TIME_LIMIT * 1000);
#else
        usleep(OOJS_TIME_LIMIT * 1000000);
#endif
        
        if (EXPECT(sLimiterStartDepth == 0 || sLimiterPauseDepth > 0))  continue;   // Most of the time, a script isn't running.
        
        // Note: if you add logging here, you need a manual autorelease pool.
        
        OOHighResTimeValue now = OOGetHighResTime();
        OOTimeDelta elapsed = OOHighResTimeDeltaInSeconds(sLimiterStart, now);
        OODisposeHighResTime(now);
        
        if (EXPECT_NOT(elapsed > sLimiterTimeLimit))
        {
            sStop = YES;
            JS_TriggerAllOperationCallbacks(_runtime);
        }
    }
}
 
@end
 
 
static JSBool OperationCallback(JSContext *context)
{
    if (!sStop)  return YES;
    
    JS_ClearPendingException(context);
    
    OOHighResTimeValue now = OOGetHighResTime();
    OOTimeDelta elapsed = OOHighResTimeDeltaInSeconds(sLimiterStart, now);
    OODisposeHighResTime(now);
    
    if (elapsed <= sLimiterTimeLimit)  return YES;
    
    OOLogERR(@"script.javaScript.timeLimit", @"Script \"%@\" ran for %g seconds and has been terminated.", [[OOJSScript currentlyRunningScript] name], elapsed);
#ifndef NDEBUG
    OOJSDumpStack(context);
#endif
    
    // FIXME: we really should put something in the JS log here, but since that's implemented in JS there are complications.
    
    return NO;
}
 
 
static JSBool ContextCallback(JSContext *context, uintN contextOp)
{
    if (contextOp == JSCONTEXT_NEW)
    {
        JS_SetOperationCallback(context, OperationCallback);
        
#if OOJS_PROFILE && defined(MOZ_TRACE_JSCALLS)
        JS_SetFunctionCallback(context, (JSFunctionCallback)FunctionCallback);  // Naughtily casts away consts, because const JSContexts and JSFunctions are useless.
#endif
    }
    return YES;
}
 
 
void OOJSTimeManagementInit(OOJavaScriptEngine *engine, JSRuntime *runtime)
{
    [NSThread detachNewThreadSelector:@selector(watchdogTimerThread)
                             toTarget:engine
                           withObject:nil];
    
    JS_SetContextCallback(runtime, ContextCallback);
}
 
 
#if OOJS_PROFILE
    
#ifndef MOZ_TRACE_JSCALLS
#warning Profiling is enabled, but MOZ_TRACE_JSCALLS is disabled, so only native functions will be profiled.
#endif
 
static BOOL                     sProfiling = NO;
static BOOL                     sTracing = NO;
static OOJSProfileStackFrame    *sProfileStack = NULL;
static NSMapTable               *sProfileInfo;
static double                   sProfilerOverhead;
static double                   sProfilerTotalNativeTime;
static double                   sProfilerTotalJavaScriptTime;
static double                   sProfilerEntryTimeLimit;
static OOHighResTimeValue       sProfilerStartTime;
 
 
@interface OOTimeProfile (Private)
 
- (void) setTotalTime:(double)value;
- (void) setNativeTime:(double)value;
#ifdef MOZ_TRACE_JSCALLS
- (void) setJavaScriptTime:(double)value;
#endif
- (void) setProfilerOverhead:(double)value;
- (void) setExtensionTime:(double)value;
- (void) setProfileEntries:(NSArray *)value;
 
- (NSDictionary *) propertyListRepresentation;
 
@end
 
 
@interface OOTimeProfileEntry (Private)
 
- (id) initWithCName:(const char *)name;
#ifdef MOZ_TRACE_JSCALLS
- (id) initWithJSFunction:(JSFunction *)function context:(JSContext *)context;
#endif
 
- (void) addSampleWithTotalTime:(OOTimeDelta)totalTime selfTime:(OOTimeDelta)selfTime;
 
- (NSDictionary *) propertyListRepresentation;
 
@end
 
 
void OOJSBeginProfiling(BOOL trace)
{
    assert(sProfiling == NO);
    sProfiling = YES;
    sTracing = trace;
    sProfileInfo = NSCreateMapTable(NSNonOwnedPointerMapKeyCallBacks, NSObjectMapValueCallBacks, 100);
    sProfilerOverhead = 0.0;
    sProfilerTotalNativeTime = 0.0;
    sProfilerTotalJavaScriptTime = 0.0;
    sProfilerEntryTimeLimit = OOJSGetTimeLimiterLimit();
    
    // This should be last for precision.
    sProfilerStartTime = OOGetHighResTime();
    
    if (trace)
    {
        OOLog(@"script.javaScript.trace", @"%@", @">>>> Beginning trace.");
        OOLogIndent();
    }
}
 
 
OOTimeProfile *OOJSEndProfiling(void)
{
    // This should be at the top for precision.
    OOHighResTimeValue now = OOGetHighResTime();
    // Time limiter should be as close to outermost as practical.
    OOJSPauseTimeLimiter();
    
    assert(sProfiling && sProfileStack == NULL);
    
    sProfiling = NO;
 
    OOTimeProfile *result = [[OOTimeProfile alloc] init];
    
    [result setTotalTime:OOHighResTimeDeltaInSeconds(sProfilerStartTime, now)];
    [result setNativeTime:sProfilerTotalNativeTime];
#ifdef MOZ_TRACE_JSCALLS
    [result setJavaScriptTime:sProfilerTotalJavaScriptTime];
#endif
    [result setProfilerOverhead:sProfilerOverhead];
    
    double currentTimeLimit = OOJSGetTimeLimiterLimit(); 
    [result setExtensionTime:currentTimeLimit - sProfilerEntryTimeLimit];
    
    [result setProfileEntries:[NSAllMapTableValues(sProfileInfo) sortedArrayUsingSelector:@selector(compareBySelfTimeReverse:)]];
    
    if (sTracing)
    {
        OOLogOutdent();
        OOLog(@"script.javaScript.trace", @"%@", @"<<<< End of trace.");
        sTracing = NO;
    }
    
    // Clean up.
    NSFreeMapTable(sProfileInfo);
    OODisposeHighResTime(sProfilerStartTime);
    
    OODisposeHighResTime(now);
    
    OOJSResumeTimeLimiter();
    return result;
}
 
 
BOOL OOJSIsProfiling(void)
{
    return sProfiling;
}
 
void OOJSBeginTracing(void);
void OOJSEndTracing(void);
BOOL OOJSIsTracing(void);
 
 
static void UpdateProfileForFrame(OOHighResTimeValue now, OOJSProfileStackFrame *frame);
 
 
#ifdef MOZ_TRACE_JSCALLS
static void CleanUpJSFrame(OOJSProfileStackFrame *frame)
{
    free(frame);
}
 
 
static void TraceEnterJSFunction(JSContext *context, JSFunction *function, OOTimeProfileEntry *profileEntry)
{
    NSMutableString     *name = [NSMutableString stringWithFormat:@"%@(", [profileEntry function]];
    BOOL                isNative = JS_GetFunctionNative(context, function) != NULL;
    NSString            *frameTag = nil;
    NSString            *logMsgClass = nil;
    
    if (!isNative)
    {
        // Get stack frame and find arguments.
        JSStackFrame        *frame = NULL;
        BOOL                first = YES;
        jsval               this;
        JSObject            *scope;
        JSPropertyDescArray properties = { 0 , NULL };
        unsigned            i;
        
        // Temporarily disable profiling as we'll call out to profiled functions to get value descriptions.
        sProfiling = NO;
        
        if (JS_FrameIterator(context, &frame) != NULL)
        {
            if (JS_IsConstructorFrame(context, frame))
            {
                [name insertString:@"new " atIndex:0];
            }
            
            if (JS_GetFrameThis(context, frame, &this))
            {
                [name appendFormat:@"this: %@", OOJSDescribeValue(context, this, YES)];
                first = NO;
            }
            
            scope = JS_GetFrameScopeChain(context, frame);
            if (scope != NULL && JS_GetPropertyDescArray(context, scope, &properties))
            {
                for (i = 0; i < properties.length; i++)
                {
                    JSPropertyDesc *prop = &properties.array[i];
                    if (prop->flags & JSPD_ARGUMENT)
                    {
                        if (!first)  [name appendFormat:@", "];
                        else  first = NO;
                        
                        [name appendFormat:@"%@: %@", OOStringFromJSValueEvenIfNull(context, prop->id), OOJSDescribeValue(context, prop->value, YES)];
                    }
                }
            }
        }
        
        sProfiling = YES;
        
        frameTag = @"JS";   // JavaScript
        logMsgClass = @"script.javaScript.trace.JS";
    }
    else
    {
        frameTag = @"NW";   // Native Wrapper
        logMsgClass = @"script.javaScript.trace.NW";
    }
    
    [name appendString:@")"];
    OOLog(logMsgClass, @">> %@ [%@]", name, frameTag);
    OOLogIndent();
}
 
 
static void FunctionCallback(JSFunction *function, JSScript *script, JSContext *context, int entering)
{
    if (EXPECT(!sProfiling))  return;
    if (EXPECT_NOT(function == NULL))  return;
    
    // Ignore native functions. Ours get their own entries anyway, SpiderMonkey's are elided.
    if (!sTracing && JS_GetFunctionNative(context, function) != NULL)  return;
    
    OOHighResTimeValue start = OOGetHighResTime();
    
    NSAutoreleasePool *pool = [NSAutoreleasePool new];
    
    if (entering > 0)
    {
        // Create profile entry up front so we can shove the JS function in it.
        OOTimeProfileEntry *entry = NSMapGet(sProfileInfo, function);
        if (entry == nil)
        {
            entry = [[OOTimeProfileEntry alloc] initWithJSFunction:function context:context];
            NSMapInsertKnownAbsent(sProfileInfo, function, entry);
            [entry release];
        }
        
        if (EXPECT_NOT(sTracing))
        {
            // We use EXPECT_NOT here because profiles are time-critical and traces are not.
            TraceEnterJSFunction(context, function, entry);
        }
        
        // Make a stack frame on the heap.
        OOJSProfileStackFrame *frame = malloc(sizeof(OOJSProfileStackFrame));
        assert(frame != NULL);
        
        *frame = (OOJSProfileStackFrame)
        {
            .back = sProfileStack,
            .key = function,
            .startTime = start,
            .subTime = 0.0,
            .total = &sProfilerTotalJavaScriptTime,
            .cleanup = CleanUpJSFrame
        };
        
        sProfileStack = frame;
    }
    else
    {
        // Exiting.
        assert(sProfileStack != NULL && sProfileStack->cleanup == CleanUpJSFrame);
        
        UpdateProfileForFrame(start, sProfileStack);
    }
    
    [pool release];
    
    OOHighResTimeValue end = OOGetHighResTime();
    double currentOverhead = OOHighResTimeDeltaInSeconds(start, end);
    sProfilerOverhead += currentOverhead;
    OODisposeHighResTime(start);
    OODisposeHighResTime(end);
}
#endif
 
 
void OOJSProfileEnter(OOJSProfileStackFrame *frame, const char *function)
{
    if (EXPECT(!sProfiling))  return;
    if (EXPECT_NOT(sTracing))
    {
        // We use EXPECT_NOT here because profiles are time-critical and traces are not.
        OOLog(@"script.javaScript.trace.ON", @">> %s [ON]", function);
        OOLogIndent();
    }
    
    *frame = (OOJSProfileStackFrame)
    {
        .back = sProfileStack,
        .key = function,
        .function = function,
        .startTime = OOGetHighResTime(),
        .total = &sProfilerTotalNativeTime
    };
    sProfileStack = frame;
}
 
 
void OOJSProfileExit(OOJSProfileStackFrame *frame)
{
    if (EXPECT(!sProfiling))  return;
    
    OOHighResTimeValue  now = OOGetHighResTime();
    NSAutoreleasePool   *pool = [NSAutoreleasePool new];
    BOOL                done = NO;
    
    /*
        It's possible there could be JavaScript frames on top of this frame if
        a JS native returned false. Or possibly not. The semantics of
        JS_SetFunctionCallback() aren't specified in detail.
        -- Ahruman 2011-01-16
    */
    for (;;)
    {
        assert(sProfileStack != NULL);
        
        done = (sProfileStack == frame);
        UpdateProfileForFrame(now, sProfileStack);
        if (EXPECT(done))  break;
    }
    
    [pool release];
    
    OODisposeHighResTime(frame->startTime);
    
    OOHighResTimeValue end = OOGetHighResTime();
    double currentOverhead = OOHighResTimeDeltaInSeconds(now, end);
    sProfilerOverhead += currentOverhead;
    
    /*  Equivalent of pausing/resuming time limiter, except that it guarantees
        excluded time will match profiler overhead if there are no other
        pauses happening.
    */
    if (sLimiterPauseDepth == 0)  sLimiterTimeLimit += currentOverhead;
    
    OODisposeHighResTime(now);
    OODisposeHighResTime(end);
}
 
 
static void UpdateProfileForFrame(OOHighResTimeValue now, OOJSProfileStackFrame *frame)
{
    sProfileStack = frame->back;
    
    OOTimeProfileEntry *entry = NSMapGet(sProfileInfo, frame->key);
    if (entry == nil)
    {
        entry = [[OOTimeProfileEntry alloc] initWithCName:frame->function];
        NSMapInsertKnownAbsent(sProfileInfo, frame->key, entry);
        [entry release];
    }
    
    OOTimeDelta time = OOHighResTimeDeltaInSeconds(frame->startTime, now);
    OOTimeDelta selfTime = time - frame->subTime;
    [entry addSampleWithTotalTime:time selfTime:selfTime];
    
    *(frame->total) += selfTime;
    if (sProfileStack != NULL)  sProfileStack->subTime += time;
    
    if (frame->cleanup != NULL)  frame->cleanup(frame);
    
    if (EXPECT_NOT(sTracing))  OOLogOutdent();
}
 
 
@implementation OOTimeProfile
 
- (void) dealloc
{
    DESTROY(_profileEntries);
    
    [super dealloc];
}
 
 
- (NSString *) description
{
    double totalTime = [self totalTime];
    
    NSMutableString *result = [NSMutableString stringWithFormat:
                              @"Total time: %g ms\n"
                               "JavaScript: %g ms, native: %g ms\n"
                               "Counted towards limit: %g ms, excluded: %g ms\n"
                               "Profiler overhead: %g ms",
                               totalTime * 1000.0,
                               [self javaScriptTime] * 1000.0, [self nativeTime] * 1000.0,
                               [self nonExtensionTime] * 1000.0, [self extensionTime] * 1000.0,
                               [self profilerOverhead] * 1000.0];
    
    NSArray *profileEntries = [self profileEntries];
    NSUInteger i, count = [profileEntries count];
    if (count != 0)
    {
        [result appendString:@"\n                                                        NAME  T  COUNT    TOTAL     SELF  TOTAL%   SELF%  SELFMAX"];
        for (i = 0; i < count; i++)
        {
        //  [result appendFormat:@"\n    %@", [_profileEntries objectAtIndex:i]];
            
            OOTimeProfileEntry *entry = [profileEntries objectAtIndex:i];
            
            double totalPc = [entry totalTimeSum] * 100.0 / totalTime;
            double selfPc = [entry selfTimeSum] * 100.0 / totalTime;
            
            [result appendFormat:@"\n%60s  %c%7lu %8.2f %8.2f   %5.1f   %5.1f %8.2f",
             [[entry function] UTF8String],
             [entry isJavaScriptFrame] ? 'J' : 'N',
             (unsigned long)[entry hitCount], [entry totalTimeSum] * 1000.0, [entry selfTimeSum] * 1000.0, totalPc, selfPc, [entry selfTimeMax] * 1000.0];
        }
    }
    
    return result;
}
 
 
- (double) totalTime
{
    return _totalTime;
}
 
 
- (void) setTotalTime:(double)value
{
    _totalTime = value;
}
 
 
- (double) javaScriptTime
{
#ifdef MOZ_TRACE_JSCALLS
    return _javaScriptTime;
#else
    return _totalTime - _nativeTime;
#endif
}
 
 
#ifdef MOZ_TRACE_JSCALLS
- (void) setJavaScriptTime:(double)value
{
    _javaScriptTime = value;
}
#endif
 
 
- (double) nativeTime
{
    return _nativeTime;
}
 
 
- (void) setNativeTime:(double)value
{
    _nativeTime = value;
}
 
 
- (double) extensionTime
{
    return _extensionTime;
}
 
 
- (void) setExtensionTime:(double)value
{
    _extensionTime = value;
}
 
 
- (double) nonExtensionTime
{
    return _totalTime - _extensionTime;
}
 
 
- (double) profilerOverhead
{
    return _profilerOverhead;
}
 
 
- (void) setProfilerOverhead:(double)value
{
    _profilerOverhead = value;
}
 
 
- (NSArray *) profileEntries
{
    return _profileEntries;
}
 
 
- (void) setProfileEntries:(NSArray *)value
{
    if (_profileEntries != value)
    {
        [_profileEntries release];
        _profileEntries = [value retain];
    }
}
 
 
- (jsval) oo_jsValueInContext:(JSContext *)context
{
    return OOJSValueFromNativeObject(context, [self propertyListRepresentation]);
}
 
 
- (NSDictionary *) propertyListRepresentation
{
    NSArray *profileEntries = [self profileEntries];
    NSMutableArray *convertedEntries = [NSMutableArray arrayWithCapacity:[profileEntries count]];
    NSEnumerator *entryEnum = nil;
    OOTimeProfileEntry *entry = nil;
    for (entryEnum = [profileEntries objectEnumerator]; (entry = [entryEnum nextObject]); )
    {
        [convertedEntries addObject:[entry propertyListRepresentation]];
    }
    
    return [NSDictionary dictionaryWithObjectsAndKeys:
            profileEntries, @"profiles",
            [NSNumber numberWithDouble:[self totalTime]], @"totalTime",
            [NSNumber numberWithDouble:[self javaScriptTime]], @"javaScriptTime",
            [NSNumber numberWithDouble:[self nativeTime]], @"nativeTime",
            [NSNumber numberWithDouble:[self extensionTime]], @"extensionTime",
            [NSNumber numberWithDouble:[self nonExtensionTime]], @"nonExtensionTime",
            [NSNumber numberWithDouble:[self profilerOverhead]], @"profilerOverhead",
            nil];
}
 
@end
 
 
@implementation OOTimeProfileEntry
 
- (id) initWithCName:(const char *)name
{
    NSAssert(sProfiling, @"Can't create profile entries while not profiling.");
    
    if ((self = [super init]))
    {
        if (name != NULL)
        {
            _function = [[NSString stringWithUTF8String:name] retain];
        }
    }
    
    return self;
}
 
 
#if MOZ_TRACE_JSCALLS
- (id) initWithJSFunction:(JSFunction *)function context:(JSContext *)context
{
    if ((self = [self initWithCName:NULL]))
    {
        // Temporarily disable profiling so we don't profile the profiler while it's profiling the profilee.
        sProfiling = NO;
        _jsFunction = function;
        
        NSString *funcName = nil;
        JSString *jsName = JS_GetFunctionId(_jsFunction);
        if (jsName != NULL)  funcName = [OOStringFromJSString(context, jsName) retain];
        else  funcName = @"<anonymous>";
        
        // If it's a non-native function, get its source location.
        NSString *location = nil;
        if (JS_GetFunctionNative(context, function) == NULL)
        {
            JSStackFrame *frame = NULL;
            if (JS_FrameIterator(context, &frame) != NULL)
            {
                location = OOJSDescribeLocation(context, frame);
            }
        }
        
        if (location != nil)
        {
            _function = [[NSString alloc] initWithFormat:@"(%@) %@", location, funcName];
        }
        else  _function = [funcName retain];
        
        sProfiling = YES;
    }
    
    return self;
}
#endif
 
 
- (void) dealloc
{
    DESTROY(_function);
    
    [super dealloc];
}
 
 
- (void) addSampleWithTotalTime:(OOTimeDelta)totalTime selfTime:(OOTimeDelta)selfTime
{
    _hitCount++;
    _totalTimeSum += totalTime;
    _selfTimeSum += selfTime;
    _totalTimeMax = fmax(_totalTimeMax, totalTime);
    _selfTimeMax = fmax(_selfTimeMax, selfTime);
}
 
 
- (NSString *) description
{
    if (_hitCount == 0)  return [NSString stringWithFormat:@"%@: --", _function];
    
    // Convert everything to milliseconds.
    float totalTimeSum = _totalTimeSum * 1000.0;
    float selfTimeSum = _selfTimeSum * 1000.0;
    float totalTimeMax = _totalTimeMax * 1000.0;
    float selfTimeMax = _selfTimeMax * 1000.0;
    
    if (totalTimeSum == selfTimeSum && totalTimeMax == selfTimeMax)
    {
        if (_hitCount == 1)
        {
            return [NSString stringWithFormat:@"%@: 1 time, %g ms", _function, totalTimeSum];
        }
        else
        {
            return [NSString stringWithFormat:@"%@: %lu times, total %g ms, avg %g ms, max %g ms", _function, _hitCount, totalTimeSum, totalTimeSum / _hitCount, totalTimeMax];
        }
    }
    else
    {
        if (_hitCount == 1)
        {
            return [NSString stringWithFormat:@"%@: 1 time, %g ms (self %g ms)", _function, totalTimeSum, selfTimeSum];
        }
        else
        {
            return [NSString stringWithFormat:@"%@: %lu times, total %g ms (self %g ms), avg %g ms (self %g ms), max %g ms, max self %g ms", _function, _hitCount, totalTimeSum, selfTimeSum, totalTimeSum / _hitCount, selfTimeSum / _hitCount, totalTimeMax, selfTimeMax];
        }
    }
}
 
 
- (NSString *) function
{
    return _function;
}
 
 
- (NSUInteger) hitCount
{
    return _hitCount;
}
 
 
- (double) totalTimeSum
{
    return _totalTimeSum;
}
 
 
- (double) selfTimeSum
{
    return _selfTimeSum;
}
 
 
- (double) totalTimeAverage
{
    return _hitCount ? (_totalTimeSum / _hitCount) : 0.0;
}
 
 
- (double) selfTimeAverage
{
    return _hitCount ? (_selfTimeSum / _hitCount) : 0.0;
}
 
 
- (double) totalTimeMax
{
    return _totalTimeMax;
}
 
 
- (double) selfTimeMax
{
    return _selfTimeMax;
}
 
 
- (BOOL) isJavaScriptFrame
{
#if MOZ_TRACE_JSCALLS
    return _jsFunction != NULL;
#else
    return NO;
#endif
}
 
 
- (NSComparisonResult) compareByTotalTime:(OOTimeProfileEntry *)other
{
    return -[self compareByTotalTimeReverse:other];
}
 
 
- (NSComparisonResult) compareByTotalTimeReverse:(OOTimeProfileEntry *)other
{
    double selfTotal = [self totalTimeSum];
    double otherTotal = [other totalTimeSum];
    
    if (selfTotal < otherTotal)  return NSOrderedDescending;
    if (selfTotal > otherTotal)  return NSOrderedAscending;
    return NSOrderedSame;
}
 
 
- (NSComparisonResult) compareBySelfTime:(OOTimeProfileEntry *)other
{
    return -[self compareBySelfTimeReverse:other];
}
 
 
- (NSComparisonResult) compareBySelfTimeReverse:(OOTimeProfileEntry *)other
{
    double selfTotal = [self selfTimeSum];
    double otherTotal = [other selfTimeSum];
    
    if (selfTotal < otherTotal)  return NSOrderedDescending;
    if (selfTotal > otherTotal)  return NSOrderedAscending;
    return NSOrderedSame;
}
 
 
- (jsval) oo_jsValueInContext:(JSContext *)context
{
    return OOJSValueFromNativeObject(context, [self propertyListRepresentation]);
}
 
 
- (NSDictionary *) propertyListRepresentation
{
    return [NSDictionary dictionaryWithObjectsAndKeys:
            _function, @"name",
            [NSNumber numberWithUnsignedInteger:[self hitCount]], @"hitCount",
            [NSNumber numberWithDouble:[self totalTimeSum]], @"totalTimeSum",
            [NSNumber numberWithDouble:[self selfTimeSum]], @"selfTimeSum",
            [NSNumber numberWithDouble:[self totalTimeAverage]], @"totalTimeAverage",
            [NSNumber numberWithDouble:[self selfTimeAverage]], @"selfTimeAverage",
            [NSNumber numberWithDouble:[self totalTimeMax]], @"totalTimeMax",
            [NSNumber numberWithDouble:[self selfTimeMax]], @"selfTimeMax",
            [NSNumber numberWithBool:[self isJavaScriptFrame]], @"isJavaScriptFrame",
            nil];
}
 
@end
 
#endif