OOJSFrameCallbacks.m File Reference

import "OOJSFrameCallbacks.h"
import "OOJSEngineTimeManagement.h"
import "OOCollectionExtractors.h"

Include dependency graph for OOJSFrameCallbacks.m:

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Classes
struct	CallbackEntry

Macros
#define	DEBUG_FCB_SIMPLE_TRACKING_IDS   0
#define	DEBUG_FCB_VERBOSE_LOGGING   0
#define	FCBLog(...)
#define	FCBLogIndentIf(key)
#define	FCBLogOutdentIf(key)

Enumerations
enum	{ kMinCount = 16 , kIDScrambleMask = 0x2315EB16 , kIDIncrement = 992699 }

Functions
static JSBool	GlobalAddFrameCallback (JSContext *context, uintN argc, jsval *vp)
static JSBool	GlobalRemoveFrameCallback (JSContext *context, uintN argc, jsval *vp)
static JSBool	GlobalIsValidFrameCallback (JSContext *context, uintN argc, jsval *vp)
static BOOL	AddCallback (JSContext *context, jsval callback, uint32 trackingID, NSString **errorString)
static BOOL	GrowCallbackList (JSContext *context, NSString **errorString)
static BOOL	GetIndexForTrackingID (uint32 trackingID, NSUInteger *outIndex)
static BOOL	RemoveCallbackWithTrackingID (JSContext *context, uint32 trackingID)
static void	RemoveCallbackAtIndex (JSContext *context, NSUInteger index)
static void	QueueDeferredOperation (NSString *opType, uint32 trackingID, OOJSValue *value)
static void	RunDeferredOperations (JSContext *context)
void	InitOOJSFrameCallbacks (JSContext *context, JSObject *global)
void	OOJSFrameCallbacksInvoke (OOTimeDelta inDeltaT)
void	OOJSFrameCallbacksRemoveAll (void)

Variables
static CallbackEntry *	sCallbacks
static NSUInteger	sCount
static NSUInteger	sSpace
static NSUInteger	sHighWaterMark
static NSMutableArray *	sDeferredOps
static uint32	sNextID
static BOOL	sRunning

Macro Definition Documentation

DEBUG_FCB_SIMPLE_TRACKING_IDS

#define DEBUG_FCB_SIMPLE_TRACKING_IDS   0

Definition at line 41 of file OOJSFrameCallbacks.m.

DEBUG_FCB_VERBOSE_LOGGING

#define DEBUG_FCB_VERBOSE_LOGGING   0

Definition at line 45 of file OOJSFrameCallbacks.m.

FCBLog

#define FCBLog

(

...

)

Value:

do {} while (0)

Definition at line 59 of file OOJSFrameCallbacks.m.

Referenced by AddCallback(), GlobalAddFrameCallback(), GlobalRemoveFrameCallback(), RemoveCallbackAtIndex(), and RunDeferredOperations().

FCBLogIndentIf

#define FCBLogIndentIf

(

key

)

Value:

do {} while (0)

Definition at line 60 of file OOJSFrameCallbacks.m.

Referenced by RunDeferredOperations().

FCBLogOutdentIf

#define FCBLogOutdentIf

(

key

)

Value:

do {} while (0)

Definition at line 61 of file OOJSFrameCallbacks.m.

Referenced by RunDeferredOperations().

Enumeration Type Documentation

anonymous enum

anonymous enum

Enumerator
kMinCount
kIDScrambleMask
kIDIncrement

Definition at line 65 of file OOJSFrameCallbacks.m.

{
    kMinCount                   = 16,
    
#if DEBUG_FCB_SIMPLE_TRACKING_IDS
    kIDScrambleMask             = 0,
    kIDIncrement                = 1
#else
    kIDScrambleMask             = 0x2315EB16,   // Just a random number.
    kIDIncrement                = 992699        // A large prime number, to produce a non-obvious sequence which still uses all 2^32 values.
#endif
};

Function Documentation

AddCallback()

static BOOL AddCallback ( JSContext * context, jsval callback, uint32 trackingID, NSString ** errorString )

static

Definition at line 291 of file OOJSFrameCallbacks.m.

{
    NSCParameterAssert(context != NULL && JS_IsInRequest(context));
    NSCParameterAssert(errorString != NULL);
    NSCAssert1(!sRunning, @"%s cannot be called while frame callbacks are running.", __PRETTY_FUNCTION__);
    
    if (EXPECT_NOT(sCount == sSpace))
    {
        if (!GrowCallbackList(context, errorString))  return NO;
    }
    
    FCBLog(@"script.frameCallback.debug.add", @"Adding frame callback with tracking ID %u.", trackingID);
    
    sCallbacks[sCount].callback = callback;
    if (sCount >= sHighWaterMark)
    {
        // If we haven't used this slot before, root it.
        
        if (EXPECT_NOT(!OOJSAddGCValueRoot(context, &sCallbacks[sCount].callback, "frame callback")))
        {
            *errorString = @"Failed to add GC root for frame callback.";
            return NO;
        }
        
        sHighWaterMark = sCount + 1;
    }
    
    sCallbacks[sCount].trackingID = trackingID;
    sCount++;
    
    return YES;
}

References CallbackEntry::callback, EXPECT_NOT, FCBLog, GrowCallbackList(), JS_IsInRequest, OOJSAddGCValueRoot, sCallbacks, sCount, sHighWaterMark, sRunning, sSpace, and CallbackEntry::trackingID.

Referenced by GlobalAddFrameCallback(), and RunDeferredOperations().

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GetIndexForTrackingID()

static BOOL GetIndexForTrackingID ( uint32 trackingID, NSUInteger * outIndex )

static

Definition at line 376 of file OOJSFrameCallbacks.m.

{
    NSCParameterAssert(outIndex != NULL);
    
    /*  It is assumed that few frame callbacks will be active at once, so a
        linear search is reasonable. If they become unexpectedly popular, we
        can switch to a sorted list or a separate lookup table without changing
        the API.
    */
    NSUInteger i;
    for (i = 0; i < sCount; i++)
    {
        if (sCallbacks[i].trackingID == trackingID)
        {
            *outIndex = i;
            return YES;
        }
    }
    
    return NO;
}

References sCallbacks, and sCount.

Referenced by GlobalIsValidFrameCallback(), and RemoveCallbackWithTrackingID().

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GlobalAddFrameCallback()

static JSBool GlobalAddFrameCallback ( JSContext * context, uintN argc, jsval * vp )

static

Definition at line 191 of file OOJSFrameCallbacks.m.

{
    OOJS_NATIVE_ENTER(context)
    
    // Get callback argument and verify that it's a function.
    jsval callback = OOJS_ARGV[0];
    if (EXPECT_NOT(argc < 1 || !OOJSValueIsFunction(context, callback)))
    {
        OOJSReportBadArguments(context, nil, @"addFrameCallback", MIN(argc, 1U), OOJS_ARGV, nil, @"function");
        return NO;
    }
    
    // Assign a tracking ID.
    uint32 trackingID = sNextID ^ kIDScrambleMask;
    sNextID += kIDIncrement;
    
    if (EXPECT(!sRunning))
    {
        // Add to list immediately.
        NSString *errorString = nil;
        if (EXPECT_NOT(!AddCallback(context, callback, trackingID, &errorString)))
        {
            OOJSReportError(context, @"%@", errorString);
            return NO;
        }
    }
    else
    {
        // Defer mutations during callback invocation.
        FCBLog(@"script.frameCallback.debug.add.deferred", @"Deferring addition of frame callback with tracking ID %u.", trackingID);
        QueueDeferredOperation(@"add", trackingID, [OOJSValue valueWithJSValue:callback inContext:context]);
    }
    
    OOJS_RETURN_INT(trackingID);
    
    OOJS_NATIVE_EXIT
}

References AddCallback(), EXPECT, EXPECT_NOT, FCBLog, kIDIncrement, kIDScrambleMask, MIN, nil, OOJS_ARGV, OOJS_NATIVE_ENTER, OOJS_NATIVE_EXIT, OOJS_RETURN_INT, OOJSReportBadArguments(), OOJSReportError(), OOJSValueIsFunction(), QueueDeferredOperation(), sNextID, and sRunning.

Referenced by InitOOJSFrameCallbacks().

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GlobalIsValidFrameCallback()

static JSBool GlobalIsValidFrameCallback ( JSContext * context, uintN argc, jsval * vp )

static

Definition at line 265 of file OOJSFrameCallbacks.m.

{
    OOJS_NATIVE_ENTER(context)
    
    if (EXPECT_NOT(argc < 1))
    {
        OOJSReportBadArguments(context, nil, @"isValidFrameCallback", 0, OOJS_ARGV, nil, @"frame callback tracking ID");
        return NO;
    }
    
    // Get tracking ID argument.
    uint32 trackingID;
    if (EXPECT_NOT(!JS_ValueToECMAUint32(context, OOJS_ARGV[0], &trackingID)))
    {
        OOJS_RETURN_BOOL(NO);
    }
    
    NSUInteger index;
    OOJS_RETURN_BOOL(GetIndexForTrackingID(trackingID, &index));
    
    OOJS_NATIVE_EXIT
}

References EXPECT_NOT, GetIndexForTrackingID(), nil, OOJS_ARGV, OOJS_NATIVE_ENTER, OOJS_NATIVE_EXIT, OOJS_RETURN_BOOL, and OOJSReportBadArguments().

Referenced by InitOOJSFrameCallbacks().

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GlobalRemoveFrameCallback()

static JSBool GlobalRemoveFrameCallback ( JSContext * context, uintN argc, jsval * vp )

static

Definition at line 231 of file OOJSFrameCallbacks.m.

{
    OOJS_NATIVE_ENTER(context)
    
    // Get tracking ID argument.
    uint32 trackingID;
    if (EXPECT_NOT(argc < 1 || !JS_ValueToECMAUint32(context, OOJS_ARGV[0], &trackingID)))
    {
        OOJSReportBadArguments(context, nil, @"removeFrameCallback", MIN(argc, 1U), OOJS_ARGV, nil, @"frame callback tracking ID");
        return NO;
    }
    
    if (EXPECT(!sRunning))
    {
        // Remove it.
        if (EXPECT_NOT(!RemoveCallbackWithTrackingID(context, trackingID)))
        {
            OOJSReportWarning(context, @"removeFrameCallback(): invalid tracking ID.");
        }
    }
    else
    {
        // Defer mutations during callback invocation.
        FCBLog(@"script.frameCallback.debug.remove.deferred", @"Deferring removal of frame callback with tracking ID %u.", trackingID);
        QueueDeferredOperation(@"remove", trackingID, nil);
    }
    
    OOJS_RETURN_VOID;
    
    OOJS_NATIVE_EXIT
}

References EXPECT, EXPECT_NOT, FCBLog, MIN, nil, OOJS_ARGV, OOJS_NATIVE_ENTER, OOJS_NATIVE_EXIT, OOJS_RETURN_VOID, OOJSReportBadArguments(), OOJSReportWarning(), QueueDeferredOperation(), RemoveCallbackWithTrackingID(), and sRunning.

Referenced by InitOOJSFrameCallbacks().

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GrowCallbackList()

static BOOL GrowCallbackList ( JSContext * context, NSString ** errorString )

static

Definition at line 325 of file OOJSFrameCallbacks.m.

{
    NSCParameterAssert(context != NULL && JS_IsInRequest(context));
    NSCParameterAssert(errorString != NULL);
    
    NSUInteger newSpace = MAX(sSpace * 2, (NSUInteger)kMinCount);
    
    CallbackEntry *newCallbacks = calloc(sizeof (CallbackEntry), newSpace);
    if (newCallbacks == NULL)  return NO;
    
    CallbackEntry *oldCallbacks = sCallbacks;
    
    // Root and copy occupied slots.
    NSUInteger newHighWaterMark = sCount;
    NSUInteger i;
    for (i = 0; i < newHighWaterMark; i++)
    {
        if (EXPECT_NOT(!OOJSAddGCValueRoot(context, &newCallbacks[i].callback, "frame callback")))
        {
            // If we can't root them all, we fail; unroot all entries to date, free the buffer and return NO.
            NSUInteger j;
            for (j = 0; j < i; j++)
            {
                JS_RemoveValueRoot(context, &newCallbacks[j].callback);
            }
            free(newCallbacks);
            
            *errorString = @"Failed to add GC root for frame callback.";
            return NO;
        }
        newCallbacks[i] = oldCallbacks[i];
    }
    
    // Unroot old array's slots.
    for (i = 0; i < sHighWaterMark; i++)
    {
        JS_RemoveValueRoot(context, &oldCallbacks[i].callback);
    }
    
    // We only rooted the occupied slots, so reset high water mark.
    sHighWaterMark = newHighWaterMark;
    
    // Replace array.
    sCallbacks = newCallbacks;
    free(oldCallbacks);
    sSpace = newSpace;
    
    return YES;
}

References EXPECT_NOT, JS_IsInRequest, kMinCount, MAX, OOJSAddGCValueRoot, sCallbacks, sCount, sHighWaterMark, and sSpace.

Referenced by AddCallback().

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InitOOJSFrameCallbacks()

void InitOOJSFrameCallbacks	(	JSContext *	context,
		JSObject *	global )

Definition at line 117 of file OOJSFrameCallbacks.m.

{
    JS_DefineFunction(context, global, "addFrameCallback", GlobalAddFrameCallback, 1, OOJS_METHOD_READONLY);
    JS_DefineFunction(context, global, "removeFrameCallback", GlobalRemoveFrameCallback, 1, OOJS_METHOD_READONLY);
    JS_DefineFunction(context, global, "isValidFrameCallback", GlobalIsValidFrameCallback, 1, OOJS_METHOD_READONLY);
    
#if DEBUG_FCB_SIMPLE_TRACKING_IDS
    sNextID = 1;
#else
    // Set randomish initial ID to catch bad habits.
    sNextID =  [[NSDate date] timeIntervalSinceReferenceDate];
#endif
}

References GlobalAddFrameCallback(), GlobalIsValidFrameCallback(), GlobalRemoveFrameCallback(), OOJS_METHOD_READONLY, and sNextID.

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OOJSFrameCallbacksInvoke()

void OOJSFrameCallbacksInvoke

(

OOTimeDelta

inDeltaT

)

Definition at line 132 of file OOJSFrameCallbacks.m.

{
    NSCAssert1(!sRunning, @"%s cannot be called while frame callbacks are running.", __PRETTY_FUNCTION__);
    
    if (sCount != 0)
    {
        const OOTimeDelta   delta = inDeltaT * [UNIVERSE timeAccelerationFactor];
        JSContext           *context = OOJSAcquireContext();
        jsval               deltaVal, result;
        NSUInteger          i;
        
        if (EXPECT(JS_NewNumberValue(context, delta, &deltaVal)))
        {
            // Block mutations.
            sRunning = YES;
            
            /*
                The watchdog timer only fires once per second in deployment builds,
                but in testrelease builds at least we can keep them on a short leash.
            */
            OOJSStartTimeLimiterWithTimeLimit(0.1);
            
            for (i = 0; i < sCount; i++)
            {
                // TODO: remove out of scope callbacks - post MNSR!
                JS_CallFunctionValue(context, NULL, sCallbacks[i].callback, 1, &deltaVal, &result);
                JS_ReportPendingException(context);
            }
            
            OOJSStopTimeLimiter();
            sRunning = NO;
            
            if (EXPECT_NOT(sDeferredOps != NULL))
            {
                RunDeferredOperations(context);
                DESTROY(sDeferredOps);
            }
        }
        OOJSRelinquishContext(context);
    }
}

References DESTROY, EXPECT, EXPECT_NOT, OOJSAcquireContext(), OOJSRelinquishContext(), OOJSStartTimeLimiterWithTimeLimit, OOJSStopTimeLimiter, RunDeferredOperations(), sCallbacks, sCount, sDeferredOps, and sRunning.

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OOJSFrameCallbacksRemoveAll()

void OOJSFrameCallbacksRemoveAll

(

void

)

Definition at line 175 of file OOJSFrameCallbacks.m.

{
    NSCAssert1(!sRunning, @"%s cannot be called while frame callbacks are running.", __PRETTY_FUNCTION__);
    
    if (sCount != 0)
    {
        JSContext *context = OOJSAcquireContext();
        while (sCount != 0)  RemoveCallbackAtIndex(context, sCount - 1);
        OOJSRelinquishContext(context);
    }
}

References OOJSAcquireContext(), OOJSRelinquishContext(), RemoveCallbackAtIndex(), sCount, and sRunning.

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QueueDeferredOperation()

static void QueueDeferredOperation ( NSString * opType, uint32 trackingID, OOJSValue * value )

static

Definition at line 438 of file OOJSFrameCallbacks.m.

{
    NSCAssert1(sRunning, @"%s can only be called while frame callbacks are running.", __PRETTY_FUNCTION__);
    
    if (sDeferredOps == nil)  sDeferredOps = [[NSMutableArray alloc] init];
    [sDeferredOps addObject:[NSDictionary dictionaryWithObjectsAndKeys:
                             opType, @"operation",
                             [NSNumber numberWithInt:trackingID], @"trackingID",
                             value, @"value",
                             nil]];
}

References nil, sDeferredOps, and sRunning.

Referenced by GlobalAddFrameCallback(), and GlobalRemoveFrameCallback().

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RemoveCallbackAtIndex()

static void RemoveCallbackAtIndex ( JSContext * context, NSUInteger index )

static

Definition at line 415 of file OOJSFrameCallbacks.m.

{
    NSCParameterAssert(context != NULL && JS_IsInRequest(context));
    NSCParameterAssert(index < sCount && sCallbacks != NULL);
    NSCAssert1(!sRunning, @"%s cannot be called while frame callbacks are running.", __PRETTY_FUNCTION__);
    
    FCBLog(@"script.frameCallback.debug.remove", @"Removing frame callback with tracking ID %u.", sCallbacks[index].trackingID);
    
    // Overwrite entry to be removed with last entry, and decrement count.
    sCount--;
    sCallbacks[index] = sCallbacks[sCount];
    sCallbacks[sCount].callback = JSVAL_NULL;
    
#if DEBUG_FCB_SIMPLE_TRACKING_IDS
    if (sCount == 0)
    {
        OOLog(@"script.frameCallback.debug.reset", @"All frame callbacks removed, resetting next ID to 1.");
        sNextID = 1;
    }
#endif
}

References CallbackEntry::callback, FCBLog, JS_IsInRequest, OOLog, sCallbacks, sCount, sNextID, and sRunning.

Referenced by OOJSFrameCallbacksRemoveAll(), and RemoveCallbackWithTrackingID().

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RemoveCallbackWithTrackingID()

static BOOL RemoveCallbackWithTrackingID ( JSContext * context, uint32 trackingID )

static

Definition at line 399 of file OOJSFrameCallbacks.m.

{
    NSCParameterAssert(context != NULL && JS_IsInRequest(context));
    NSCAssert1(!sRunning, @"%s cannot be called while frame callbacks are running.", __PRETTY_FUNCTION__);
    
    NSUInteger index = 0;
    if (GetIndexForTrackingID(trackingID, &index))
    {
        RemoveCallbackAtIndex(context, index);
        return YES;
    }
    
    return NO;
}

References GetIndexForTrackingID(), JS_IsInRequest, RemoveCallbackAtIndex(), and sRunning.

Referenced by GlobalRemoveFrameCallback(), and RunDeferredOperations().

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RunDeferredOperations()

static void RunDeferredOperations ( JSContext * context )

static

Definition at line 451 of file OOJSFrameCallbacks.m.

{
    NSDictionary        *operation = nil;
    NSEnumerator        *operationEnum = nil;
    
    FCBLog(@"script.frameCallback.debug.run-deferred", @"Running %lu deferred frame callback operations.", (long)[sDeferredOps count]);
    FCBLogIndentIf(@"script.frameCallback.debug.run-deferred");
    
    for (operationEnum = [sDeferredOps objectEnumerator]; (operation = [operationEnum nextObject]); )
    {
        NSString    *opType = [operation objectForKey:@"operation"];
        uint32      trackingID = [operation oo_intForKey:@"trackingID"];
        
        if ([opType isEqualToString:@"add"])
        {
            OOJSValue   *callbackObj = [operation objectForKey:@"value"];
            NSString    *errorString = nil;
            
            if (!AddCallback(context, OOJSValueFromNativeObject(context, callbackObj), trackingID, &errorString))
            {
                OOLogWARN(@"script.frameCallback.deferredAdd.failed", @"Deferred frame callback insertion failed: %@", errorString);
            }
        }
        else if ([opType isEqualToString:@"remove"])
        {
            RemoveCallbackWithTrackingID(context, trackingID);
        }
    }
    
    FCBLogOutdentIf(@"script.frameCallback.debug.run-deferred");
}

References AddCallback(), count, FCBLog, FCBLogIndentIf, FCBLogOutdentIf, nil, OOJSValueFromNativeObject(), OOLogWARN, RemoveCallbackWithTrackingID(), and sDeferredOps.

Referenced by OOJSFrameCallbacksInvoke().

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Variable Documentation

sCallbacks

CallbackEntry* sCallbacks

static

Definition at line 87 of file OOJSFrameCallbacks.m.

Referenced by AddCallback(), GetIndexForTrackingID(), GrowCallbackList(), OOJSFrameCallbacksInvoke(), and RemoveCallbackAtIndex().

sCount

NSUInteger sCount

static

Definition at line 88 of file OOJSFrameCallbacks.m.

Referenced by AddCallback(), GetIndexForTrackingID(), GrowCallbackList(), OOJSFrameCallbacksInvoke(), OOJSFrameCallbacksRemoveAll(), and RemoveCallbackAtIndex().

sDeferredOps

NSMutableArray* sDeferredOps

static

Definition at line 91 of file OOJSFrameCallbacks.m.

Referenced by OOJSFrameCallbacksInvoke(), QueueDeferredOperation(), and RunDeferredOperations().

sHighWaterMark

NSUInteger sHighWaterMark

static

Definition at line 90 of file OOJSFrameCallbacks.m.

Referenced by AddCallback(), and GrowCallbackList().

sNextID

uint32 sNextID

static

Definition at line 92 of file OOJSFrameCallbacks.m.

Referenced by GlobalAddFrameCallback(), InitOOJSFrameCallbacks(), and RemoveCallbackAtIndex().

sRunning

BOOL sRunning

static

Definition at line 93 of file OOJSFrameCallbacks.m.

Referenced by AddCallback(), GlobalAddFrameCallback(), GlobalRemoveFrameCallback(), OOJSFrameCallbacksInvoke(), OOJSFrameCallbacksRemoveAll(), QueueDeferredOperation(), RemoveCallbackAtIndex(), and RemoveCallbackWithTrackingID().

sSpace

NSUInteger sSpace

static

Definition at line 89 of file OOJSFrameCallbacks.m.

Referenced by AddCallback(), and GrowCallbackList().