What is the correct way to implement a callback on the RemoteIO after the aumixer has done it's thang.
If i use ;
result = AUGraphSetNodeInputCallback(mGraph, outputNode,1, &remoteIOCallback);
It doesn't call my function
If I use ..
result = AudioUnitSetProperty(mIONode, kAudioOutputUnitProperty_SetInputCallback, kAudioUnitScope_Input, 1 , &remoteIOCallback, sizeof(remoteIOCallback));
It calls my callback but when i try to create a pointer to the ioData
AudioSampleType *inData = (AudioSampleType *) ioData->mBuffers[0].mData;
it crashes.
I cannot see the problem at all. Is this a problem with the buffers? But then i'm not allocating anything to the buffer, just a pointer to it.
Cheers
Instead of immediately casting to an AudioSampleType*, first try casting ioData to your custom data type. Then try accessing the data in the buffer.
Related
all.I want to call a js function to show something in my plugin.This is my code
NPObject* npwindow = NULL;
NPError ret = browser->getvalue(mInstanceForJS, NPNVWindowNPObject, &npwindow);
if (ret != NPERR_NO_ERROR)
return ;
// Get window object.
NPVariant windowVar;
NPIdentifier winID = browser->getstringidentifier("window");
bool bRet = browser->getproperty(mInstanceForJS, npwindow, winID, &windowVar);
if (!bRet)
{
browser->releaseobject(npwindow);
return ;
}
NPObject* window = NPVARIANT_TO_OBJECT(windowVar);
NPVariant voidResponse;
NPVariant elementId;
STRINGZ_TO_NPVARIANT([info UTF8String], elementId);
NPVariant args[] = {elementId};
NPIdentifier funcID= browser->getstringidentifier([funName UTF8String]);
bRet = browser->invoke(mInstanceForJS, window, funcID, args, 1, &voidResponse);
browser->releasevariantvalue(&windowVar);
when called bRet = browser->invoke(mInstanceForJS, window, funcID, args, 1, &voidResponse);,Safari can not responsed.Is there any errors?
npwindow is already the window object; you're effectively querying for "window.window". Granted, I don't know why this wouldn't work, but it seems a little weird.
That's problem #1.
Problem #2 is that you're using STRINGZ_TO_NPVARIANT to store the result of UTF8String. STRINGZ_TO_NPVARIANT doesn't copy the memory, so you could be in trouble if the function wanted to hang onto that string, since the string returned by that will be freed when your autorelease pool cycles. Of course, that could also be a memory leak. Either way, the correct way to pass a string to the browser is to allocate memory for it using NPN_MemAlloc and then copy the string in. Then pass that pointer to the browser. See http://npapi.com/memory for more info.
Problem #3 is that you haven't given us any idea of when you are running this code; it's quite possible that you are trying to run this code too early in the plugin or page lifecycle and thus it may not work because of that.
Then there is another question: What do you mean by "Safari can no responsed"? Forgetting the grammatical error, I'm not sure what you mean by this. Does it hang? is bRet false? Does your computer suddenly get encased in ice, thus halting all processing? If the above is not helpful, please answer these questions and I'll try again.
I tried this code:
battery_info_t **pointer=NULL;
battery_get_info(pointer);
return battery_info_get_time_to_empty(*pointer); // needs simple pointer (*pointer)
My question is: how can i convert **pointer to *pointer
In this usage the battery_info_... function calls take a pointer to a battery_info_t type, so you would declare pointer as that and use it as the argument to those calls. To set pointer to the correct value you pass a pointer to it to battery_get_info(). You must also free the memory allocated to pointer when you are done:
battery_info_t *pointer = NULL;
battery_get_info(&pointer);
int t = battery_info_get_time_to_empty(pointer);
battery_free_info(&pointer);
return t;
This works:
battery_info_t *pointer=NULL;
battery_get_info(&pointer);
return battery_info_get_time_to_empty(pointer);
But returns 65535, on an emulator, so i can't tell if it works or not, because i don have an BB10...
I am using the libical library to parse the iCalendar format and read the information I need out of it. It is working absolutely fine so far, but there is one odd thing concerning ical.
This is my code:
icalcomponent *root = icalparser_parse_string([iCalData cStringUsingEncoding:NSUTF8StringEncoding]);
if (root)
{
icalcomponent *currentEvent = icalcomponent_get_first_component(root, ICAL_VEVENT_COMPONENT);
while (currentEvent)
{
while(currentProperty)
{
icalvalue *value = icalproperty_get_value(currentProperty);
char *icalString = icalvalue_as_ical_string_r(value); //seems to leak
NSString *currentValueAsString = [NSString stringWithCString:icalString
encoding:NSUTF8StringEncoding];
icalvalue_free(value);
//...
//import data
//...
icalString = nil;
currentValueAsString = nil;
icalproperty_free(currentProperty);
currentProperty = icalcomponent_get_next_property(currentEvent, ICAL_ANY_PROPERTY);
} //end while
} //end while
icalcomponent_free(currentEvent);
}
icalcomponent_free(root);
//...
I did use instruments to check my memory usage and were able to find out, that this line seems to leak:
char *icalString = icalvalue_as_ical_string_r(value); //seems to leak
If I'd copy and paste this line 5 or six times my memory usage would grow about 400kb and never get released anymore.
There is no free method for the icalvalue_as_ical_string_r method because it's returning a char *..
Any suggestions how to solve this issue? I would appreciate any help!
EDIT
Taking a look at the apple doc says the following:
To get a C string from a string object, you are recommended to use UTF8String. This returns a const char * using UTF8 string encoding.
const char *cString = [#"Hello, world" UTF8String];
The C string you receive is owned by a temporary object, and will become invalid when automatic deallocation takes place. If you want to get a permanent C string, you must create a buffer and copy the contents of the const char * returned by the method.
But how to release a char * string properly now if using arc?
I tried to add #autorelease {...} in front of my while-loop but without any effort. Still increasing memory usage...
Careful with the statement "no free method...because it's returning a char*"; that is never something you can just assume.
In the absence of documentation you can look at the source code of the library to see what it does; for example:
http://libical.sourcearchive.com/documentation/0.44-2/icalvalue_8c-source.html
Unfortunately this function can do a lot of different things. There are certainly some cases where calling free() on the returned buffer would be right but maybe that hasn't been ensured in every case.
I think it would be best to request a proper deallocation method from the maintainers of the library. They need to clean up their own mess; the icalvalue_as_ical_string_r() function has at least a dozen cases in a switch that might have different deallocation requirements.
icalvalue_as_ical_string_r returns a char * because it has done a malloc() for your result string. If your pointer is non-NULL, you have to free() it after use.
I am coding an audio app for the iphone where I need to use some C code to deal with the audio files. In short, I have a memory leak that is causing the app to crash after so many files have been loaded. The problem is related to a Struct that I create that holds the audio files when read in. The Struct is created as follows;
typedef struct {
UInt32 frameCount; // the total number of frames in the audio data
UInt32 sampleNumber; // the next audio sample to play
BOOL isStereo; // set to true if there is data audioDataRight member
AudioUnitSampleType *audioDataLeft; // complete left channel of audio data read from file
AudioUnitSampleType *audioDataRight; // complete right channel of audio data read file
} soundStruct, *soundStructPtr;
The Struct is then Initialized in the header like this;
soundStruct phraseSynthStructArray[3];
I then attempt to join two files that have been read into phraseSynthStructArray[phrase1Index] and phraseSynthStructArray[phrase2Index] and put the combined file into phraseSynthStructArray[synthPhraseIndex] like this;
- (BOOL) joinPhrases:(UInt32)phrase1Index phrase2Index:(UInt32)phrase2Index synthPhraseIndex:(UInt32)synthPhraseIndex{
// get the combined frame count
UInt64 totalFramesInFile = inArray[phrase1Index].frameCount + inArray[phrase2Index].frameCount;
//now resize the synthPhrase slot buffer to be the same size as both files combined
// phraseOut is used to hold the combined data prior to it being passed into the soundStructArray slot
free(phraseSynthStructArray[synthPhraseIndex].audioDataLeft);
phraseSynthStructArray[synthPhraseIndex].audioDataLeft = NULL;
phraseSynthStructArray[synthPhraseIndex].frameCount = 0;
phraseSynthStructArray[synthPhraseIndex].frameCount = totalFramesInFile;
phraseSynthStructArray[synthPhraseIndex].audioDataLeft = (AudioUnitSampleType *) calloc(totalFramesInFile, sizeof (AudioUnitSampleType));
for (UInt32 frameNumber = 0; frameNumber < inArray[phrase1Index].frameCount; ++frameNumber) {
phraseSynthStructArray[synthPhraseIndex].audioDataLeft[frameNumber] = phraseSynthStructArray[phrase1Index].audioDataLeft[frameNumber];
}
UInt32 sampleNumber=0;
for (UInt32 frameNumber = phraseSynthStructArray[phrase1Index].frameCount; frameNumber < totalFramesInFile; ++frameNumber) {
phraseSynthStructArray[synthPhraseIndex].audioDataLeft[frameNumber] = phraseSynthStructArray[phrase2Index].audioDataLeft[sampleNumber];
sampleNumber++;
}
return YES;
}
This all works fine and the resulting file is joined and can be used. The isuue I am having is when I allocate the memory here, phraseSynthStructArray[synthPhraseIndex].audioDataLeft = (AudioUnitSampleType *) calloc(totalFramesInFile, sizeof (AudioUnitSampleType)); then next time the method is called, this memory leaks each time and eventually crashes the app. The reason I need to allocate the memory here is because the memory has to be resized to accomodate the joined file which varies in length depending on the size of the input files.
I cannot free the memory after the operation as its needed elsewhere after the method has been called and I have tried to free it before (in joinPhrases method above), but this does not seem to work. I have also tried using realloc to free/reallocate the memory by passing the pointer to the previously allocated memory but this casues a crash stating EXEC_BAD_ACCESS.
I am not a seasoned C programmer and Cannot figure out what I am doing wrong here to cause the leak. I would appreciate some advice to help me track down this issue as I have been banging my head against this for days with no joy. I have read thats its a bad idea to have Pointers in Structs, could this be the root of my problem?
Thanks in advance,
K.
Maybe this helps:
- (BOOL) joinPhrases:(UInt32)phrase1Index phrase2Index:(UInt32)phrase2Index synthPhraseIndex:(UInt32)synthPhraseIndex{
// get the combined frame count
UInt64 totalFramesInFile = inArray[phrase1Index].frameCount + inArray[phrase2Index].frameCount;
. . .
void* old_ptr = phraseSynthStructArray[synthPhraseIndex].audioDataLeft;
phraseSynthStructArray[synthPhraseIndex].audioDataLeft = (AudioUnitSampleType *) calloc(totalFramesInFile, sizeof (AudioUnitSampleType));
if( old_ptr ) free(old_ptr);
. . .
return YES;
}
And make sure that there is no garbage in phraseSynthStructArray[synthPhraseIndex]
I have the following instance method (adapted from Listing 3-6 of the Event Handling section in the iPhone Application Programming Guide):
- (CGPoint)originOfTouch:(UITouch *)touch
{
CGPoint *touchOriginPoint = (CGPoint *)CFDictionaryGetValue(touchOriginPoints, touch);
if (touchOriginPoint == NULL)
{
touchOriginPoint = (CGPoint *)malloc(sizeof(CGPoint)); // leaks
CFDictionarySetValue(touchOriginPoints, touch, touchOriginPoint);
*touchOriginPoint = [touch locationInView:touch.view];
}
return *touchOriginPoint;
}
Every once in a while my app leaks 16 Bytes as a result of the call to malloc(). I'm not sure how to return touchOriginPoint while free()ing it as well.
If you do not care a minor performance loss, use an NSMutableDictionary and store the point as an NSValue:
NSValue* touchOriginPointValue = [touchOriginPoints objectForKey:touch];
if (touchOriginPointValue == nil) {
touchOriginPointValue = [NSValue valueWithCGPoint:[touch locationInView:touch.view]];
[touchOriginPoints setObject:touchOriginPointValue forKey:touch];
}
return [touchOriginPointValue CGPointValue];
If you must use the CFDictionary approach, you have to find a place to free those malloc-ed memory when the values are not needed. Therefore, you have to pass the values callbacks when creating the dictionary
static void free_malloced_memory (CFAllocatorRef allocator, const void *value) {
free((void*)value);
}
static const CFDictionaryValueCallBacks values_callbacks = {0, NULL, free_malloced_memory, NULL, NULL};
...
touchOriginPoints = CFDictionaryCreateMutable(NULL, 0, &kCFTypeDictionaryKeyCallBacks, & values_callbacks);
...
If you must return the malloc'd value from the function, then you have passed the responsibility for freeing the memory to the calling function, or one of its callers.
Since we can't see the calling functions, we can't diagnose any more.
If you are going to be returning an object that is allocated, then either you need to have the caller free() it, or else you need to be using some kind of garbage collection (so it gets freed automatically).
you don't actually return a pointer, the value is copied to a temp value when it is returned, so you aren't really returning the allocation at all, the problem is that you just aren't freeing it either, you add the allocation to the dictionary and just leave it there?
is there like an EndOfTouch function? where you remove the touch from the dictionary? if there is, call free on your allocation there and you should be fine