Image Memory Leak

[drwheeler]

This simple little loop chews through all the memory on my Debian box. I'm nulling the Image instance every time through.
Running with node --trace_gc tst6.js shows that garbage collection is happening but this script will use 2GB of memory in short order then get killed. In real life the interval would be 10s

...

setInterval(timestampImage, 100);

function timestampImage() {
var cameraImage = new Image;

cameraImage.onload = onLoad;
cameraImage.onerror = function(err) {
                          console.log(err);
                      };

cameraImage.src = blackJpeg;

cameraImage = null;

}

function onLoad() {

...

Put the image in a canvas, add a text timestamp, save

...

}

https://gist.github.com/1720778#file_timestamp.js

[tj]

thanks for the report i'll take a peek tomorrow

[enobrev]

Having similar results, with the past couple versions, at least. Hadn't found the time to pull it out of my code to explicitly test it (nicely done, @drwheeler).

[tj]

it's probably something pretty obvious, just need a minute to check it out, should have time today

[enobrev]

My C is incredibly subpar, so I'm not sure how to implement this correctly, but it seems to me that the data pointer is never freed when an image is successfully loaded. I assume that should happen in the destructor, but that's where my capability seems to fail miserably.

To test, in Image.cc, in the Image::loadJPEGFromBuffer method, I moved free(data); above the final if (status) condition and ran @drwheeler's test. The memory usage was stable.

Unfortunately, doing it there means there is no output, likely because according to the docs:

"The output buffer must be kept around until the cairo_surface_t is destroyed or cairo_surface_finish() is called on the surface."

I could go on about my silly attempts to initialize *data in the constructor and free it in the destructor, but I assume you get the idea. One of these days pointers may actually make some sense to me. Obviously not today.

I also did a free(data) move as enobrev mentioned. In Image::loadJPEGFromBuffer in canvas/src/Image.cc

free(data);
if (status) {
    return status;
}

Followed by a node-waf configure build, that change seemed to resolve the leak for my specific usage of this library.

I saw the memory leak in XCode Instruments while looking at Malloc 's while attached to the node.js process (which is what lead me to the that loadJPEGFromBuffer).

I can't see what broke. I assume I'm doing something else wrong. It seemed to work for my simple case of doing a resize from buffer passed from redis before sending on to the browser through express. Not isolated at all, but code is here >> https://github.com/proksoup/thlip.com/blob/ffcb87ab723b2a98a74c2a9182075f6c2fc584b9/app.coffee#L265-L278

[swogger]

The issue is still there:
Calling this method several times completely fills the memory. (canvas version 1.1.6)

function loadImage(url, finish){
request.get({url:url, encoding:null}, imageLoaded);
function imageLoaded(err,res,body) {
if(err) return finish(err);
var image = new Image();
image.onerror = function(e) {
finish(e);
};
image.onload = function(){
finish(image);
};
image.src = new Buffer(body, 'binary');
};
}