NSImage initwithData memory leak - objective-c

Question

When I wanna create a NSImage object, I encountered memory leak. I compiled the code by:
clang -o test test.m -framework Foundation -fsanitize=leak -framework CoreGraphics -framework AppKit, the clang I used is from this way: gist
// test.m
#include <Foundation/Foundation.h>
#include <Foundation/NSURL.h>
#include <dlfcn.h>
#include <stdint.h>
#include <sys/shm.h>
#include <dirent.h>
#import <Cocoa/Cocoa.h>
#import <ImageIO/ImageIO.h>
int main(int argc, const char * argv[]) {
if (argc < 2) {
printf("Usage: %s path/to/image\n", argv[0]);
return 0;
}
NSString* path = [NSString stringWithUTF8String:argv[1]];
NSData* content = [NSData dataWithContentsOfFile:path];
while(true) {
NSImage* img = [[NSImage alloc] initWithData:content];
[img release];
}
[content release];
[path release];
return 0;
}
Then I invoked it by ./test test.tiff, asan reported error that initWithData has memory leak.
If it runs in while loop, the memory consumption keeps increasing.
It works with the answer provided by #Asperi. But when I want to do more works related with NSImage, like this: this code will crash, because the CGImageRelease(cgImg); and [img release]; can not be enabled meanwhile. But if I disabled one of them, the code won't crash, but the memory consumption will keep increasing.
#include <Foundation/Foundation.h>
#include <Foundation/NSURL.h>
#include <dlfcn.h>
#include <stdint.h>
#include <sys/shm.h>
#include <dirent.h>
#import <Cocoa/Cocoa.h>
#import <ImageIO/ImageIO.h>
int main(int argc, const char * argv[]) {
if (argc < 2) {
printf("Usage: %s path/to/image\n", argv[0]);
return 0;
}
NSString* path = [NSString stringWithUTF8String:argv[1]];
NSData* content = [NSData dataWithContentsOfFile:path];
while(true) {
#autoreleasepool {
NSImage* img = [[NSImage alloc] initWithData:content];
NSLog(#"Image # %p: %#\n", img, img);
CGImageRef cgImg = [img CGImageForProposedRect:nil context:nil hints:nil];
if (cgImg) {
size_t width = CGImageGetWidth(cgImg);
size_t height = CGImageGetHeight(cgImg);
CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB();
CGContextRef ctx = CGBitmapContextCreate(0, width, height, 8, 0, colorspace, 1);
CGRect rect = CGRectMake(0, 0, width, height);
CGContextDrawImage(ctx, rect, cgImg);
CGColorSpaceRelease(colorspace);
CGContextRelease(ctx);
CGImageRelease(cgImg);
}
[img release];
}
}
[content release];
[path release];
return 0;
}

Answer 1

There might be autoreleased objected created inside SDK, so try to use (it is always good practice for such cycles with objective-c objects)
while(true) {
#autoreleasepool {
NSImage* img = [[NSImage alloc] initWithData:content];
[img release];
}
}