01 retain_release_debug.m

#if 1
- (id)retain {
    NSUInteger oldRetainCount = [super retainCount];
    id result = [super retain];
    NSUInteger newRetainCount = [super retainCount];
    printf("%s<%p> ++retainCount: %lu => %lu\n", [[self className] UTF8String], self, oldRetainCount, newRetainCount);
    printf("%s\n", [[[NSThread callStackSymbols] description] UTF8String]);
    return result;
}

- (void)release {
    NSUInteger oldRetainCount = [super retainCount];
    BOOL gonnaDealloc = oldRetainCount == 1;
    if (gonnaDealloc) {
        printf("%s<%p> --retainCount: 1 => 0 (gonna dealloc)\n", [[self className] UTF8String], self);
        printf("%s\n", [[[NSThread callStackSymbols] description] UTF8String]);
    }
    [super release];
    if (!gonnaDealloc) {
        NSUInteger newRetainCount = [super retainCount];
        printf("%s<%p> --retainCount: %lu => %lu\n", [[self className] UTF8String], self, oldRetainCount, newRetainCount);
        printf("%s\n", [[[NSThread callStackSymbols] description] UTF8String]);
    }
}
#endif

02 retain_release_debug_10_5.m

#if 1
- (id)retain {
    NSUInteger oldRetainCount = [super retainCount];
    id result = [super retain];
    NSUInteger newRetainCount = [super retainCount];
    printf("%s<%p> ++retainCount: %d => %d\n %s", [[self className] UTF8String], self, oldRetainCount, newRetainCount, [[[NSThread currentThread] description] UTF8String]);
    printf("%s\n", [[[NSThread callStackSymbols] description] UTF8String]);
    return result;
}

- (void)release {
    NSUInteger oldRetainCount = [super retainCount];
    BOOL gonnaDealloc = oldRetainCount == 1;
    if (gonnaDealloc) {
        printf("%s<%p> --retainCount: 1 => 0 (gonna dealloc) %s\n", [[self className] UTF8String], self, [[[NSThread currentThread] description] UTF8String]);
        printf("%s\n", [[[NSThread callStackSymbols] description] UTF8String]);
    }
    [super release];
    if (!gonnaDealloc) {
        NSUInteger newRetainCount = [super retainCount];
        printf("%s<%p> --retainCount: %d => %d %s\n", [[self className] UTF8String], self, oldRetainCount, newRetainCount, [[[NSThread currentThread] description] UTF8String]);
        printf("%s\n", [[[NSThread callStackSymbols] description] UTF8String]);
    }
}
#endif

03 retain_autorelease_debug.m

#include <objc/runtime.h>
#if 1
static char sAutoreleaseCountKey;
- (id)retain {
    NSUInteger oldRetainCount = [super retainCount];
    id result = [super retain];
    NSUInteger newRetainCount = [super retainCount];
    NSUInteger autoreleaseCount = 0;
    
    NSData *autoreleaseCountObj = objc_getAssociatedObject(self, &sAutoreleaseCountKey);
    if (autoreleaseCountObj) {
        autoreleaseCount = *(NSUInteger*)[autoreleaseCountObj bytes];
    }
    NSUInteger effectiveRetainCount = newRetainCount - autoreleaseCount;
    
    printf("%s<%p> retain: retainCount:%lu => %lu (%lu)\n",
           [[self className] UTF8String],
           self,
           oldRetainCount,
           newRetainCount,
           effectiveRetainCount);
    printf("%s\n", [[[NSThread callStackSymbols] description] UTF8String]);
    return result;
}

- (id)autorelease {
    NSUInteger oldRetainCount = [super retainCount];
    id result = [super autorelease];
    NSUInteger newRetainCount = [super retainCount];
    
    NSMutableData *autoreleaseCountObj = objc_getAssociatedObject(self, &sAutoreleaseCountKey);
    if (!autoreleaseCountObj) {
        NSUInteger zero = 0;
        autoreleaseCountObj = [NSMutableData dataWithBytes:&zero length:sizeof(zero)];
        objc_setAssociatedObject(self,
                                 &sAutoreleaseCountKey,
                                 autoreleaseCountObj,
                                 OBJC_ASSOCIATION_RETAIN);
    }
    NSUInteger *autoreleaseCount = (NSUInteger*)[autoreleaseCountObj mutableBytes];
    (*autoreleaseCount)++;
    
    NSUInteger effectiveRetainCount = newRetainCount - *autoreleaseCount;
    printf("%s<%p> autorelease: retainCount:%lu => %lu (%lu)\n",
           [[self className] UTF8String],
           self,
           oldRetainCount,
           newRetainCount,
           effectiveRetainCount);
    printf("%s\n", [[[NSThread callStackSymbols] description] UTF8String]);
    
    return result;
}

- (void)release {
    NSArray *callStack = [NSThread callStackSymbols];
    
    BOOL isAutoreleasing = NO;
    for (NSString *stackSymbol in callStack) {
        if ([stackSymbol rangeOfString:@" _CFAutoreleasePoolPop "].location != NSNotFound) {
            isAutoreleasing = YES;
            break;
        }
    }
    const char *method = isAutoreleasing ? "release (auto)" : "release (manual)";
    
    NSUInteger oldRetainCount = [super retainCount];
    BOOL gonnaDealloc = oldRetainCount == 1;
    if (gonnaDealloc) {
        printf("%s<%p> %s: retainCount:1 => 0 (gonna dealloc)\n",
               [[self className] UTF8String],
               self,
               method);
        printf("%s\n", [[callStack description] UTF8String]);
    }
    
    [super release];
    
    if (!gonnaDealloc) {
        NSUInteger autoreleaseCount = 0;
        if (isAutoreleasing) {
            NSMutableData *autoreleaseCountObj = objc_getAssociatedObject(self, &sAutoreleaseCountKey);
            if (autoreleaseCountObj) {
                NSUInteger *autoreleaseCountPtr = (NSUInteger*)[autoreleaseCountObj mutableBytes];
                (*autoreleaseCountPtr)--;
                autoreleaseCount = *autoreleaseCountPtr;
            }
        }
        NSUInteger newRetainCount = [super retainCount];
        NSUInteger effectiveRetainCount = newRetainCount - autoreleaseCount;
        printf("%s<%p> %s: retainCount:%lu => %lu (%lu)\n",
               [[self className] UTF8String],
               self,
               method,
               oldRetainCount,
               newRetainCount,
               effectiveRetainCount);
        printf("%s\n", [[callStack description] UTF8String]);
    }
}
#endif