TSanResolveMethodDemo

@import Foundation;
@import ObjectiveC.runtime;

@interface Foo: NSObject

- (instancetype)initWithTag:(NSString*)tag;

@property(nonatomic, readonly, copy) NSString* tag;

+ (instancetype)foo_1;
+ (instancetype)foo_2;
+ (instancetype)foo_3;

@end

@implementation Foo

- (instancetype)initWithTag:(NSString*)tag {
    if ((self = [super init])) {
        _tag = [tag copy];
    }
    return self;
}

+ (BOOL)resolveClassMethod:(SEL)sel {
    Foo *methodRetVal = [[self alloc] initWithTag:NSStringFromSelector(sel)];
    Foo * (^block)(id blockSelf) = ^Foo *(id blockSelf) {
        return methodRetVal; // <- Read happens here, when heap block is invoked and reads captured variable
    };
    IMP imp = imp_implementationWithBlock(block); // <- Write happens here, when captured variable is copyied from stack block to heap block
    class_addMethod(object_getClass(self), sel, imp, "@@:");
    return YES;
}

@end


int main(int argc, char * argv[]) {
    @autoreleasepool {
        for (int i = 0; i < 100; ++i) {
            dispatch_async(dispatch_get_global_queue(QOS_CLASS_DEFAULT, 0), ^{
                NSLog(@"%@", [Foo foo_1].tag);
            });
        }
        return 0;
    }
}