I asked a similar question last year, and got no responses. I've written a much simpler (no network extension!) case that seems to demonstrate what I'm confused about.
Simple app with an XPC service. I have an ObjectiveC class TestObject which has an NSString* and an NSData* (which I never actually use). I have a protocol defined in Swift:
@objc protocol XPCTestServiceProtocol {
func logData(entry: TestObject) -> Void
func logData(entry: TestObject, completion: ((String) -> Void))
}
In the Switt XPC service, the code is:
class XPCTestService: NSObject, XPCTestServiceProtocol {
var totalBytes = 0
var lastName = ""
@objc func logData(entry: TestObject) {
totalBytes += (entry.data?.count ?? 0)
}
@objc func logData(entry: TestObject, completion: ((String) -> Void)) {
totalBytes += (entry.data?.count ?? 0)
completion("Finished")
}
I've got this code in the ObjC app:
id<XPCTestServiceProtocol> proxy = [self.connection remoteObjectProxyWithErrorHandler:^(NSError* error) {
self.stopRun = YES;
NSLog(@"Proxy got error %@", error);
}];
while (self.stopRun == NO) {
@synchronized (self) {
NSNumber *objNum = [NSNumber numberWithUnsignedLongLong:self.count++];
NSString *objName = [NSString stringWithFormat:@"Object %@", objNum];
TestObject __weak *toWeak = to;
#if USE_COMPLETION
[proxy logDataWithEntry:to completion:^(NSString *str) {
to = nil;
}];
#else
[proxy logDataWithEntry:to];
#endif
}
}
attached to a start button (and self.stopRun is set by a stop button, this is all super simple).
So I run that, start the test, and things start going (122k calls/second it says). According to Activity Monitor, my app is using about 1gbyte after 20 seconds or so.
However, if I run it under Instruments' Leaks template... Activity Monitor says it's used only about 60mbytes. (And at the end of the run, Instruments says it's used about 30mbytes.)
Now... if I use the completion and a synchronous proxy, then even without Instruments, Activity Monitor says it's 60mbytes or so.
Is the memory reported by Activity Monitor real? Or not real?
