On Wed, 12 Oct 2022 10:54:50 GMT, Daniel Fuchs <[email protected]> wrote:
>> When [JDK-8277969](https://bugs.openjdk.org/browse/JDK-8277969) was >> implemented, a list of outstanding response subscribers was added to >> `HttpClientImpl`. A body subscriber is added to the list after being created >> and is removed from the list when it is completed, either successfully or >> exceptionally. >> >> It appears that in the case where the subscription is cancelled before the >> subscriber is completed, the subscriber might remain registered in the list >> forever, or at least until the HttpClient gets garbage collected. This can >> be easily reproduced using streaming subscribers, such as >> BodySubscriber::ofInputStream. In the case where the input stream is closed >> without having read all the bytes, Subscription::cancel will be called. >> Whether the subscriber gets unregistered or not at that point becomes racy. >> >> Indeed, the reactive stream specification doesn't guarantee whether >> onComplete or onError will be called or not after a subscriber cancels its >> subscription. Any cleanup that would have been performed by >> onComplete/onError might therefore need to be performed when the >> subscription is cancelled too. > > That's exactly what this change is going to fix. What happens in the code > you're showing here is that if the status code is not 200, then the input > stream is closed without having read any bytes. This will cause the > underlying subscriber to cancel its subscription, possibly before any > response bytes have been received. And that is where the leak comes from, as > there's no guarantee that the subscriber's onComplete/onError will ever be > called in that case. With this fix, the subscriber will be taken off the list > when the subscription is cancelled, and that should fix the leak. @dfuch see if (httpResponse.headers().firstValueAsLong("Content-Length").orElse(-1) > minRedAlertEventContentLength) there are cases that the response code is 200 but for my reasons I don't want to read the body (for example body that contains only BOM bytes). I guess that fixes it too 😃 thanks!! ------------- PR: https://git.openjdk.org/jdk/pull/10659
