Version
4.5.11
Context
While upgrading my application to 4.5.11 from 4.4.x, I saw a significant performance regression (almost 3x slower) when removing my usage of the vertx virtual threads incubator and replacing with ThreadingModel.VIRTUAL_THREADS. The root cause was that in my fork of the threads incubator, awaiting a Future will check if the future is complete and return immediately or throw. Upstream, the virtual thread always parks. This is inefficient.
Do you have a reproducer?
This implementation of await exhibits the issue (this is just upstream await):
public static <T> T await(Future<T> fut) {
return io.vertx.core.Future.await(fut);
}This does not:
public static <T> T await(Future<T> fut) {
if (fut == null) {
throw new IllegalArgumentException("Future cannot be null");
}
if (fut.isComplete()) {
if (fut.succeeded()) {
return fut.result();
} else if (fut.cause() != null) {
throwAsUnchecked(fut.cause());
} else {
throw new RuntimeException();
}
}
var ctx = Vertx.currentContext();
if (ctx == null) {
try {
return fut.toCompletionStage().toCompletableFuture().get();
} catch (InterruptedException | ExecutionException e) {
throw new RuntimeException(e);
}
}
return io.vertx.core.Future.await(fut);
}Steps to reproduce
The tests in vert-x3/vertx-virtual-threads-incubator#8 previously investigated and reported the issue.
Version
4.5.11
Context
While upgrading my application to 4.5.11 from 4.4.x, I saw a significant performance regression (almost 3x slower) when removing my usage of the vertx virtual threads incubator and replacing with
ThreadingModel.VIRTUAL_THREADS. The root cause was that in my fork of the threads incubator,awaiting aFuturewill check if the future is complete and return immediately or throw. Upstream, the virtual thread always parks. This is inefficient.Do you have a reproducer?
This implementation of await exhibits the issue (this is just upstream await):
This does not:
Steps to reproduce
The tests in vert-x3/vertx-virtual-threads-incubator#8 previously investigated and reported the issue.