http: add missing async_hooks destroy before asyncReset

[basti1302]

Emit a destroy before calling asyncReset because otherwise the old
async_id never gets destroyed.

Refs: #19859

This fixes one of the two issues described in here: #19859 (comment), namely the missing destroy event when an http agent gets reused.

Reasoning: When calling asyncReset on the socket, we need to be aware that this will overwrite the socket's asyncId. The asyncId assigned to the socket before asyncReset is then lost, thus, a destroy event will never be emitted for this "old" asyncId. The added emitDestroy makes sure that a matching destroy event is emitted before we assign the new asyncId in asyncReset.

See also: #23263

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• commit message follows commit guidelines

[basti1302]

This also adds a test that fails without the change and passes when the fix is applied.

I'd like to bring up two questions for potential reviewers:

• Would it be preferable to issue the destroy event from C++ (that is, from within src/async_wrap.cc, void AsyncWrap::AsyncReset(double execution_async_id, bool silent))? The issue I see with that is that this method is also used for initializing new resources, where there is no "old" asyncId for which we need to emit a destroy.
• The test I added has a lot of code in common with test/parallel/test-async-hooks-http-agent.js - should I rather merge my assertion into that? I can certainly do that, I just kept em separate because I feel making bunch of assertions in one test case is a bit meh.

[AyushG3112]

cc @nodejs/http @nodejs/async_hooks

[addaleax]

Would it be preferable to issue the destroy event from C++ (that is, from within src/async_wrap.cc, void AsyncWrap::AsyncReset(double execution_async_id, bool silent))?

I think that might be a good idea, yes. This issue doesn’t seem to be specific to HTTP, but rather generally applies to AsyncWrap instances that are to be reset?

The test I added has a lot of code in common with test/parallel/test-async-hooks-http-agent.js - should I rather merge my assertion into that?

That’s your call… adding assertions to existing tests isn’t a bad thing in any way, though.

[addaleax]

If we do the destroy from JS, can we cache the result of getAsyncId()? Calls into C++ are, unfortunately, not the cheapest…

[basti1302]

This call no longer exists in #23272.

[basti1302]

@addaleax Thanks for providing feedback. You are right, calling the destroy from C++ is probably the better call. It also saves a few trips to C++. I merged this and #23263 together and moved the EmitDestroy into C++ for all cases.

Closing this in favor of #23272.

[basti1302]

For completeness sake:

That’s your call… adding assertions to existing tests isn’t a bad thing in any way, though.

Well opinions differ on that, there are a bunch of folks who insist that tests should always only assert one thing. If there are no strong opinions I would keep the tests separate.