This change fixes the semantics of Close to actually wait for
in-flight requests before closing the ReadWriteCloser. (Previously,
the Close method closed the ReadWriteCloser immediately, which I
suspect is what led to many of the failures observed in
golang/go#49387 and golang/go#46520.)
It achieves this by explicitly tracking the number of in-flight
requests, including requests with pending async responses, and
explicitly rejecting new Call requests (while keeping the read loop
open!) once Close has begun.
To make it easier for me to reason about the request lifetimes, I
reduced the number of long-lived goroutines from three to just one
(the Read loop), with an additional Handler goroutine that runs only
while the Handler queue is non-empty. Now, it is clearer (I hope!)
that the number of in-flight async requests strictly decreases
after Close has begun, even though the Read goroutine continues
to read requests (and, importantly, responses) and to forward
Notifications to the preempter.
For golang/go#49387
For golang/go#46520
Change-Id: Idf5960f848108a7ced78c5382099c8692e9b181e
Reviewed-on: https://go-review.googlesource.com/c/tools/+/388134
gopls-CI: kokoro <noreply+kokoro@google.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>
This eliminates a race between a successful Accept call and a
concurrent Close call, which previously could have shut down the
'run' goroutine before Accept sent to the newConns channel, causing
Accept to deadlock.
In fact, it eliminates the long-running 'run' goroutine entirely
(replacing it with a time.Timer), and in the process avoids leaking
O(N) closed connections when only the very first one is long-lived.
It also eliminates a potential double-Close bug: if the run method had
called l.wrapped.Close due to an idle timeout, a subsequent call to
Close would invoke l.wrapped.Close again. The io.Closer method
explicitly documents doubled Close calls as undefined behavior, and
many Closer implementations (especially test fakes) panic or deadlock
in that case.
It also eliminates a timer leak if the Listener rapidly oscillates
between active and idle: previously the implementation used
time.After, but it now uses an explicit time.Timer which can be
stopped (and garbage-collected) when the listener becomes active.
Idleness is now tracked based on the connection's Close method rather
than Read: we have no guarantee in general that a caller will ever
actually invoke Read (if, for example, they Close the connection as
soon as it is dialed), but we can reasonably expect a caller to at
least try to ensure that Close is always called.
We now also verify, using a finalizer on a best-effort basis, that the
Close method on each connection is called. We use the finalizer to
verify the Close call — rather than to close the connection implicitly
— because closing the connection in a finalizer would delay the start
of the idle timer by an arbitrary and unbounded duration after the
last connection is actually no longer in use.
Fixesgolang/go#46047.
Fixesgolang/go#51435.
For golang/go#46520.
For golang/go#49387.
Change-Id: If173a3ed7a44aff14734b72c8340122e8d020f26
Reviewed-on: https://go-review.googlesource.com/c/tools/+/388597
Run-TryBot: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>
Auto-Submit: Bryan Mills <bcmills@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
Update the new binder tests to run both with a standalone server, and
with a forwarding chain.
Make a few superficial improvements along the way as well.
Change-Id: Icd197698093a3f6149ab58171806b2388ed75b7f
Reviewed-on: https://go-review.googlesource.com/c/tools/+/321134
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>
There was already handling in isClosingErr for errors from Stdin/Stdout
and TCP connections. Add handling for io.Pipe closing errors.
Change-Id: I8d171ab49a3fffe0fca9f0482f6b92d61b1fae1f
Reviewed-on: https://go-review.googlesource.com/c/tools/+/320849
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>
