Flipcall refinements.

Note that some of these changes affect the protocol in
backward-incompatible ways.

- Replace use of "initially-active" and "initially-inactive" with
"client" and "server" respectively for clarity.

- Fix a race condition involving Endpoint.Shutdown() by repeatedly
invoking FUTEX_WAKE until it is confirmed that no local thread is
blocked in FUTEX_WAIT.

- Drop flipcall.ControlMode.

PiperOrigin-RevId: 260981382

1 files changed, 0 insertions, 45 deletions

diff --git a/pkg/flipcall/endpoint_futex.go b/pkg/flipcall/endpoint_futex.go
deleted file mode 100644
index 5cab02b1d..000000000
--- a/pkg/flipcall/endpoint_futex.go
+++ /dev/null
@@ -1,45 +0,0 @@
-// Copyright 2019 The gVisor Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package flipcall
-
-import (
-	"fmt"
-)
-
-type endpointControlState struct{}
-
-func (ep *Endpoint) initControlState(ctrlMode ControlMode) error {
-	if ctrlMode != ControlModeFutex {
-		return fmt.Errorf("unsupported control mode: %v", ctrlMode)
-	}
-	return nil
-}
-
-func (ep *Endpoint) doRoundTrip() error {
-	return ep.doFutexRoundTrip()
-}
-
-func (ep *Endpoint) doWaitFirst() error {
-	return ep.doFutexWaitFirst()
-}
-
-func (ep *Endpoint) doNotifyLast() error {
-	return ep.doFutexNotifyLast()
-}
-
-// Preconditions: ep.isShutdown() == true.
-func (ep *Endpoint) interruptForShutdown() {
-	ep.doFutexInterruptForShutdown()
-}