1 files changed, 0 insertions, 94 deletions
diff --git a/pkg/flipcall/futex_linux.go b/pkg/flipcall/futex_linux.go
deleted file mode 100644
index 3f592ad16..000000000
--- a/pkg/flipcall/futex_linux.go
+++ /dev/null
@@ -1,94 +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.
-
-// +build linux
-
-package flipcall
-
-import (
-	"fmt"
-	"math"
-	"sync/atomic"
-	"syscall"
-
-	"gvisor.dev/gvisor/pkg/abi/linux"
-	"gvisor.dev/gvisor/pkg/log"
-)
-
-func (ep *Endpoint) doFutexRoundTrip() error {
-	ourSeq, err := ep.doFutexNotifySeq()
-	if err != nil {
-		return err
-	}
-	return ep.doFutexWaitSeq(ourSeq)
-}
-
-func (ep *Endpoint) doFutexWaitFirst() error {
-	return ep.doFutexWaitSeq(0)
-}
-
-func (ep *Endpoint) doFutexNotifyLast() error {
-	_, err := ep.doFutexNotifySeq()
-	return err
-}
-
-func (ep *Endpoint) doFutexNotifySeq() (uint32, error) {
-	ourSeq := atomic.AddUint32(ep.seq(), 1)
-	if err := ep.futexWake(1); err != nil {
-		return ourSeq, fmt.Errorf("failed to FUTEX_WAKE peer Endpoint: %v", err)
-	}
-	return ourSeq, nil
-}
-
-func (ep *Endpoint) doFutexWaitSeq(prevSeq uint32) error {
-	nextSeq := prevSeq + 1
-	for {
-		if ep.isShutdown() {
-			return endpointShutdownError{}
-		}
-		if err := ep.futexWait(prevSeq); err != nil {
-			return fmt.Errorf("failed to FUTEX_WAIT for peer Endpoint: %v", err)
-		}
-		seq := atomic.LoadUint32(ep.seq())
-		if seq == nextSeq {
-			return nil
-		}
-		if seq != prevSeq {
-			return fmt.Errorf("invalid packet sequence number %d (expected %d or %d)", seq, prevSeq, nextSeq)
-		}
-	}
-}
-
-func (ep *Endpoint) doFutexInterruptForShutdown() {
-	// Wake MaxInt32 threads to prevent a malicious or broken peer from
-	// swallowing our wakeup by FUTEX_WAITing from multiple threads.
-	if err := ep.futexWake(math.MaxInt32); err != nil {
-		log.Warningf("failed to FUTEX_WAKE Endpoint: %v", err)
-	}
-}
-
-func (ep *Endpoint) futexWake(numThreads int32) error {
-	if _, _, e := syscall.RawSyscall(syscall.SYS_FUTEX, uintptr(ep.packet), linux.FUTEX_WAKE, uintptr(numThreads)); e != 0 {
-		return e
-	}
-	return nil
-}
-
-func (ep *Endpoint) futexWait(seq uint32) error {
-	_, _, e := syscall.Syscall6(syscall.SYS_FUTEX, uintptr(ep.packet), linux.FUTEX_WAIT, uintptr(seq), 0, 0, 0)
-	if e != 0 && e != syscall.EAGAIN && e != syscall.EINTR {
-		return e
-	}
-	return nil
-}