1 files changed, 0 insertions, 111 deletions
diff --git a/pkg/flipcall/futex_linux.go b/pkg/flipcall/futex_linux.go
deleted file mode 100644
index e7dd812b3..000000000
--- a/pkg/flipcall/futex_linux.go
+++ /dev/null
@@ -1,111 +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 (
-	"encoding/json"
-	"fmt"
-	"runtime"
-	"sync/atomic"
-	"syscall"
-
-	"gvisor.dev/gvisor/pkg/abi/linux"
-)
-
-func (ep *Endpoint) futexConnect(req *ctrlHandshakeRequest) (ctrlHandshakeResponse, error) {
-	var resp ctrlHandshakeResponse
-
-	// Write the handshake request.
-	w := ep.NewWriter()
-	if err := json.NewEncoder(w).Encode(req); err != nil {
-		return resp, fmt.Errorf("error writing handshake request: %v", err)
-	}
-	*ep.dataLen() = w.Len()
-
-	// Exchange control with the server.
-	if err := ep.futexSwitchToPeer(); err != nil {
-		return resp, err
-	}
-	if err := ep.futexSwitchFromPeer(); err != nil {
-		return resp, err
-	}
-
-	// Read the handshake response.
-	respLen := atomic.LoadUint32(ep.dataLen())
-	if respLen > ep.dataCap {
-		return resp, fmt.Errorf("invalid handshake response length %d (maximum %d)", respLen, ep.dataCap)
-	}
-	if err := json.NewDecoder(ep.NewReader(respLen)).Decode(&resp); err != nil {
-		return resp, fmt.Errorf("error reading handshake response: %v", err)
-	}
-
-	return resp, nil
-}
-
-func (ep *Endpoint) futexSwitchToPeer() error {
-	// Update connection state to indicate that the peer should be active.
-	if !atomic.CompareAndSwapUint32(ep.connState(), ep.activeState, ep.inactiveState) {
-		return fmt.Errorf("unexpected connection state before FUTEX_WAKE: %v", atomic.LoadUint32(ep.connState()))
-	}
-
-	// Wake the peer's Endpoint.futexSwitchFromPeer().
-	if err := ep.futexWakeConnState(1); err != nil {
-		return fmt.Errorf("failed to FUTEX_WAKE peer Endpoint: %v", err)
-	}
-	return nil
-}
-
-func (ep *Endpoint) futexSwitchFromPeer() error {
-	for {
-		switch cs := atomic.LoadUint32(ep.connState()); cs {
-		case ep.activeState:
-			return nil
-		case ep.inactiveState:
-			// Continue to FUTEX_WAIT.
-		default:
-			return fmt.Errorf("unexpected connection state before FUTEX_WAIT: %v", cs)
-		}
-		if ep.isShutdownLocally() {
-			return shutdownError{}
-		}
-		if err := ep.futexWaitConnState(ep.inactiveState); err != nil {
-			return fmt.Errorf("failed to FUTEX_WAIT for peer Endpoint: %v", err)
-		}
-	}
-}
-
-func (ep *Endpoint) futexWakeConnState(numThreads int32) error {
-	if _, _, e := syscall.RawSyscall(syscall.SYS_FUTEX, ep.packet, linux.FUTEX_WAKE, uintptr(numThreads)); e != 0 {
-		return e
-	}
-	return nil
-}
-
-func (ep *Endpoint) futexWaitConnState(curState uint32) error {
-	_, _, e := syscall.Syscall6(syscall.SYS_FUTEX, ep.packet, linux.FUTEX_WAIT, uintptr(curState), 0, 0, 0)
-	if e != 0 && e != syscall.EAGAIN && e != syscall.EINTR {
-		return e
-	}
-	return nil
-}
-
-func yieldThread() {
-	syscall.Syscall(syscall.SYS_SCHED_YIELD, 0, 0, 0)
-	// The thread we're trying to yield to may be waiting for a Go runtime P.
-	// runtime.Gosched() will hand off ours if necessary.
-	runtime.Gosched()
-}