1 files changed, 0 insertions, 197 deletions
diff --git a/pkg/syncevent/waiter_unsafe.go b/pkg/syncevent/waiter_unsafe.go
deleted file mode 100644
index b6ed2852d..000000000
--- a/pkg/syncevent/waiter_unsafe.go
+++ /dev/null
@@ -1,197 +0,0 @@
-// Copyright 2020 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 syncevent
-
-import (
-	"sync/atomic"
-	"unsafe"
-
-	"gvisor.dev/gvisor/pkg/sync"
-)
-
-// Waiter allows a goroutine to block on pending events received by a Receiver.
-//
-// Waiter.Init() must be called before first use.
-type Waiter struct {
-	r Receiver
-
-	// g is one of:
-	//
-	// - 0: No goroutine is blocking in Wait.
-	//
-	// - preparingG: A goroutine is in Wait preparing to sleep, but hasn't yet
-	// completed waiterUnlock(). Thus the wait can only be interrupted by
-	// replacing the value of g with 0 (the G may not be in state Gwaiting yet,
-	// so we can't call goready.)
-	//
-	// - Otherwise: g is a pointer to the runtime.g in state Gwaiting for the
-	// goroutine blocked in Wait, which can only be woken by calling goready.
-	g uintptr `state:"zerovalue"`
-}
-
-const preparingG = 1
-
-// Init must be called before first use of w.
-func (w *Waiter) Init() {
-	w.r.Init(w)
-}
-
-// Receiver returns the Receiver that receives events that unblock calls to
-// w.Wait().
-func (w *Waiter) Receiver() *Receiver {
-	return &w.r
-}
-
-// Pending returns the set of pending events.
-func (w *Waiter) Pending() Set {
-	return w.r.Pending()
-}
-
-// Wait blocks until at least one event is pending, then returns the set of
-// pending events. It does not affect the set of pending events; callers must
-// call w.Ack() to do so, or use w.WaitAndAck() instead.
-//
-// Precondition: Only one goroutine may call any Wait* method at a time.
-func (w *Waiter) Wait() Set {
-	return w.WaitFor(AllEvents)
-}
-
-// WaitFor blocks until at least one event in es is pending, then returns the
-// set of pending events (including those not in es). It does not affect the
-// set of pending events; callers must call w.Ack() to do so.
-//
-// Precondition: Only one goroutine may call any Wait* method at a time.
-func (w *Waiter) WaitFor(es Set) Set {
-	for {
-		// Optimization: Skip the atomic store to w.g if an event is already
-		// pending.
-		if p := w.r.Pending(); p&es != NoEvents {
-			return p
-		}
-
-		// Indicate that we're preparing to go to sleep.
-		atomic.StoreUintptr(&w.g, preparingG)
-
-		// If an event is pending, abort the sleep.
-		if p := w.r.Pending(); p&es != NoEvents {
-			atomic.StoreUintptr(&w.g, 0)
-			return p
-		}
-
-		// If w.g is still preparingG (i.e. w.NotifyPending() has not been
-		// called or has not reached atomic.SwapUintptr()), go to sleep until
-		// w.NotifyPending() => goready().
-		sync.Gopark(waiterCommit, unsafe.Pointer(&w.g), sync.WaitReasonSelect, sync.TraceEvGoBlockSelect, 0)
-	}
-}
-
-//go:norace
-//go:nosplit
-func waiterCommit(g uintptr, wg unsafe.Pointer) bool {
-	// The only way this CAS can fail is if a call to Waiter.NotifyPending()
-	// has replaced *wg with nil, in which case we should not sleep.
-	return sync.RaceUncheckedAtomicCompareAndSwapUintptr((*uintptr)(wg), preparingG, g)
-}
-
-// Ack marks the given events as not pending.
-func (w *Waiter) Ack(es Set) {
-	w.r.Ack(es)
-}
-
-// WaitAndAckAll blocks until at least one event is pending, then marks all
-// events as not pending and returns the set of previously-pending events.
-//
-// Precondition: Only one goroutine may call any Wait* method at a time.
-func (w *Waiter) WaitAndAckAll() Set {
-	// Optimization: Skip the atomic store to w.g if an event is already
-	// pending. Call Pending() first since, in the common case that events are
-	// not yet pending, this skips an atomic swap on w.r.pending.
-	if w.r.Pending() != NoEvents {
-		if p := w.r.PendingAndAckAll(); p != NoEvents {
-			return p
-		}
-	}
-
-	for {
-		// Indicate that we're preparing to go to sleep.
-		atomic.StoreUintptr(&w.g, preparingG)
-
-		// If an event is pending, abort the sleep.
-		if w.r.Pending() != NoEvents {
-			if p := w.r.PendingAndAckAll(); p != NoEvents {
-				atomic.StoreUintptr(&w.g, 0)
-				return p
-			}
-		}
-
-		// If w.g is still preparingG (i.e. w.NotifyPending() has not been
-		// called or has not reached atomic.SwapUintptr()), go to sleep until
-		// w.NotifyPending() => goready().
-		sync.Gopark(waiterCommit, unsafe.Pointer(&w.g), sync.WaitReasonSelect, sync.TraceEvGoBlockSelect, 0)
-
-		// Check for pending events. We call PendingAndAckAll() directly now since
-		// we only expect to be woken after events become pending.
-		if p := w.r.PendingAndAckAll(); p != NoEvents {
-			return p
-		}
-	}
-}
-
-// Notify marks the given events as pending, possibly unblocking concurrent
-// calls to w.Wait() or w.WaitFor().
-func (w *Waiter) Notify(es Set) {
-	w.r.Notify(es)
-}
-
-// NotifyPending implements ReceiverCallback.NotifyPending. Users of Waiter
-// should not call NotifyPending.
-func (w *Waiter) NotifyPending() {
-	// Optimization: Skip the atomic swap on w.g if there is no sleeping
-	// goroutine. NotifyPending is called after w.r.Pending() is updated, so
-	// concurrent and future calls to w.Wait() will observe pending events and
-	// abort sleeping.
-	if atomic.LoadUintptr(&w.g) == 0 {
-		return
-	}
-	// Wake a sleeping G, or prevent a G that is preparing to sleep from doing
-	// so. Swap is needed here to ensure that only one call to NotifyPending
-	// calls goready.
-	if g := atomic.SwapUintptr(&w.g, 0); g > preparingG {
-		sync.Goready(g, 0)
-	}
-}
-
-var waiterPool = sync.Pool{
-	New: func() interface{} {
-		w := &Waiter{}
-		w.Init()
-		return w
-	},
-}
-
-// GetWaiter returns an unused Waiter. PutWaiter should be called to release
-// the Waiter once it is no longer needed.
-//
-// Where possible, users should prefer to associate each goroutine that calls
-// Waiter.Wait() with a distinct pre-allocated Waiter to avoid allocation of
-// Waiters in hot paths.
-func GetWaiter() *Waiter {
-	return waiterPool.Get().(*Waiter)
-}
-
-// PutWaiter releases an unused Waiter previously returned by GetWaiter.
-func PutWaiter(w *Waiter) {
-	waiterPool.Put(w)
-}