1 files changed, 0 insertions, 109 deletions
diff --git a/src/pkg/sync/mutex.go b/src/pkg/sync/mutex.go
deleted file mode 100644
index 73b337702..000000000
--- a/src/pkg/sync/mutex.go
+++ /dev/null
@@ -1,109 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Package sync provides basic synchronization primitives such as mutual
-// exclusion locks.  Other than the Once and WaitGroup types, most are intended
-// for use by low-level library routines.  Higher-level synchronization is
-// better done via channels and communication.
-//
-// Values containing the types defined in this package should not be copied.
-package sync
-
-import (
-	"sync/atomic"
-	"unsafe"
-)
-
-// A Mutex is a mutual exclusion lock.
-// Mutexes can be created as part of other structures;
-// the zero value for a Mutex is an unlocked mutex.
-type Mutex struct {
-	state int32
-	sema  uint32
-}
-
-// A Locker represents an object that can be locked and unlocked.
-type Locker interface {
-	Lock()
-	Unlock()
-}
-
-const (
-	mutexLocked = 1 << iota // mutex is locked
-	mutexWoken
-	mutexWaiterShift = iota
-)
-
-// Lock locks m.
-// If the lock is already in use, the calling goroutine
-// blocks until the mutex is available.
-func (m *Mutex) Lock() {
-	// Fast path: grab unlocked mutex.
-	if atomic.CompareAndSwapInt32(&m.state, 0, mutexLocked) {
-		if raceenabled {
-			raceAcquire(unsafe.Pointer(m))
-		}
-		return
-	}
-
-	awoke := false
-	for {
-		old := m.state
-		new := old | mutexLocked
-		if old&mutexLocked != 0 {
-			new = old + 1<<mutexWaiterShift
-		}
-		if awoke {
-			// The goroutine has been woken from sleep,
-			// so we need to reset the flag in either case.
-			new &^= mutexWoken
-		}
-		if atomic.CompareAndSwapInt32(&m.state, old, new) {
-			if old&mutexLocked == 0 {
-				break
-			}
-			runtime_Semacquire(&m.sema)
-			awoke = true
-		}
-	}
-
-	if raceenabled {
-		raceAcquire(unsafe.Pointer(m))
-	}
-}
-
-// Unlock unlocks m.
-// It is a run-time error if m is not locked on entry to Unlock.
-//
-// A locked Mutex is not associated with a particular goroutine.
-// It is allowed for one goroutine to lock a Mutex and then
-// arrange for another goroutine to unlock it.
-func (m *Mutex) Unlock() {
-	if raceenabled {
-		_ = m.state
-		raceRelease(unsafe.Pointer(m))
-	}
-
-	// Fast path: drop lock bit.
-	new := atomic.AddInt32(&m.state, -mutexLocked)
-	if (new+mutexLocked)&mutexLocked == 0 {
-		panic("sync: unlock of unlocked mutex")
-	}
-
-	old := new
-	for {
-		// If there are no waiters or a goroutine has already
-		// been woken or grabbed the lock, no need to wake anyone.
-		if old>>mutexWaiterShift == 0 || old&(mutexLocked|mutexWoken) != 0 {
-			return
-		}
-		// Grab the right to wake someone.
-		new = (old - 1<<mutexWaiterShift) | mutexWoken
-		if atomic.CompareAndSwapInt32(&m.state, old, new) {
-			runtime_Semrelease(&m.sema)
-			return
-		}
-		old = m.state
-	}
-}