1 files changed, 0 insertions, 86 deletions
diff --git a/src/pkg/sync/rwmutex.go b/src/pkg/sync/rwmutex.go
deleted file mode 100644
index 9248b4b03..000000000
--- a/src/pkg/sync/rwmutex.go
+++ /dev/null
@@ -1,86 +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
-
-import "sync/atomic"
-
-// An RWMutex is a reader/writer mutual exclusion lock.
-// The lock can be held by an arbitrary number of readers
-// or a single writer.
-// RWMutexes can be created as part of other
-// structures; the zero value for a RWMutex is
-// an unlocked mutex.
-//
-// Writers take priority over Readers: no new RLocks
-// are granted while a blocked Lock call is waiting.
-type RWMutex struct {
-	w           Mutex // held if there are pending readers or writers
-	r           Mutex // held if the w is being rd
-	readerCount int32 // number of pending readers
-}
-
-// RLock locks rw for reading.
-// If the lock is already locked for writing or there is a writer already waiting
-// to release the lock, RLock blocks until the writer has released the lock.
-func (rw *RWMutex) RLock() {
-	// Use rw.r.Lock() to block granting the RLock if a goroutine
-	// is waiting for its Lock. This is the prevent starvation of W in
-	// this situation:
-	//   A: rw.RLock()  // granted
-	//   W: rw.Lock()   // waiting for rw.w().Lock()
-	//   B: rw.RLock()  // granted
-	//   C: rw.RLock()  // granted
-	//   B: rw.RUnlock()
-	//   ... (new readers come and go indefinitely, W is starving)
-	rw.r.Lock()
-	if atomic.AddInt32(&rw.readerCount, 1) == 1 {
-		// The first reader locks rw.w, so writers will be blocked
-		// while the readers have the RLock.
-		rw.w.Lock()
-	}
-	rw.r.Unlock()
-}
-
-// RUnlock undoes a single RLock call;
-// it does not affect other simultaneous readers.
-// It is a run-time error if rw is not locked for reading
-// on entry to RUnlock.
-func (rw *RWMutex) RUnlock() {
-	if atomic.AddInt32(&rw.readerCount, -1) == 0 {
-		// last reader finished, enable writers
-		rw.w.Unlock()
-	}
-}
-
-// Lock locks rw for writing.
-// If the lock is already locked for reading or writing,
-// Lock blocks until the lock is available.
-// To ensure that the lock eventually becomes available,
-// a blocked Lock call excludes new readers from acquiring
-// the lock.
-func (rw *RWMutex) Lock() {
-	rw.r.Lock()
-	rw.w.Lock()
-	rw.r.Unlock()
-}
-
-// Unlock unlocks rw for writing.  It is a run-time error if rw is
-// not locked for writing on entry to Unlock.
-//
-// As with Mutexes, a locked RWMutex is not associated with a particular
-// goroutine.  One goroutine may RLock (Lock) an RWMutex and then
-// arrange for another goroutine to RUnlock (Unlock) it.
-func (rw *RWMutex) Unlock() { rw.w.Unlock() }
-
-// RLocker returns a Locker interface that implements
-// the Lock and Unlock methods by calling rw.RLock and rw.RUnlock.
-func (rw *RWMutex) RLocker() Locker {
-	return (*rlocker)(rw)
-}
-
-type rlocker RWMutex
-
-func (r *rlocker) Lock()   { (*RWMutex)(r).RLock() }
-func (r *rlocker) Unlock() { (*RWMutex)(r).RUnlock() }