1 files changed, 0 insertions, 128 deletions
diff --git a/src/pkg/sync/rwmutex.go b/src/pkg/sync/rwmutex.go
deleted file mode 100644
index 3db541995..000000000
--- a/src/pkg/sync/rwmutex.go
+++ /dev/null
@@ -1,128 +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"
-	"unsafe"
-)
-
-// 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.
-type RWMutex struct {
-	w           Mutex  // held if there are pending writers
-	writerSem   uint32 // semaphore for writers to wait for completing readers
-	readerSem   uint32 // semaphore for readers to wait for completing writers
-	readerCount int32  // number of pending readers
-	readerWait  int32  // number of departing readers
-}
-
-const rwmutexMaxReaders = 1 << 30
-
-// RLock locks rw for reading.
-func (rw *RWMutex) RLock() {
-	if raceenabled {
-		_ = rw.w.state
-		raceDisable()
-	}
-	if atomic.AddInt32(&rw.readerCount, 1) < 0 {
-		// A writer is pending, wait for it.
-		runtime_Semacquire(&rw.readerSem)
-	}
-	if raceenabled {
-		raceEnable()
-		raceAcquire(unsafe.Pointer(&rw.readerSem))
-	}
-}
-
-// 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 raceenabled {
-		_ = rw.w.state
-		raceReleaseMerge(unsafe.Pointer(&rw.writerSem))
-		raceDisable()
-	}
-	if atomic.AddInt32(&rw.readerCount, -1) < 0 {
-		// A writer is pending.
-		if atomic.AddInt32(&rw.readerWait, -1) == 0 {
-			// The last reader unblocks the writer.
-			runtime_Semrelease(&rw.writerSem)
-		}
-	}
-	if raceenabled {
-		raceEnable()
-	}
-}
-
-// 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() {
-	if raceenabled {
-		_ = rw.w.state
-		raceDisable()
-	}
-	// First, resolve competition with other writers.
-	rw.w.Lock()
-	// Announce to readers there is a pending writer.
-	r := atomic.AddInt32(&rw.readerCount, -rwmutexMaxReaders) + rwmutexMaxReaders
-	// Wait for active readers.
-	if r != 0 && atomic.AddInt32(&rw.readerWait, r) != 0 {
-		runtime_Semacquire(&rw.writerSem)
-	}
-	if raceenabled {
-		raceEnable()
-		raceAcquire(unsafe.Pointer(&rw.readerSem))
-		raceAcquire(unsafe.Pointer(&rw.writerSem))
-	}
-}
-
-// 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() {
-	if raceenabled {
-		_ = rw.w.state
-		raceRelease(unsafe.Pointer(&rw.readerSem))
-		raceRelease(unsafe.Pointer(&rw.writerSem))
-		raceDisable()
-	}
-
-	// Announce to readers there is no active writer.
-	r := atomic.AddInt32(&rw.readerCount, rwmutexMaxReaders)
-	// Unblock blocked readers, if any.
-	for i := 0; i < int(r); i++ {
-		runtime_Semrelease(&rw.readerSem)
-	}
-	// Allow other writers to proceed.
-	rw.w.Unlock()
-	if raceenabled {
-		raceEnable()
-	}
-}
-
-// 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() }