1 files changed, 0 insertions, 86 deletions
diff --git a/src/pkg/sync/waitgroup.go b/src/pkg/sync/waitgroup.go
deleted file mode 100644
index 05478c630..000000000
--- a/src/pkg/sync/waitgroup.go
+++ /dev/null
@@ -1,86 +0,0 @@
-// Copyright 2011 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 "runtime"
-
-// A WaitGroup waits for a collection of goroutines to finish.
-// The main goroutine calls Add to set the number of
-// goroutines to wait for.  Then each of the goroutines
-// runs and calls Done when finished.  At the same time,
-// Wait can be used to block until all goroutines have finished.
-//
-// For example:
-//
-//   for i := 0; i < n; i++ {
-//       if !condition(i) {
-//           continue
-//       }
-//       wg.Add(1)
-//       go func() {
-//           // Do something.
-//           wg.Done()
-//       }()
-//   }
-//   wg.Wait()
-// 
-type WaitGroup struct {
-	m       Mutex
-	counter int
-	waiters int
-	sema    *uint32
-}
-
-// WaitGroup creates a new semaphore each time the old semaphore
-// is released. This is to avoid the following race:
-//
-// G1: Add(1)
-// G1: go G2()
-// G1: Wait() // Context switch after Unlock() and before Semacquire().
-// G2: Done() // Release semaphore: sema == 1, waiters == 0. G1 doesn't run yet.
-// G3: Wait() // Finds counter == 0, waiters == 0, doesn't block.
-// G3: Add(1) // Makes counter == 1, waiters == 0.
-// G3: go G4()
-// G3: Wait() // G1 still hasn't run, G3 finds sema == 1, unblocked! Bug.
-
-// Add adds delta, which may be negative, to the WaitGroup counter.
-// If the counter becomes zero, all goroutines blocked on Wait() are released.
-func (wg *WaitGroup) Add(delta int) {
-	wg.m.Lock()
-	if delta < -wg.counter {
-		wg.m.Unlock()
-		panic("sync: negative WaitGroup count")
-	}
-	wg.counter += delta
-	if wg.counter == 0 && wg.waiters > 0 {
-		for i := 0; i < wg.waiters; i++ {
-			runtime.Semrelease(wg.sema)
-		}
-		wg.waiters = 0
-		wg.sema = nil
-	}
-	wg.m.Unlock()
-}
-
-// Done decrements the WaitGroup counter.
-func (wg *WaitGroup) Done() {
-	wg.Add(-1)
-}
-
-// Wait blocks until the WaitGroup counter is zero.
-func (wg *WaitGroup) Wait() {
-	wg.m.Lock()
-	if wg.counter == 0 {
-		wg.m.Unlock()
-		return
-	}
-	wg.waiters++
-	if wg.sema == nil {
-		wg.sema = new(uint32)
-	}
-	s := wg.sema
-	wg.m.Unlock()
-	runtime.Semacquire(s)
-}