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-rw-r--r--test/fixedbugs/issue9110.go91
1 files changed, 91 insertions, 0 deletions
diff --git a/test/fixedbugs/issue9110.go b/test/fixedbugs/issue9110.go
new file mode 100644
index 0000000..086be77
--- /dev/null
+++ b/test/fixedbugs/issue9110.go
@@ -0,0 +1,91 @@
+// run
+
+// Copyright 2014 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.
+
+// Scenario that used to leak arbitrarily many SudoG structs.
+// See golang.org/issue/9110.
+
+package main
+
+import (
+ "runtime"
+ "runtime/debug"
+ "sync"
+ "time"
+)
+
+func main() {
+ runtime.GOMAXPROCS(1)
+ debug.SetGCPercent(1000000) // only GC when we ask for GC
+
+ var stats, stats1, stats2 runtime.MemStats
+
+ release := func() {}
+ for i := 0; i < 20; i++ {
+ if i == 10 {
+ // Should be warmed up by now.
+ runtime.ReadMemStats(&stats1)
+ }
+
+ c := make(chan int)
+ for i := 0; i < 10; i++ {
+ go func() {
+ select {
+ case <-c:
+ case <-c:
+ case <-c:
+ }
+ }()
+ }
+ time.Sleep(1 * time.Millisecond)
+ release()
+
+ close(c) // let select put its sudog's into the cache
+ time.Sleep(1 * time.Millisecond)
+
+ // pick up top sudog
+ var cond1 sync.Cond
+ var mu1 sync.Mutex
+ cond1.L = &mu1
+ go func() {
+ mu1.Lock()
+ cond1.Wait()
+ mu1.Unlock()
+ }()
+ time.Sleep(1 * time.Millisecond)
+
+ // pick up next sudog
+ var cond2 sync.Cond
+ var mu2 sync.Mutex
+ cond2.L = &mu2
+ go func() {
+ mu2.Lock()
+ cond2.Wait()
+ mu2.Unlock()
+ }()
+ time.Sleep(1 * time.Millisecond)
+
+ // put top sudog back
+ cond1.Broadcast()
+ time.Sleep(1 * time.Millisecond)
+
+ // drop cache on floor
+ runtime.GC()
+
+ // release cond2 after select has gotten to run
+ release = func() {
+ cond2.Broadcast()
+ time.Sleep(1 * time.Millisecond)
+ }
+ }
+
+ runtime.GC()
+
+ runtime.ReadMemStats(&stats2)
+
+ if int(stats2.HeapObjects)-int(stats1.HeapObjects) > 20 { // normally at most 1 or 2; was 300 with leak
+ print("BUG: object leak: ", stats.HeapObjects, " -> ", stats1.HeapObjects, " -> ", stats2.HeapObjects, "\n")
+ }
+}