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-rw-r--r--test/chan/select2.go54
1 files changed, 54 insertions, 0 deletions
diff --git a/test/chan/select2.go b/test/chan/select2.go
new file mode 100644
index 0000000..31e27d7
--- /dev/null
+++ b/test/chan/select2.go
@@ -0,0 +1,54 @@
+// run
+
+// Copyright 2010 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.
+
+// Test that selects do not consume undue memory.
+
+package main
+
+import "runtime"
+
+func sender(c chan int, n int) {
+ for i := 0; i < n; i++ {
+ c <- 1
+ }
+}
+
+func receiver(c, dummy chan int, n int) {
+ for i := 0; i < n; i++ {
+ select {
+ case <-c:
+ // nothing
+ case <-dummy:
+ panic("dummy")
+ }
+ }
+}
+
+func main() {
+ runtime.MemProfileRate = 0
+
+ c := make(chan int)
+ dummy := make(chan int)
+
+ // warm up
+ go sender(c, 100000)
+ receiver(c, dummy, 100000)
+ runtime.GC()
+ memstats := new(runtime.MemStats)
+ runtime.ReadMemStats(memstats)
+ alloc := memstats.Alloc
+
+ // second time shouldn't increase footprint by much
+ go sender(c, 100000)
+ receiver(c, dummy, 100000)
+ runtime.GC()
+ runtime.ReadMemStats(memstats)
+
+ // Be careful to avoid wraparound.
+ if memstats.Alloc > alloc && memstats.Alloc-alloc > 1.1e5 {
+ println("BUG: too much memory for 100,000 selects:", memstats.Alloc-alloc)
+ }
+}