-// $G $D/$F.go && $L $F.$A && ./$A.out
+// run
-// Copyright 2011 The Go Authors. All rights reserved.
+// 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.
go send(c)
<-c
- const chunk = 1 << 20
- memstats := new(runtime.MemStats)
- runtime.ReadMemStats(memstats)
- sys := memstats.Sys
- b := make([]byte, chunk)
+ const N = 1000
+ const MB = 1 << 20
+ b := make([]byte, MB)
for i := range b {
b[i] = byte(i%10 + '0')
}
s := string(b)
- for i := 0; i < 1000; i++ {
+
+ memstats := new(runtime.MemStats)
+ runtime.ReadMemStats(memstats)
+ sys, numGC := memstats.Sys, memstats.NumGC
+
+ // Generate 1,000 MB of garbage, only retaining 1 MB total.
+ for i := 0; i < N; i++ {
x = []byte(s)
}
+
+ // Verify that the garbage collector ran by seeing if we
+ // allocated fewer than N*MB bytes from the system.
runtime.ReadMemStats(memstats)
- sys1 := memstats.Sys
- if sys1-sys > chunk*50 {
- println("allocated 1000 chunks of", chunk, "and used ", sys1-sys, "memory")
+ sys1, numGC1 := memstats.Sys, memstats.NumGC
+ if sys1-sys >= N*MB || numGC1 == numGC {
+ println("allocated 1000 chunks of", MB, "and used ", sys1-sys, "memory")
+ println("numGC went", numGC, "to", numGC1)
+ panic("init1")
}
}