go/test/chan/select2.go
Russ Cox ec53627ed5 runtime: correct memory leak in select
* adds pass 3 to dequeue from channels eagerly

various other cleanup/churn:
  * use switch on cas->send in each pass to
    factor out common code.
  * longer goto labels, commented at target
  * be more agressive about can't happen:
    throw instead of print + cope.
  * use "select" instead of "selectgo" in errors
  * use printf for debug prints when possible

R=ken2, ken3
CC=golang-dev, r
https://golang.org/cl/875041
2010-04-01 11:56:18 -07:00

49 lines
888 B
Go

// $G $D/$F.go && $L $F.$A && ./$A.out
// 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.
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()
runtime.MemStats.Alloc = 0
// second time shouldn't increase footprint by much
go sender(c, 100000)
receiver(c, dummy, 100000)
runtime.GC()
if runtime.MemStats.Alloc > 1e5 {
println("BUG: too much memory for 100,000 selects:", runtime.MemStats.Alloc)
}
}