This question already has an answer here:
I have some long running goroutines that exec shell commands. This fails after an arbitrary number of commands have been run (288 times on my Linux box for this example, and 400 for my Mac). If I run the exact same code outside a goroutine, it continues as expected without stopping or errors. I've tried debugging by setting breakpoints, but to no avail. Any help would be greatly appreciated.
Does not work:
func main() {
go doAlot()
for {
}
}
func doAlot() {
i := 0
for {
time.Sleep(time.Millisecond * 100)
cmd := exec.Command("echo", "hello")
var stdout, stderr bytes.Buffer
cmd.Stdout = &stdout
cmd.Stderr = &stderr
err := cmd.Run()
if err != nil {
log.Fatalf("cmd.Run() failed with %s
", err)
}
outStr, errStr := string(stdout.Bytes()), string(stderr.Bytes())
fmt.Printf("%d
out: %serr: %s
", i, outStr, errStr)
i++
}
}
Works:
func main() {
i := 0
for {
time.Sleep(time.Millisecond * 100)
cmd := exec.Command("echo", "hello")
var stdout, stderr bytes.Buffer
cmd.Stdout = &stdout
cmd.Stderr = &stderr
err := cmd.Run()
if err != nil {
log.Fatalf("cmd.Run() failed with %s
", err)
}
outStr, errStr := string(stdout.Bytes()), string(stderr.Bytes())
fmt.Printf("%d
out: %serr: %s
", i, outStr, errStr)
i++
}
}
My only (uneducated/wild) guess, is that it relates to garbage collection and buffers, but somehow connected specifically to running inside a goroutine.
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