open-consul/agent/proxy/process.go

43 lines
1.2 KiB
Go

package proxy
import (
"strings"
"time"
)
// isProcessAlreadyFinishedErr does a janky comparison with an error string
// defined in os/exec_unix.go and os/exec_windows.go which we encounter due to
// races with polling the external process. These case tests to fail since Stop
// returns an error sometimes so we should notice if this string stops matching
// the error in a future go version.
func isProcessAlreadyFinishedErr(err error) bool {
return strings.Contains(err.Error(), "os: process already finished")
}
// externalWait mimics process.Wait for an external process. The returned
// channel is closed when the process exits. It works by polling the process
// with signal 0 and verifying no error is returned. A closer func is also
// returned that can be invoked to terminate the waiter early.
func externalWait(pid int, pollInterval time.Duration) (<-chan struct{}, func()) {
ch := make(chan struct{})
stopCh := make(chan struct{})
closer := func() {
close(stopCh)
}
go func() {
for {
select {
case <-stopCh:
return
default:
}
if _, err := findProcess(pid); err != nil {
close(ch)
return
}
time.Sleep(pollInterval)
}
}()
return ch, closer
}