veyron/lib/modules: allow Shutdown to return an error status and avoid races.
Change-Id: I36c45fc1944aed97220eb627276f58b770b4c382
diff --git a/lib/modules/func.go b/lib/modules/func.go
index e5fd73b..5a7c149 100644
--- a/lib/modules/func.go
+++ b/lib/modules/func.go
@@ -17,6 +17,9 @@
main Main
stdin, stderr, stdout pipe
bufferedStdout *bufio.Reader
+ err error
+ sh *Shell
+ wg sync.WaitGroup
}
func newFunctionHandle(main Main) command {
@@ -35,15 +38,23 @@
return fh.stderr.r
}
-func (fh *functionHandle) Stdin() io.WriteCloser {
+func (fh *functionHandle) Stdin() io.Writer {
fh.mu.Lock()
defer fh.mu.Unlock()
return fh.stdin.w
}
+func (fh *functionHandle) CloseStdin() {
+ fh.mu.Lock()
+ fd := fh.stdin.w.Fd()
+ fh.mu.Unlock()
+ syscall.Close(int(fd))
+}
+
func (fh *functionHandle) start(sh *Shell, args ...string) (Handle, error) {
fh.mu.Lock()
defer fh.mu.Unlock()
+ fh.sh = sh
for _, p := range []*pipe{&fh.stdin, &fh.stdout, &fh.stderr} {
var err error
if p.r, p.w, err = os.Pipe(); err != nil {
@@ -51,30 +62,43 @@
}
}
fh.bufferedStdout = bufio.NewReader(fh.stdout.r)
+ fh.wg.Add(1)
+
go func() {
err := fh.main(fh.stdin.r, fh.stdout.w, fh.stderr.w, sh.mergeOSEnv(), args...)
if err != nil {
fmt.Fprintf(fh.stderr.w, "%s\n", err)
}
- // See the comment below in Shutdown.
- syscall.Close(int(fh.stdin.r.Fd()))
- syscall.Close(int(fh.stdout.w.Fd()))
- syscall.Close(int(fh.stderr.w.Fd()))
+ fh.mu.Lock()
+ // We close these files using the Close system call since there
+ // may be an oustanding read on them that would otherwise trigger
+ // a test failure with go test -race
+ syscall.Close(int(fh.stdin.w.Fd()))
+ syscall.Close(int(fh.stdout.r.Fd()))
+ syscall.Close(int(fh.stderr.r.Fd()))
+ fh.err = err
+ fh.mu.Unlock()
+ fh.wg.Done()
}()
return fh, nil
}
-func (fh *functionHandle) Shutdown(output io.Writer) {
+func (fh *functionHandle) Shutdown(output io.Writer) error {
fh.mu.Lock()
- defer fh.mu.Unlock()
- scanner := bufio.NewScanner(fh.stderr.r)
- for scanner.Scan() {
- fmt.Fprintf(output, "%s\n", scanner.Text())
- }
- // We close these files using the Close system call since there
- // may be an oustanding read on them that would otherwise trigger
- // a test failure with go test -race
syscall.Close(int(fh.stdin.w.Fd()))
- syscall.Close(int(fh.stdout.r.Fd()))
- syscall.Close(int(fh.stderr.r.Fd()))
+ if output != nil {
+ scanner := bufio.NewScanner(fh.stderr.r)
+ for scanner.Scan() {
+ fmt.Fprintf(output, "%s\n", scanner.Text())
+ }
+ }
+ fh.mu.Unlock()
+
+ fh.wg.Wait()
+
+ fh.mu.Lock()
+ err := fh.err
+ fh.sh.forget(fh)
+ fh.mu.Unlock()
+ return err
}
