Replace flock() with fcntl() locks

[goredo.git] / run.go

diff --git a/run.go b/run.go
index a3740c25a83d9c8e7576e4856b974d76368526c2..6366f4a0aad03c79272acf524a0cd8d8972843de 100644 (file)
--- a/run.go
+++ b/run.go
@@ -198,9 +198,14 @@ func runScript(tgtOrig string, errs chan error, traced bool) error {
        if err != nil {
                return TgtError{tgtOrig, err}
        }
+       flock := unix.Flock_t{
+               Type:   unix.F_WRLCK,
+               Whence: io.SeekStart,
+       }
        lockRelease := func() {
                tracef(CLock, "LOCK_UN: %s", fdLock.Name())
-               if err := unix.Flock(int(fdLock.Fd()), unix.LOCK_UN); err != nil {
+               flock.Type = unix.F_UNLCK
+               if err := unix.FcntlFlock(fdLock.Fd(), unix.F_SETLK, &flock); err != nil {
                        log.Fatalln(err)
                }
                fdLock.Close()
@@ -208,13 +213,16 @@ func runScript(tgtOrig string, errs chan error, traced bool) error {
        tracef(CLock, "LOCK_NB: %s", fdLock.Name())
 
        // Waiting for job completion, already taken by someone else
-       if err = unix.Flock(int(fdLock.Fd()), unix.LOCK_EX|unix.LOCK_NB); err != nil {
-               if uintptr(err.(syscall.Errno)) != uintptr(unix.EWOULDBLOCK) {
+       if err = unix.FcntlFlock(fdLock.Fd(), unix.F_SETLK, &flock); err != nil {
+               if uintptr(err.(syscall.Errno)) != uintptr(unix.EAGAIN) {
                        fdLock.Close()
                        return TgtError{tgtOrig, err}
                }
                Jobs.Add(1)
-               tracef(CDebug, "waiting: %s", tgtOrig)
+               if err = unix.FcntlFlock(fdLock.Fd(), unix.F_GETLK, &flock); err != nil {
+                       log.Fatalln(err)
+               }
+               tracef(CDebug, "waiting: %s (pid=%d)", tgtOrig, flock.Pid)
                if FdStatus != nil {
                        if _, err = FdStatus.Write([]byte{StatusWait}); err != nil {
                                log.Fatalln(err)
@@ -223,7 +231,7 @@ func runScript(tgtOrig string, errs chan error, traced bool) error {
                go func() {
                        defer Jobs.Done()
                        tracef(CLock, "LOCK_EX: %s", fdLock.Name())
-                       if err := unix.Flock(int(fdLock.Fd()), unix.LOCK_EX); err != nil {
+                       if err := unix.FcntlFlock(fdLock.Fd(), unix.F_SETLKW, &flock); err != nil {
                                log.Fatalln(err)
                        }
                        lockRelease()