diff options
Diffstat (limited to 'cmd/podman/utils.go')
| -rw-r--r-- | cmd/podman/utils.go | 99 |
1 files changed, 42 insertions, 57 deletions
diff --git a/cmd/podman/utils.go b/cmd/podman/utils.go index 522b74926..25bb36b60 100644 --- a/cmd/podman/utils.go +++ b/cmd/podman/utils.go @@ -1,6 +1,7 @@ package main import ( + "context" "fmt" "os" gosignal "os/signal" @@ -19,6 +20,7 @@ type RawTtyFormatter struct { // Attach to a container func attachCtr(ctr *libpod.Container, stdout, stderr, stdin *os.File, detachKeys string, sigProxy bool) error { + ctx := context.Background() resize := make(chan remotecommand.TerminalSize) haveTerminal := terminal.IsTerminal(int(os.Stdin.Fd())) @@ -28,12 +30,10 @@ func attachCtr(ctr *libpod.Container, stdout, stderr, stdin *os.File, detachKeys if haveTerminal && ctr.Spec().Process.Terminal { logrus.Debugf("Handling terminal attach") - resizeTerminate := make(chan interface{}) - defer func() { - resizeTerminate <- true - close(resizeTerminate) - }() - resizeTty(resize, resizeTerminate) + subCtx, cancel := context.WithCancel(ctx) + defer cancel() + + resizeTty(subCtx, resize) oldTermState, err := term.SaveState(os.Stdin.Fd()) if err != nil { @@ -46,19 +46,6 @@ func attachCtr(ctr *libpod.Container, stdout, stderr, stdin *os.File, detachKeys defer restoreTerminal(oldTermState) } - // There may be on the other size of the resize channel a goroutine trying to send. - // So consume all data inside the channel before exiting to avoid a deadlock. - defer func() { - for { - select { - case <-resize: - logrus.Debugf("Consumed resize command from channel") - default: - return - } - } - }() - streams := new(libpod.AttachStreams) streams.OutputStream = stdout streams.ErrorStream = stderr @@ -89,6 +76,7 @@ func attachCtr(ctr *libpod.Container, stdout, stderr, stdin *os.File, detachKeys // Start and attach to a container func startAttachCtr(ctr *libpod.Container, stdout, stderr, stdin *os.File, detachKeys string, sigProxy bool) error { + ctx := context.Background() resize := make(chan remotecommand.TerminalSize) haveTerminal := terminal.IsTerminal(int(os.Stdin.Fd())) @@ -98,12 +86,10 @@ func startAttachCtr(ctr *libpod.Container, stdout, stderr, stdin *os.File, detac if haveTerminal && ctr.Spec().Process.Terminal { logrus.Debugf("Handling terminal attach") - resizeTerminate := make(chan interface{}) - defer func() { - resizeTerminate <- true - close(resizeTerminate) - }() - resizeTty(resize, resizeTerminate) + subCtx, cancel := context.WithCancel(ctx) + defer cancel() + + resizeTty(subCtx, resize) oldTermState, err := term.SaveState(os.Stdin.Fd()) if err != nil { @@ -116,19 +102,6 @@ func startAttachCtr(ctr *libpod.Container, stdout, stderr, stdin *os.File, detac defer restoreTerminal(oldTermState) } - // There may be on the other size of the resize channel a goroutine trying to send. - // So consume all data inside the channel before exiting to avoid a deadlock. - defer func() { - for { - select { - case <-resize: - logrus.Debugf("Consumed resize command from channel") - default: - return - } - } - }() - streams := new(libpod.AttachStreams) streams.OutputStream = stdout streams.ErrorStream = stderr @@ -171,33 +144,45 @@ func startAttachCtr(ctr *libpod.Container, stdout, stderr, stdin *os.File, detac return nil } +// getResize returns a TerminalSize command matching stdin's current +// size on success, and nil on errors. +func getResize() *remotecommand.TerminalSize { + winsize, err := term.GetWinsize(os.Stdin.Fd()) + if err != nil { + logrus.Warnf("Could not get terminal size %v", err) + return nil + } + return &remotecommand.TerminalSize{ + Width: winsize.Width, + Height: winsize.Height, + } +} + // Helper for prepareAttach - set up a goroutine to generate terminal resize events -func resizeTty(resize chan remotecommand.TerminalSize, resizeTerminate chan interface{}) { +func resizeTty(ctx context.Context, resize chan remotecommand.TerminalSize) { sigchan := make(chan os.Signal, 1) gosignal.Notify(sigchan, signal.SIGWINCH) - sendUpdate := func() { - winsize, err := term.GetWinsize(os.Stdin.Fd()) - if err != nil { - logrus.Warnf("Could not get terminal size %v", err) - return - } - resize <- remotecommand.TerminalSize{ - Width: winsize.Width, - Height: winsize.Height, - } - } go func() { defer close(resize) // Update the terminal size immediately without waiting // for a SIGWINCH to get the correct initial size. - sendUpdate() + resizeEvent := getResize() for { - select { - case <-resizeTerminate: - return - - case <-sigchan: - sendUpdate() + if resizeEvent == nil { + select { + case <-ctx.Done(): + return + case <-sigchan: + resizeEvent = getResize() + } + } else { + select { + case <-ctx.Done(): + return + case <-sigchan: + resizeEvent = getResize() + case resize <- *resizeEvent: + } } } }() |