Password input: Handle SIGTSTP

tools/tty/tty.go

@@ -4,7 +4,9 @@ package tty
 
 import (
 	"encoding/base64"
+	"errors"
 	"fmt"
+	"io"
 	"os"
 	"time"
 
@@ -207,6 +209,22 @@ func (self *Term) RestoreAndClose() error {
 	return self.Close()
 }
 
+func (self *Term) SuspendAndRun(callback func() error) error {
+	var state unix.Termios
+	err := self.Tcgetattr(&state)
+	if err != nil {
+		return err
+	}
+	if len(self.states) > 0 {
+		err := self.Tcsetattr(TCSANOW, &self.states[0])
+		if err != nil {
+			return err
+		}
+	}
+	defer self.Tcsetattr(TCSANOW, &state)
+	return callback()
+}
+
 func clamp(v, lo, hi int64) int64 {
 	if v < lo {
 		return lo
@@ -245,6 +263,17 @@ func (self *Term) Write(b []byte) (int, error) {
 	return self.os_file.Write(b)
 }
 
+func (self *Term) WriteAll(b []byte) error {
+	for len(b) > 0 {
+		n, err := self.os_file.Write(b)
+		if err != nil && !errors.Is(err, io.ErrShortWrite) {
+			return err
+		}
+		b = b[n:]
+	}
+	return nil
+}
+
 func (self *Term) WriteString(b string) (int, error) {
 	return self.os_file.WriteString(b)
 }

tools/tui/loop/api.go

@@ -6,7 +6,6 @@ import (
 	"encoding/base64"
 	"fmt"
 	"kitty/tools/tty"
-	"os"
 	"time"
 
 	"golang.org/x/sys/unix"
@@ -45,8 +44,8 @@ type Loop struct {
 	timers, timers_temp                    []*timer
 	timer_id_counter, write_msg_id_counter IdType
 	wakeup_channel                         chan byte
-	signal_channel                         chan os.Signal
 	pending_writes                         []*write_msg
+	on_SIGTSTP                             func() error
 
 	// Callbacks
 
@@ -71,6 +70,9 @@ type Loop struct {
 
 	// Called when any input from tty is received
 	OnReceivedData func(data []byte) error
+
+	// Called when resuming from a SIGTSTP or Ctrl-z
+	OnResumeFromStop func() error
 }
 
 func New(options ...func(self *Loop)) (*Loop, error) {

tools/tui/loop/run.go

@@ -75,7 +75,6 @@ func (self *Loop) handle_csi(raw []byte) error {
 }
 
 func (self *Loop) handle_key_event(ev *KeyEvent) error {
-	self.DebugPrintln(ev)
 	if self.OnKeyEvent != nil {
 		err := self.OnKeyEvent(ev)
 		if err != nil {
@@ -177,14 +176,6 @@ func (self *Loop) on_SIGTERM() error {
 	return nil
 }
 
-func (self *Loop) on_SIGTSTP() error {
-	signal.Reset(unix.SIGTSTP)
-	unix.Kill(os.Getpid(), unix.SIGTSTP)
-	time.Sleep(20 * time.Millisecond)
-	signal.Notify(self.signal_channel, unix.SIGTSTP)
-	return nil
-}
-
 func (self *Loop) on_SIGHUP() error {
 	self.death_signal = unix.SIGHUP
 	self.keep_going = false
@@ -192,9 +183,9 @@ func (self *Loop) on_SIGHUP() error {
 }
 
 func (self *Loop) run() (err error) {
-	self.signal_channel = make(chan os.Signal, 256)
+	signal_channel := make(chan os.Signal, 256)
 	handled_signals := []os.Signal{unix.SIGINT, unix.SIGTERM, unix.SIGTSTP, unix.SIGHUP, unix.SIGWINCH, unix.SIGPIPE}
-	signal.Notify(self.signal_channel, handled_signals...)
+	signal.Notify(signal_channel, handled_signals...)
 	defer signal.Reset(handled_signals...)
 
 	controlling_term, err := tty.OpenControllingTerm()
@@ -203,10 +194,10 @@ func (self *Loop) run() (err error) {
 	}
 	self.controlling_term = controlling_term
 	defer func() {
-		self.controlling_term.RestoreAndClose()
+		controlling_term.RestoreAndClose()
 		self.controlling_term = nil
 	}()
-	err = self.controlling_term.ApplyOperations(tty.TCSANOW, tty.SetRaw)
+	err = controlling_term.ApplyOperations(tty.TCSANOW, tty.SetRaw)
 	if err != nil {
 		return nil
 	}
@@ -239,6 +230,7 @@ func (self *Loop) run() (err error) {
 		return err
 	}
 	self.QueueWriteBytesDangerous(self.terminal_options.SetStateEscapeCodes())
+	needs_reset_escape_codes := true
 
 	defer func() {
 		// notify tty reader that we are shutting down
@@ -248,7 +240,9 @@ func (self *Loop) run() (err error) {
 		if finalizer != "" {
 			self.QueueWriteString(finalizer)
 		}
-		self.QueueWriteBytesDangerous(self.terminal_options.ResetStateEscapeCodes())
+		if needs_reset_escape_codes {
+			self.QueueWriteBytesDangerous(self.terminal_options.ResetStateEscapeCodes())
+		}
 		// flush queued data and wait for it to be written for a timeout, then wait for writer to shutdown
 		flush_writer(w_w, tty_write_channel, write_done_channel, self.pending_writes, 2*time.Second)
 		self.pending_writes = nil
@@ -257,8 +251,8 @@ func (self *Loop) run() (err error) {
 		}
 	}()
 
-	go write_to_tty(w_r, self.controlling_term, tty_write_channel, err_channel, write_done_channel)
-	go read_from_tty(r_r, self.controlling_term, tty_read_channel, err_channel, tty_reading_done_channel)
+	go write_to_tty(w_r, controlling_term, tty_write_channel, err_channel, write_done_channel)
+	go read_from_tty(r_r, controlling_term, tty_read_channel, err_channel, tty_reading_done_channel)
 
 	if self.OnInitialize != nil {
 		finalizer, err = self.OnInitialize()
@@ -267,6 +261,33 @@ func (self *Loop) run() (err error) {
 		}
 	}
 
+	self.on_SIGTSTP = func() error {
+		write_id := self.QueueWriteBytesDangerous(self.terminal_options.ResetStateEscapeCodes())
+		needs_reset_escape_codes = false
+		err := self.wait_for_write_to_complete(write_id, tty_write_channel, write_done_channel, 2*time.Second)
+		if err != nil {
+			return err
+		}
+		err = controlling_term.SuspendAndRun(func() error {
+			unix.Kill(os.Getpid(), unix.SIGSTOP)
+			time.Sleep(20 * time.Millisecond)
+			return nil
+		})
+		if err != nil {
+			return err
+		}
+		write_id = self.QueueWriteBytesDangerous(self.terminal_options.SetStateEscapeCodes())
+		needs_reset_escape_codes = true
+		err = self.wait_for_write_to_complete(write_id, tty_write_channel, write_done_channel, 2*time.Second)
+		if err != nil {
+			return err
+		}
+		if self.OnResumeFromStop != nil {
+			return self.OnResumeFromStop()
+		}
+		return nil
+	}
+
 	for self.keep_going {
 		self.flush_pending_writes(tty_write_channel)
 		timeout_chan := no_timeout_channel
@@ -296,7 +317,7 @@ func (self *Loop) run() (err error) {
 					return err
 				}
 			}
-		case s := <-self.signal_channel:
+		case s := <-signal_channel:
 			err = self.on_signal(s.(unix.Signal))
 			if err != nil {
 				return err

tools/tui/loop/write.go

@@ -69,6 +69,31 @@ func (self *Loop) flush_pending_writes(tty_write_channel chan<- *write_msg) {
 	}
 }
 
+func (self *Loop) wait_for_write_to_complete(sentinel IdType, tty_write_channel chan<- *write_msg, write_done_channel <-chan IdType, timeout time.Duration) error {
+	for len(self.pending_writes) > 0 {
+		select {
+		case tty_write_channel <- self.pending_writes[0]:
+			self.pending_writes = self.pending_writes[1:]
+		case write_id, more := <-write_done_channel:
+			if write_id == sentinel {
+				return nil
+			}
+			if self.OnWriteComplete != nil {
+				err := self.OnWriteComplete(write_id)
+				if err != nil {
+					return err
+				}
+			}
+			if !more {
+				return fmt.Errorf("The write_done_channel was unexpectedly closed")
+			}
+		case <-time.After(timeout):
+			return os.ErrDeadlineExceeded
+		}
+	}
+	return nil
+}
+
 func (self *Loop) add_write_to_pending_queue(data *write_msg) {
 	self.pending_writes = append(self.pending_writes, data)
 }
@@ -183,7 +208,7 @@ func flush_writer(pipe_w *os.File, tty_write_channel chan<- *write_msg, write_do
 		}
 	}()
 	deadline := time.Now().Add(timeout)
-	for len(pending_writes) > 0 {
+	for len(pending_writes) > 0 && !writer_quit {
 		timeout = deadline.Sub(time.Now())
 		if timeout <= 0 {
 			return
@@ -213,7 +238,7 @@ func flush_writer(pipe_w *os.File, tty_write_channel chan<- *write_msg, write_do
 				writer_quit = true
 			}
 		case <-time.After(timeout):
-			break
+			return
 		}
 	}
 	return

tools/tui/password.go

@@ -79,6 +79,11 @@ func ReadPassword(prompt string, kill_if_signaled bool) (password string, err er
 		return nil
 	}
 
+	lp.OnResumeFromStop = func() error {
+		lp.QueueWriteString("\r" + prompt + shadow)
+		return nil
+	}
+
 	err = lp.Run()
 	if err != nil {
 		return