jesseduffield.lazygit/pkg/gui/gui_driver.go
Stefan Haller 0ce857c717 Fix a deadlock between task.Done() and the integration test's idle wait
Running the integration tests in a loop under the race detector
eventually hung in demo/bisect. The goroutine dump shows the cycle: a
background worker's task.Done() held the task manager's mutex while
blocking on the unbuffered idle-listener channel send, and the test
runner goroutine — the only reader of that channel — was itself blocked
in NewTask on that same mutex, on its way to enqueueing a caption
render (SetCaption -> Render -> OnUIThread). Neither side could
proceed: the notification couldn't be delivered until the test
goroutine got the mutex, and the mutex couldn't be released until the
notification was delivered.

The root problem is that the busy-to-idle notification is a blocking
rendezvous performed while holding the mutex, so it needs the waiter's
cooperation at a moment where the waiter may legitimately need the
mutex first.

Make the notification fire-and-forget instead: WaitUntilIdle waits on a
condition variable and re-checks "is any task busy?" under the mutex,
and the busy-to-idle transition broadcasts, which never blocks. Waiting
is now level-triggered rather than edge-triggered, which is also more
robust: a wait can no longer be satisfied by a stale idle transition
produced by an unrelated background task, because the predicate is
evaluated against the current state. This relies on the previous commit
having made replayed input events carry their task from submission;
without that, the wait could return in the window where an event is in
flight but not yet picked up by the main loop.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-15 15:01:04 +02:00

192 lines
4.6 KiB
Go

package gui
import (
"fmt"
"os"
"strings"
"time"
"github.com/gdamore/tcell/v3"
"github.com/jesseduffield/lazygit/pkg/commands/models"
"github.com/jesseduffield/lazygit/pkg/config"
"github.com/jesseduffield/lazygit/pkg/gocui"
"github.com/jesseduffield/lazygit/pkg/gui/types"
integrationTypes "github.com/jesseduffield/lazygit/pkg/integration/types"
)
// this gives our integration test a way of interacting with the gui for sending keypresses
// and reading state.
type GuiDriver struct {
gui *Gui
toastChan chan string
headless bool
}
var _ integrationTypes.GuiDriver = &GuiDriver{}
func (self *GuiDriver) PressKey(keyStr string) {
self.CheckAllToastsAcknowledged()
key, ok := config.KeyFromLabel(keyStr)
if !ok {
self.Fail("Unrecognized key: " + keyStr)
}
self.gui.g.ReplayKeyEvent(gocui.NewTcellKeyEventWrapper(
tcell.NewEventKey(tcell.Key(key.KeyName()), key.Str(), tcell.ModMask(key.Mod())),
0,
))
self.waitTillIdle()
}
func (self *GuiDriver) Click(x, y int) {
self.CheckAllToastsAcknowledged()
self.gui.g.ReplayMouseEvent(gocui.NewTcellMouseEventWrapper(
tcell.NewEventMouse(x, y, tcell.ButtonPrimary, 0),
0,
))
self.waitTillIdle()
self.gui.g.ReplayMouseEvent(gocui.NewTcellMouseEventWrapper(
tcell.NewEventMouse(x, y, tcell.ButtonNone, 0),
0,
))
self.waitTillIdle()
}
// FocusIn simulates the terminal window regaining focus, which is how lazygit
// learns to reload changed config files. Tests use it to exercise the live
// config-reload path.
func (self *GuiDriver) FocusIn() {
self.gui.g.ReplayFocusEvent(gocui.NewTcellFocusEventWrapper(
tcell.NewEventFocus(true),
0,
))
self.waitTillIdle()
}
func (self *GuiDriver) PretendMergeOrRebaseStartedInLazygit() {
self.gui.onUIThread(func() error {
self.gui.State.SetMergeOrRebaseStartedInLazygit(true)
return nil
})
self.waitTillIdle()
}
// wait until lazygit is idle (i.e. all processing is done) before continuing
func (self *GuiDriver) waitTillIdle() {
self.gui.g.WaitUntilIdle()
}
func (self *GuiDriver) CheckAllToastsAcknowledged() {
if t := self.NextToast(); t != nil {
self.Fail("Toast not acknowledged: " + *t)
}
}
func (self *GuiDriver) Keys() config.KeybindingConfig {
return self.gui.Config.GetUserConfig().Keybinding
}
func (self *GuiDriver) CurrentContext() types.Context {
return self.gui.c.Context().Current()
}
func (self *GuiDriver) ContextForView(viewName string) types.Context {
context, ok := self.gui.helpers.View.ContextForView(viewName)
if !ok {
return nil
}
return context
}
func (self *GuiDriver) Fail(message string) {
currentView := self.gui.g.CurrentView()
// Check for unacknowledged toast: it may give us a hint as to why the test failed
toastMessage := ""
if t := self.NextToast(); t != nil {
toastMessage = fmt.Sprintf("Unacknowledged toast message: %s\n", *t)
}
fullMessage := fmt.Sprintf(
"%s\nFinal Lazygit state:\n%s\nUpon failure, focused view was '%s'.\n%sLog:\n%s", message,
self.gui.g.Snapshot(),
currentView.Name(),
toastMessage,
strings.Join(self.gui.GuiLog, "\n"),
)
self.gui.g.Close()
// need to give the gui time to close
time.Sleep(time.Millisecond * 100)
_, err := fmt.Fprintln(os.Stderr, fullMessage)
if err != nil {
panic("Test failed. Failed writing to stderr")
}
panic("Test failed")
}
// logs to the normal place that you log to i.e. viewable with `lazygit --logs`
func (self *GuiDriver) Log(message string) {
self.gui.c.Log.Warn(message)
}
// logs in the actual UI (in the commands panel)
func (self *GuiDriver) LogUI(message string) {
self.gui.c.LogAction(message)
}
func (self *GuiDriver) CheckedOutRef() *models.Branch {
return self.gui.helpers.Refs.GetCheckedOutRef()
}
func (self *GuiDriver) MainView() *gocui.View {
return self.gui.mainView()
}
func (self *GuiDriver) SecondaryView() *gocui.View {
return self.gui.secondaryView()
}
func (self *GuiDriver) View(viewName string) *gocui.View {
view, err := self.gui.g.View(viewName)
if err != nil {
panic(err)
}
return view
}
// TopViewInWindow returns the frontmost visible view in the given window, i.e.
// the tab that is currently shown when a window holds several tabbed views.
func (self *GuiDriver) TopViewInWindow(windowName string) *gocui.View {
return self.gui.helpers.Window.TopViewInWindow(windowName, false)
}
func (self *GuiDriver) SetCaption(caption string) {
self.gui.setCaption(caption)
self.waitTillIdle()
}
func (self *GuiDriver) SetCaptionPrefix(prefix string) {
self.gui.setCaptionPrefix(prefix)
self.waitTillIdle()
}
func (self *GuiDriver) NextToast() *string {
select {
case t := <-self.toastChan:
return &t
default:
return nil
}
}
func (self *GuiDriver) Headless() bool {
return self.headless
}