starred/terminal
1
0
Fork 0
mirror of https://github.com/microsoft/terminal.git synced 2026-02-04 05:35:20 +00:00
Code Issues 19.0k Packages Projects Releases 20 Wiki Activity

[PR #14282] [MERGED] Wait for clients to exit on ConPTY shutdown #30039

New Issue
Open
opened 2026-01-31 09:38:18 +00:00 by claunia · 0 comments
claunia commented 2026-01-31 09:38:18 +00:00
Owner
Copy Link

📋 Pull Request Information

Original PR: https://github.com/microsoft/terminal/pull/14282
Author: @lhecker
Created: 10/23/2022
Status: ✅ Merged
Merged: 11/29/2022
Merged by: @lhecker

Base: main ← Head: dev/lhecker/14132-shutdown-deadlock-part2

📝 Commits (10+)

  • 8bccc33 Wait for clients to exit on ConPTY shutdown
  • 6f177cf Fix code that used to rely on noreturn, Fix hPtyReference
  • a7db7a9 Fix build
  • 688a587 Fix typo
  • d693df4 Fix another deadlock on shutdown
  • f5f22ff Merge remote-tracking branch 'origin/main' into dev/lhecker/14132-shutdown-deadlock-part2
  • f24689f Merge remote-tracking branch 'origin/main' into dev/lhecker/14132-shutdown-deadlock-part2
  • 7fb6ffa Fix merge origin/main
  • bfd9004 Address feedback
  • 0a1da70 Fix build failure

📊 Changes

11 files changed (+73 additions, -138 deletions)

View changed files

📝 src/host/PtySignalInputThread.cpp (+39 -39)
📝 src/host/PtySignalInputThread.hpp (+2 -2)
📝 src/host/VtInputThread.cpp (+1 -4)
📝 src/host/VtInputThread.hpp (+1 -1)
📝 src/host/VtIo.cpp (+0 -12)
📝 src/host/VtIo.hpp (+2 -2)
📝 src/host/output.cpp (+4 -10)
📝 src/interactivity/base/ServiceLocator.cpp (+9 -1)
📝 src/winconpty/ft_pty/ConPtyTests.cpp (+4 -59)
📝 src/winconpty/winconpty.cpp (+10 -8)
📝 src/winconpty/winconpty.h (+1 -0)

📄 Description

#14160 didn't fix #14132 entirely. There seems to be a race condition left
where (on my system) 9 out of 10 times everything works correctly,
but sometimes OpenConsole exits, while pwsh and bash keep running.

My leading theory is that the new code is exiting OpenConsole faster than the
old code. This prevents clients from calling console APIs, etc. causing them
to get stuck. The old code (and new code) calls ExitProcess when the ConPTY
pipes break and I think this is wrong: In conhost when you close the window we
only call CloseConsoleProcessState via the WM_CLOSE event and that's it.
Solution: Remove the call to RundownAndExit for ConPTY.

During testing I found that continuously printing text inside msys2 will cause
child processes to only exit slowly one by one every 5 seconds.
This happens because CloseConsoleProcessState calls HandleCtrlEvent without
holding the console lock. This creates a race condition where most of the time
the console IO thread is the one picking up the CTRL_CLOSE_EVENT. But that's
problematic because the CTRL_CLOSE_EVENT leads to a ConsoleControl call of
type ConsoleEndTask which calls back into conhost's IO thread and
so you got the IO thread waiting on itself to respond.
Solution: Don't race conditions.

Validation Steps Performed

  • Enter-VsDevShell and close the tab
    Everything exits after 5s ✅
  • Run msys2 bash from within pwsh and close the tab
    Everything exits instantly ✅
  • Run cat bigfile.txt and close the tab
    Everything exits instantly ✅
  • Patch conhost.exe with sfpcopy, as well as KernelBase.dll
    with the recent changes to winconpty, then launch and exit
    shells and applications via VS Code's terminal ✅
  • On the main branch without this modification remove the call to
    TriggerTeardown in RundownAndExit (this speeds up the shutdown).
    Run (msys2's) bash.exe --login and hold enter and then press Ctrl+Shift+W
    simultaneously. The tab should close and randomly OpenConsole should exit
    early while pwsh/bash keep running. Then retry this with this branch and
    observe how the child processes don't stick around forever anymore. ✅

🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.

## 📋 Pull Request Information **Original PR:** https://github.com/microsoft/terminal/pull/14282 **Author:** [@lhecker](https://github.com/lhecker) **Created:** 10/23/2022 **Status:** ✅ Merged **Merged:** 11/29/2022 **Merged by:** [@lhecker](https://github.com/lhecker) **Base:** `main` ← **Head:** `dev/lhecker/14132-shutdown-deadlock-part2` --- ### 📝 Commits (10+) - [`8bccc33`](https://github.com/microsoft/terminal/commit/8bccc33f9aac00caf5ef66b06bcbe66019da23c1) Wait for clients to exit on ConPTY shutdown - [`6f177cf`](https://github.com/microsoft/terminal/commit/6f177cf78b193cbe88595c8dd7165ebbc9f60a4e) Fix code that used to rely on [[noreturn]], Fix hPtyReference - [`a7db7a9`](https://github.com/microsoft/terminal/commit/a7db7a9309194679f95e869147489b7977e0ee4c) Fix build - [`688a587`](https://github.com/microsoft/terminal/commit/688a58721f090053326256ad18e6e58302bd7d4b) Fix typo - [`d693df4`](https://github.com/microsoft/terminal/commit/d693df4a6dea75842161409f2afc4fa76d60ce38) Fix another deadlock on shutdown - [`f5f22ff`](https://github.com/microsoft/terminal/commit/f5f22ff0df93e57ce0095a127871a7b53bffe9c7) Merge remote-tracking branch 'origin/main' into dev/lhecker/14132-shutdown-deadlock-part2 - [`f24689f`](https://github.com/microsoft/terminal/commit/f24689f027cbabe2aab19b3d0c9d892998a9b8fc) Merge remote-tracking branch 'origin/main' into dev/lhecker/14132-shutdown-deadlock-part2 - [`7fb6ffa`](https://github.com/microsoft/terminal/commit/7fb6ffa6a938a522d74ef70d5e217b153c566df2) Fix merge origin/main - [`bfd9004`](https://github.com/microsoft/terminal/commit/bfd900492b788c849964b89f497ff879df5d9749) Address feedback - [`0a1da70`](https://github.com/microsoft/terminal/commit/0a1da70708884d4b07fbaf66ac9df4515ff3b421) Fix build failure ### 📊 Changes **11 files changed** (+73 additions, -138 deletions) <details> <summary>View changed files</summary> 📝 `src/host/PtySignalInputThread.cpp` (+39 -39) 📝 `src/host/PtySignalInputThread.hpp` (+2 -2) 📝 `src/host/VtInputThread.cpp` (+1 -4) 📝 `src/host/VtInputThread.hpp` (+1 -1) 📝 `src/host/VtIo.cpp` (+0 -12) 📝 `src/host/VtIo.hpp` (+2 -2) 📝 `src/host/output.cpp` (+4 -10) 📝 `src/interactivity/base/ServiceLocator.cpp` (+9 -1) 📝 `src/winconpty/ft_pty/ConPtyTests.cpp` (+4 -59) 📝 `src/winconpty/winconpty.cpp` (+10 -8) 📝 `src/winconpty/winconpty.h` (+1 -0) </details> ### 📄 Description #14160 didn't fix #14132 entirely. There seems to be a race condition left where (on my system) 9 out of 10 times everything works correctly, but sometimes OpenConsole exits, while pwsh and bash keep running. My leading theory is that the new code is exiting OpenConsole faster than the old code. This prevents clients from calling console APIs, etc. causing them to get stuck. The old code (and new code) calls `ExitProcess` when the ConPTY pipes break and I think this is wrong: In conhost when you close the window we only call `CloseConsoleProcessState` via the `WM_CLOSE` event and that's it. Solution: Remove the call to `RundownAndExit` for ConPTY. During testing I found that continuously printing text inside msys2 will cause child processes to only exit slowly one by one every 5 seconds. This happens because `CloseConsoleProcessState` calls `HandleCtrlEvent` without holding the console lock. This creates a race condition where most of the time the console IO thread is the one picking up the `CTRL_CLOSE_EVENT`. But that's problematic because the `CTRL_CLOSE_EVENT` leads to a `ConsoleControl` call of type `ConsoleEndTask` which calls back into conhost's IO thread and so you got the IO thread waiting on itself to respond. Solution: Don't race conditions. ## Validation Steps Performed * `Enter-VsDevShell` and close the tab Everything exits after 5s ✅ * Run msys2 bash from within pwsh and close the tab Everything exits instantly ✅ * Run `cat bigfile.txt` and close the tab Everything exits instantly ✅ * Patch `conhost.exe` with `sfpcopy`, as well as `KernelBase.dll` with the recent changes to `winconpty`, then launch and exit shells and applications via VS Code's terminal ✅ * On the main branch without this modification remove the call to `TriggerTeardown` in `RundownAndExit` (this speeds up the shutdown). Run (msys2's) `bash.exe --login` and hold enter and then press Ctrl+Shift+W simultaneously. The tab should close and randomly OpenConsole should exit early while pwsh/bash keep running. Then retry this with this branch and observe how the child processes don't stick around forever anymore. ✅ --- <sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>
claunia added the pull-request label 2026-01-31 09:38:18 +00:00
Sign in to join this conversation.
No Branch/Tag Specified
Branches Tags
Labels
Clear labels
⛺ Reserved
A11yCO
A11yMAS
A11ySev1
A11ySev2
A11ySev3
A11yTTValidated
A11yUsable
A11yVoiceAccess
A11yWCAG
Area-Accessibility
Area-AtlasEngine
Area-AzureShell
Area-Build
Area-Build
Area-Chat
Area-CmdPal
Area-CodeHealth
Area-Commandline
Area-CookedRead
Area-DefApp
Area-Extensibility
Area-Fonts
Area-GroupPolicy
Area-i18n
Area-Input
Area-Interaction
Area-Interop
Area-Localization
Area-Output
Area-Performance
Area-Portable
Area-Quality
Area-Remoting
Area-Rendering
Area-Schema
Area-Server
Area-Settings
Area-SettingsUI
Area-ShellExtension
Area-ShellExtension
Area-ShellExtension
Area-Suggestions
Area-Suggestions
Area-TerminalConnection
Area-TerminalControl
Area-Theming
Area-UserInterface
Area-VT
Area-Windowing
Area-WPFControl
AutoMerge
Blocking-Ingestion
Culprit-Centennial
Culprit-WinUI
Disability-All
Disability-Blind
Disability-LowVision
Disability-Mobility
External-Blocked-WinUI3
Fixed
Gathering-Data
good first issue
HCL-E+D
HCL-WindowsTerminal
Help Wanted
Impact-Compatibility
Impact-Compliance
Impact-Correctness
Impact-Visual
In-PR
InclusionBacklog
InclusionBacklog-Windows TerminalWin32
InclusionCommitted-202206
Issue-Bug
Issue-Docs
Issue-Feature
Issue-Feature
Issue-Question
Issue-Samples
Issue-Scenario
Issue-Task
Needs-Attention
Needs-Author-Feedback
Needs-Bisect
Needs-Discussion
Needs-Repro
Needs-Tag-Fix
Needs-Tag-Fix
Needs-Triage
No-Recent-Activity
Priority-0
Priority-1
Priority-2
Priority-3
Product-Cmd.exe
Product-Colortool
Product-Colortool
Product-Colortool
Product-Conhost
Product-Conpty
Product-Meta
Product-Powershell
Product-Terminal
Product-WSL
pull-request
Mirrored from GitHub Pull Request
 Resolution-Answered
Resolution-By-Design
Resolution-Duplicate
Resolution-External
Resolution-Fix-Available
Resolution-Fix-Committed
Resolution-No-Repro
Resolution-Won't-Fix
Severity-Blocking
Severity-Crash
Severity-DataLoss
spam
this-will-be-a-breaking-change
Tracking-External
WindowsTerminal_Win32
Work-Item
zAskModeBug
zInbox-Bug
No Label pull-request
Milestone
No items
No Milestone
Projects
Clear projects
No project
Assignees
Clear assignees
claunia
No Assignees
1 Participants
Notifications
Due Date
No due date set.
Dependencies

No dependencies set.

Reference: starred/terminal#30039
Delete Branch "%!s()"

Deleting a branch is permanent. Although the deleted branch may continue to exist for a short time before it actually gets removed, it CANNOT be undone in most cases. Continue?