starred/terminal
1
0
Fork 0
mirror of https://github.com/microsoft/terminal.git synced 2026-02-03 21:25:34 +00:00
Code Issues 19.0k Packages Projects Releases 20 Wiki Activity

Console process order changed in 15063's v2 console making npm harder to close #129

New Issue
Closed
opened 2026-01-30 21:43:12 +00:00 by claunia · 7 comments
claunia commented 2026-01-30 21:43:12 +00:00
Owner
Copy Link

Originally created by @bitcrazed on GitHub (Feb 16, 2018).

Originally assigned to: @miniksa on GitHub.

From @rprichard on May 29, 2017 4:40

In 15063's v1 console, and any console in Windows 10.0.14393 and older, Windows seems to order the processes from newest-to-oldest for GetConsoleProcessList (probably the opposite of the attachment order). When a console is closed, Windows considers each process, in order, and delivers it a CTRL_CLOSE_EVENT event. Windows gives the process 5 seconds to exit, after which point it terminates the process.

In 15063's v2 console, the order of the process list has reversed and is now oldest-to-newest. Maybe the change was intentional? Regardless, it affects npm (the node package manager), as detailed here: https://github.com/Microsoft/vscode/issues/26807#issuecomment-304503591.

The test case given on https://github.com/Microsoft/vscode/issues/26807 was fairly easy for me to reproduce, and it doesn't require VSCode. Installing node.js adds node.bat and npm.cmd to the PATH. Run the commands in an ordinary console, and instead of "pressing the garbage bin button", try to close the console window. In my experience, the first click leaves the youngest node.exe process running, and the second click finishes the job. (VSCode's "garbage bin button" eventually turns into winpty posting a WM_CLOSE message, which kills winpty-agent.exe. The console window survives, but it's hidden, so the node.exe is leaked.)

Starting in Windows 8, when the console is delivering CTRL_CLOSE_EVENT events, it seems to abort the operation if a process exits on its own accord. Windows 7, on the other hand, skips over dead processes.

The combination of the 15063 v2 change and the Win8 change breaks npm, which has a process tree like so:

  • A: node.exe (npm run, owns Job1)
    • B: cmd.exe (assigned to Job1)
      • C: node.exe (tsc --watch)

Windows delivers CTRL_CLOSE_EVENT to A(node.exe). node.exe turns it into a libuv-emulated SIGHUP signal, which is sent to Node's main thread and ignored. After 5 seconds, Windows kills A(node.exe). Killing A(node.exe) destroys Job1, which destroys B(cmd.exe). Apparently the console then aborts the close operation because B(cmd.exe) is missing.

Previously, Windows signaled C(node.exe) first, and after C exited, the other two processes would definitely exit.

Also: There seems to be a race condition between process cleanup (in the kernel?) and the close event signaling (in conhost.exe?), and sometimes the console close operation is able to skip over already-dead processes.

I wrote a test program demonstrating things discussed in this report -- closetest.cc, https://gist.github.com/rprichard/7ec3fe1b199f513bee82fea196a82a79. It has notes at the top of the file and a --help option.

  • To see the change in signaling order (EXAMPLE 1 in closetest.cc), run Sysinternals dbgview.exe, then closetest.exe without arguments.

  • To create a console that's hard to close (EXAMPLE 2), run closetest.exe -d alternate --gap -n N. In Windows 8 and up, you'll have to close the console N + 1 times. In Vista or Windows 7, just once is enough.

  • To see the race condition (EXAMPLE 3), try:

    • closetest.exe -d [backward/forward] -m job -n 10 --alloc 1, or
    • closetest.exe -d [backward/forward] -m job -n 50

    On a v1 or <= 14393 console, use -d backward. On the v2 15063 console, use -d forward.

  • The closest analog to npm's issue is closetest.exe -d forward -m job -n 2 --alloc 100. With the 15063 v2 console, this command usually takes two Close clicks to destroy the console.

Windows build number: 10.0.15063.332

Copied from original issue: Microsoft/WSL#2170

Originally created by @bitcrazed on GitHub (Feb 16, 2018). Originally assigned to: @miniksa on GitHub. _From @rprichard on May 29, 2017 4:40_ In 15063's v1 console, and any console in Windows 10.0.14393 and older, Windows seems to order the processes from newest-to-oldest for `GetConsoleProcessList` (probably the opposite of the attachment order). When a console is closed, Windows considers each process, in order, and delivers it a `CTRL_CLOSE_EVENT` event. Windows gives the process 5 seconds to exit, after which point it terminates the process. In 15063's v2 console, the order of the process list has reversed and is now oldest-to-newest. Maybe the change was intentional? Regardless, it affects npm (the node package manager), as detailed here: https://github.com/Microsoft/vscode/issues/26807#issuecomment-304503591. The test case given on https://github.com/Microsoft/vscode/issues/26807 was fairly easy for me to reproduce, and it doesn't require VSCode. Installing node.js adds `node.bat` and `npm.cmd` to the PATH. Run the commands in an ordinary console, and instead of "pressing the garbage bin button", try to close the console window. In my experience, the first click leaves the youngest `node.exe` process running, and the second click finishes the job. (VSCode's "garbage bin button" eventually turns into winpty posting a `WM_CLOSE` message, which kills `winpty-agent.exe`. The console window survives, but it's hidden, so the `node.exe` is leaked.) Starting in Windows 8, when the console is delivering `CTRL_CLOSE_EVENT` events, it seems to abort the operation if a process exits on its own accord. Windows 7, on the other hand, skips over dead processes. The combination of the 15063 v2 change and the Win8 change breaks npm, which has a process tree like so: * A: node.exe (npm run, owns Job1) * B: cmd.exe (assigned to Job1) * C: node.exe (tsc --watch) Windows delivers `CTRL_CLOSE_EVENT` to A(node.exe). node.exe turns it into a libuv-emulated SIGHUP signal, which is sent to Node's main thread and ignored. After 5 seconds, Windows kills A(node.exe). Killing A(node.exe) destroys Job1, which destroys B(cmd.exe). Apparently the console then aborts the close operation because B(cmd.exe) is missing. Previously, Windows signaled C(node.exe) first, and after C exited, the other two processes would definitely exit. Also: There seems to be a race condition between process cleanup (in the kernel?) and the close event signaling (in `conhost.exe`?), and sometimes the console close operation is able to skip over already-dead processes. I wrote a test program demonstrating things discussed in this report -- `closetest.cc`, https://gist.github.com/rprichard/7ec3fe1b199f513bee82fea196a82a79. It has notes at the top of the file and a `--help` option. * To see the change in signaling order (EXAMPLE 1 in `closetest.cc`), run Sysinternals `dbgview.exe`, then `closetest.exe` without arguments. * To create a console that's hard to close (EXAMPLE 2), run `closetest.exe -d alternate --gap -n N`. In Windows 8 and up, you'll have to close the console N + 1 times. In Vista or Windows 7, just once is enough. * To see the race condition (EXAMPLE 3), try: * `closetest.exe -d [backward/forward] -m job -n 10 --alloc 1`, or * `closetest.exe -d [backward/forward] -m job -n 50` On a v1 or <= 14393 console, use `-d backward`. On the v2 15063 console, use `-d forward`. * The closest analog to npm's issue is `closetest.exe -d forward -m job -n 2 --alloc 100`. With the 15063 v2 console, this command usually takes two Close clicks to destroy the console. Windows build number: 10.0.15063.332 _Copied from original issue: Microsoft/WSL#2170_
claunia commented 2026-01-30 21:43:14 +00:00
Author
Owner
Copy Link

@bitcrazed commented on GitHub (Feb 16, 2018):

From @miniksa on July 3, 2017 21:32

This wasn't intentional and I'm making a change to put the process order back to how it was.

Basically, what happened was that I decided to use std::list instead of NT Driver LIST_ENTRY for the process list.

Somehow the "InsertHeadList" command from the NT LIST_ENTRY structures got converted into a .push_back instead of a .push_front in the new std::list usage. Probably my fault. Probably my brain screwed up. Sorry about that.

The fix should make it into Insiders builds within the next few weeks. Thanks for your report!

@bitcrazed commented on GitHub (Feb 16, 2018): _From @miniksa on July 3, 2017 21:32_ This wasn't intentional and I'm making a change to put the process order back to how it was. Basically, what happened was that I decided to use std::list instead of NT Driver LIST_ENTRY for the process list. Somehow the "InsertHeadList" command from the NT LIST_ENTRY structures got converted into a .push_back instead of a .push_front in the new std::list usage. Probably my fault. Probably my brain screwed up. Sorry about that. The fix should make it into Insiders builds within the next few weeks. Thanks for your report!
claunia commented 2026-01-30 21:43:14 +00:00
Author
Owner
Copy Link

@bitcrazed commented on GitHub (Feb 16, 2018):

From @miniksa on July 7, 2017 20:6

Hey @rprichard,

I'm interested in using your code sample above at https://gist.github.com/rprichard/7ec3fe1b199f513bee82fea196a82a79 as a part of our test suites to prevent further regressions in this area, but I didn't see any licensing information. Would you be able to provide the code under an open source license? Generally we prefer a permissive license such as MIT, but please choose whatever license fits best for you. You can take a look at https://choosealicense.com/ if you need help choosing a license.

Thanks,
--Michael

@bitcrazed commented on GitHub (Feb 16, 2018): _From @miniksa on July 7, 2017 20:6_ Hey @rprichard, I'm interested in using your code sample above at https://gist.github.com/rprichard/7ec3fe1b199f513bee82fea196a82a79 as a part of our test suites to prevent further regressions in this area, but I didn't see any licensing information. Would you be able to provide the code under an open source license? Generally we prefer a permissive license such as MIT, but please choose whatever license fits best for you. You can take a look at https://choosealicense.com/ if you need help choosing a license. Thanks, --Michael
claunia commented 2026-01-30 21:43:14 +00:00
Author
Owner
Copy Link

@bitcrazed commented on GitHub (Feb 16, 2018):

From @rprichard on July 8, 2017 2:35

@miniksa That sounds good to me. I'm traveling at the moment, but I'll add an MIT license file once I have the chance.

@bitcrazed commented on GitHub (Feb 16, 2018): _From @rprichard on July 8, 2017 2:35_ @miniksa That sounds good to me. I'm traveling at the moment, but I'll add an MIT license file once I have the chance.
claunia commented 2026-01-30 21:43:14 +00:00
Author
Owner
Copy Link

@bitcrazed commented on GitHub (Feb 16, 2018):

From @rprichard on July 8, 2017 8:0

@miniksa I updated the Gist by adding an MIT License block at the front (revisions 2 and then 3).

@bitcrazed commented on GitHub (Feb 16, 2018): _From @rprichard on July 8, 2017 8:0_ @miniksa I updated the Gist by adding an MIT License block at the front (revisions 2 and then 3).
claunia commented 2026-01-30 21:43:15 +00:00
Author
Owner
Copy Link

@bitcrazed commented on GitHub (Feb 16, 2018):

From @miniksa on July 10, 2017 16:15

@rprichard Thank you very much!

@bitcrazed commented on GitHub (Feb 16, 2018): _From @miniksa on July 10, 2017 16:15_ @rprichard Thank you very much!
claunia commented 2026-01-30 21:43:15 +00:00
Author
Owner
Copy Link

@bitcrazed commented on GitHub (Feb 16, 2018):

From @benhillis on August 3, 2017 16:50

Fixed in 16257.

@bitcrazed commented on GitHub (Feb 16, 2018): _From @benhillis on August 3, 2017 16:50_ Fixed in 16257.
claunia commented 2026-01-30 21:43:15 +00:00
Author
Owner
Copy Link

@DHowett-MSFT commented on GitHub (May 18, 2019):

This was marked fixed and then unmarked without explanation; closing.

@DHowett-MSFT commented on GitHub (May 18, 2019): This was marked fixed and then unmarked without explanation; closing.
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 Area-Server Issue-Bug Product-Conhost Resolution-Fix-Available Work-Item
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#129
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?