Expose terminal process ID through API

[Tyriar]

Part of #11422

[Tyriar]

Extension authors want to get at the process ID of the shell so they can track what they run, at least on a low level. The problem is that due to a bug in electron (electron/electron#38) there is another process in between the renderer thread and the shell which launches the shell, meaning it's an async operation to grab the PID after the terminal is created.

Therefore, in order to maintain backwards compatibility I think this will need to be exposed as a promise:

// Returns the shell PID
getProcessID(): Thenable<number>;

Alternatively we could expose the in-between process synchronously, it would probably mean more work and confusion for extension authors though:

// Returns the PID of the process that launches the shell
getProcessID(): number;

@jrieken does the Thenable version look reasonable given the situation?

[jrieken]

You could just expose the tenable property? Like

interface Terminal {
 // ...
 pid: Thenable<number>
}

[Tyriar]

If that's preferable 👍

[jrieken]

Yeah - I think that more JavaScript'ish

[Tyriar]

FYI @weinand for the debug stuff we discussed #9957

[Tyriar]

I ended up expanding to processId for clarity:

interface Terminal {
  processId: Thenable<number>
}

FYI @daviwil

[daviwil]

Awesome, thanks man!

[wclr]

@Tyriar So it is not there yet? Updated to latest insiders and terminal._id stopped to work.

[Tyriar]

@whitecolor insiders just exposed the above API terminal.processId. For your use case though you should use window.onDidCloseTerminal.

[wclr]

@Tyriar Ok processId is available now. As I've mentioned I used pid for getting number of child processes not only to determine if is opened/closed, but aslo its state (depending on number of currently running processes).

There seem to be a problemwith processId: it seem to expose some other id that was previously in terminal._id - number of its child processes always is zero (I use psTree to get running children).

And aslo why setProcessId is a public method? What does it supposed to do? https://github.com/Microsoft/vscode/blob/7236f593e7e8363ac940660a105c15e4f51ea198/src/vs/workbench/api/node/extHostTerminalService.ts#L70

[Tyriar]

@whitecolor processId is the shell process, not the process that launches the shell:

Before: _id was the pid of terminalProcess which spawned bash/zsh/cmd/etc.
After: processId is the pid of bash/zsh/cmd/etc. that was spawned by terminalProcess

The child processes of processId should be the programs launched by the shell.

setProcessId is public on ExtHostTerminalService but it's not part of the API interface so you should not be touching it, vscode.d.ts defines the API.

[wclr]

ok, but it seem that internal processes (running inside the console) is spawned not by this processesId, but by teminalProcess.

Btw processId is not available on the terminal just after window.createTerminal executed, have to wait some time, possible to fix?

[jrieken]

@Tyriar Maybe we should not make setProcessId a public method. How about a ctor argument which is the (still unresolved) promise of the process id. That will also not require having this ugly wait loop

[Tyriar]

@whitecolor processId being a promise cannot change due to a bug in Electron (electron/electron#38) forcing the in between process to begin with.

It doesn't seem right that the processes would be children of terminalProcess.js which only spawns the shell. I looked into this in the past and it worked fine. There's only a single spawn in terminalProcess https://github.com/Microsoft/vscode/blob/master/src/vs/workbench/parts/terminal/electron-browser/terminalProcess.js#L30 The processes launched by the terminal are launched by the shell that they're run in.

[Tyriar]

@jrieken 👍 #12434

[wclr]

@Tyriar ok, thanks, I will look into it more carefully

[wclr]

@Tyriar I check all process running in windows (wmic.exe PROCESS GET Name,ProcessId,ParentProcessId,Status) after terminal created and I can not find there pid returned by terminal.processId.then(...)

[Tyriar]

Can you launch vscode, the terminal and then some program in the terminal and see what the tree looks like? I expect it to be:

• VS Code
  • ...
  • terminalProcess.js
    • cmd.exe
      • program ran in cmd.exe

[wclr]

and see what the tree looks like

What tree? (where should I look it)? I just get pid, and check it either using wmic or process exlorer, there is not such pid at all. Should it be there?

[Tyriar]

@whitecolor depends on your platform, on Linux I can run pstree. This is the output I get, you can see that gulp is under bash:

        │         │         │         ├─code-insiders─┬─code-insiders───code-insiders─┬─code-insiders─┬─2*[code-insiders───{code-insiders}]
        │         │         │         │               │                               │               ├─code-insiders─┬─{WorkerPool/1113}
        │         │         │         │               │                               │               │               └─{code-insiders}
        │         │         │         │               │                               │               ├─{WorkerPool/1120}
        │         │         │         │               │                               │               └─5*[{code-insiders}]
        │         │         │         │               │                               ├─code-insiders─┬─2*[{WorkerPool/1150}]
        │         │         │         │               │                               │               ├─6*[{WorkerPool/1151}]
        │         │         │         │               │                               │               ├─{WorkerPool/9554}
        │         │         │         │               │                               │               └─5*[{code-insiders}]
        │         │         │         │               │                               ├─code-insiders─┬─{WorkerPool/1079}
        │         │         │         │               │                               │               ├─{WorkerPool/6316}
        │         │         │         │               │                               │               ├─{WorkerPool/7855}
        │         │         │         │               │                               │               └─5*[{code-insiders}]
        │         │         │         │               │                               ├─code-insiders─┬─bash───gulp─┬─4*[{V8 WorkerThread}]
        │         │         │         │               │                               │               │             ├─4*[{gulp}]
        │         │         │         │               │                               │               │             └─{node}
        │         │         │         │               │                               │               ├─2*[{WorkerPool/1149}]
        │         │         │         │               │                               │               └─2*[{code-insiders}]
        │         │         │         │               │                               ├─{Chrome_ChildIOT}
        │         │         │         │               │                               ├─3*[{CompositorTileW}]
        │         │         │         │               │                               ├─{Compositor}
        │         │         │         │               │                               ├─{HTMLParserThrea}
        │         │         │         │               │                               ├─{WorkerPool/1010}
        │         │         │         │               │                               ├─3*[{WorkerPool/1011}]
        │         │         │         │               │                               └─5*[{code-insiders}]

[wclr]

I run node:

There is pid 984 for node and 1436 for cmd

And processId gives 868 (no such pid at all)

[wclr]

@Tyriar can you confirm my issue with process id?

[Tyriar]

@whitecolor it's being tested today by 2 team members that will verify the process ID.

[wclr]

@Tyriar Was it a bug and fixed?

[Tyriar]

@whitecolor no bug has been reported so far, not sure how many people are using it though.

[wclr]

it's being tested today by 2 team members that will verify the process ID.

So it was tested and you can not confirm it?

[Tyriar]

Yes nothing was reported during the test phase and it's currently in stable.

[wclr]

@Tyriar Well I'm not sure how I should demonstate that something wrong here.

For me terminal.processId promise gives the PID value that doesn't exist in processes list at all. The terminal is running.

[Tyriar]

Created #14286 to track your issue