Configurable SIGTERM instead of SIGKILL

[plievone]

Hi, debug adapter uses SIGKILL (-9) to terminate child processes in Linux and MacOS:

• https://github.com/Microsoft/vscode-node-debug2/blob/2090b79/src/terminateProcess.sh#L7
• https://github.com/Microsoft/vscode-node-debug2/blob/2090b79/src/utils.ts#L37-L55

Could it be made configurable, so that one could use SIGTERM if one has some quick cleanup tasks in the process to be debugged? Currently they cannot run, as SIGKILL cannot be listened to. In the meantime, one can workaround this somewhat by using nodemon or such.

In case child processes won't exit when such non-default signals are used and there are leftover processes, they could be killed manually. Or perhaps one could implement treekill in cross platform way similar to https://github.com/indexzero/ps-tree .

[weinand]

The corresponding issue for node-debug is this microsoft/vscode-node-debug#1

(node-debug's very first issue!)

[weinand]

@plievone @roblourens
my proposal would be to use SIGTERM for the existing "Terminate" action and SIGKILL for a new "kill" action. A shortcut could be to use a modifier key when pressing the "Terminate" button.

Opinions?

[plievone]

@weinand That would be perfect, but would it mean that the "Terminate" action would need to check if the processes exited properly, so that the same debug toolbar can be used for "Kill" in case it is needed (instead of the toolbar hiding automatically)? Or is that a rare situation?

Also "Restart" action would need to use sigterm, that is the important one.

[samir-mahendra]

@weinand May I propose that you make the Terminate action a Launch Configuration attribute?

It could be called "stopSignal" or "terminateSignal", and default to "SIGKILL" if not specified (to maintain current functionality).

Then users could override it in their Launch Configuration. E.g., to send a "SIGINT" instead of "SIGKILL", they could update their launch configuration to:

// Proposed changed to launch.json
{
   "name": "Start",
   "type": "node",
   "request": "launch",
   "program": "${workspaceRoot}/start.js",
   "terminateSignal": "SIGINT" // <-- Proposed new configuration parameter.
}

[roblourens]

This is implemented now