Very Confused why ProcessStartInfo.CreateNewProcessGroup is Windows only

[joshudson]

It doesn't make a lot of sense to me. Linux has a very similar concept by the same name; where a new process can be created in a new process group; causing ^C and ^Z handling to change by virtue of being in the other group.

[stephentoub]

#117105 (comment)
cc: @jkotas

[jkotas]

On Windows, process groups are console-level concept that has to be used in a very specific way. The parent and child have to cooperate - the child process that starts the process group has to call SetConsoleCtrlHandler API to allow the console events to be delivered.

On Unix, process groups are kernel-level concept, independent on the terminal. Windows job objects are closer equivalent. Process groups on Unix are used for resource control, they are more flexible, there is no handshake cooperation required between parent and child to enable signal delivery,

It would be certainly possible to overload CreateNewProcessGroup to do something on non-Windows too. My concern was that it may lead to confusion since the accompanying code would likely need to have Windows-specific conditions to handle the Windows vs. non-Windows differences.

[jkotas]

For reference, dotnet/sdk#49847 is the change that took advantage of this flag in .NET SDK on Windows - look for all Windows-specific code in that change.

[joshudson]

Well, I thought I had an active potential user (currently P/Invoking setpgrp after the exec) but on trying to find it I concluded it doesn't exist anymore. Oh well.