Improve child process management

[gsoltis]

• When we receive an external signal, send SIGINT to our child processes
• When a child process exits w/ a non-zero exit code, and --continue is not set, send SIGINT to all of our child processes

Practically, this means that hitting Ctrl+C on the terminal will shut down all of the child processes via SIGINT. Additionally, if one task fails, other tasks will not be left lingering, and will be sent a SIGINT.

Some considerations: if turbo is invoked via yarn or npm, it will not be the root of the process tree, and as such Ctrl+C will hand control back to the user before turbo has exited, meaning that the user will likely get stdout/stderr after the prompt has reappeared. I don't think there's anything we can do about this.

Running turbo directly should avoid this, with the exception of a child process failing to exit in the 10-second grace period.

Also note that as a result of this change, each child process is given its own process group. This is done so that we can send SIGINT to an entire child process tree without also sending it to ourselves. By default, all child processes would be in the same process tree as turbo.

Remaining work:

• testing
• resolve some questions on structure between process.Manager and the signal handling code
• document code modified from hashicorp/consul-template

Fixes #444
Fixes #470

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[jaredpalmer]

Makes sense so far to me

[scorsi]

In which Turbo version this PR will be available ? :)

[jaredpalmer]

Canary channel

On Thu, Feb 3, 2022 at 4:43 PM Sylvain Corsini ***@***.***> wrote: In which Turbo version this PR will be available ? :) — Reply to this email directly, view it on GitHub <#663 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AA67IG3XIDC7XGX5TJRPU43UZLZGPANCNFSM5NKQF65A> . You are receiving this because you modified the open/close state.Message ID: ***@***.***>

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