archivmail/internal/safego/safego.go

// Package safego starts background goroutines that cannot take the process
// down. A panic inside a detached goroutine is fatal for the whole binary in
// Go — there is no per-goroutine boundary like net/http provides for request
// handlers. Every "fire and forget" goroutine in archivmail (mail sending,
// importer runs, boot-resume jobs) therefore goes through Go/Run.
package safego

import (
	"fmt"
	"log/slog"
)

// Run executes fn synchronously and recovers from a panic, logging it with the
// given name. It returns true when fn completed without panicking.
func Run(logger *slog.Logger, name string, fn func()) (ok bool) {
	defer func() {
		if r := recover(); r != nil {
			ok = false
			if logger != nil {
				logger.Error("recovered from panic in background task",
					"task", name, "panic", fmt.Sprintf("%v", r))
			}
		}
	}()
	fn()
	return true
}

// Go runs fn in a new goroutine, recovering and logging any panic.
func Go(logger *slog.Logger, name string, fn func()) {
	go Run(logger, name, fn) //nolint:errcheck // result is irrelevant for detached tasks
}