Terminate owned subprocess trees

internal/adapters/subprocess/process_tree_unix.go

@@ -0,0 +1,50 @@
+//go:build linux || darwin
+
+package subprocess
+
+import (
+	"errors"
+	"os"
+	"os/exec"
+	"syscall"
+)
+
+type unixProcessTree struct {
+	processGroupID int
+}
+
+func newOwnedProcessTree() (ownedProcessTree, error) {
+	return &unixProcessTree{}, nil
+}
+
+func (tree *unixProcessTree) Start(cmd *exec.Cmd) error {
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
+	if err := cmd.Start(); err != nil {
+		return err
+	}
+	tree.processGroupID = cmd.Process.Pid
+	return nil
+}
+
+func (tree *unixProcessTree) TerminateGracefully() error {
+	return tree.signal(syscall.SIGTERM)
+}
+
+func (tree *unixProcessTree) TerminateForcefully() error {
+	return tree.signal(syscall.SIGKILL)
+}
+
+func (tree *unixProcessTree) Close() error {
+	return nil
+}
+
+func (tree *unixProcessTree) signal(signal syscall.Signal) error {
+	if tree.processGroupID <= 0 {
+		return nil
+	}
+	err := syscall.Kill(-tree.processGroupID, signal)
+	if errors.Is(err, syscall.ESRCH) || errors.Is(err, os.ErrProcessDone) {
+		return nil
+	}
+	return err
+}