Files
narratio/internal/adapters/subprocess/process_tree_unix.go

105 lines
2.5 KiB
Go

//go:build linux || darwin
package subprocess
import (
"errors"
"fmt"
"os"
"os/exec"
"syscall"
"time"
)
const processGroupPollInterval = 10 * time.Millisecond
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) Dispose() error {
hasMembers, err := tree.hasMembers()
if err != nil || !hasMembers {
return err
}
cleanupErr := tree.TerminateGracefully()
empty, waitErr := tree.waitUntilEmpty(gracefulTerminationWait)
cleanupErr = joinErrors(cleanupErr, waitErr)
if empty {
return cleanupErr
}
cleanupErr = joinErrors(cleanupErr, tree.TerminateForcefully())
empty, waitErr = tree.waitUntilEmpty(forcefulTerminationWait)
cleanupErr = joinErrors(cleanupErr, waitErr)
if !empty {
cleanupErr = joinErrors(cleanupErr, fmt.Errorf("owned subprocess group did not exit within %s after forceful termination", forcefulTerminationWait))
}
return cleanupErr
}
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
}
func (tree *unixProcessTree) hasMembers() (bool, error) {
if tree.processGroupID <= 0 {
return false, nil
}
err := syscall.Kill(-tree.processGroupID, 0)
if err == nil || errors.Is(err, syscall.EPERM) {
return true, nil
}
if errors.Is(err, syscall.ESRCH) || errors.Is(err, os.ErrProcessDone) {
return false, nil
}
return false, fmt.Errorf("inspect owned subprocess group: %w", err)
}
func (tree *unixProcessTree) waitUntilEmpty(timeout time.Duration) (bool, error) {
deadline := time.Now().Add(timeout)
for {
hasMembers, err := tree.hasMembers()
if err != nil || !hasMembers {
return !hasMembers, err
}
remaining := time.Until(deadline)
if remaining <= 0 {
return false, nil
}
if remaining > processGroupPollInterval {
remaining = processGroupPollInterval
}
time.Sleep(remaining)
}
}