//go:build windows

// Package processalive probes whether an operating-system process id still
// maps to a live process.
package processalive

import (
	"errors"

	"golang.org/x/sys/windows"
)

// Alive reports whether pid exists. Access denied counts as alive: the process
// exists even if the current user cannot wait on it.
func Alive(pid int) bool {
	if pid <= 0 {
		return false
	}
	handle, err := windows.OpenProcess(windows.SYNCHRONIZE, false, uint32(pid))
	if err != nil {
		return errors.Is(err, windows.ERROR_ACCESS_DENIED)
	}
	defer windows.CloseHandle(handle)

	status, err := windows.WaitForSingleObject(handle, 0)
	if err != nil {
		return false
	}
	return status == uint32(windows.WAIT_TIMEOUT)
}