dotcloud/docker

package process

import (
    "os"

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

// Alive returns true if process with a given pid is running.
func Alive(pid int) bool {
    h, err := windows.OpenProcess(windows.PROCESS_QUERY_LIMITED_INFORMATION, false, uint32(pid))
    if err != nil {
        return false
    }
    var c uint32
    err = windows.GetExitCodeProcess(h, &c)
    _ = windows.CloseHandle(h)
    if err != nil {
        // From the GetExitCodeProcess function (processthreadsapi.h) API docs:
        // https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-getexitcodeprocess
        //
        // The GetExitCodeProcess function returns a valid error code defined by the
        // application only after the thread terminates. Therefore, an application should
        // not use STILL_ACTIVE (259) as an error code (STILL_ACTIVE is a macro for
        // STATUS_PENDING (minwinbase.h)). If a thread returns STILL_ACTIVE (259) as
        // an error code, then applications that test for that value could interpret it
        // to mean that the thread is still running, and continue to test for the
        // completion of the thread after the thread has terminated, which could put
        // the application into an infinite loop.
        return c == uint32(windows.STATUS_PENDING)
    }
    return true
}

// Kill force-stops a process.
func Kill(pid int) error {
    p, err := os.FindProcess(pid)
    if err == nil {
        err = p.Kill()
        if err != nil && err != os.ErrProcessDone {
            return err
        }
    }
    return nil
}