libgo/go/os/exec.go

   1 // Copyright 2009 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 package os
   6
   7 import (
   8         "runtime"
   9         "sync"
  10         "sync/atomic"
  11         "syscall"
  12 )
  13
  14 // Process stores the information about a process created by StartProcess.
  15 type Process struct {
  16         Pid    int
  17         handle uintptr      // handle is accessed atomically on Windows
  18         isdone uint32       // process has been successfully waited on, non zero if true
  19         sigMu  sync.RWMutex // avoid race between wait and signal
  20 }
  21
  22 func newProcess(pid int, handle uintptr) *Process {
  23         p := &Process{Pid: pid, handle: handle}
  24         runtime.SetFinalizer(p, (*Process).Release)
  25         return p
  26 }
  27
  28 func (p *Process) setDone() {
  29         atomic.StoreUint32(&p.isdone, 1)
  30 }
  31
  32 func (p *Process) done() bool {
  33         return atomic.LoadUint32(&p.isdone) > 0
  34 }
  35
  36 // ProcAttr holds the attributes that will be applied to a new process
  37 // started by StartProcess.
  38 type ProcAttr struct {
  39         // If Dir is non-empty, the child changes into the directory before
  40         // creating the process.
  41         Dir string
  42         // If Env is non-nil, it gives the environment variables for the
  43         // new process in the form returned by Environ.
  44         // If it is nil, the result of Environ will be used.
  45         Env []string
  46         // Files specifies the open files inherited by the new process. The
  47         // first three entries correspond to standard input, standard output, and
  48         // standard error. An implementation may support additional entries,
  49         // depending on the underlying operating system. A nil entry corresponds
  50         // to that file being closed when the process starts.
  51         Files []*File
  52
  53         // Operating system-specific process creation attributes.
  54         // Note that setting this field means that your program
  55         // may not execute properly or even compile on some
  56         // operating systems.
  57         Sys *syscall.SysProcAttr
  58 }
  59
  60 // A Signal represents an operating system signal.
  61 // The usual underlying implementation is operating system-dependent:
  62 // on Unix it is syscall.Signal.
  63 type Signal interface {
  64         String() string
  65         Signal() // to distinguish from other Stringers
  66 }
  67
  68 // Getpid returns the process id of the caller.
  69 func Getpid() int { return syscall.Getpid() }
  70
  71 // Getppid returns the process id of the caller's parent.
  72 func Getppid() int { return syscall.Getppid() }