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 // +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris 6 7 package os 8 9 import ( 10 "errors" 11 "runtime" 12 "syscall" 13 "time" 14 ) 15 16 func (p *Process) wait() (ps *ProcessState, err error) { 17 if p.Pid == -1 { 18 return nil, syscall.EINVAL 19 } 20 21 // If we can block until Wait4 will succeed immediately, do so. 22 ready, err := p.blockUntilWaitable() 23 if err != nil { 24 return nil, err 25 } 26 if ready { 27 // Mark the process done now, before the call to Wait4, 28 // so that Process.signal will not send a signal. 29 p.setDone() 30 // Acquire a write lock on sigMu to wait for any 31 // active call to the signal method to complete. 32 p.sigMu.Lock() 33 p.sigMu.Unlock() 34 } 35 36 var status syscall.WaitStatus 37 var rusage syscall.Rusage 38 pid1, e := syscall.Wait4(p.Pid, &status, 0, &rusage) 39 if e != nil { 40 return nil, NewSyscallError("wait", e) 41 } 42 if pid1 != 0 { 43 p.setDone() 44 } 45 ps = &ProcessState{ 46 pid: pid1, 47 status: status, 48 rusage: &rusage, 49 } 50 return ps, nil 51 } 52 53 var errFinished = errors.New("os: process already finished") 54 55 func (p *Process) signal(sig Signal) error { 56 if p.Pid == -1 { 57 return errors.New("os: process already released") 58 } 59 if p.Pid == 0 { 60 return errors.New("os: process not initialized") 61 } 62 p.sigMu.RLock() 63 defer p.sigMu.RUnlock() 64 if p.done() { 65 return errFinished 66 } 67 s, ok := sig.(syscall.Signal) 68 if !ok { 69 return errors.New("os: unsupported signal type") 70 } 71 if e := syscall.Kill(p.Pid, s); e != nil { 72 if e == syscall.ESRCH { 73 return errFinished 74 } 75 return e 76 } 77 return nil 78 } 79 80 func (p *Process) release() error { 81 // NOOP for unix. 82 p.Pid = -1 83 // no need for a finalizer anymore 84 runtime.SetFinalizer(p, nil) 85 return nil 86 } 87 88 func findProcess(pid int) (p *Process, err error) { 89 // NOOP for unix. 90 return newProcess(pid, 0), nil 91 } 92 93 func (p *ProcessState) userTime() time.Duration { 94 return time.Duration(p.rusage.Utime.Nano()) * time.Nanosecond 95 } 96 97 func (p *ProcessState) systemTime() time.Duration { 98 return time.Duration(p.rusage.Stime.Nano()) * time.Nanosecond 99 } 100
