Source file src/pkg/os/exec_unix.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	// +build aix darwin dragonfly freebsd js,wasm 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	

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