exec_unix.go

Documentation: os

     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  //go:build aix || darwin || dragonfly || freebsd || (js && wasm) || linux || netbsd || openbsd || solaris
     6  // +build aix darwin dragonfly freebsd js,wasm linux netbsd openbsd solaris
     7  
     8  package os
     9  
    10  import (
    11  	"errors"
    12  	"runtime"
    13  	"syscall"
    14  	"time"
    15  )
    16  
    17  func (p *Process) wait() (ps *ProcessState, err error) {
    18  	if p.Pid == -1 {
    19  		return nil, syscall.EINVAL
    20  	}
    21  
    22  	// If we can block until Wait4 will succeed immediately, do so.
    23  	ready, err := p.blockUntilWaitable()
    24  	if err != nil {
    25  		return nil, err
    26  	}
    27  	if ready {
    28  		// Mark the process done now, before the call to Wait4,
    29  		// so that Process.signal will not send a signal.
    30  		p.setDone()
    31  		// Acquire a write lock on sigMu to wait for any
    32  		// active call to the signal method to complete.
    33  		p.sigMu.Lock()
    34  		p.sigMu.Unlock()
    35  	}
    36  
    37  	var (
    38  		status syscall.WaitStatus
    39  		rusage syscall.Rusage
    40  		pid1   int
    41  		e      error
    42  	)
    43  	for {
    44  		pid1, e = syscall.Wait4(p.Pid, &status, 0, &rusage)
    45  		if e != syscall.EINTR {
    46  			break
    47  		}
    48  	}
    49  	if e != nil {
    50  		return nil, NewSyscallError("wait", e)
    51  	}
    52  	if pid1 != 0 {
    53  		p.setDone()
    54  	}
    55  	ps = &ProcessState{
    56  		pid:    pid1,
    57  		status: status,
    58  		rusage: &rusage,
    59  	}
    60  	return ps, nil
    61  }
    62  
    63  func (p *Process) signal(sig Signal) error {
    64  	if p.Pid == -1 {
    65  		return errors.New("os: process already released")
    66  	}
    67  	if p.Pid == 0 {
    68  		return errors.New("os: process not initialized")
    69  	}
    70  	p.sigMu.RLock()
    71  	defer p.sigMu.RUnlock()
    72  	if p.done() {
    73  		return ErrProcessDone
    74  	}
    75  	s, ok := sig.(syscall.Signal)
    76  	if !ok {
    77  		return errors.New("os: unsupported signal type")
    78  	}
    79  	if e := syscall.Kill(p.Pid, s); e != nil {
    80  		if e == syscall.ESRCH {
    81  			return ErrProcessDone
    82  		}
    83  		return e
    84  	}
    85  	return nil
    86  }
    87  
    88  func (p *Process) release() error {
    89  	// NOOP for unix.
    90  	p.Pid = -1
    91  	// no need for a finalizer anymore
    92  	runtime.SetFinalizer(p, nil)
    93  	return nil
    94  }
    95  
    96  func findProcess(pid int) (p *Process, err error) {
    97  	// NOOP for unix.
    98  	return newProcess(pid, 0), nil
    99  }
   100  
   101  func (p *ProcessState) userTime() time.Duration {
   102  	return time.Duration(p.rusage.Utime.Nano()) * time.Nanosecond
   103  }
   104  
   105  func (p *ProcessState) systemTime() time.Duration {
   106  	return time.Duration(p.rusage.Stime.Nano()) * time.Nanosecond
   107  }
   108
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