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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