mirror of https://go.googlesource.com/go
119 lines
2.7 KiB
Go
119 lines
2.7 KiB
Go
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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//go:build unix || (js && wasm) || wasip1
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package os
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import (
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"errors"
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"runtime"
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"syscall"
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"time"
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)
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func (p *Process) wait() (ps *ProcessState, err error) {
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if p.Pid == -1 {
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return nil, syscall.EINVAL
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}
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// Wait on pidfd if possible; fallback to using pid on ENOSYS.
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//
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// When pidfd is used, there is no wait/kill race (described in CL 23967)
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// because PID recycle issue doesn't exist (IOW, pidfd, unlike PID, is
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// guaranteed to refer to one particular process). Thus, there is no
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// need for the workaround (blockUntilWaitable + sigMu) below.
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if ps, e := p.pidfdWait(); e != syscall.ENOSYS {
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return ps, NewSyscallError("waitid", e)
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}
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// If we can block until Wait4 will succeed immediately, do so.
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ready, err := p.blockUntilWaitable()
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if err != nil {
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return nil, err
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}
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if ready {
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// Mark the process done now, before the call to Wait4,
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// so that Process.signal will not send a signal.
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p.setDone()
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// Acquire a write lock on sigMu to wait for any
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// active call to the signal method to complete.
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p.sigMu.Lock()
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p.sigMu.Unlock()
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}
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var (
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status syscall.WaitStatus
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rusage syscall.Rusage
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pid1 int
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e error
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)
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for {
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pid1, e = syscall.Wait4(p.Pid, &status, 0, &rusage)
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if e != syscall.EINTR {
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break
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}
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}
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if e != nil {
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return nil, NewSyscallError("wait", e)
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}
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p.setDone()
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ps = &ProcessState{
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pid: pid1,
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status: status,
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rusage: &rusage,
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}
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return ps, nil
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}
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func (p *Process) signal(sig Signal) error {
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if p.Pid == -1 {
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return errors.New("os: process already released")
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}
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if p.Pid == 0 {
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return errors.New("os: process not initialized")
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}
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s, ok := sig.(syscall.Signal)
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if !ok {
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return errors.New("os: unsupported signal type")
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}
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// Use pidfd if possible; fallback on ENOSYS.
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if err := p.pidfdSendSignal(s); err != syscall.ENOSYS {
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return err
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}
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p.sigMu.RLock()
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defer p.sigMu.RUnlock()
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if p.done() {
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return ErrProcessDone
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}
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return convertESRCH(syscall.Kill(p.Pid, s))
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}
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func convertESRCH(err error) error {
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if err == syscall.ESRCH {
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return ErrProcessDone
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}
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return err
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}
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func (p *Process) release() error {
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p.pidfdRelease()
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p.Pid = -1
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// no need for a finalizer anymore
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runtime.SetFinalizer(p, nil)
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return nil
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}
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func findProcess(pid int) (p *Process, err error) {
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// NOOP for unix.
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return newProcess(pid, unsetHandle), nil
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}
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func (p *ProcessState) userTime() time.Duration {
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return time.Duration(p.rusage.Utime.Nano()) * time.Nanosecond
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}
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func (p *ProcessState) systemTime() time.Duration {
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return time.Duration(p.rusage.Stime.Nano()) * time.Nanosecond
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}
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