// Copyright 2016 The Go Authors. All rights reserved.
|
// Use of this source code is governed by a BSD-style
|
// license that can be found in the LICENSE file.
|
|
// We used to used this code for Darwin, but according to issue #19314
|
// waitid returns if the process is stopped, even when using WEXITED.
|
|
// +build linux
|
|
package os
|
|
import (
|
"runtime"
|
"syscall"
|
"unsafe"
|
)
|
|
const _P_PID = 1
|
|
// blockUntilWaitable attempts to block until a call to p.Wait will
|
// succeed immediately, and reports whether it has done so.
|
// It does not actually call p.Wait.
|
func (p *Process) blockUntilWaitable() (bool, error) {
|
// The waitid system call expects a pointer to a siginfo_t,
|
// which is 128 bytes on all GNU/Linux systems.
|
// On Darwin, it requires greater than or equal to 64 bytes
|
// for darwin/{386,arm} and 104 bytes for darwin/amd64.
|
// We don't care about the values it returns.
|
var siginfo [16]uint64
|
psig := &siginfo[0]
|
_, _, e := syscall.Syscall6(syscall.SYS_WAITID, _P_PID, uintptr(p.Pid), uintptr(unsafe.Pointer(psig)), syscall.WEXITED|syscall.WNOWAIT, 0, 0)
|
runtime.KeepAlive(p)
|
if e != 0 {
|
// waitid has been available since Linux 2.6.9, but
|
// reportedly is not available in Ubuntu on Windows.
|
// See issue 16610.
|
if e == syscall.ENOSYS {
|
return false, nil
|
}
|
return false, NewSyscallError("waitid", e)
|
}
|
return true, nil
|
}
|
