github.com/code-reading/golang@v0.0.0-20220303082512-ba5bc0e589a3/go/src/os/wait_wait6.go (about) 1 // Copyright 2016 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 dragonfly || freebsd || netbsd 6 // +build dragonfly freebsd netbsd 7 8 package os 9 10 import ( 11 "runtime" 12 "syscall" 13 ) 14 15 const _P_PID = 0 16 17 // blockUntilWaitable attempts to block until a call to p.Wait will 18 // succeed immediately, and reports whether it has done so. 19 // It does not actually call p.Wait. 20 func (p *Process) blockUntilWaitable() (bool, error) { 21 var errno syscall.Errno 22 for { 23 // The arguments on 32-bit FreeBSD look like the following: 24 // - freebsd32_wait6_args{ idtype, id1, id2, status, options, wrusage, info } or 25 // - freebsd32_wait6_args{ idtype, pad, id1, id2, status, options, wrusage, info } when PAD64_REQUIRED=1 on ARM, MIPS or PowerPC 26 if runtime.GOOS == "freebsd" && runtime.GOARCH == "386" { 27 _, _, errno = syscall.Syscall9(syscall.SYS_WAIT6, _P_PID, uintptr(p.Pid), 0, 0, syscall.WEXITED|syscall.WNOWAIT, 0, 0, 0, 0) 28 } else if runtime.GOOS == "freebsd" && runtime.GOARCH == "arm" { 29 _, _, errno = syscall.Syscall9(syscall.SYS_WAIT6, _P_PID, 0, uintptr(p.Pid), 0, 0, syscall.WEXITED|syscall.WNOWAIT, 0, 0, 0) 30 } else { 31 _, _, errno = syscall.Syscall6(syscall.SYS_WAIT6, _P_PID, uintptr(p.Pid), 0, syscall.WEXITED|syscall.WNOWAIT, 0, 0) 32 } 33 if errno != syscall.EINTR { 34 break 35 } 36 } 37 runtime.KeepAlive(p) 38 if errno == syscall.ENOSYS { 39 return false, nil 40 } else if errno != 0 { 41 return false, NewSyscallError("wait6", errno) 42 } 43 return true, nil 44 }