wait_wait6.go

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