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author | Mikio Hara <mikioh.mikioh@gmail.com> | 2016-06-11 19:55:34 +0900 |
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committer | Mikio Hara <mikioh.mikioh@gmail.com> | 2016-06-13 22:13:56 +0000 |
commit | 5d876e3e2eb3a30a8c66888912cf41785fa65a96 (patch) | |
tree | a2186c02c9ccbb2bcd8df54d528920909985ca98 | |
parent | ccd9a55609fcc8814146a7c61898b47e3a7aea7d (diff) | |
download | go-5d876e3e2eb3a30a8c66888912cf41785fa65a96.tar.gz go-5d876e3e2eb3a30a8c66888912cf41785fa65a96.zip |
os: use wait6 to avoid wait/kill race on freebsd
This change is a followup to https://go-review.googlesource.com/23967
for FreeBSD.
Updates #13987.
Updates #16028.
Change-Id: I0f0737372fce6df89d090fe9847305749b79eb4c
Reviewed-on: https://go-review.googlesource.com/24021
Reviewed-by: Ian Lance Taylor <iant@golang.org>
-rw-r--r-- | src/os/wait_unimp.go | 2 | ||||
-rw-r--r-- | src/os/wait_wait6.go | 46 |
2 files changed, 47 insertions, 1 deletions
diff --git a/src/os/wait_unimp.go b/src/os/wait_unimp.go index 254bf7ec17..7059e59ab2 100644 --- a/src/os/wait_unimp.go +++ b/src/os/wait_unimp.go @@ -2,7 +2,7 @@ // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. -// +build dragonfly freebsd nacl netbsd openbsd solaris +// +build dragonfly nacl netbsd openbsd solaris package os diff --git a/src/os/wait_wait6.go b/src/os/wait_wait6.go new file mode 100644 index 0000000000..279c6f2804 --- /dev/null +++ b/src/os/wait_wait6.go @@ -0,0 +1,46 @@ +// 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. + +// +build freebsd + +package os + +import ( + "runtime" + "syscall" +) + +const _P_PID = 0 + +// blockUntilWaitable attempts to block until a call to p.Wait will +// succeed immediately, and returns whether it has done so. +// It does not actually call p.Wait. +func (p *Process) blockUntilWaitable() (bool, error) { + var errno syscall.Errno + switch runtime.GOARCH { + case "386", "arm": + // The arguments on 32-bit FreeBSD look like the + // following: + // - freebsd32_wait6_args{ idtype, id1, id2, status, options, wrusage, info } or + // - freebsd32_wait6_args{ idtype, pad, id1, id2, status, options, wrusage, info } when PAD64_REQUIRED=1 on MIPS or PowerPC + _, _, errno = syscall.Syscall9(syscall.SYS_WAIT6, _P_PID, 0, uintptr(p.Pid), 0, syscall.WEXITED|syscall.WNOWAIT, 0, 0, 0, 0) + default: + _, _, errno = syscall.Syscall6(syscall.SYS_WAIT6, _P_PID, uintptr(p.Pid), 0, syscall.WEXITED|syscall.WNOWAIT, 0, 0) + } + if errno != 0 { + // The wait6 system call is supported only on FreeBSD + // 9.3 and above, so it may return an ENOSYS error. + // Also the system call may return an ECHILD error + // when the child process has not finished the + // transformation using execve system call. + // In both cases, we just leave the care of child + // process to the following wait4 system call in + // Process.wait. + if errno == syscall.ENOSYS || errno == syscall.ECHILD { + return false, nil + } + return false, NewSyscallError("wait6", errno) + } + return true, nil +} |