1 files changed, 41 insertions, 0 deletions
diff --git a/libgo/go/os/wait_wait6.go b/libgo/go/os/wait_wait6.go
new file mode 100644
index 0000000000..b30981199e
--- /dev/null
+++ b/libgo/go/os/wait_wait6.go
@@ -0,0 +1,41 @@
+// 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
+	// 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 ARM, MIPS or PowerPC
+	if runtime.GOARCH == "386" {
+		_, _, errno = syscall.Syscall9(syscall.SYS_WAIT6, _P_PID, uintptr(p.Pid), 0, 0, syscall.WEXITED|syscall.WNOWAIT, 0, 0, 0, 0)
+	} else if runtime.GOARCH == "arm" {
+		_, _, errno = syscall.Syscall9(syscall.SYS_WAIT6, _P_PID, 0, uintptr(p.Pid), 0, 0, syscall.WEXITED|syscall.WNOWAIT, 0, 0, 0)
+	} else {
+		_, _, errno = syscall.Syscall6(syscall.SYS_WAIT6, _P_PID, uintptr(p.Pid), 0, syscall.WEXITED|syscall.WNOWAIT, 0, 0)
+	}
+	runtime.KeepAlive(p)
+	if errno != 0 {
+		// The wait6 system call is supported only on FreeBSD
+		// 9.3 and above, so it may return an ENOSYS error.
+		if errno == syscall.ENOSYS {
+			return false, nil
+		}
+		return false, NewSyscallError("wait6", errno)
+	}
+	return true, nil
+}