1 files changed, 36 insertions, 0 deletions
diff --git a/pkg/eventfd/eventfd_unsafe.go b/pkg/eventfd/eventfd_unsafe.go
new file mode 100644
index 000000000..bb9698f95
--- /dev/null
+++ b/pkg/eventfd/eventfd_unsafe.go
@@ -0,0 +1,36 @@
+// Copyright 2021 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package eventfd
+
+import (
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
+
+// nonBlockingWrite writes the given buffer to a file descriptor. It fails if
+// partial data is written.
+func nonBlockingWrite(fd int, buf []byte) (int, error) {
+	var ptr unsafe.Pointer
+	if len(buf) > 0 {
+		ptr = unsafe.Pointer(&buf[0])
+	}
+
+	nwritten, _, errno := unix.RawSyscall(unix.SYS_WRITE, uintptr(fd), uintptr(ptr), uintptr(len(buf)))
+	if errno != 0 {
+		return int(nwritten), errno
+	}
+	return int(nwritten), nil
+}