Check in gVisor.

PiperOrigin-RevId: 194583126
Change-Id: Ica1d8821a90f74e7e745962d71801c598c652463

1 files changed, 36 insertions, 0 deletions

diff --git a/pkg/sentry/platform/context.go b/pkg/sentry/platform/context.go
new file mode 100644
index 000000000..0d200a5e2
--- /dev/null
+++ b/pkg/sentry/platform/context.go
@@ -0,0 +1,36 @@
+// Copyright 2018 Google Inc.
+//
+// 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 platform
+
+import (
+	"gvisor.googlesource.com/gvisor/pkg/sentry/context"
+)
+
+// contextID is the auth package's type for context.Context.Value keys.
+type contextID int
+
+const (
+	// CtxPlatform is a Context.Value key for a Platform.
+	CtxPlatform contextID = iota
+)
+
+// FromContext returns the Platform that is used to execute ctx's application
+// code, or nil if no such Platform exists.
+func FromContext(ctx context.Context) Platform {
+	if v := ctx.Value(CtxPlatform); v != nil {
+		return v.(Platform)
+	}
+	return nil
+}