1 files changed, 38 insertions, 0 deletions
diff --git a/tools/checklocks/test/defer.go b/tools/checklocks/test/defer.go
new file mode 100644
index 000000000..6e574e5eb
--- /dev/null
+++ b/tools/checklocks/test/defer.go
@@ -0,0 +1,38 @@
+// Copyright 2020 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 test
+
+func testDeferValidUnlock(tc *oneGuardStruct) {
+	tc.mu.Lock()
+	tc.guardedField = 1
+	defer tc.mu.Unlock()
+}
+
+func testDeferValidAccess(tc *oneGuardStruct) {
+	tc.mu.Lock()
+	defer func() {
+		tc.guardedField = 1
+		tc.mu.Unlock()
+	}()
+}
+
+func testDeferInvalidAccess(tc *oneGuardStruct) {
+	tc.mu.Lock()
+	defer func() {
+		// N.B. Executed after tc.mu.Unlock().
+		tc.guardedField = 1 // +checklocksfail
+	}()
+	tc.mu.Unlock()
+}