1 files changed, 56 insertions, 0 deletions
diff --git a/tools/checklocks/test/branches.go b/tools/checklocks/test/branches.go
new file mode 100644
index 000000000..81fec29e5
--- /dev/null
+++ b/tools/checklocks/test/branches.go
@@ -0,0 +1,56 @@
+// 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
+
+import (
+	"math/rand"
+)
+
+func testInconsistentReturn(tc *oneGuardStruct) { // +checklocksfail
+	if x := rand.Intn(10); x%2 == 1 {
+		tc.mu.Lock()
+	}
+}
+
+func testConsistentBranching(tc *oneGuardStruct) {
+	x := rand.Intn(10)
+	if x%2 == 1 {
+		tc.mu.Lock()
+	} else {
+		tc.mu.Lock()
+	}
+	tc.guardedField = 1
+	if x%2 == 1 {
+		tc.mu.Unlock()
+	} else {
+		tc.mu.Unlock()
+	}
+}
+
+func testInconsistentBranching(tc *oneGuardStruct) { // +checklocksfail:2
+	// We traverse the control flow graph in all consistent ways. We cannot
+	// determine however, that the first if block and second if block will
+	// evaluate to the same condition. Therefore, there are two consistent
+	// paths through this code, and two inconsistent paths. Either way, the
+	// guardedField should be also marked as an invalid access.
+	x := rand.Intn(10)
+	if x%2 == 1 {
+		tc.mu.Lock()
+	}
+	tc.guardedField = 1 // +checklocksfail
+	if x%2 == 1 {
+		tc.mu.Unlock() // +checklocksforce
+	}
+}