Merge "block_suspend: test util to block suspend from shell"

Android.bp

@@ -74,3 +74,14 @@ cc_library_shared {
         "uevent.c",
     ],
 }
+
+cc_test {
+    name: "block_suspend",
+    defaults: ["libpower_defaults"],
+    srcs: ["block_suspend.cpp"],
+    static_libs: ["libpower"],
+    shared_libs: [
+        "android.system.suspend@1.0",
+    ],
+    gtest: false,
+}

block_suspend.cpp

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#include <iostream>
+
+#include <wakelock/wakelock.h>
+
+static constexpr const char *gWakeLockName = "block_suspend";
+
+static void usage() {
+    std::cout << "Usage: block_suspend\n"
+              << "Prevent device from suspending indefinitely. "
+              << "Process must be killed to unblock suspend.\n";
+}
+
+int main(int argc, char ** /* argv */) {
+    if (argc > 1) {
+        usage();
+        return 0;
+    }
+
+    android::wakelock::WakeLock wl{gWakeLockName};  // RAII object
+    while (true) {};
+    std::abort();  // should never reach here
+    return 0;
+}