Perf test to measure various mechanisms to track CPU.

Change-Id: I84cac933c62b03421632a7321a40526d9d3884cf
Test: this is a test

1 files changed, 80 insertions, 0 deletions

diff --git a/apct-tests/perftests/core/src/android/os/CpuUsageTrackingPerfTest.java b/apct-tests/perftests/core/src/android/os/CpuUsageTrackingPerfTest.java
new file mode 100644
index 000000000000..4961b4f94057
--- /dev/null
+++ b/apct-tests/perftests/core/src/android/os/CpuUsageTrackingPerfTest.java
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+package android.os;
+
+import android.perftests.utils.BenchmarkState;
+import android.perftests.utils.PerfStatusReporter;
+import android.support.test.filters.LargeTest;
+import android.support.test.runner.AndroidJUnit4;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.nio.file.Files;
+import java.nio.file.Paths;
+
+
+/**
+ * Performance tests collecting CPU data different mechanisms.
+ */
+@RunWith(AndroidJUnit4.class)
+@LargeTest
+public class CpuUsageTrackingPerfTest {
+    @Rule
+    public PerfStatusReporter mPerfStatusReporter = new PerfStatusReporter();
+
+    @Test
+    public void timeSystemThread() {
+        final BenchmarkState state = mPerfStatusReporter.getBenchmarkState();
+        Binder b = new Binder();
+        while (state.keepRunning()) {
+            SystemClock.currentThreadTimeMicro();
+        }
+    }
+
+    @Test
+    public void timeReadStatFileDirectly() throws Exception {
+        final BenchmarkState state = mPerfStatusReporter.getBenchmarkState();
+        // CPU usage by frequency for this pid. Data is in text format.
+        final String procFile = "/proc/self/stat";
+        while (state.keepRunning()) {
+            byte[] data = Files.readAllBytes(Paths.get(procFile));
+        }
+    }
+
+    @Test
+    public void timeReadPidProcDirectly() throws Exception {
+        final BenchmarkState state = mPerfStatusReporter.getBenchmarkState();
+        // CPU usage by frequency for this pid. Data is in text format.
+        final String procFile = "/proc/self/time_in_state";
+        while (state.keepRunning()) {
+            byte[] data = Files.readAllBytes(Paths.get(procFile));
+        }
+    }
+
+    @Test
+    public void timeReadThreadProcDirectly() throws Exception {
+        final BenchmarkState state = mPerfStatusReporter.getBenchmarkState();
+        // CPU usage by frequency for this UID. Data is in text format.
+        final String procFile = "/proc/self/task/" + android.os.Process.myTid()
+                + "/time_in_state";
+        while (state.keepRunning()) {
+            byte[] data = Files.readAllBytes(Paths.get(procFile));
+        }
+    }
+}