SystemMemoryTest: Introduce Device class.

As an abstraction to hold common utilities for interacting with the
device.

Also, coalesce exceptions into a new common TestException class.

Bug: 111830582
Test: atest -v system-memory-test
Change-Id: Ia297427bdcabce38631e7f760149d58c8a5bdd27

5 files changed, 143 insertions, 69 deletions

diff --git a/tests/SystemMemoryTest/host/src/com/android/tests/sysmem/host/Cujs.java b/tests/SystemMemoryTest/host/src/com/android/tests/sysmem/host/Cujs.java
index 1b638747ee09..b605e62db0f2 100644
--- a/tests/SystemMemoryTest/host/src/com/android/tests/sysmem/host/Cujs.java
+++ b/tests/SystemMemoryTest/host/src/com/android/tests/sysmem/host/Cujs.java
@@ -16,24 +16,21 @@
 
 package com.android.tests.sysmem.host;
 
-import com.android.tradefed.device.DeviceNotAvailableException;
-import com.android.tradefed.device.ITestDevice;
-
 /**
  * Critical user journeys with which to exercise the system, driven from the
  * host.
  */
 public class Cujs {
-    private ITestDevice mDevice;
+    private Device mDevice;
 
-    public Cujs(ITestDevice device) {
+    public Cujs(Device device) {
         this.mDevice = device;
     }
 
     /**
      * Runs the critical user journeys.
      */
-    public void run() throws DeviceNotAvailableException {
+    public void run() throws TestException {
         // Invoke the Device Cujs instrumentation to run the cujs.
         // TODO: Consider exercising the system in other interesting ways as
         // well.
diff --git a/tests/SystemMemoryTest/host/src/com/android/tests/sysmem/host/Device.java b/tests/SystemMemoryTest/host/src/com/android/tests/sysmem/host/Device.java
new file mode 100644
index 000000000000..03503cec5fec
--- /dev/null
+++ b/tests/SystemMemoryTest/host/src/com/android/tests/sysmem/host/Device.java
@@ -0,0 +1,86 @@
+/*
+ * 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 com.android.tests.sysmem.host;
+
+import com.android.tradefed.device.DeviceNotAvailableException;
+import com.android.tradefed.device.ITestDevice;
+
+import java.util.InputMismatchException;
+import java.util.Scanner;
+
+/**
+ * Wrapper around ITestDevice exposing useful device functions.
+ */
+class Device {
+
+    private ITestDevice mDevice;
+
+    Device(ITestDevice device) {
+        mDevice = device;
+    }
+
+    /**
+     * Execute a shell command and return the output as a string.
+     */
+    public String executeShellCommand(String command) throws TestException {
+        try {
+            return mDevice.executeShellCommand(command);
+        } catch (DeviceNotAvailableException e) {
+            throw new TestException(e);
+        }
+    }
+
+    /**
+     * Enable adb root
+     */
+    public void enableAdbRoot() throws TestException {
+        try {
+            mDevice.enableAdbRoot();
+        } catch (DeviceNotAvailableException e) {
+            throw new TestException(e);
+        }
+    }
+
+    /**
+     * Returns the pid for the process with the given name.
+     */
+    public int getPidForProcess(String name) throws TestException {
+        String psout = executeShellCommand("ps -A -o PID,CMD");
+        Scanner sc = new Scanner(psout);
+        try {
+            // ps output is of the form:
+            //  PID CMD
+            //    1 init
+            //    2 kthreadd
+            //    ...
+            // 9693 ps
+            sc.nextLine();
+            while (sc.hasNextLine()) {
+                int pid = sc.nextInt();
+                String cmd = sc.next();
+
+                if (name.equals(cmd)) {
+                    return pid;
+                }
+            }
+        } catch (InputMismatchException e) {
+            throw new TestException("unexpected ps output format: " + psout, e);
+        }
+
+        throw new TestException("failed to get pid for process " + name);
+    }
+}
diff --git a/tests/SystemMemoryTest/host/src/com/android/tests/sysmem/host/MemoryTest.java b/tests/SystemMemoryTest/host/src/com/android/tests/sysmem/host/MemoryTest.java
index cfd598da1a5f..48b7f393d0a3 100644
--- a/tests/SystemMemoryTest/host/src/com/android/tests/sysmem/host/MemoryTest.java
+++ b/tests/SystemMemoryTest/host/src/com/android/tests/sysmem/host/MemoryTest.java
@@ -16,7 +16,6 @@
 
 package com.android.tests.sysmem.host;
 
-import com.android.tradefed.device.DeviceNotAvailableException;
 import com.android.tradefed.device.ITestDevice;
 import com.android.tradefed.testtype.DeviceJUnit4ClassRunner;
 import com.android.tradefed.testtype.DeviceJUnit4ClassRunner.TestLogData;
@@ -27,8 +26,6 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
-import java.io.IOException;
-
 /**
  * Runs a system memory test.
  */
@@ -44,8 +41,9 @@ public class MemoryTest implements IDeviceTest {
     private Cujs mCujs;
 
     @Override
-    public void setDevice(ITestDevice device) {
-        mTestDevice = device;
+    public void setDevice(ITestDevice testDevice) {
+        mTestDevice = testDevice;
+        Device device = new Device(testDevice);
         mMetrics = new Metrics(device, testMetrics, testLogs);
         mCujs = new Cujs(device);
     }
@@ -56,14 +54,13 @@ public class MemoryTest implements IDeviceTest {
     }
 
     // Invoke a single iteration of running the cujs.
-    private void runCujs() throws DeviceNotAvailableException {
+    private void runCujs() throws TestException {
         mCujs.run();
         mIterations++;
     }
 
     // Sample desired memory.
-    private void sample()
-            throws DeviceNotAvailableException, IOException, Metrics.MetricsException {
+    private void sample() throws TestException {
         mMetrics.sample(String.format("%03d", mIterations));
     }
 
@@ -71,7 +68,7 @@ public class MemoryTest implements IDeviceTest {
      * Runs the memory tests.
      */
     @Test
-    public void run() throws Exception {
+    public void run() throws TestException {
         sample();   // Sample before running cujs
         runCujs();
         sample();   // Sample after first iteration of cujs
diff --git a/tests/SystemMemoryTest/host/src/com/android/tests/sysmem/host/Metrics.java b/tests/SystemMemoryTest/host/src/com/android/tests/sysmem/host/Metrics.java
index 70bc22c485e1..b408a81d8f93 100644
--- a/tests/SystemMemoryTest/host/src/com/android/tests/sysmem/host/Metrics.java
+++ b/tests/SystemMemoryTest/host/src/com/android/tests/sysmem/host/Metrics.java
@@ -16,8 +16,6 @@
 
 package com.android.tests.sysmem.host;
 
-import com.android.tradefed.device.DeviceNotAvailableException;
-import com.android.tradefed.device.ITestDevice;
 import com.android.tradefed.result.FileInputStreamSource;
 import com.android.tradefed.result.LogDataType;
 import com.android.tradefed.testtype.DeviceJUnit4ClassRunner.TestLogData;
@@ -34,24 +32,11 @@ import java.util.Scanner;
  */
 class Metrics {
 
-    private ITestDevice mDevice;
+    private Device mDevice;
     private TestMetrics mMetrics;
     private TestLogData mLogs;
 
     /**
-     * Exception thrown in case of error sampling metrics.
-     */
-    public static class MetricsException extends Exception {
-        MetricsException(String msg) {
-            super(msg);
-        }
-
-        MetricsException(String msg, Exception cause) {
-            super(msg, cause);
-        }
-    }
-
-    /**
      * Constructs a metrics instance that will output high level metrics and
      * more detailed breakdowns using the given <code>metrics</code> and
      * <code>logs</code> objects.
@@ -60,7 +45,7 @@ class Metrics {
      * @param metrics where to log the high level metrics when taking a sample
      * @param logs where to log detailed breakdowns when taking a sample
      */
-    Metrics(ITestDevice device, TestMetrics metrics, TestLogData logs) {
+    Metrics(Device device, TestMetrics metrics, TestLogData logs) {
         this.mDevice = device;
         this.mMetrics = metrics;
         this.mLogs = logs;
@@ -69,43 +54,17 @@ class Metrics {
     /**
      * Writes the given <code>text</code> to a log with the given label.
      */
-    private void logText(String label, String text) throws IOException {
-        File file = File.createTempFile(label, "txt");
-        PrintStream ps = new PrintStream(file);
-        ps.print(text);
-        try (FileInputStreamSource dataStream = new FileInputStreamSource(file)) {
-            mLogs.addTestLog(label, LogDataType.TEXT, dataStream);
-        }
-    }
-
-    /**
-     * Returns the pid for the process with the given name.
-     */
-    private int getPidForProcess(String name)
-            throws DeviceNotAvailableException, IOException, MetricsException {
-        String psout = mDevice.executeShellCommand("ps -A -o PID,CMD");
-        Scanner sc = new Scanner(psout);
+    private void logText(String label, String text) throws TestException {
         try {
-            // ps output is of the form:
-            //  PID CMD
-            //    1 init
-            //    2 kthreadd
-            //    ...
-            // 9693 ps
-            sc.nextLine();
-            while (sc.hasNextLine()) {
-                int pid = sc.nextInt();
-                String cmd = sc.next();
-
-                if (name.equals(cmd)) {
-                    return pid;
-                }
+            File file = File.createTempFile(label, "txt");
+            PrintStream ps = new PrintStream(file);
+            ps.print(text);
+            try (FileInputStreamSource dataStream = new FileInputStreamSource(file)) {
+                mLogs.addTestLog(label, LogDataType.TEXT, dataStream);
             }
-        } catch (InputMismatchException e) {
-            throw new MetricsException("unexpected ps output format: " + psout, e);
+        } catch (IOException e) {
+            throw new TestException(e);
         }
-
-        throw new MetricsException("failed to get pid for process " + name);
     }
 
     /**
@@ -116,11 +75,11 @@ class Metrics {
      *
      * @param label prefix to use for metrics and logs output for this sample.
      */
-    void sample(String label) throws DeviceNotAvailableException, IOException, MetricsException {
+    void sample(String label) throws TestException {
         // adb root access is required to get showmap
         mDevice.enableAdbRoot();
 
-        int pid = getPidForProcess("system_server");
+        int pid = mDevice.getPidForProcess("system_server");
 
         // Read showmap for system server and add it as a test log
         String showmap = mDevice.executeShellCommand("showmap " + pid);
@@ -146,7 +105,7 @@ class Metrics {
             mMetrics.addTestMetric(label + ".system_server.rss", Long.toString(rss));
             mMetrics.addTestMetric(label + ".system_server.pss", Long.toString(pss));
         } catch (InputMismatchException e) {
-            throw new MetricsException("unexpected showmap format", e);
+            throw new TestException("unexpected showmap format", e);
         }
 
         // Run debuggerd -j to get GC stats for system server and add it as a
diff --git a/tests/SystemMemoryTest/host/src/com/android/tests/sysmem/host/TestException.java b/tests/SystemMemoryTest/host/src/com/android/tests/sysmem/host/TestException.java
new file mode 100644
index 000000000000..dc3b68f4b455
--- /dev/null
+++ b/tests/SystemMemoryTest/host/src/com/android/tests/sysmem/host/TestException.java
@@ -0,0 +1,35 @@
+/*
+ * 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 com.android.tests.sysmem.host;
+
+/**
+ * Exception thrown in case of unexpected error encountered when executing the
+ * test.
+ */
+class TestException extends Exception {
+    TestException(Exception cause) {
+        super(cause);
+    }
+
+    TestException(String msg) {
+        super(msg);
+    }
+
+    TestException(String msg, Exception cause) {
+        super(msg, cause);
+    }
+}