Merge "Adding executor with repeat functionality" into rvc-dev am: 3eb14956fd am: 69aab16963

Change-Id: I6284262085ef25717808aaa5aedb9a1f315c0857

packages/SystemUI/src/com/android/systemui/util/concurrency/ConcurrencyModule.java

@@ -136,6 +136,36 @@ public abstract class ConcurrencyModule {
         return new ExecutorImpl(looper);
     }
 
+    /**
+     * Provide a Background-Thread Executor by default.
+     */
+    @Provides
+    @Singleton
+    public static RepeatableExecutor provideRepeatableExecutor(@Background DelayableExecutor exec) {
+        return new RepeatableExecutorImpl(exec);
+    }
+
+    /**
+     * Provide a Background-Thread Executor.
+     */
+    @Provides
+    @Singleton
+    @Background
+    public static RepeatableExecutor provideBackgroundRepeatableExecutor(
+            @Background DelayableExecutor exec) {
+        return new RepeatableExecutorImpl(exec);
+    }
+
+    /**
+     * Provide a Main-Thread Executor.
+     */
+    @Provides
+    @Singleton
+    @Main
+    public static RepeatableExecutor provideMainRepeatableExecutor(@Main DelayableExecutor exec) {
+        return new RepeatableExecutorImpl(exec);
+    }
+
     /**
      * Provide an Executor specifically for running UI operations on a separate thread.
      *

packages/SystemUI/src/com/android/systemui/util/concurrency/RepeatableExecutor.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 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.
+ */
+
+package com.android.systemui.util.concurrency;
+
+import java.util.concurrent.Executor;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * A sub-class of {@link Executor} that allows scheduling commands to execute periodically.
+ */
+public interface RepeatableExecutor extends Executor {
+
+    /**
+     * Execute supplied Runnable on the Executors thread after initial delay, and subsequently with
+     * the given delay between the termination of one execution and the commencement of the next.
+     *
+     * Each invocation of the supplied Runnable will be scheduled after the previous invocation
+     * completes. For example, if you schedule the Runnable with a 60 second delay, and the Runnable
+     * itself takes 1 second, the effective delay will be 61 seconds between each invocation.
+     *
+     * See {@link java.util.concurrent.ScheduledExecutorService#scheduleRepeatedly(Runnable,
+     * long, long)}
+     *
+     * @return A Runnable that, when run, removes the supplied argument from the Executor queue.
+     */
+    default Runnable executeRepeatedly(Runnable r, long initialDelayMillis, long delayMillis) {
+        return executeRepeatedly(r, initialDelayMillis, delayMillis, TimeUnit.MILLISECONDS);
+    }
+
+    /**
+     * Execute supplied Runnable on the Executors thread after initial delay, and subsequently with
+     * the given delay between the termination of one execution and the commencement of the next..
+     *
+     * See {@link java.util.concurrent.ScheduledExecutorService#scheduleRepeatedly(Runnable,
+     * long, long)}
+     *
+     * @return A Runnable that, when run, removes the supplied argument from the Executor queue.
+     */
+    Runnable executeRepeatedly(Runnable r, long initialDelay, long delay, TimeUnit unit);
+}

packages/SystemUI/src/com/android/systemui/util/concurrency/RepeatableExecutorImpl.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 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.
+ */
+
+package com.android.systemui.util.concurrency;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Implementation of {@link RepeatableExecutor} for SystemUI.
+ */
+class RepeatableExecutorImpl implements RepeatableExecutor {
+
+    private final DelayableExecutor mExecutor;
+
+    RepeatableExecutorImpl(DelayableExecutor executor) {
+        mExecutor = executor;
+    }
+
+    @Override
+    public void execute(Runnable command) {
+        mExecutor.execute(command);
+    }
+
+    @Override
+    public Runnable executeRepeatedly(Runnable r, long initDelay, long delay, TimeUnit unit) {
+        ExecutionToken token = new ExecutionToken(r, delay, unit);
+        token.start(initDelay, unit);
+        return token::cancel;
+    }
+
+    private class ExecutionToken implements Runnable {
+        private final Runnable mCommand;
+        private final long mDelay;
+        private final TimeUnit mUnit;
+        private final Object mLock = new Object();
+        private Runnable mCancel;
+
+        ExecutionToken(Runnable r, long delay, TimeUnit unit) {
+            mCommand = r;
+            mDelay = delay;
+            mUnit = unit;
+        }
+
+        @Override
+        public void run() {
+            mCommand.run();
+            synchronized (mLock) {
+                if (mCancel != null) {
+                    mCancel = mExecutor.executeDelayed(this, mDelay, mUnit);
+                }
+            }
+        }
+
+        /** Starts execution that will repeat the command until {@link cancel}. */
+        public void start(long startDelay, TimeUnit unit) {
+            synchronized (mLock) {
+                mCancel = mExecutor.executeDelayed(this, startDelay, unit);
+            }
+        }
+
+        /** Cancel repeated execution of command. */
+        public void cancel() {
+            synchronized (mLock) {
+                if (mCancel != null) {
+                    mCancel.run();
+                    mCancel = null;
+                }
+            }
+        }
+    }
+}

packages/SystemUI/tests/src/com/android/systemui/util/concurrency/RepeatableExecutorTest.java

@@ -0,0 +1,162 @@
+/*
+ * Copyright (C) 2020 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.systemui.util.concurrency;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import android.testing.AndroidTestingRunner;
+
+import androidx.test.filters.SmallTest;
+
+import com.android.systemui.SysuiTestCase;
+import com.android.systemui.util.time.FakeSystemClock;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@SmallTest
+@RunWith(AndroidTestingRunner.class)
+public class RepeatableExecutorTest extends SysuiTestCase {
+
+    private static final int DELAY = 100;
+
+    private FakeSystemClock mFakeClock;
+    private FakeExecutor mFakeExecutor;
+    private RepeatableExecutor mExecutor;
+    private CountingTask mCountingTask;
+
+    @Before
+    public void setUp() throws Exception {
+        mFakeClock = new FakeSystemClock();
+        mFakeExecutor = new FakeExecutor(mFakeClock);
+        mCountingTask = new CountingTask();
+        mExecutor = new RepeatableExecutorImpl(mFakeExecutor);
+    }
+
+    /**
+     * Test FakeExecutor that receives non-delayed items to execute.
+     */
+    @Test
+    public void testExecute() {
+        mExecutor.execute(mCountingTask);
+        mFakeExecutor.runAllReady();
+        assertThat(mCountingTask.getCount()).isEqualTo(1);
+    }
+
+    @Test
+    public void testRepeats() {
+        // GIVEN that a command is queued to repeat
+        mExecutor.executeRepeatedly(mCountingTask, DELAY, DELAY);
+        // WHEN The clock advances and the task is run
+        mFakeExecutor.advanceClockToNext();
+        mFakeExecutor.runAllReady();
+        // THEN another task is queued
+        assertThat(mCountingTask.getCount()).isEqualTo(1);
+        assertThat(mFakeExecutor.numPending()).isEqualTo(1);
+    }
+
+    @Test
+    public void testNoExecutionBeforeStartDelay() {
+        // WHEN a command is queued with a start delay
+        mExecutor.executeRepeatedly(mCountingTask, 2 * DELAY, DELAY);
+        mFakeExecutor.runAllReady();
+        // THEN then it doesn't run immediately
+        assertThat(mCountingTask.getCount()).isEqualTo(0);
+        assertThat(mFakeExecutor.numPending()).isEqualTo(1);
+    }
+
+    @Test
+    public void testExecuteAfterStartDelay() {
+        // GIVEN that a command is queued to repeat with a longer start delay
+        mExecutor.executeRepeatedly(mCountingTask, 2 * DELAY, DELAY);
+        // WHEN the clock advances the start delay
+        mFakeClock.advanceTime(2 * DELAY);
+        mFakeExecutor.runAllReady();
+        // THEN the command has run and another task is queued
+        assertThat(mCountingTask.getCount()).isEqualTo(1);
+        assertThat(mFakeExecutor.numPending()).isEqualTo(1);
+    }
+
+    @Test
+    public void testExecuteWithZeroStartDelay() {
+        // WHEN a command is queued with no start delay
+        mExecutor.executeRepeatedly(mCountingTask, 0L, DELAY);
+        mFakeExecutor.runAllReady();
+        // THEN the command has run and another task is queued
+        assertThat(mCountingTask.getCount()).isEqualTo(1);
+        assertThat(mFakeExecutor.numPending()).isEqualTo(1);
+    }
+
+    @Test
+    public void testAdvanceTimeTwice() {
+        // GIVEN that a command is queued to repeat
+        mExecutor.executeRepeatedly(mCountingTask, DELAY, DELAY);
+        // WHEN the clock advances the time DELAY twice
+        mFakeClock.advanceTime(DELAY);
+        mFakeExecutor.runAllReady();
+        mFakeClock.advanceTime(DELAY);
+        mFakeExecutor.runAllReady();
+        // THEN the command has run twice and another task is queued
+        assertThat(mCountingTask.getCount()).isEqualTo(2);
+        assertThat(mFakeExecutor.numPending()).isEqualTo(1);
+    }
+
+    @Test
+    public void testCancel() {
+        // GIVEN that a scheduled command has been cancelled
+        Runnable cancel = mExecutor.executeRepeatedly(mCountingTask, DELAY, DELAY);
+        cancel.run();
+        // WHEN the clock advances the time DELAY
+        mFakeClock.advanceTime(DELAY);
+        mFakeExecutor.runAllReady();
+        // THEN the comamnd has not run and no further tasks are queued
+        assertThat(mCountingTask.getCount()).isEqualTo(0);
+        assertThat(mFakeExecutor.numPending()).isEqualTo(0);
+    }
+
+    @Test
+    public void testCancelAfterStart() {
+        // GIVEN that a command has reapeated a few times
+        Runnable cancel = mExecutor.executeRepeatedly(mCountingTask, DELAY, DELAY);
+        mFakeClock.advanceTime(DELAY);
+        mFakeExecutor.runAllReady();
+        // WHEN cancelled and time advances
+        cancel.run();
+        // THEN the command has only run the first time
+        assertThat(mCountingTask.getCount()).isEqualTo(1);
+        assertThat(mFakeExecutor.numPending()).isEqualTo(0);
+    }
+
+    /**
+     * Runnable used for testing that counts the number of times run() is invoked.
+     */
+    private static class CountingTask implements Runnable {
+
+        private int mRunCount;
+
+        @Override
+        public void run() {
+            mRunCount++;
+        }
+
+        /** Gets the run count. */
+        public int getCount() {
+            return mRunCount;
+        }
+    }
+}