Add quit and fix HSM EBNF. (1b8b98b3) · Commits · e / os / android_frameworks_base

core/java/com/android/internal/util/HierarchicalStateMachine.java

+72 −3

Original line number	Diff line number	Diff line
		@@ -69,6 +69,10 @@ import java.util.HashMap;
		* and invoke <code>halting</code>. Any message subsequently received by the state
		* machine will cause <code>haltedProcessMessage</code> to be invoked.
		*
		* If it is desirable to completely stop the state machine call <code>quit</code>. This
		* will exit the current state and its parent and then exit from the controlling thread
		* and no further messages will be processed.
		*
		* In addition to <code>processMessage</code> each <code>HierarchicalState</code> has
		* an <code>enter</code> method and <code>exit</exit> method which may be overridden.
		*
		@@ -422,13 +426,13 @@ class Hsm1 extends HierarchicalStateMachine {
		* HSM EBNF:
		* HSM = HSM_NAME "{" { STATE }+ "}" ;
		* HSM_NAME = alpha_numeric_name ;
		* STATE = INTRODUCE_STATE [ ENTER ] "{" [ MESSAGES ] "}" [ EXIT ] ;
		* STATE = INTRODUCE_STATE [ ENTER \| [ ENTER EXIT ] "{" [ MESSAGES ] "}" [ EXIT ] ;
		* INTRODUCE_STATE = { STATE_DEPTH }+ [ INITIAL_STATE_INDICATOR ] STATE_NAME ;
		* STATE_DEPTH = "+" ;
		* INITIAL_STATE_INDICATOR = "#"
		* ENTER = "e(" SEND_ACTION \| TRANSITION_ACTION \| HALT_ACTION ")" ;
		* MESSAGES = { MSG_LIST MESSAGE_ACTIONS } ;
		* MSG_LIST = { MSG_NAME { "," MSG_NAME } ;
		* MSG_LIST = { MSG_NAME { "," MSG_NAME } };
		* EXIT = "x(" SEND_ACTION \| TRANSITION_ACTION \| HALT_ACTION ")" ;
		* PROCESS_COMPLETION = PROCESS_IN_PARENT_OR_COMPLETE \| PROCESS_COMPLETE ;
		* SEND_ACTION = "$" MSG_NAME ;
		@@ -454,11 +458,16 @@ public class HierarchicalStateMachine {
		private static final String TAG = "HierarchicalStateMachine";
		private String mName;

		public static final int HSM_QUIT_CMD = -1;

		private static class HsmHandler extends Handler {

		/** The debug flag */
		private boolean mDbg = false;

		/** The quit object */
		private static final Object mQuitObj = new Object();

		/** A list of messages that this state machine has processed */
		private ProcessedMessages mProcessedMessages = new ProcessedMessages();

		@@ -480,6 +489,9 @@ public class HierarchicalStateMachine {
		/** State used when state machine is halted */
		private HaltingState mHaltingState = new HaltingState();

		/** State used when state machine is quitting */
		private QuittingState mQuittingState = new QuittingState();

		/** Reference to the HierarchicalStateMachine */
		private HierarchicalStateMachine mHsm;

		@@ -532,6 +544,16 @@ public class HierarchicalStateMachine {
		}
		}

		/**
		* State entered when a valid quit message is handled.
		*/
		private class QuittingState extends HierarchicalState {
		@Override
		public boolean processMessage(Message msg) {
		throw new RuntimeException("QuitingState: processMessage called should not happen");
		}
		}

		/**
		* Handle messages sent to the state machine by calling
		* the current state's processMessage. It also handles
		@@ -586,7 +608,13 @@ public class HierarchicalStateMachine {
		* state. All subsequent messages will be processed in
		* in the halting state which invokes haltedProcessMessage(msg);
		*/
		if (mDestState == mHaltingState) {
		if (mDestState == mQuittingState) {
		mHsm.quitting();
		if (mHsm.mHsmThread != null) {
		// If we made the thread then quit looper
		getLooper().quit();
		}
		} else if (mDestState == mHaltingState) {
		mHsm.halting();
		}
		mDestState = null;
		@@ -651,6 +679,9 @@ public class HierarchicalStateMachine {
		* No parents left so it's not handled
		*/
		mHsm.unhandledMessage(msg);
		if (isQuit(msg)) {
		transitionTo(mQuittingState);
		}
		break;
		}
		if (mDbg) {
		@@ -851,6 +882,7 @@ public class HierarchicalStateMachine {
		mHsm = hsm;

		addState(mHaltingState, null);
		addState(mQuittingState, null);
		}

		/** @see HierarchicalStateMachine#setInitialState(HierarchicalState) */
		@@ -876,6 +908,17 @@ public class HierarchicalStateMachine {
		mDeferredMessages.add(newMsg);
		}

		/** @see HierarchicalStateMachine#deferMessage(Message) */
		private final void quit() {
		if (mDbg) Log.d(TAG, "quit:");
		sendMessage(obtainMessage(HSM_QUIT_CMD, mQuitObj));
		}

		/** @see HierarchicalStateMachine#isQuit(Message) */
		private final boolean isQuit(Message msg) {
		return (msg.what == HSM_QUIT_CMD) && (msg.obj == mQuitObj);
		}

		/** @see HierarchicalStateMachine#isDbg() */
		private final boolean isDbg() {
		return mDbg;
		@@ -1039,6 +1082,13 @@ public class HierarchicalStateMachine {
		protected void halting() {
		}

		/**
		* Called after the quitting message was NOT handled and
		* just before the quit actually occurs.
		*/
		protected void quitting() {
		}

		/**
		* @return the name
		*/
		@@ -1138,6 +1188,25 @@ public class HierarchicalStateMachine {
		mHsmHandler.sendMessageAtFrontOfQueue(msg);
		}

		/**
		* Conditionally quit the looper and stop execution.
		*
		* This sends the HSM_QUIT_MSG to the state machine and
		* if not handled by any state's processMessage then the
		* state machine will be stopped and no further messages
		* will be processed.
		*/
		public final void quit() {
		mHsmHandler.quit();
		}

		/**
		* @return ture if msg is quit
		*/
		protected final boolean isQuit(Message msg) {
		return mHsmHandler.isQuit(msg);
		}

		/**
		* @return if debugging is enabled
		*/

core/tests/coretests/src/android/os/HierarchicalStateMachineTest.java

+101 −1

Original line number	Diff line number	Diff line
		@@ -51,6 +51,106 @@ public class HierarchicalStateMachineTest extends TestCase {
		private static final boolean WAIT_FOR_DEBUGGER = false;
		private static final String TAG = "HierarchicalStateMachineTest";

		/**
		* Tests that we can quit the state machine.
		*/
		class StateMachineQuitTest extends HierarchicalStateMachine {
		private int mQuitCount = 0;

		StateMachineQuitTest(String name) {
		super(name);
		mThisSm = this;
		setDbg(DBG);

		// Setup state machine with 1 state
		addState(mS1);

		// Set the initial state
		setInitialState(mS1);
		}

		class S1 extends HierarchicalState {
		@Override protected boolean processMessage(Message message) {
		if (isQuit(message)) {
		mQuitCount += 1;
		if (mQuitCount > 2) {
		// Returning false to actually quit
		return false;
		} else {
		// Do NOT quit
		return true;
		}
		} else {
		// All other message are handled
		return true;
		}
		}
		}

		@Override
		protected void quitting() {
		synchronized (mThisSm) {
		mThisSm.notifyAll();
		}
		}

		private StateMachineQuitTest mThisSm;
		private S1 mS1 = new S1();
		}

		@SmallTest
		public void testStateMachineQuitTest() throws Exception {
		//if (WAIT_FOR_DEBUGGER) Debug.waitForDebugger();

		StateMachineQuitTest smQuitTest = new StateMachineQuitTest("smQuitTest");
		smQuitTest.start();
		if (smQuitTest.isDbg()) Log.d(TAG, "testStateMachineQuitTest E");

		synchronized (smQuitTest) {
		// Send 6 messages
		for (int i = 1; i <= 6; i++) {
		smQuitTest.sendMessage(smQuitTest.obtainMessage(i));
		}

		// First two are ignored
		smQuitTest.quit();
		smQuitTest.quit();

		// Now we will quit
		smQuitTest.quit();

		try {
		// wait for the messages to be handled
		smQuitTest.wait();
		} catch (InterruptedException e) {
		Log.e(TAG, "testStateMachineQuitTest: exception while waiting " + e.getMessage());
		}
		}

		assertTrue(smQuitTest.getProcessedMessagesCount() == 9);

		ProcessedMessages.Info pmi;

		// The first two message didn't quit and were handled by mS1
		pmi = smQuitTest.getProcessedMessage(6);
		assertEquals(HierarchicalStateMachine.HSM_QUIT_CMD, pmi.getWhat());
		assertEquals(smQuitTest.mS1, pmi.getState());
		assertEquals(smQuitTest.mS1, pmi.getOriginalState());

		pmi = smQuitTest.getProcessedMessage(7);
		assertEquals(HierarchicalStateMachine.HSM_QUIT_CMD, pmi.getWhat());
		assertEquals(smQuitTest.mS1, pmi.getState());
		assertEquals(smQuitTest.mS1, pmi.getOriginalState());

		// The last message was never handled so the states are null
		pmi = smQuitTest.getProcessedMessage(8);
		assertEquals(HierarchicalStateMachine.HSM_QUIT_CMD, pmi.getWhat());
		assertEquals(null, pmi.getState());
		assertEquals(null, pmi.getOriginalState());

		if (smQuitTest.isDbg()) Log.d(TAG, "testStateMachineQuitTest X");
		}

		/**
		* Tests that ProcessedMessage works as a circular buffer.
		*/
		@@ -90,7 +190,7 @@ public class HierarchicalStateMachineTest extends TestCase {

		@SmallTest
		public void testStateMachine0() throws Exception {
		if (WAIT_FOR_DEBUGGER) Debug.waitForDebugger();
		//if (WAIT_FOR_DEBUGGER) Debug.waitForDebugger();

		StateMachine0 sm0 = new StateMachine0("sm0");
		sm0.start();