Allow transitionTo in enter/exit.
bug: 2435366
Change-Id: Id15c5e2cca49ced5ebbda24887f8c490e717f101
diff --git a/core/java/com/android/internal/util/HierarchicalState.java b/core/java/com/android/internal/util/HierarchicalState.java
index 002338a..b37f46c 100644
--- a/core/java/com/android/internal/util/HierarchicalState.java
+++ b/core/java/com/android/internal/util/HierarchicalState.java
@@ -21,10 +21,9 @@
/**
* {@hide}
*
- * The abstract class for implementing states in a
- * HierarchicalStateMachine and HandlerStateMachine.
+ * The class for implementing states in a HierarchicalStateMachine
*/
-public abstract class HierarchicalState {
+public class HierarchicalState {
/**
* Constructor
@@ -54,7 +53,9 @@
* if the parent state's processMessage should
* be invoked.
*/
- abstract protected boolean processMessage(Message msg);
+ protected boolean processMessage(Message msg) {
+ return false;
+ }
/**
* Called when a state is exited.
diff --git a/core/java/com/android/internal/util/HierarchicalStateMachine.java b/core/java/com/android/internal/util/HierarchicalStateMachine.java
index 7d7f130..9911f48 100644
--- a/core/java/com/android/internal/util/HierarchicalStateMachine.java
+++ b/core/java/com/android/internal/util/HierarchicalStateMachine.java
@@ -574,23 +574,41 @@
}
/**
- * Process the message abiding by the hierarchical semantics.
+ * Process the message abiding by the hierarchical semantics
+ * and perform any requested transitions.
*/
processMsg(msg);
+ performTransitions();
+ if (mDbg) Log.d(TAG, "handleMessage: X");
+ }
+
+ /**
+ * Do any transitions
+ */
+ private void performTransitions() {
/**
* If transitionTo has been called, exit and then enter
- * the appropriate states.
+ * the appropriate states. We loop on this to allow
+ * enter and exit methods to use transitionTo.
*/
- if (mDestState != null) {
+ HierarchicalState destState = null;
+ while (mDestState != null) {
if (mDbg) Log.d(TAG, "handleMessage: new destination call exit");
/**
+ * Save mDestState locally and set to null
+ * to know if enter/exit use transitionTo.
+ */
+ destState = mDestState;
+ mDestState = null;
+
+ /**
* Determine the states to exit and enter and return the
* common ancestor state of the enter/exit states. Then
* invoke the exit methods then the enter methods.
*/
- StateInfo commonStateInfo = setupTempStateStackWithStatesToEnter(mDestState);
+ StateInfo commonStateInfo = setupTempStateStackWithStatesToEnter(destState);
invokeExitMethods(commonStateInfo);
int stateStackEnteringIndex = moveTempStateStackToStateStack();
invokeEnterMethods(stateStackEnteringIndex);
@@ -603,25 +621,31 @@
* message queue.
*/
moveDeferredMessageAtFrontOfQueue();
+ }
- /**
- * Call halting() if we've transitioned to the halting
- * state. All subsequent messages will be processed in
- * in the halting state which invokes haltedProcessMessage(msg);
- */
- if (mDestState == mQuittingState) {
+ /**
+ * After processing all transitions check and
+ * see if the last transition was to quit or halt.
+ */
+ if (destState != null) {
+ if (destState == mQuittingState) {
+ /**
+ * We are quitting so ignore all messages.
+ */
mHsm.quitting();
if (mHsm.mHsmThread != null) {
// If we made the thread then quit looper
getLooper().quit();
}
- } else if (mDestState == mHaltingState) {
+ } else if (destState == mHaltingState) {
+ /**
+ * Call halting() if we've transitioned to the halting
+ * state. All subsequent messages will be processed in
+ * in the halting state which invokes haltedProcessMessage(msg);
+ */
mHsm.halting();
}
- mDestState = null;
}
-
- if (mDbg) Log.d(TAG, "handleMessage: X");
}
/**
@@ -657,6 +681,11 @@
mIsConstructionCompleted = true;
invokeEnterMethods(0);
+ /**
+ * Perform any transitions requested by the enter methods
+ */
+ performTransitions();
+
if (mDbg) Log.d(TAG, "completeConstruction: X");
}
@@ -1167,7 +1196,6 @@
return Message.obtain(mHsmHandler, what, obj);
}
-
/**
* Enqueue a message to this state machine.
*/
diff --git a/core/tests/coretests/src/android/os/HierarchicalStateMachineTest.java b/core/tests/coretests/src/android/os/HierarchicalStateMachineTest.java
index c51fecc..89b3fb6 100644
--- a/core/tests/coretests/src/android/os/HierarchicalStateMachineTest.java
+++ b/core/tests/coretests/src/android/os/HierarchicalStateMachineTest.java
@@ -48,7 +48,7 @@
private static final int TEST_CMD_6 = 6;
private static final boolean DBG = true;
- private static final boolean WAIT_FOR_DEBUGGER = false;
+ private static final boolean WAIT_FOR_DEBUGGER = true;
private static final String TAG = "HierarchicalStateMachineTest";
/**
@@ -152,6 +152,154 @@
}
/**
+ * Test enter/exit can use transitionTo
+ */
+ class StateMachineEnterExitTransitionToTest extends HierarchicalStateMachine {
+ StateMachineEnterExitTransitionToTest(String name) {
+ super(name);
+ mThisSm = this;
+ setDbg(DBG);
+
+ // Setup state machine with 1 state
+ addState(mS1);
+ addState(mS2);
+ addState(mS3);
+ addState(mS4);
+
+ // Set the initial state
+ setInitialState(mS1);
+ }
+
+ class S1 extends HierarchicalState {
+ @Override protected void enter() {
+ // Test that a transition in enter and the initial state works
+ mS1EnterCount += 1;
+ transitionTo(mS2);
+ Log.d(TAG, "S1.enter");
+ }
+ @Override protected void exit() {
+ mS1ExitCount += 1;
+ Log.d(TAG, "S1.exit");
+ }
+ }
+
+ class S2 extends HierarchicalState {
+ @Override protected void enter() {
+ mS2EnterCount += 1;
+ Log.d(TAG, "S2.enter");
+ }
+ @Override protected void exit() {
+ // Test transition in exit work
+ mS2ExitCount += 1;
+ transitionTo(mS4);
+ Log.d(TAG, "S2.exit");
+ }
+ @Override protected boolean processMessage(Message message) {
+ // Start a transition to S3 but it will be
+ // changed to a transition to S4
+ transitionTo(mS3);
+ Log.d(TAG, "S2.processMessage");
+ return true;
+ }
+ }
+
+ class S3 extends HierarchicalState {
+ @Override protected void enter() {
+ // Test that we can do halting in an enter/exit
+ transitionToHaltingState();
+ mS3EnterCount += 1;
+ Log.d(TAG, "S3.enter");
+ }
+ @Override protected void exit() {
+ mS3ExitCount += 1;
+ Log.d(TAG, "S3.exit");
+ }
+ }
+
+
+ class S4 extends HierarchicalState {
+ @Override protected void enter() {
+ // Test that we can do halting in an enter/exit
+ transitionToHaltingState();
+ mS4EnterCount += 1;
+ Log.d(TAG, "S4.enter");
+ }
+ @Override protected void exit() {
+ mS4ExitCount += 1;
+ Log.d(TAG, "S4.exit");
+ }
+ }
+
+ @Override
+ protected void halting() {
+ synchronized (mThisSm) {
+ mThisSm.notifyAll();
+ }
+ }
+
+ private StateMachineEnterExitTransitionToTest mThisSm;
+ private S1 mS1 = new S1();
+ private S2 mS2 = new S2();
+ private S3 mS3 = new S3();
+ private S4 mS4 = new S4();
+ private int mS1EnterCount = 0;
+ private int mS1ExitCount = 0;
+ private int mS2EnterCount = 0;
+ private int mS2ExitCount = 0;
+ private int mS3EnterCount = 0;
+ private int mS3ExitCount = 0;
+ private int mS4EnterCount = 0;
+ private int mS4ExitCount = 0;
+ }
+
+ @SmallTest
+ public void testStateMachineEnterExitTransitionToTest() throws Exception {
+ //if (WAIT_FOR_DEBUGGER) Debug.waitForDebugger();
+
+ StateMachineEnterExitTransitionToTest smEnterExitTranstionToTest =
+ new StateMachineEnterExitTransitionToTest("smEnterExitTranstionToTest");
+ smEnterExitTranstionToTest.start();
+ if (smEnterExitTranstionToTest.isDbg()) {
+ Log.d(TAG, "testStateMachineEnterExitTransitionToTest E");
+ }
+
+ synchronized (smEnterExitTranstionToTest) {
+ smEnterExitTranstionToTest.sendMessage(1);
+
+ try {
+ // wait for the messages to be handled
+ smEnterExitTranstionToTest.wait();
+ } catch (InterruptedException e) {
+ Log.e(TAG, "testStateMachineEnterExitTransitionToTest: exception while waiting "
+ + e.getMessage());
+ }
+ }
+
+ assertTrue(smEnterExitTranstionToTest.getProcessedMessagesCount() == 1);
+
+ ProcessedMessages.Info pmi;
+
+ // Message should be handled by mS2.
+ pmi = smEnterExitTranstionToTest.getProcessedMessage(0);
+ assertEquals(TEST_CMD_1, pmi.getWhat());
+ assertEquals(smEnterExitTranstionToTest.mS2, pmi.getState());
+ assertEquals(smEnterExitTranstionToTest.mS2, pmi.getOriginalState());
+
+ assertEquals(smEnterExitTranstionToTest.mS1EnterCount, 1);
+ assertEquals(smEnterExitTranstionToTest.mS1ExitCount, 1);
+ assertEquals(smEnterExitTranstionToTest.mS2EnterCount, 1);
+ assertEquals(smEnterExitTranstionToTest.mS2ExitCount, 1);
+ assertEquals(smEnterExitTranstionToTest.mS3EnterCount, 1);
+ assertEquals(smEnterExitTranstionToTest.mS3ExitCount, 1);
+ assertEquals(smEnterExitTranstionToTest.mS3EnterCount, 1);
+ assertEquals(smEnterExitTranstionToTest.mS3ExitCount, 1);
+
+ if (smEnterExitTranstionToTest.isDbg()) {
+ Log.d(TAG, "testStateMachineEnterExitTransitionToTest X");
+ }
+ }
+
+ /**
* Tests that ProcessedMessage works as a circular buffer.
*/
class StateMachine0 extends HierarchicalStateMachine {