Fix StateMachine init/quit race.
The quitNow method places the SM_QUIT_CMD at the front
of the queue. This can cause StateMachine to throw exception
if it has not yet processed the SM_INIT_CMD from start().
Bug: 67370902
Test: make checkbuild
Test: StatMachineTest unittest
Change-Id: I409242845854e70b77ad9b2378b69faed076847c
Merged-In: I7cec7bb91e0447e3c565d33cb7c34ccf59566639
diff --git a/core/java/com/android/internal/util/StateMachine.java b/core/java/com/android/internal/util/StateMachine.java
index 8d9630f..e5ad1f4 100644
--- a/core/java/com/android/internal/util/StateMachine.java
+++ b/core/java/com/android/internal/util/StateMachine.java
@@ -804,7 +804,7 @@
/** State that processed the message */
State msgProcessedState = null;
- if (mIsConstructionCompleted) {
+ if (mIsConstructionCompleted || (mMsg.what == SM_QUIT_CMD)) {
/** Normal path */
msgProcessedState = processMsg(msg);
} else if (!mIsConstructionCompleted && (mMsg.what == SM_INIT_CMD)
diff --git a/core/tests/utiltests/src/com/android/internal/util/StateMachineTest.java b/core/tests/utiltests/src/com/android/internal/util/StateMachineTest.java
index eb2a516..76aa93f 100644
--- a/core/tests/utiltests/src/com/android/internal/util/StateMachineTest.java
+++ b/core/tests/utiltests/src/com/android/internal/util/StateMachineTest.java
@@ -24,6 +24,7 @@
import android.os.Looper;
import android.os.Message;
import android.os.SystemClock;
+import android.os.test.TestLooper;
import android.test.suitebuilder.annotation.Suppress;
import com.android.internal.util.State;
@@ -343,6 +344,100 @@
}
/**
+ * Tests {@link StateMachine#quitNow()} immediately after {@link StateMachine#start()}.
+ */
+ class StateMachineQuitNowAfterStartTest extends StateMachine {
+ Collection<LogRec> mLogRecs;
+
+ StateMachineQuitNowAfterStartTest(String name, Looper looper) {
+ super(name, looper);
+ mThisSm = this;
+ setDbg(DBG);
+
+ // Setup state machine with 1 state
+ addState(mS1);
+
+ // Set the initial state
+ setInitialState(mS1);
+ }
+
+ @Override
+ public void onQuitting() {
+ tlog("onQuitting");
+ addLogRec(ON_QUITTING);
+ mLogRecs = mThisSm.copyLogRecs();
+ synchronized (mThisSm) {
+ mThisSm.notifyAll();
+ }
+ }
+
+ class S1 extends State {
+ @Override
+ public void enter() {
+ tlog("S1.enter");
+ addLogRec(ENTER);
+ }
+ @Override
+ public void exit() {
+ tlog("S1.exit");
+ addLogRec(EXIT);
+ }
+ @Override
+ public boolean processMessage(Message message) {
+ switch(message.what) {
+ // Sleep and assume the other messages will be queued up.
+ case TEST_CMD_1: {
+ tlog("TEST_CMD_1");
+ sleep(500);
+ break;
+ }
+ default: {
+ tlog("default what=" + message.what);
+ break;
+ }
+ }
+ return HANDLED;
+ }
+ }
+
+ private StateMachineQuitNowAfterStartTest mThisSm;
+ private S1 mS1 = new S1();
+ }
+
+ /**
+ * When quitNow() is called immediately after start(), the QUIT_CMD gets processed
+ * before the INIT_CMD. This test ensures that the StateMachine can gracefully handle
+ * this sequencing of messages (QUIT before INIT).
+ */
+ @SmallTest
+ public void testStateMachineQuitNowAfterStart() throws Exception {
+ if (WAIT_FOR_DEBUGGER) Debug.waitForDebugger();
+
+ TestLooper testLooper = new TestLooper();
+ StateMachineQuitNowAfterStartTest smQuitNowAfterStartTest =
+ new StateMachineQuitNowAfterStartTest(
+ "smQuitNowAfterStartTest", testLooper.getLooper());
+ smQuitNowAfterStartTest.start();
+ smQuitNowAfterStartTest.quitNow();
+ if (smQuitNowAfterStartTest.isDbg()) tlog("testStateMachineQuitNowAfterStart E");
+
+ testLooper.dispatchAll();
+ dumpLogRecs(smQuitNowAfterStartTest.mLogRecs);
+ assertEquals(2, smQuitNowAfterStartTest.mLogRecs.size());
+
+ LogRec lr;
+ Iterator<LogRec> itr = smQuitNowAfterStartTest.mLogRecs.iterator();
+ lr = itr.next();
+ assertEquals(EXIT, lr.getInfo());
+ assertEquals(smQuitNowAfterStartTest.mS1, lr.getState());
+
+ lr = itr.next();
+ assertEquals(ON_QUITTING, lr.getInfo());
+
+ if (smQuitNowAfterStartTest.isDbg()) tlog("testStateMachineQuitNowAfterStart X");
+ }
+
+ /**
* Test enter/exit can use transitionTo
*/
class StateMachineEnterExitTransitionToTest extends StateMachine {