Add a callback to listen to uid foreground-ness change.

Bug: 276941957
Test: atest services/tests/mockingservicestests/src/com/android/server/am/BroadcastQueueTest.java
Test: atest services/tests/mockingservicestests/src/com/android/server/am/BroadcastQueueModernImplTest.java
Change-Id: Id11bb1c06025bf758a6c6b40f538ed45548381e8

5 files changed, 200 insertions, 33 deletions

diff --git a/services/core/java/com/android/server/am/BroadcastProcessQueue.java b/services/core/java/com/android/server/am/BroadcastProcessQueue.java
index 5c68e6759083..e73153342db7 100644
--- a/services/core/java/com/android/server/am/BroadcastProcessQueue.java
+++ b/services/core/java/com/android/server/am/BroadcastProcessQueue.java
@@ -194,6 +194,7 @@ class BroadcastProcessQueue {
      */
     private boolean mLastDeferredStates;
 
+    private boolean mUidForeground;
     private boolean mUidCached;
     private boolean mProcessInstrumented;
     private boolean mProcessPersistent;
@@ -403,7 +404,8 @@ class BroadcastProcessQueue {
      *         {@link BroadcastQueueModernImpl#updateRunnableList}
      */
     @CheckResult
-    public boolean setProcessAndUidCached(@Nullable ProcessRecord app, boolean uidCached) {
+    public boolean setProcessAndUidState(@Nullable ProcessRecord app, boolean uidForeground,
+            boolean uidCached) {
         this.app = app;
 
         // Since we may have just changed our PID, invalidate cached strings
@@ -413,10 +415,12 @@ class BroadcastProcessQueue {
         boolean didSomething = false;
         if (app != null) {
             didSomething |= setUidCached(uidCached);
+            didSomething |= setUidForeground(uidForeground);
             didSomething |= setProcessInstrumented(app.getActiveInstrumentation() != null);
             didSomething |= setProcessPersistent(app.isPersistent());
         } else {
             didSomething |= setUidCached(uidCached);
+            didSomething |= setUidForeground(false);
             didSomething |= setProcessInstrumented(false);
             didSomething |= setProcessPersistent(false);
         }
@@ -424,6 +428,22 @@ class BroadcastProcessQueue {
     }
 
     /**
+     * Update if the UID this process is belongs to is in "foreground" state, which signals
+     * broadcast dispatch should prioritize delivering broadcasts to this process to minimize any
+     * delays in UI updates.
+     */
+    @CheckResult
+    private boolean setUidForeground(boolean uidForeground) {
+        if (mUidForeground != uidForeground) {
+            mUidForeground = uidForeground;
+            invalidateRunnableAt();
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+    /**
      * Update if this process is in the "cached" state, typically signaling that
      * broadcast dispatch should be paused or delayed.
      */
@@ -917,7 +937,7 @@ class BroadcastProcessQueue {
     static final int REASON_CONTAINS_RESULT_TO = 15;
     static final int REASON_CONTAINS_INSTRUMENTED = 16;
     static final int REASON_CONTAINS_MANIFEST = 17;
-    static final int REASON_FOREGROUND_ACTIVITIES = 18;
+    static final int REASON_FOREGROUND = 18;
 
     @IntDef(flag = false, prefix = { "REASON_" }, value = {
             REASON_EMPTY,
@@ -937,7 +957,7 @@ class BroadcastProcessQueue {
             REASON_CONTAINS_RESULT_TO,
             REASON_CONTAINS_INSTRUMENTED,
             REASON_CONTAINS_MANIFEST,
-            REASON_FOREGROUND_ACTIVITIES,
+            REASON_FOREGROUND,
     })
     @Retention(RetentionPolicy.SOURCE)
     public @interface Reason {}
@@ -961,7 +981,7 @@ class BroadcastProcessQueue {
             case REASON_CONTAINS_RESULT_TO: return "CONTAINS_RESULT_TO";
             case REASON_CONTAINS_INSTRUMENTED: return "CONTAINS_INSTRUMENTED";
             case REASON_CONTAINS_MANIFEST: return "CONTAINS_MANIFEST";
-            case REASON_FOREGROUND_ACTIVITIES: return "FOREGROUND_ACTIVITIES";
+            case REASON_FOREGROUND: return "FOREGROUND";
             default: return Integer.toString(reason);
         }
     }
@@ -1000,11 +1020,9 @@ class BroadcastProcessQueue {
             } else if (mProcessInstrumented) {
                 mRunnableAt = runnableAt + constants.DELAY_URGENT_MILLIS;
                 mRunnableAtReason = REASON_INSTRUMENTED;
-            } else if (app != null && app.hasForegroundActivities()) {
-                // TODO: Listen for uid state changes to check when an uid goes in and out of
-                // the TOP state.
+            } else if (mUidForeground) {
                 mRunnableAt = runnableAt + constants.DELAY_URGENT_MILLIS;
-                mRunnableAtReason = REASON_FOREGROUND_ACTIVITIES;
+                mRunnableAtReason = REASON_FOREGROUND;
             } else if (mCountOrdered > 0) {
                 mRunnableAt = runnableAt;
                 mRunnableAtReason = REASON_CONTAINS_ORDERED;
@@ -1274,7 +1292,11 @@ class BroadcastProcessQueue {
     @NeverCompile
     private void dumpProcessState(@NonNull IndentingPrintWriter pw) {
         final StringBuilder sb = new StringBuilder();
+        if (mUidForeground) {
+            sb.append("FG");
+        }
         if (mUidCached) {
+            if (sb.length() > 0) sb.append("|");
             sb.append("CACHED");
         }
         if (mProcessInstrumented) {
diff --git a/services/core/java/com/android/server/am/BroadcastQueueModernImpl.java b/services/core/java/com/android/server/am/BroadcastQueueModernImpl.java
index 96e152320282..9d36d4289ad1 100644
--- a/services/core/java/com/android/server/am/BroadcastQueueModernImpl.java
+++ b/services/core/java/com/android/server/am/BroadcastQueueModernImpl.java
@@ -211,6 +211,17 @@ class BroadcastQueueModernImpl extends BroadcastQueue {
             new AtomicReference<>();
 
     /**
+     * Map from UID to its last known "foreground" state. A UID is considered to be in
+     * "foreground" state when it's procState is {@link ActivityManager#PROCESS_STATE_TOP}.
+     * <p>
+     * We manually maintain this data structure since the lifecycle of
+     * {@link ProcessRecord} and {@link BroadcastProcessQueue} can be
+     * mismatched.
+     */
+    @GuardedBy("mService")
+    private final SparseBooleanArray mUidForeground = new SparseBooleanArray();
+
+    /**
      * Map from UID to its last known "cached" state.
      * <p>
      * We manually maintain this data structure since the lifecycle of
@@ -1212,11 +1223,24 @@ class BroadcastQueueModernImpl extends BroadcastQueue {
                 return UserHandle.getUserId(q.uid) == userId;
             };
             broadcastPredicate = BROADCAST_PREDICATE_ANY;
+
+            cleanupUserStateLocked(mUidCached, userId);
+            cleanupUserStateLocked(mUidForeground, userId);
         }
         return forEachMatchingBroadcast(queuePredicate, broadcastPredicate,
                 mBroadcastConsumerSkip, true);
     }
 
+    @GuardedBy("mService")
+    private void cleanupUserStateLocked(@NonNull SparseBooleanArray uidState, int userId) {
+        for (int i = uidState.size() - 1; i >= 0; --i) {
+            final int uid = uidState.keyAt(i);
+            if (UserHandle.getUserId(uid) == userId) {
+                uidState.removeAt(i);
+            }
+        }
+    }
+
     private static final Predicate<BroadcastProcessQueue> QUEUE_PREDICATE_ANY =
             (q) -> true;
     private static final BroadcastPredicate BROADCAST_PREDICATE_ANY =
@@ -1332,6 +1356,19 @@ class BroadcastQueueModernImpl extends BroadcastQueue {
 
         mService.registerUidObserver(new UidObserver() {
             @Override
+            public void onUidStateChanged(int uid, int procState, long procStateSeq,
+                    int capability) {
+                synchronized (mService) {
+                    if (procState == ActivityManager.PROCESS_STATE_TOP) {
+                        mUidForeground.put(uid, true);
+                    } else {
+                        mUidForeground.delete(uid);
+                    }
+                    refreshProcessQueuesLocked(uid);
+                }
+            }
+
+            @Override
             public void onUidCachedChanged(int uid, boolean cached) {
                 synchronized (mService) {
                     if (cached) {
@@ -1339,18 +1376,11 @@ class BroadcastQueueModernImpl extends BroadcastQueue {
                     } else {
                         mUidCached.delete(uid);
                     }
-
-                    BroadcastProcessQueue leaf = mProcessQueues.get(uid);
-                    while (leaf != null) {
-                        // Update internal state by refreshing values previously
-                        // read from any known running process
-                        setQueueProcess(leaf, leaf.app);
-                        leaf = leaf.processNameNext;
-                    }
-                    enqueueUpdateRunningList();
+                    refreshProcessQueuesLocked(uid);
                 }
             }
-        }, ActivityManager.UID_OBSERVER_CACHED, 0, "android");
+        }, ActivityManager.UID_OBSERVER_PROCSTATE | ActivityManager.UID_OBSERVER_CACHED,
+                ActivityManager.PROCESS_STATE_TOP, "android");
 
         // Kick off periodic health checks
         mLocalHandler.sendEmptyMessage(MSG_CHECK_HEALTH);
@@ -1522,8 +1552,9 @@ class BroadcastQueueModernImpl extends BroadcastQueue {
             // warm via this operation, we're going to immediately promote it to
             // be running, and any side effect of this operation will then apply
             // after it's finished and is returned to the runnable list.
-            queue.setProcessAndUidCached(
+            queue.setProcessAndUidState(
                     mService.getProcessRecordLocked(queue.processName, queue.uid),
+                    mUidForeground.get(queue.uid, false),
                     mUidCached.get(queue.uid, false));
         }
     }
@@ -1535,12 +1566,29 @@ class BroadcastQueueModernImpl extends BroadcastQueue {
      */
     private void setQueueProcess(@NonNull BroadcastProcessQueue queue,
             @Nullable ProcessRecord app) {
-        if (queue.setProcessAndUidCached(app, mUidCached.get(queue.uid, false))) {
+        if (queue.setProcessAndUidState(app, mUidForeground.get(queue.uid, false),
+                mUidCached.get(queue.uid, false))) {
             updateRunnableList(queue);
         }
     }
 
     /**
+     * Refresh the process queues with the latest process state so that runnableAt
+     * can be updated.
+     */
+    @GuardedBy("mService")
+    private void refreshProcessQueuesLocked(int uid) {
+        BroadcastProcessQueue leaf = mProcessQueues.get(uid);
+        while (leaf != null) {
+            // Update internal state by refreshing values previously
+            // read from any known running process
+            setQueueProcess(leaf, leaf.app);
+            leaf = leaf.processNameNext;
+        }
+        enqueueUpdateRunningList();
+    }
+
+    /**
      * Inform other parts of OS that the given broadcast queue has started
      * running, typically for internal bookkeeping.
      */
@@ -1861,7 +1909,13 @@ class BroadcastQueueModernImpl extends BroadcastQueue {
 
         ipw.println("Cached UIDs:");
         ipw.increaseIndent();
-        ipw.println(mUidCached.toString());
+        ipw.println(mUidCached);
+        ipw.decreaseIndent();
+        ipw.println();
+
+        ipw.println("Foreground UIDs:");
+        ipw.increaseIndent();
+        ipw.println(mUidForeground);
         ipw.decreaseIndent();
         ipw.println();
 
diff --git a/services/core/java/com/android/server/am/ProcessRecord.java b/services/core/java/com/android/server/am/ProcessRecord.java
index 438a08c44ef4..ca160b70d707 100644
--- a/services/core/java/com/android/server/am/ProcessRecord.java
+++ b/services/core/java/com/android/server/am/ProcessRecord.java
@@ -1057,11 +1057,6 @@ class ProcessRecord implements WindowProcessListener {
         return mState.isCached();
     }
 
-    @GuardedBy(anyOf = {"mService", "mProcLock"})
-    public boolean hasForegroundActivities() {
-        return mState.hasForegroundActivities();
-    }
-
     boolean hasActivities() {
         return mWindowProcessController.hasActivities();
     }
diff --git a/services/tests/mockingservicestests/src/com/android/server/am/BroadcastQueueModernImplTest.java b/services/tests/mockingservicestests/src/com/android/server/am/BroadcastQueueModernImplTest.java
index acfea85d60a2..626c6dc7280e 100644
--- a/services/tests/mockingservicestests/src/com/android/server/am/BroadcastQueueModernImplTest.java
+++ b/services/tests/mockingservicestests/src/com/android/server/am/BroadcastQueueModernImplTest.java
@@ -393,9 +393,9 @@ public final class BroadcastQueueModernImplTest {
                 List.of(makeMockRegisteredReceiver()), false);
         enqueueOrReplaceBroadcast(queue, airplaneRecord, 0);
 
-        queue.setProcessAndUidCached(null, false);
+        queue.setProcessAndUidState(null, false, false);
         final long notCachedRunnableAt = queue.getRunnableAt();
-        queue.setProcessAndUidCached(null, true);
+        queue.setProcessAndUidState(null, false, true);
         final long cachedRunnableAt = queue.getRunnableAt();
         assertThat(cachedRunnableAt).isGreaterThan(notCachedRunnableAt);
         assertFalse(queue.isRunnable());
@@ -420,9 +420,9 @@ public final class BroadcastQueueModernImplTest {
                 List.of(makeMockRegisteredReceiver()), false);
         enqueueOrReplaceBroadcast(queue, airplaneRecord, 0);
 
-        queue.setProcessAndUidCached(null, false);
+        queue.setProcessAndUidState(null, false, false);
         final long notCachedRunnableAt = queue.getRunnableAt();
-        queue.setProcessAndUidCached(null, true);
+        queue.setProcessAndUidState(null, false, true);
         final long cachedRunnableAt = queue.getRunnableAt();
         assertThat(cachedRunnableAt).isGreaterThan(notCachedRunnableAt);
         assertTrue(queue.isRunnable());
@@ -452,13 +452,13 @@ public final class BroadcastQueueModernImplTest {
         // verify that:
         // (a) the queue is immediately runnable by existence of a fg-priority broadcast
         // (b) the next one up is the fg-priority broadcast despite its later enqueue time
-        queue.setProcessAndUidCached(null, false);
+        queue.setProcessAndUidState(null, false, false);
         assertTrue(queue.isRunnable());
         assertThat(queue.getRunnableAt()).isAtMost(airplaneRecord.enqueueClockTime);
         assertEquals(ProcessList.SCHED_GROUP_UNDEFINED, queue.getPreferredSchedulingGroupLocked());
         assertEquals(queue.peekNextBroadcastRecord(), airplaneRecord);
 
-        queue.setProcessAndUidCached(null, true);
+        queue.setProcessAndUidState(null, false, true);
         assertTrue(queue.isRunnable());
         assertThat(queue.getRunnableAt()).isAtMost(airplaneRecord.enqueueClockTime);
         assertEquals(ProcessList.SCHED_GROUP_UNDEFINED, queue.getPreferredSchedulingGroupLocked());
@@ -515,6 +515,28 @@ public final class BroadcastQueueModernImplTest {
         assertEquals(BroadcastProcessQueue.REASON_MAX_PENDING, queue.getRunnableAtReason());
     }
 
+    @Test
+    public void testRunnableAt_uidForeground() {
+        final BroadcastProcessQueue queue = new BroadcastProcessQueue(mConstants, PACKAGE_GREEN,
+                getUidForPackage(PACKAGE_GREEN));
+
+        final Intent timeTick = new Intent(Intent.ACTION_TIME_TICK);
+        final BroadcastRecord timeTickRecord = makeBroadcastRecord(timeTick,
+                List.of(makeMockRegisteredReceiver()));
+        enqueueOrReplaceBroadcast(queue, timeTickRecord, 0);
+
+        assertThat(queue.getRunnableAt()).isGreaterThan(timeTickRecord.enqueueTime);
+        assertEquals(BroadcastProcessQueue.REASON_NORMAL, queue.getRunnableAtReason());
+
+        queue.setProcessAndUidState(mProcess, true, false);
+        assertThat(queue.getRunnableAt()).isLessThan(timeTickRecord.enqueueTime);
+        assertEquals(BroadcastProcessQueue.REASON_FOREGROUND, queue.getRunnableAtReason());
+
+        queue.setProcessAndUidState(mProcess, false, false);
+        assertThat(queue.getRunnableAt()).isGreaterThan(timeTickRecord.enqueueTime);
+        assertEquals(BroadcastProcessQueue.REASON_NORMAL, queue.getRunnableAtReason());
+    }
+
     /**
      * Verify that a cached process that would normally be delayed becomes
      * immediately runnable when the given broadcast is enqueued.
@@ -522,7 +544,7 @@ public final class BroadcastQueueModernImplTest {
     private void doRunnableAt_Cached(BroadcastRecord testRecord, int testRunnableAtReason) {
         final BroadcastProcessQueue queue = new BroadcastProcessQueue(mConstants,
                 PACKAGE_GREEN, getUidForPackage(PACKAGE_GREEN));
-        queue.setProcessAndUidCached(null, true);
+        queue.setProcessAndUidState(null, false, true);
 
         final BroadcastRecord lazyRecord = makeBroadcastRecord(
                 new Intent(Intent.ACTION_AIRPLANE_MODE_CHANGED),
diff --git a/services/tests/mockingservicestests/src/com/android/server/am/BroadcastQueueTest.java b/services/tests/mockingservicestests/src/com/android/server/am/BroadcastQueueTest.java
index 7be1d7cde27f..bc6f5029ea17 100644
--- a/services/tests/mockingservicestests/src/com/android/server/am/BroadcastQueueTest.java
+++ b/services/tests/mockingservicestests/src/com/android/server/am/BroadcastQueueTest.java
@@ -25,12 +25,15 @@ import static com.android.server.am.BroadcastProcessQueue.reasonToString;
 import static com.android.server.am.BroadcastRecord.deliveryStateToString;
 import static com.android.server.am.BroadcastRecord.isReceiverEquals;
 
+import static com.google.common.truth.Truth.assertThat;
+
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyBoolean;
 import static org.mockito.ArgumentMatchers.anyInt;
@@ -2102,4 +2105,75 @@ public class BroadcastQueueTest {
         waitForIdle();
         verifyScheduleRegisteredReceiver(times(1), receiverGreenApp, airplane);
     }
+
+    @Test
+    public void testBroadcastDelivery_uidForeground() throws Exception {
+        // Legacy stack doesn't support prioritization to foreground app.
+        Assume.assumeTrue(mImpl == Impl.MODERN);
+
+        final ProcessRecord callerApp = makeActiveProcessRecord(PACKAGE_RED);
+        final ProcessRecord receiverBlueApp = makeActiveProcessRecord(PACKAGE_BLUE);
+        final ProcessRecord receiverGreenApp = makeActiveProcessRecord(PACKAGE_GREEN);
+
+        mUidObserver.onUidStateChanged(receiverGreenApp.info.uid,
+                ActivityManager.PROCESS_STATE_TOP, 0, ActivityManager.PROCESS_CAPABILITY_NONE);
+
+        final Intent airplane = new Intent(Intent.ACTION_AIRPLANE_MODE_CHANGED);
+        final Intent timeTick = new Intent(Intent.ACTION_TIME_TICK);
+
+        final BroadcastFilter receiverBlue = makeRegisteredReceiver(receiverBlueApp);
+        final BroadcastFilter receiverGreen = makeRegisteredReceiver(receiverGreenApp);
+        final BroadcastRecord airplaneRecord = makeBroadcastRecord(airplane, callerApp,
+                List.of(receiverBlue));
+        final BroadcastRecord timeTickRecord = makeBroadcastRecord(timeTick, callerApp,
+                List.of(receiverBlue, receiverGreen));
+
+        enqueueBroadcast(airplaneRecord);
+        enqueueBroadcast(timeTickRecord);
+
+        waitForIdle();
+        // Verify that broadcasts to receiverGreenApp gets scheduled first.
+        assertThat(getReceiverScheduledTime(timeTickRecord, receiverGreen))
+                .isLessThan(getReceiverScheduledTime(airplaneRecord, receiverBlue));
+        assertThat(getReceiverScheduledTime(timeTickRecord, receiverGreen))
+                .isLessThan(getReceiverScheduledTime(timeTickRecord, receiverBlue));
+    }
+
+    @Test
+    public void testPrioritizedBroadcastDelivery_uidForeground() throws Exception {
+        // Legacy stack doesn't support prioritization to foreground app.
+        Assume.assumeTrue(mImpl == Impl.MODERN);
+
+        final ProcessRecord callerApp = makeActiveProcessRecord(PACKAGE_RED);
+        final ProcessRecord receiverBlueApp = makeActiveProcessRecord(PACKAGE_BLUE);
+        final ProcessRecord receiverGreenApp = makeActiveProcessRecord(PACKAGE_GREEN);
+
+        mUidObserver.onUidStateChanged(receiverGreenApp.info.uid,
+                ActivityManager.PROCESS_STATE_TOP, 0, ActivityManager.PROCESS_CAPABILITY_NONE);
+
+        final Intent timeTick = new Intent(Intent.ACTION_TIME_TICK);
+
+        final BroadcastFilter receiverBlue = makeRegisteredReceiver(receiverBlueApp, 10);
+        final BroadcastFilter receiverGreen = makeRegisteredReceiver(receiverGreenApp, 5);
+        final BroadcastRecord prioritizedRecord = makeBroadcastRecord(timeTick, callerApp,
+                List.of(receiverBlue, receiverGreen));
+
+        enqueueBroadcast(prioritizedRecord);
+
+        waitForIdle();
+        // Verify that uid foreground-ness does not impact that delivery of prioritized broadcast.
+        // That is, broadcast to receiverBlueApp gets scheduled before the one to receiverGreenApp.
+        assertThat(getReceiverScheduledTime(prioritizedRecord, receiverGreen))
+                .isGreaterThan(getReceiverScheduledTime(prioritizedRecord, receiverBlue));
+    }
+
+    private long getReceiverScheduledTime(@NonNull BroadcastRecord r, @NonNull Object receiver) {
+        for (int i = 0; i < r.receivers.size(); ++i) {
+            if (isReceiverEquals(receiver, r.receivers.get(i))) {
+                return r.scheduledTime[i];
+            }
+        }
+        fail(receiver + "not found in " + r);
+        return -1;
+    }
 }