Make GET_TASKS signature|system.

Normal apps can't hold it now.  If they try to use
getRecentTasks() or getRunningTasks() without the permission,
they will only see their own tasks and home in the list.

Also took this opportunity to eradicate all of the old pending
thumbnail stuff.

Change-Id: I6dc52a06221c78097162e4a8b482027b798bf3ee

6 files changed, 36 insertions, 277 deletions

diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index 9eaddbd..042bf5f 100644
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -95,7 +95,6 @@ import android.app.INotificationManager;
 import android.app.IProcessObserver;
 import android.app.IServiceConnection;
 import android.app.IStopUserCallback;
-import android.app.IThumbnailReceiver;
 import android.app.IUiAutomationConnection;
 import android.app.IUserSwitchObserver;
 import android.app.Instrumentation;
@@ -703,13 +702,6 @@ public final class ActivityManagerService extends ActivityManagerNative
     String mBackupAppName = null;
     BackupRecord mBackupTarget = null;
 
-    /**
-     * List of PendingThumbnailsRecord objects of clients who are still
-     * waiting to receive all of the thumbnails for a task.
-     */
-    final ArrayList<PendingThumbnailsRecord> mPendingThumbnails =
-            new ArrayList<PendingThumbnailsRecord>();
-
     final ProviderMap mProviderMap;
 
     /**
@@ -5452,21 +5444,15 @@ public final class ActivityManagerService extends ActivityManagerNative
             throw new IllegalArgumentException("File descriptors passed in Bundle");
         }
 
-        ActivityRecord r = null;
-
         final long origId = Binder.clearCallingIdentity();
 
         synchronized (this) {
-            r = ActivityRecord.isInStackLocked(token);
+            ActivityRecord r = ActivityRecord.isInStackLocked(token);
             if (r != null) {
                 r.task.stack.activityStoppedLocked(r, icicle, thumbnail, description);
             }
         }
 
-        if (r != null) {
-            sendPendingThumbnail(r, null, null, null, false);
-        }
-
         trimApplications();
 
         Binder.restoreCallingIdentity(origId);
@@ -6982,66 +6968,24 @@ public final class ActivityManagerService extends ActivityManagerNative
     // =========================================================
 
     @Override
-    public List<RunningTaskInfo> getTasks(int maxNum, int flags,
-                         IThumbnailReceiver receiver) {
+    public List<RunningTaskInfo> getTasks(int maxNum, int flags) {
+        final int callingUid = Binder.getCallingUid();
         ArrayList<RunningTaskInfo> list = new ArrayList<RunningTaskInfo>();
 
-        PendingThumbnailsRecord pending = new PendingThumbnailsRecord(receiver);
-        ActivityRecord topRecord = null;
-
         synchronized(this) {
             if (localLOGV) Slog.v(
-                TAG, "getTasks: max=" + maxNum + ", flags=" + flags
-                + ", receiver=" + receiver);
+                TAG, "getTasks: max=" + maxNum + ", flags=" + flags);
 
-            if (checkCallingPermission(android.Manifest.permission.GET_TASKS)
-                    != PackageManager.PERMISSION_GRANTED) {
-                if (receiver != null) {
-                    // If the caller wants to wait for pending thumbnails,
-                    // it ain't gonna get them.
-                    try {
-                        receiver.finished();
-                    } catch (RemoteException ex) {
-                    }
-                }
-                String msg = "Permission Denial: getTasks() from pid="
-                        + Binder.getCallingPid()
-                        + ", uid=" + Binder.getCallingUid()
-                        + " requires " + android.Manifest.permission.GET_TASKS;
-                Slog.w(TAG, msg);
-                throw new SecurityException(msg);
+            final boolean allowed = checkCallingPermission(
+                    android.Manifest.permission.GET_TASKS)
+                    == PackageManager.PERMISSION_GRANTED;
+            if (!allowed) {
+                Slog.w(TAG, "getTasks: caller " + callingUid
+                        + " does not hold GET_TASKS; limiting output");
             }
 
             // TODO: Improve with MRU list from all ActivityStacks.
-            topRecord = mStackSupervisor.getTasksLocked(maxNum, receiver, pending, list);
-
-            if (!pending.pendingRecords.isEmpty()) {
-                mPendingThumbnails.add(pending);
-            }
-        }
-
-        if (localLOGV) Slog.v(TAG, "We have pending thumbnails: " + pending);
-
-        if (topRecord != null) {
-            if (localLOGV) Slog.v(TAG, "Requesting top thumbnail");
-            try {
-                IApplicationThread topThumbnail = topRecord.app.thread;
-                topThumbnail.requestThumbnail(topRecord.appToken);
-            } catch (Exception e) {
-                Slog.w(TAG, "Exception thrown when requesting thumbnail", e);
-                sendPendingThumbnail(null, topRecord.appToken, null, null, true);
-            }
-        }
-
-        if (pending.pendingRecords.isEmpty() && receiver != null) {
-            // In this case all thumbnails were available and the client
-            // is being asked to be told when the remaining ones come in...
-            // which is unusually, since the top-most currently running
-            // activity should never have a canned thumbnail!  Oh well.
-            try {
-                receiver.finished();
-            } catch (RemoteException ex) {
-            }
+            mStackSupervisor.getTasksLocked(maxNum, list, callingUid, allowed);
         }
 
         return list;
@@ -7054,12 +6998,18 @@ public final class ActivityManagerService extends ActivityManagerNative
     @Override
     public List<ActivityManager.RecentTaskInfo> getRecentTasks(int maxNum,
             int flags, int userId) {
-        userId = handleIncomingUser(Binder.getCallingPid(), Binder.getCallingUid(), userId,
+        final int callingUid = Binder.getCallingUid();
+        userId = handleIncomingUser(Binder.getCallingPid(), callingUid, userId,
                 false, true, "getRecentTasks", null);
 
         synchronized (this) {
-            enforceCallingPermission(android.Manifest.permission.GET_TASKS,
-                    "getRecentTasks()");
+            final boolean allowed = checkCallingPermission(
+                    android.Manifest.permission.GET_TASKS)
+                    == PackageManager.PERMISSION_GRANTED;
+            if (!allowed) {
+                Slog.w(TAG, "getRecentTasks: caller " + callingUid
+                        + " does not hold GET_TASKS; limiting output");
+            }
             final boolean detailed = checkCallingPermission(
                     android.Manifest.permission.GET_DETAILED_TASKS)
                     == PackageManager.PERMISSION_GRANTED;
@@ -7094,6 +7044,13 @@ public final class ActivityManagerService extends ActivityManagerNative
                         || (tr.intent == null)
                         || ((tr.intent.getFlags()
                                 &Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS) == 0)) {
+                    if (!allowed) {
+                        // If the caller doesn't have the GET_TASKS permission, then only
+                        // allow them to see a small subset of tasks -- their own and home.
+                        if (!tr.isHomeTask() && tr.creatorUid != callingUid) {
+                            continue;
+                        }
+                    }
                     ActivityManager.RecentTaskInfo rti
                             = new ActivityManager.RecentTaskInfo();
                     rti.id = tr.numActivities > 0 ? tr.taskId : -1;
@@ -7635,82 +7592,6 @@ public final class ActivityManagerService extends ActivityManagerNative
     }
 
     // =========================================================
-    // THUMBNAILS
-    // =========================================================
-
-    public void reportThumbnail(IBinder token,
-            Bitmap thumbnail, CharSequence description) {
-        //System.out.println("Report thumbnail for " + token + ": " + thumbnail);
-        final long origId = Binder.clearCallingIdentity();
-        sendPendingThumbnail(null, token, thumbnail, description, true);
-        Binder.restoreCallingIdentity(origId);
-    }
-
-    final void sendPendingThumbnail(ActivityRecord r, IBinder token,
-            Bitmap thumbnail, CharSequence description, boolean always) {
-        TaskRecord task;
-        ArrayList<PendingThumbnailsRecord> receivers = null;
-
-        //System.out.println("Send pending thumbnail: " + r);
-
-        synchronized(this) {
-            if (r == null) {
-                r = ActivityRecord.isInStackLocked(token);
-                if (r == null) {
-                    return;
-                }
-            }
-            if (thumbnail == null && r.thumbHolder != null) {
-                thumbnail = r.thumbHolder.lastThumbnail;
-                description = r.thumbHolder.lastDescription;
-            }
-            if (thumbnail == null && !always) {
-                // If there is no thumbnail, and this entry is not actually
-                // going away, then abort for now and pick up the next
-                // thumbnail we get.
-                return;
-            }
-            task = r.task;
-
-            int N = mPendingThumbnails.size();
-            int i=0;
-            while (i<N) {
-                PendingThumbnailsRecord pr = mPendingThumbnails.get(i);
-                //System.out.println("Looking in " + pr.pendingRecords);
-                if (pr.pendingRecords.remove(r)) {
-                    if (receivers == null) {
-                        receivers = new ArrayList<PendingThumbnailsRecord>();
-                    }
-                    receivers.add(pr);
-                    if (pr.pendingRecords.size() == 0) {
-                        pr.finished = true;
-                        mPendingThumbnails.remove(i);
-                        N--;
-                        continue;
-                    }
-                }
-                i++;
-            }
-        }
-
-        if (receivers != null) {
-            final int N = receivers.size();
-            for (int i=0; i<N; i++) {
-                try {
-                    PendingThumbnailsRecord pr = receivers.get(i);
-                    pr.receiver.newThumbnail(
-                        task != null ? task.taskId : -1, thumbnail, description);
-                    if (pr.finished) {
-                        pr.receiver.finished();
-                    }
-                } catch (Exception e) {
-                    Slog.w(TAG, "Exception thrown when sending thumbnail", e);
-                }
-            }
-        }
-    }
-
-    // =========================================================
     // CONTENT PROVIDERS
     // =========================================================
 
diff --git a/services/core/java/com/android/server/am/ActivityRecord.java b/services/core/java/com/android/server/am/ActivityRecord.java
index 7a44473..7a08cdd 100755
--- a/services/core/java/com/android/server/am/ActivityRecord.java
+++ b/services/core/java/com/android/server/am/ActivityRecord.java
@@ -131,7 +131,6 @@ final class ActivityRecord {
     boolean sleeping;       // have we told the activity to sleep?
     boolean waitingVisible; // true if waiting for a new act to become vis
     boolean nowVisible;     // is this activity's window visible?
-    boolean thumbnailNeeded;// has someone requested a thumbnail?
     boolean idle;           // has the activity gone idle?
     boolean hasBeenLaunched;// has this activity ever been launched?
     boolean frozenBeforeDestroy;// has been frozen but not yet destroyed.
@@ -239,7 +238,6 @@ final class ActivityRecord {
                 pw.print(" immersive="); pw.print(immersive);
                 pw.print(" launchMode="); pw.println(launchMode);
         pw.print(prefix); pw.print("frozenBeforeDestroy="); pw.print(frozenBeforeDestroy);
-                pw.print(" thumbnailNeeded="); pw.print(thumbnailNeeded);
                 pw.print(" forceNewConfig="); pw.println(forceNewConfig);
         pw.print(prefix); pw.print("mActivityType=");
                 pw.println(activityTypeToString(mActivityType));
@@ -375,7 +373,6 @@ final class ActivityRecord {
         visible = true;
         waitingVisible = false;
         nowVisible = false;
-        thumbnailNeeded = false;
         idle = false;
         hasBeenLaunched = false;
         mStackSupervisor = supervisor;
diff --git a/services/core/java/com/android/server/am/ActivityStack.java b/services/core/java/com/android/server/am/ActivityStack.java
index 6769c9c..5beb17d 100755
--- a/services/core/java/com/android/server/am/ActivityStack.java
+++ b/services/core/java/com/android/server/am/ActivityStack.java
@@ -53,7 +53,6 @@ import android.app.ActivityManager;
 import android.app.ActivityOptions;
 import android.app.AppGlobals;
 import android.app.IActivityController;
-import android.app.IThumbnailReceiver;
 import android.app.ResultInfo;
 import android.app.ActivityManager.RunningTaskInfo;
 import android.content.ComponentName;
@@ -73,7 +72,6 @@ import android.os.Looper;
 import android.os.Message;
 import android.os.RemoteException;
 import android.os.SystemClock;
-import android.os.SystemProperties;
 import android.os.Trace;
 import android.os.UserHandle;
 import android.util.EventLog;
@@ -2537,13 +2535,6 @@ final class ActivityStack {
 
         finishActivityResultsLocked(r, resultCode, resultData);
 
-        if (!mService.mPendingThumbnails.isEmpty()) {
-            // There are clients waiting to receive thumbnails so, in case
-            // this is an activity that someone is waiting for, add it
-            // to the pending list so we can correctly update the clients.
-            mStackSupervisor.mCancelledThumbnails.add(r);
-        }
-
         if (mResumedActivity == r) {
             boolean endTask = index <= 0;
             if (DEBUG_VISBILITY || DEBUG_TRANSITION) Slog.v(TAG,
@@ -2782,13 +2773,6 @@ final class ActivityStack {
             cleanUpActivityServicesLocked(r);
         }
 
-        if (!mService.mPendingThumbnails.isEmpty()) {
-            // There are clients waiting to receive thumbnails so, in case
-            // this is an activity that someone is waiting for, add it
-            // to the pending list so we can correctly update the clients.
-            mStackSupervisor.mCancelledThumbnails.add(r);
-        }
-
         // Get rid of any pending idle timeouts.
         removeTimeoutsForActivityLocked(r);
     }
@@ -3535,9 +3519,7 @@ final class ActivityStack {
         return didSomething;
     }
 
-    ActivityRecord getTasksLocked(IThumbnailReceiver receiver,
-            PendingThumbnailsRecord pending, List<RunningTaskInfo> list) {
-        ActivityRecord topRecord = null;
+    void getTasksLocked(List<RunningTaskInfo> list, int callingUid, boolean allowed) {
         for (int taskNdx = mTaskHistory.size() - 1; taskNdx >= 0; --taskNdx) {
             final TaskRecord task = mTaskHistory.get(taskNdx);
             ActivityRecord r = null;
@@ -3548,6 +3530,9 @@ final class ActivityStack {
             if (activities.isEmpty()) {
                 continue;
             }
+            if (!allowed && !task.isHomeTask() && task.creatorUid != callingUid) {
+                continue;
+            }
             for (int activityNdx = activities.size() - 1; activityNdx >= 0; --activityNdx) {
                 r = activities.get(activityNdx);
 
@@ -3581,23 +3566,8 @@ final class ActivityStack {
             ci.numRunning = numRunning;
             //System.out.println(
             //    "#" + maxNum + ": " + " descr=" + ci.description);
-            if (receiver != null) {
-                if (localLOGV) Slog.v(
-                    TAG, "State=" + top.state + "Idle=" + top.idle
-                    + " app=" + top.app
-                    + " thr=" + (top.app != null ? top.app.thread : null));
-                if (top.state == ActivityState.RESUMED || top.state == ActivityState.PAUSING) {
-                    if (top.idle && top.app != null && top.app.thread != null) {
-                        topRecord = top;
-                    } else {
-                        top.thumbnailNeeded = true;
-                    }
-                }
-                pending.pendingRecords.add(top);
-            }
             list.add(ci);
         }
-        return topRecord;
     }
 
     public void unhandledBackLocked() {
diff --git a/services/core/java/com/android/server/am/ActivityStackSupervisor.java b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
index 3770a07..9107cb6 100644
--- a/services/core/java/com/android/server/am/ActivityStackSupervisor.java
+++ b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
@@ -41,7 +41,6 @@ import android.app.IActivityContainer;
 import android.app.IActivityContainerCallback;
 import android.app.IActivityManager;
 import android.app.IApplicationThread;
-import android.app.IThumbnailReceiver;
 import android.app.PendingIntent;
 import android.app.ActivityManager.RunningTaskInfo;
 import android.app.IActivityManager.WaitResult;
@@ -191,10 +190,6 @@ public final class ActivityStackSupervisor implements DisplayListener {
     /** List of activities that are in the process of going to sleep. */
     final ArrayList<ActivityRecord> mGoingToSleepActivities = new ArrayList<ActivityRecord>();
 
-    /** List of ActivityRecord objects that have been finished and must still report back to a
-     * pending thumbnail receiver. */
-    final ArrayList<ActivityRecord> mCancelledThumbnails = new ArrayList<ActivityRecord>();
-
     /** Used on user changes */
     final ArrayList<UserStartedState> mStartingUsers = new ArrayList<UserStartedState>();
 
@@ -591,10 +586,7 @@ public final class ActivityStackSupervisor implements DisplayListener {
         return null;
     }
 
-    ActivityRecord getTasksLocked(int maxNum, IThumbnailReceiver receiver,
-            PendingThumbnailsRecord pending, List<RunningTaskInfo> list) {
-        ActivityRecord r = null;
-
+    void getTasksLocked(int maxNum, List<RunningTaskInfo> list, int callingUid, boolean allowed) {
         // Gather all of the running tasks for each stack into runningTaskLists.
         ArrayList<ArrayList<RunningTaskInfo>> runningTaskLists =
                 new ArrayList<ArrayList<RunningTaskInfo>>();
@@ -605,10 +597,7 @@ public final class ActivityStackSupervisor implements DisplayListener {
                 final ActivityStack stack = stacks.get(stackNdx);
                 ArrayList<RunningTaskInfo> stackTaskList = new ArrayList<RunningTaskInfo>();
                 runningTaskLists.add(stackTaskList);
-                final ActivityRecord ar = stack.getTasksLocked(receiver, pending, stackTaskList);
-                if (r == null && isFrontStack(stack)) {
-                    r = ar;
-                }
+                stack.getTasksLocked(stackTaskList, callingUid, allowed);
             }
         }
 
@@ -635,8 +624,6 @@ public final class ActivityStackSupervisor implements DisplayListener {
                 break;
             }
         }
-
-        return r;
     }
 
     ActivityInfo resolveActivity(Intent intent, String resolvedType, int startFlags,
@@ -1912,7 +1899,6 @@ public final class ActivityStackSupervisor implements DisplayListener {
         ArrayList<UserStartedState> startingUsers = null;
         int NS = 0;
         int NF = 0;
-        IApplicationThread sendThumbnail = null;
         boolean booting = false;
         boolean enableScreen = false;
         boolean activityRemoved = false;
@@ -1940,11 +1926,6 @@ public final class ActivityStackSupervisor implements DisplayListener {
             // us, we can now deliver.
             r.idle = true;
 
-            if (r.thumbnailNeeded && r.app != null && r.app.thread != null) {
-                sendThumbnail = r.app.thread;
-                r.thumbnailNeeded = false;
-            }
-
             //Slog.i(TAG, "IDLE: mBooted=" + mBooted + ", fromTimeout=" + fromTimeout);
             if (!mService.mBooted && isFrontStack(r.task.stack)) {
                 mService.mBooted = true;
@@ -1976,15 +1957,6 @@ public final class ActivityStackSupervisor implements DisplayListener {
             mFinishingActivities.clear();
         }
 
-        final ArrayList<ActivityRecord> thumbnails;
-        final int NT = mCancelledThumbnails.size();
-        if (NT > 0) {
-            thumbnails = new ArrayList<ActivityRecord>(mCancelledThumbnails);
-            mCancelledThumbnails.clear();
-        } else {
-            thumbnails = null;
-        }
-
         if (isFrontStack(mHomeStack)) {
             booting = mService.mBooting;
             mService.mBooting = false;
@@ -1995,28 +1967,6 @@ public final class ActivityStackSupervisor implements DisplayListener {
             mStartingUsers.clear();
         }
 
-        // Perform the following actions from unsynchronized state.
-        final IApplicationThread thumbnailThread = sendThumbnail;
-        mHandler.post(new Runnable() {
-            @Override
-            public void run() {
-                if (thumbnailThread != null) {
-                    try {
-                        thumbnailThread.requestThumbnail(token);
-                    } catch (Exception e) {
-                        Slog.w(TAG, "Exception thrown when requesting thumbnail", e);
-                        mService.sendPendingThumbnail(null, token, null, null, true);
-                    }
-                }
-
-                // Report back to any thumbnail receivers.
-                for (int i = 0; i < NT; i++) {
-                    ActivityRecord r = thumbnails.get(i);
-                    mService.sendPendingThumbnail(r, null, null, null, true);
-                }
-            }
-        });
-
         // Stop any activities that are scheduled to do so but have been
         // waiting for the next one to start.
         for (int i = 0; i < NS; i++) {
diff --git a/services/core/java/com/android/server/am/PendingThumbnailsRecord.java b/services/core/java/com/android/server/am/PendingThumbnailsRecord.java
deleted file mode 100644
index e4eb4d0..0000000
--- a/services/core/java/com/android/server/am/PendingThumbnailsRecord.java
+++ /dev/null
@@ -1,39 +0,0 @@
-/*
- * Copyright (C) 2006 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.server.am;
-
-import android.app.IThumbnailReceiver;
-
-import java.util.HashSet;
-
-/**
- * This class keeps track of calls to getTasks() that are still
- * waiting for thumbnail images.
- */
-final class PendingThumbnailsRecord
-{
-    final IThumbnailReceiver receiver;   // who is waiting.
-    final HashSet<ActivityRecord> pendingRecords; // HistoryRecord objects we still wait for.
-    boolean finished;       // Is pendingRecords empty?
-
-    PendingThumbnailsRecord(IThumbnailReceiver _receiver)
-    {
-        receiver = _receiver;
-        pendingRecords = new HashSet<ActivityRecord>();
-        finished = false;
-    }
-}
diff --git a/services/core/java/com/android/server/am/TaskRecord.java b/services/core/java/com/android/server/am/TaskRecord.java
index 68da54d..f4dd15e 100644
--- a/services/core/java/com/android/server/am/TaskRecord.java
+++ b/services/core/java/com/android/server/am/TaskRecord.java
@@ -52,6 +52,7 @@ final class TaskRecord extends ThumbnailHolder {
 
     String stringName;      // caching of toString() result.
     int userId;             // user for which this task was created
+    int creatorUid;         // The app uid that originally created the task
 
     int numFullscreen;      // Number of fullscreen activities.
 
@@ -131,9 +132,8 @@ final class TaskRecord extends ThumbnailHolder {
             rootWasReset = true;
         }
 
-        if (info.applicationInfo != null) {
-            userId = UserHandle.getUserId(info.applicationInfo.uid);
-        }
+        userId = UserHandle.getUserId(info.applicationInfo.uid);
+        creatorUid = info.applicationInfo.uid;
     }
 
     void disposeThumbnail() {