Move the waiting for the publishing of content provider to client side

...except the external provider client.

Previously the waiting is within the system_server and holds a binder
thread of the system_server. Now the waiting will be in client side
and the system_server will notify the client when the provider is
ready.

Bug: 149935749
Bug: 162450085
Test: atest CtsContentTestCases:android.content.cts
Test: atest FrameworksCoreTests:android.content
Test: atest ActivityManagerPerfTests:ContentProviderPerfTest
Change-Id: I0c8ef1c397103ac38f2fb7da79e647c0b8cd63cc
diff --git a/core/java/android/app/ActivityThread.java b/core/java/android/app/ActivityThread.java
index 9b13d25..dde0be5 100644
--- a/core/java/android/app/ActivityThread.java
+++ b/core/java/android/app/ActivityThread.java
@@ -421,9 +421,14 @@
         final String authority;
         final int userId;
 
+        @GuardedBy("mLock")
+        ContentProviderHolder mHolder; // Temp holder to be used between notifier and waiter
+        Object mLock; // The lock to be used to get notified when the provider is ready
+
         public ProviderKey(String authority, int userId) {
             this.authority = authority;
             this.userId = userId;
+            this.mLock = new Object();
         }
 
         @Override
@@ -437,7 +442,11 @@
 
         @Override
         public int hashCode() {
-            return ((authority != null) ? authority.hashCode() : 0) ^ userId;
+            return hashCode(authority, userId);
+        }
+
+        public static int hashCode(final String auth, final int userIdent) {
+            return ((auth != null) ? auth.hashCode() : 0) ^ userIdent;
         }
     }
 
@@ -458,9 +467,8 @@
     // Mitigation for b/74523247: Used to serialize calls to AM.getContentProvider().
     // Note we never removes items from this map but that's okay because there are only so many
     // users and so many authorities.
-    // TODO Remove it once we move CPR.wait() from AMS to the client side.
-    @GuardedBy("mGetProviderLocks")
-    final ArrayMap<ProviderKey, Object> mGetProviderLocks = new ArrayMap<>();
+    @GuardedBy("mGetProviderKeys")
+    final SparseArray<ProviderKey> mGetProviderKeys = new SparseArray<>();
 
     final ArrayMap<Activity, ArrayList<OnActivityPausedListener>> mOnPauseListeners
         = new ArrayMap<Activity, ArrayList<OnActivityPausedListener>>();
@@ -1751,6 +1759,16 @@
                     ActivityThread.this, activityToken, actionId, arguments,
                     cancellationSignal, resultCallback));
         }
+
+        @Override
+        public void notifyContentProviderPublishStatus(@NonNull ContentProviderHolder holder,
+                @NonNull String auth, int userId, boolean published) {
+            final ProviderKey key = getGetProviderKey(auth, userId);
+            synchronized (key.mLock) {
+                key.mHolder = holder;
+                key.mLock.notifyAll();
+            }
+        }
     }
 
     private @NonNull SafeCancellationTransport createSafeCancellationTransport(
@@ -6796,13 +6814,33 @@
         // provider since it might take a long time to run and it could also potentially
         // be re-entrant in the case where the provider is in the same process.
         ContentProviderHolder holder = null;
+        final ProviderKey key = getGetProviderKey(auth, userId);
         try {
-            synchronized (getGetProviderLock(auth, userId)) {
+            synchronized (key) {
                 holder = ActivityManager.getService().getContentProvider(
                         getApplicationThread(), c.getOpPackageName(), auth, userId, stable);
+                // If the returned holder is non-null but its provider is null and it's not
+                // local, we'll need to wait for the publishing of the provider.
+                if (holder != null && holder.provider == null && !holder.mLocal) {
+                    synchronized (key.mLock) {
+                        key.mLock.wait(ContentResolver.CONTENT_PROVIDER_READY_TIMEOUT_MILLIS);
+                        holder = key.mHolder;
+                    }
+                    if (holder != null && holder.provider == null) {
+                        // probably timed out
+                        holder = null;
+                    }
+                }
             }
         } catch (RemoteException ex) {
             throw ex.rethrowFromSystemServer();
+        } catch (InterruptedException e) {
+            holder = null;
+        } finally {
+            // Clear the holder from the key since the key itself is never cleared.
+            synchronized (key.mLock) {
+                key.mHolder = null;
+            }
         }
         if (holder == null) {
             if (UserManager.get(c).isUserUnlocked(userId)) {
@@ -6820,13 +6858,13 @@
         return holder.provider;
     }
 
-    private Object getGetProviderLock(String auth, int userId) {
-        final ProviderKey key = new ProviderKey(auth, userId);
-        synchronized (mGetProviderLocks) {
-            Object lock = mGetProviderLocks.get(key);
+    private ProviderKey getGetProviderKey(String auth, int userId) {
+        final int key = ProviderKey.hashCode(auth, userId);
+        synchronized (mGetProviderKeys) {
+            ProviderKey lock = mGetProviderKeys.get(key);
             if (lock == null) {
-                lock = key;
-                mGetProviderLocks.put(key, lock);
+                lock = new ProviderKey(auth, userId);
+                mGetProviderKeys.put(key, lock);
             }
             return lock;
         }
diff --git a/core/java/android/app/ContentProviderHolder.java b/core/java/android/app/ContentProviderHolder.java
index 3d74583..e330a30 100644
--- a/core/java/android/app/ContentProviderHolder.java
+++ b/core/java/android/app/ContentProviderHolder.java
@@ -39,6 +39,11 @@
     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
     public boolean noReleaseNeeded;
 
+    /**
+     * Whether the provider here is a local provider or not.
+     */
+    public boolean mLocal;
+
     @UnsupportedAppUsage
     public ContentProviderHolder(ProviderInfo _info) {
         info = _info;
@@ -59,6 +64,7 @@
         }
         dest.writeStrongBinder(connection);
         dest.writeInt(noReleaseNeeded ? 1 : 0);
+        dest.writeInt(mLocal ? 1 : 0);
     }
 
     public static final @android.annotation.NonNull Parcelable.Creator<ContentProviderHolder> CREATOR
@@ -81,5 +87,6 @@
                 source.readStrongBinder());
         connection = source.readStrongBinder();
         noReleaseNeeded = source.readInt() != 0;
+        mLocal = source.readInt() != 0;
     }
-}
\ No newline at end of file
+}
diff --git a/core/java/android/app/IApplicationThread.aidl b/core/java/android/app/IApplicationThread.aidl
index 6e9157e..e5d4a76 100644
--- a/core/java/android/app/IApplicationThread.aidl
+++ b/core/java/android/app/IApplicationThread.aidl
@@ -16,6 +16,7 @@
 
 package android.app;
 
+import android.app.ContentProviderHolder;
 import android.app.IInstrumentationWatcher;
 import android.app.IUiAutomationConnection;
 import android.app.ProfilerInfo;
@@ -147,4 +148,6 @@
     void performDirectAction(IBinder activityToken, String actionId,
             in Bundle arguments, in RemoteCallback cancellationCallback,
             in RemoteCallback resultCallback);
+    void notifyContentProviderPublishStatus(in ContentProviderHolder holder, String auth,
+            int userId, boolean published);
 }
diff --git a/core/tests/coretests/src/android/app/servertransaction/TransactionParcelTests.java b/core/tests/coretests/src/android/app/servertransaction/TransactionParcelTests.java
index f11adef..ea8df83 100644
--- a/core/tests/coretests/src/android/app/servertransaction/TransactionParcelTests.java
+++ b/core/tests/coretests/src/android/app/servertransaction/TransactionParcelTests.java
@@ -24,6 +24,7 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 
+import android.app.ContentProviderHolder;
 import android.app.IApplicationThread;
 import android.app.IInstrumentationWatcher;
 import android.app.IUiAutomationConnection;
@@ -664,5 +665,10 @@
         public void performDirectAction(IBinder activityToken, String actionId, Bundle arguments,
                 RemoteCallback cancellationCallback, RemoteCallback resultCallback) {
         }
+
+        @Override
+        public void notifyContentProviderPublishStatus(ContentProviderHolder holder, String auth,
+                int userId, boolean published) {
+        }
     }
 }
diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index 91a1487..5555650 100644
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -1579,6 +1579,7 @@
     static final int DISPATCH_OOM_ADJ_OBSERVER_MSG = 70;
     static final int KILL_APP_ZYGOTE_MSG = 71;
     static final int BINDER_HEAVYHITTER_AUTOSAMPLER_TIMEOUT_MSG = 72;
+    static final int WAIT_FOR_CONTENT_PROVIDER_TIMEOUT_MSG = 73;
 
     static final int FIRST_BROADCAST_QUEUE_MSG = 200;
 
@@ -1915,6 +1916,11 @@
                 case BINDER_HEAVYHITTER_AUTOSAMPLER_TIMEOUT_MSG: {
                     handleBinderHeavyHitterAutoSamplerTimeOut();
                 } break;
+                case WAIT_FOR_CONTENT_PROVIDER_TIMEOUT_MSG: {
+                    synchronized (ActivityManagerService.this) {
+                        ((ContentProviderRecord) msg.obj).onProviderPublishStatusLocked(false);
+                    }
+                } break;
             }
         }
     }
diff --git a/services/core/java/com/android/server/am/ContentProviderHelper.java b/services/core/java/com/android/server/am/ContentProviderHelper.java
index 5cc7aba..bfba4af 100644
--- a/services/core/java/com/android/server/am/ContentProviderHelper.java
+++ b/services/core/java/com/android/server/am/ContentProviderHelper.java
@@ -50,6 +50,7 @@
 import android.os.Bundle;
 import android.os.Debug;
 import android.os.IBinder;
+import android.os.Message;
 import android.os.Process;
 import android.os.RemoteCallback;
 import android.os.RemoteException;
@@ -218,7 +219,7 @@
                     // of being published...  but it is also allowed to run
                     // in the caller's process, so don't make a connection
                     // and just let the caller instantiate its own instance.
-                    ContentProviderHolder holder = cpr.newHolder(null);
+                    ContentProviderHolder holder = cpr.newHolder(null, true);
                     // don't give caller the provider object, it needs to make its own.
                     holder.provider = null;
                     return holder;
@@ -415,7 +416,7 @@
                     // info and allow the caller to instantiate it.  Only do
                     // this if the provider is the same user as the caller's
                     // process, or can run as root (so can be in any process).
-                    return cpr.newHolder(null);
+                    return cpr.newHolder(null, true);
                 }
 
                 if (ActivityManagerDebugConfig.DEBUG_PROVIDER) {
@@ -513,6 +514,38 @@
                     UserHandle.getAppId(cpi.applicationInfo.uid));
         }
 
+        if (caller != null) {
+            // The client will be waiting, and we'll notify it when the provider is ready.
+            synchronized (cpr) {
+                if (cpr.provider == null) {
+                    if (cpr.launchingApp == null) {
+                        Slog.w(TAG, "Unable to launch app "
+                                + cpi.applicationInfo.packageName + "/"
+                                + cpi.applicationInfo.uid + " for provider "
+                                + name + ": launching app became null");
+                        EventLogTags.writeAmProviderLostProcess(
+                                UserHandle.getUserId(cpi.applicationInfo.uid),
+                                cpi.applicationInfo.packageName,
+                                cpi.applicationInfo.uid, name);
+                        return null;
+                    }
+
+                    if (conn != null) {
+                        conn.waiting = true;
+                    }
+                    Message msg = mService.mHandler.obtainMessage(
+                            ActivityManagerService.WAIT_FOR_CONTENT_PROVIDER_TIMEOUT_MSG);
+                    msg.obj = cpr;
+                    mService.mHandler.sendMessageDelayed(msg,
+                            ContentResolver.CONTENT_PROVIDER_READY_TIMEOUT_MILLIS);
+                }
+            }
+            // Return a holder instance even if we are waiting for the publishing of the provider,
+            // client will check for the holder.provider to see if it needs to wait for it.
+            return cpr.newHolder(conn, false);
+        }
+
+        // Because of the provider's external client (i.e., SHELL), we'll have to wait right here.
         // Wait for the provider to be published...
         final long timeout =
                 SystemClock.uptimeMillis() + ContentResolver.CONTENT_PROVIDER_READY_TIMEOUT_MILLIS;
@@ -569,7 +602,7 @@
                     + " caller=" + callerName + "/" + Binder.getCallingUid());
             return null;
         }
-        return cpr.newHolder(conn);
+        return cpr.newHolder(conn, false);
     }
 
     void publishContentProviders(IApplicationThread caller, List<ContentProviderHolder> providers) {
@@ -622,6 +655,8 @@
                 }
                 if (wasInLaunchingProviders) {
                     mService.mHandler.removeMessages(
+                            ActivityManagerService.WAIT_FOR_CONTENT_PROVIDER_TIMEOUT_MSG, dst);
+                    mService.mHandler.removeMessages(
                             ActivityManagerService.CONTENT_PROVIDER_PUBLISH_TIMEOUT_MSG, r);
                 }
                 // Make sure the package is associated with the process.
@@ -635,6 +670,7 @@
                     dst.provider = src.provider;
                     dst.setProcess(r);
                     dst.notifyAll();
+                    dst.onProviderPublishStatusLocked(true);
                 }
                 dst.mRestartCount = 0;
                 mService.updateOomAdjLocked(r, true, OomAdjuster.OOM_ADJ_REASON_GET_PROVIDER);
@@ -1504,6 +1540,9 @@
             synchronized (cpr) {
                 cpr.launchingApp = null;
                 cpr.notifyAll();
+                cpr.onProviderPublishStatusLocked(false);
+                mService.mHandler.removeMessages(
+                        ActivityManagerService.WAIT_FOR_CONTENT_PROVIDER_TIMEOUT_MSG, cpr);
             }
             final int userId = UserHandle.getUserId(cpr.uid);
             // Don't remove from provider map if it doesn't match
diff --git a/services/core/java/com/android/server/am/ContentProviderRecord.java b/services/core/java/com/android/server/am/ContentProviderRecord.java
index d8d8ccc..fb8b5d4 100644
--- a/services/core/java/com/android/server/am/ContentProviderRecord.java
+++ b/services/core/java/com/android/server/am/ContentProviderRecord.java
@@ -85,11 +85,12 @@
         noReleaseNeeded = cpr.noReleaseNeeded;
     }
 
-    public ContentProviderHolder newHolder(ContentProviderConnection conn) {
+    public ContentProviderHolder newHolder(ContentProviderConnection conn, boolean local) {
         ContentProviderHolder holder = new ContentProviderHolder(info);
         holder.provider = provider;
         holder.noReleaseNeeded = noReleaseNeeded;
         holder.connection = conn;
+        holder.mLocal = local;
         return holder;
     }
 
@@ -179,6 +180,50 @@
         return !connections.isEmpty() || hasExternalProcessHandles();
     }
 
+    /**
+     * Notify all clients that the provider has been published and ready to use,
+     * or timed out.
+     *
+     * @param status true: successfully published; false: timed out
+     */
+    void onProviderPublishStatusLocked(boolean status) {
+        final int numOfConns = connections.size();
+        final int userId = UserHandle.getUserId(appInfo.uid);
+        for (int i = 0; i < numOfConns; i++) {
+            final ContentProviderConnection conn = connections.get(i);
+            if (conn.waiting && conn.client != null) {
+                final ProcessRecord client = conn.client;
+                if (!status) {
+                    if (launchingApp == null) {
+                        Slog.w(TAG_AM, "Unable to launch app "
+                                + appInfo.packageName + "/"
+                                + appInfo.uid + " for provider "
+                                + info.authority + ": launching app became null");
+                        EventLogTags.writeAmProviderLostProcess(
+                                userId,
+                                appInfo.packageName,
+                                appInfo.uid, info.authority);
+                    } else {
+                        Slog.wtf(TAG_AM, "Timeout waiting for provider "
+                                + appInfo.packageName + "/"
+                                + appInfo.uid + " for provider "
+                                + info.authority
+                                + " caller=" + client);
+                    }
+                }
+                if (client.thread != null) {
+                    try {
+                        client.thread.notifyContentProviderPublishStatus(
+                                newHolder(status ? conn : null, false),
+                                info.authority, userId, status);
+                    } catch (RemoteException e) {
+                    }
+                }
+            }
+            conn.waiting = false;
+        }
+    }
+
     void dump(PrintWriter pw, String prefix, boolean full) {
         if (full) {
             pw.print(prefix); pw.print("package=");