Refactoring ChildProcessConnection.

content/public/android/java/src/org/chromium/content/browser/ChildProcessConnection.java

-// Copyright 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-package org.chromium.content.browser;
-
-import android.os.IBinder;
-
-import org.chromium.base.process_launcher.ChildProcessCreationParams;
-import org.chromium.base.process_launcher.FileDescriptorInfo;
-import org.chromium.base.process_launcher.IChildProcessService;
-
-import javax.annotation.Nullable;
-
-/**
- * Manages a connection between the browser activity and a child service. ChildProcessConnection is
- * responsible for estabilishing the connection (start()), closing it (stop()) and manipulating the
- * bindings held onto the service (addStrongBinding(), removeStrongBinding(),
- * removeInitialBinding()).
- */
-public interface ChildProcessConnection {
-    /**
-     * Used to notify the consumer about disconnection of the service. This callback is provided
-     * earlier than ConnectionCallbacks below, as a child process might die before the connection is
-     * fully set up.
-     */
-    interface DeathCallback {
-        // Called on Launcher thread.
-        void onChildProcessDied(ChildProcessConnection connection);
-    }
-
-    /**
-     * Used to notify the consumer about the process start. These callbacks will be invoked before
-     * the ConnectionCallbacks.
-     */
-    interface StartCallback {
-        /**
-         * Called when the child process has successfully started and is ready for connection
-         * setup.
-         */
-        void onChildStarted();
-
-        /**
-         * Called when the child process failed to start. This can happen if the process is already
-         * in use by another client.
-         */
-        void onChildStartFailed();
-    }
-
-    /**
-     * Used to notify the consumer about the connection being established.
-     */
-    interface ConnectionCallback {
-        /**
-         * Called when the connection to the service is established.
-         * @param pid the pid of the child process
-         */
-        void onConnected(int pid);
-    }
-
-    int getServiceNumber();
-
-    boolean isInSandbox();
-
-    String getPackageName();
-
-    ChildProcessCreationParams getCreationParams();
-
-    IChildProcessService getService();
-
-    /**
-     * @return the connection pid, or 0 if not yet connected
-     */
-    int getPid();
-
-    /**
-     * Starts a connection to an IChildProcessService. This must be followed by a call to
-     * setupConnection() to setup the connection parameters. start() and setupConnection() are
-     * separate to allow to pass whatever parameters are available in start(), and complete the
-     * remainder later while reducing the connection setup latency.
-     * @param startCallback (optional) callback when the child process starts or fails to start.
-     */
-    void start(StartCallback startCallback);
-
-    /**
-     * Setups the connection after it was started with start().
-     * @param commandLine (optional) will be ignored if the command line was already sent in start()
-     * @param filesToBeMapped a list of file descriptors that should be registered
-     * @param callback optional client specified callbacks that the child can use to communicate
-     *                 with the parent process
-     * @param connectionCallback will be called exactly once after the connection is set up or the
-     *                           setup fails
-     */
-    void setupConnection(String[] commandLine, FileDescriptorInfo[] filesToBeMapped,
-            @Nullable IBinder callback, ConnectionCallback connectionCallback);
-
-    /**
-     * Terminates the connection to IChildProcessService, closing all bindings. It is safe to call
-     * this multiple times.
-     */
-    void stop();
-
-    /** @return true iff the initial oom binding is currently bound. */
-    boolean isInitialBindingBound();
-
-    /** @return true iff the strong oom binding is currently bound. */
-    boolean isStrongBindingBound();
-
-    /**
-     * Called to remove the strong binding established when the connection was started. It is safe
-     * to call this multiple times.
-     */
-    void removeInitialBinding();
-
-    /**
-     * For live connections, this returns true iff either the initial or the strong binding is
-     * bound, i.e. the connection has at least one oom binding. For connections that disconnected
-     * (did not exit properly), this returns true iff the connection had at least one oom binding
-     * when it disconnected.
-     */
-    boolean isOomProtectedOrWasWhenDied();
-
-    /**
-     * Unbinds the bindings that protect the process from oom killing. It is safe to call this
-     * multiple times, before as well as after stop().
-     */
-    void dropOomBindings();
-
-    /**
-     * Attaches a strong binding that will make the service as important as the main process. Each
-     * call should be succeeded by removeStrongBinding(), but multiple strong bindings can be
-     * requested and released independently.
-     */
-    void addStrongBinding();
-
-    /**
-     * Called when the service is no longer in active use of the consumer.
-     */
-    void removeStrongBinding();
-
-    /**
-     * Attaches a moderate binding that will give the service the priority of a visible process, but
-     * keep the priority below a strongly bound process.
-     */
-    void addModerateBinding();
-
-    /**
-     * Called when the service is no longer in moderate use of the consumer.
-     */
-    void removeModerateBinding();
-
-    /** @return true iff the moderate oom binding is currently bound. */
-    boolean isModerateBindingBound();
-}