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// Copyright (c) 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.
#include "base/callback.h"
#include "content/common/content_export.h"
namespace content {
class ServiceManagerConnection;
// This class contains different "stages" to be executed by |BrowserMain()|,
// Each stage is represented by a single BrowserMainParts method, called from
// the corresponding method in |BrowserMainLoop| (e.g., EarlyInitialization())
// which does the following:
// - calls a method (e.g., "PreEarlyInitialization()") which implements
// platform / tookit specific code for that stage.
// - calls various methods for things common to all platforms (for that stage).
// - calls a method (e.g., "PostEarlyInitialization()") for platform-specific
// code to be called after the common code.
// Stages:
// - EarlyInitialization: things which should be done as soon as possible on
// program start (such as setting up signal handlers) and things to be done
// at some generic time before the start of the main message loop.
// - MainMessageLoopStart: things beginning with the start of the main message
// loop and ending with initialization of the main thread; platform-specific
// things which should be done immediately before the start of the main
// message loop should go in |PreMainMessageLoopStart()|.
// - RunMainMessageLoopParts: things to be done before and after invoking the
// main message loop run method (e.g. MessageLoopCurrentForUI::Get()->Run()).
// How to add stuff (to existing parts):
// - Figure out when your new code should be executed. What must happen
// before/after your code is executed? Are there performance reasons for
// running your code at a particular time? Document these things!
// - Split out any platform-specific bits. Please avoid #ifdefs it at all
// possible. You have two choices for platform-specific code: (1) Execute it
// from one of the platform-specific |Pre/Post...()| methods; do this if the
// code is unique to a platform type. Or (2) execute it from one of the
// "parts" (e.g., |EarlyInitialization()|) and provide platform-specific
// implementations of your code (in a virtual method); do this if you need to
// provide different implementations across most/all platforms.
// - Unless your new code is just one or two lines, put it into a separate
// method with a well-defined purpose. (Likewise, if you're adding to an
// existing chunk which makes it longer than one or two lines, please move
// the code out into a separate method.)
class CONTENT_EXPORT BrowserMainParts {
BrowserMainParts() {}
virtual ~BrowserMainParts() {}
// A return value other than RESULT_CODE_NORMAL_EXIT indicates error and is
// used as the exit status.
virtual int PreEarlyInitialization();
virtual void PostEarlyInitialization() {}
virtual void PreMainMessageLoopStart() {}
virtual void PostMainMessageLoopStart() {}
// Allows an embedder to do any extra toolkit initialization.
virtual void ToolkitInitialized() {}
// Called just before any child threads owned by the content
// framework are created.
// The main message loop has been started at this point (but has not
// been run), and the toolkit has been initialized. Returns the error code
// (or 0 if no error).
virtual int PreCreateThreads();
// This is called right after all child threads owned by the content framework
// are created.
virtual void PostCreateThreads() {}
virtual void ServiceManagerConnectionStarted(
ServiceManagerConnection* connection) {}
// This is called just before the main message loop is run. The
// various browser threads have all been created at this point
virtual void PreMainMessageLoopRun() {}
// Returns true if the message loop was run, false otherwise.
// If this returns false, the default implementation will be run.
// May set |result_code|, which will be returned by |BrowserMain()|.
virtual bool MainMessageLoopRun(int* result_code);
// Provides an embedder with a Closure which will quit the default main
// message loop. This is call only if MainMessageLoopRun returns false.
virtual void PreDefaultMainMessageLoopRun(base::OnceClosure quit_closure) {}
// This happens after the main message loop has stopped, but before
// threads are stopped.
virtual void PostMainMessageLoopRun() {}
// Called when shutdown is about to begin.
virtual void PreShutdown() {}
// Called as the very last part of shutdown, after threads have been
// stopped and destroyed.
virtual void PostDestroyThreads() {}
} // namespace content