text: // 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.
  
  #ifndef CONTENT_BROWSER_RENDERER_HOST_BROWSER_RENDER_PROCESS_HOST_IMPL_H_
  #define CONTENT_BROWSER_RENDERER_HOST_BROWSER_RENDER_PROCESS_HOST_IMPL_H_
  
  #include <map>
  #include <queue>
  #include <string>
  
  #include "base/memory/scoped_ptr.h"
  #include "base/process.h"
  #include "base/synchronization/waitable_event.h"
  #include "base/timer.h"
  #include "content/browser/child_process_launcher.h"
  #include "content/common/content_export.h"
  #include "content/public/browser/render_process_host.h"
  #include "ipc/ipc_channel_proxy.h"
  #include "ui/surface/transport_dib.h"
  
  class CommandLine;
  
  namespace base {
  class MessageLoop;
  }
  
  namespace gfx {
  class Size;
  }
  
  namespace content {
  class GpuMessageFilter;
  class PeerConnectionTrackerHost;
  class RendererMainThread;
  class RenderWidgetHelper;
  class RenderWidgetHost;
  class RenderWidgetHostImpl;
  class RenderWidgetHostViewFrameSubscriber;
  class StoragePartition;
  class StoragePartitionImpl;
  
  // Implements a concrete RenderProcessHost for the browser process for talking
  // to actual renderer processes (as opposed to mocks).
  //
  // Represents the browser side of the browser <--> renderer communication
  // channel. There will be one RenderProcessHost per renderer process.
  //
  // This object is refcounted so that it can release its resources when all
  // hosts using it go away.
  //
  // This object communicates back and forth with the RenderProcess object
  // running in the renderer process. Each RenderProcessHost and RenderProcess
  // keeps a list of RenderView (renderer) and WebContentsImpl (browser) which
  // are correlated with IDs. This way, the Views and the corresponding ViewHosts
  // communicate through the two process objects.
  //
  // A RenderProcessHost is also associated with one and only one
  // StoragePartition.  This allows us to implement strong storage isolation
  // because all the IPCs from the RenderViews (renderer) will only ever be able
  // to access the partition they are assigned to.
  class CONTENT_EXPORT RenderProcessHostImpl
      : public RenderProcessHost,
        public ChildProcessLauncher::Client {
   public:
    RenderProcessHostImpl(BrowserContext* browser_context,
                          StoragePartitionImpl* storage_partition_impl,
                          bool supports_browser_plugin,
                          bool is_guest);
    virtual ~RenderProcessHostImpl();
  
    // RenderProcessHost implementation (public portion).
    virtual void EnableSendQueue() OVERRIDE;
    virtual bool Init() OVERRIDE;
    virtual int GetNextRoutingID() OVERRIDE;
    virtual void SimulateSwapOutACK(const ViewMsg_SwapOut_Params& params)
        OVERRIDE;
    virtual bool WaitForBackingStoreMsg(int render_widget_id,
                                        const base::TimeDelta& max_delay,
                                        IPC::Message* msg) OVERRIDE;
    virtual void ReceivedBadMessage() OVERRIDE;
    virtual void WidgetRestored() OVERRIDE;
    virtual void WidgetHidden() OVERRIDE;
    virtual int VisibleWidgetCount() const OVERRIDE;
    virtual bool IsGuest() const OVERRIDE;
    virtual StoragePartition* GetStoragePartition() const OVERRIDE;
    virtual bool FastShutdownIfPossible() OVERRIDE;
    virtual void DumpHandles() OVERRIDE;
    virtual base::ProcessHandle GetHandle() const OVERRIDE;
    virtual TransportDIB* GetTransportDIB(TransportDIB::Id dib_id) OVERRIDE;
    virtual BrowserContext* GetBrowserContext() const OVERRIDE;
    virtual bool InSameStoragePartition(
        StoragePartition* partition) const OVERRIDE;
    virtual int GetID() const OVERRIDE;
    virtual bool HasConnection() const OVERRIDE;
    virtual RenderWidgetHost* GetRenderWidgetHostByID(int routing_id)
        OVERRIDE;
    virtual void SetIgnoreInputEvents(bool ignore_input_events) OVERRIDE;
    virtual bool IgnoreInputEvents() const OVERRIDE;
    virtual void Attach(RenderWidgetHost* host, int routing_id)
        OVERRIDE;
    virtual void Release(int routing_id) OVERRIDE;
    virtual void Cleanup() OVERRIDE;
    virtual void AddPendingView() OVERRIDE;
    virtual void RemovePendingView() OVERRIDE;
    virtual void SetSuddenTerminationAllowed(bool enabled) OVERRIDE;
    virtual bool SuddenTerminationAllowed() const OVERRIDE;
    virtual IPC::ChannelProxy* GetChannel() OVERRIDE;
    virtual RenderWidgetHostsIterator GetRenderWidgetHostsIterator() OVERRIDE;
    virtual bool FastShutdownForPageCount(size_t count) OVERRIDE;
    virtual bool FastShutdownStarted() const OVERRIDE;
    virtual base::TimeDelta GetChildProcessIdleTime() const OVERRIDE;
    virtual void SurfaceUpdated(int32 surface_id) OVERRIDE;
    virtual void ResumeRequestsForView(int route_id) OVERRIDE;
  
    // IPC::Sender via RenderProcessHost.
    virtual bool Send(IPC::Message* msg) OVERRIDE;
  
    // IPC::Listener via RenderProcessHost.
    virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
    virtual void OnChannelConnected(int32 peer_pid) OVERRIDE;
    virtual void OnChannelError() OVERRIDE;
  
    // ChildProcessLauncher::Client implementation.
    virtual void OnProcessLaunched() OVERRIDE;
  
    // Call this function when it is evident that the child process is actively
    // performing some operation, for example if we just received an IPC message.
    void mark_child_process_activity_time() {
      child_process_activity_time_ = base::TimeTicks::Now();
    }
  
    // Returns the current number of active views in this process.  Excludes
    // any RenderViewHosts that are swapped out.
    int GetActiveViewCount();
  
    // Start and end frame subscription for a specific renderer.
    // This API only supports subscription to accelerated composited frames.
    void BeginFrameSubscription(
        int route_id,
        scoped_ptr<RenderWidgetHostViewFrameSubscriber> subscriber);
    void EndFrameSubscription(int route_id);
  
    // Register/unregister the host identified by the host id in the global host
    // list.
    static void RegisterHost(int host_id, RenderProcessHost* host);
    static void UnregisterHost(int host_id);
  
    // Returns true if |host| is suitable for launching a new view with |site_url|
    // in the given |browser_context|.
    static bool IsSuitableHost(RenderProcessHost* host,
                               BrowserContext* browser_context,
                               const GURL& site_url);
  
    // Returns whether the process-per-site model is in use (globally or just for
    // the current site), in which case we should ensure there is only one
    // RenderProcessHost per site for the entire browser context.
    static bool ShouldUseProcessPerSite(BrowserContext* browser_context,
                                        const GURL& url);
  
    // Returns an existing RenderProcessHost for |url| in |browser_context|,
    // if one exists.  Otherwise a new RenderProcessHost should be created and
    // registered using RegisterProcessHostForSite().
    // This should only be used for process-per-site mode, which can be enabled
    // globally with a command line flag or per-site, as determined by
    // SiteInstanceImpl::ShouldUseProcessPerSite.
    static RenderProcessHost* GetProcessHostForSite(
        BrowserContext* browser_context,
        const GURL& url);
  
    // Registers the given |process| to be used for any instance of |url|
    // within |browser_context|.
    // This should only be used for process-per-site mode, which can be enabled
    // globally with a command line flag or per-site, as determined by
    // SiteInstanceImpl::ShouldUseProcessPerSite.
    static void RegisterProcessHostForSite(
        BrowserContext* browser_context,
        RenderProcessHost* process,
        const GURL& url);
  
    static base::MessageLoop* GetInProcessRendererThreadForTesting();
  
   protected:
    // A proxy for our IPC::Channel that lives on the IO thread (see
    // browser_process.h)
    scoped_ptr<IPC::ChannelProxy> channel_;
  
    // The registered render widget hosts. When this list is empty or all NULL,
    // we should delete ourselves
    IDMap<RenderWidgetHost> render_widget_hosts_;
  
    // True if fast shutdown has been performed on this RPH.
    bool fast_shutdown_started_;
  
    // True if we've posted a DeleteTask and will be deleted soon.
    bool deleting_soon_;
  
    // The count of currently swapped out but pending RenderViews.  We have
    // started to swap these in, so the renderer process should not exit if
    // this count is non-zero.
    int32 pending_views_;
  
   private:
    friend class VisitRelayingRenderProcessHost;
  
    // Creates and adds the IO thread message filters.
    void CreateMessageFilters();
  
    // Control message handlers.
    void OnShutdownRequest();
    void OnDumpHandlesDone();
    void SuddenTerminationChanged(bool enabled);
    void OnUserMetricsRecordAction(const std::string& action);
    void OnSavedPageAsMHTML(int job_id, int64 mhtml_file_size);
  
    // CompositorSurfaceBuffersSwapped handler when there's no RWH.
    void OnCompositorSurfaceBuffersSwappedNoHost(int32 surface_id,
                                                 uint64 surface_handle,
                                                 int32 route_id,
                                                 const gfx::Size& size,
                                                 int32 gpu_process_host_id);
  
    // Generates a command line to be used to spawn a renderer and appends the
    // results to |*command_line|.
    void AppendRendererCommandLine(CommandLine* command_line) const;
  
    // Copies applicable command line switches from the given |browser_cmd| line
    // flags to the output |renderer_cmd| line flags. Not all switches will be
    // copied over.
    void PropagateBrowserCommandLineToRenderer(const CommandLine& browser_cmd,
                                               CommandLine* renderer_cmd) const;
  
    // Callers can reduce the RenderProcess' priority.
    void SetBackgrounded(bool backgrounded);
  
    // Handle termination of our process.
    void ProcessDied(bool already_dead);
  
    // The count of currently visible widgets.  Since the host can be a container
    // for multiple widgets, it uses this count to determine when it should be
    // backgrounded.
    int32 visible_widgets_;
  
    // Does this process have backgrounded priority.
    bool backgrounded_;
  
    // Used to allow a RenderWidgetHost to intercept various messages on the
    // IO thread.
    scoped_refptr<RenderWidgetHelper> widget_helper_;
  
    // The filter for GPU-related messages coming from the renderer.
    // Thread safety note: this field is to be accessed from the UI thread.
    // We don't keep a reference to it, to avoid it being destroyed on the UI
    // thread, but we clear this field when we clear channel_. When channel_ goes
    // away, it posts a task to the IO thread to destroy it there, so we know that
    // it's valid if non-NULL.
    GpuMessageFilter* gpu_message_filter_;
  
    // A map of transport DIB ids to cached TransportDIBs
    std::map<TransportDIB::Id, TransportDIB*> cached_dibs_;
  
    enum {
      // This is the maximum size of |cached_dibs_|
      MAX_MAPPED_TRANSPORT_DIBS = 3,
    };
  
    // Map a transport DIB from its Id and return it. Returns NULL on error.
    TransportDIB* MapTransportDIB(TransportDIB::Id dib_id);
  
    void ClearTransportDIBCache();
    // This is used to clear our cache five seconds after the last use.
    base::DelayTimer<RenderProcessHostImpl> cached_dibs_cleaner_;
  
    // Used in single-process mode.
    scoped_ptr<RendererMainThread> in_process_renderer_;
  
    // True after Init() has been called. We can't just check channel_ because we
    // also reset that in the case of process termination.
    bool is_initialized_;
  
    // Used to launch and terminate the process without blocking the UI thread.
    scoped_ptr<ChildProcessLauncher> child_process_launcher_;
  
    // Messages we queue while waiting for the process handle.  We queue them here
    // instead of in the channel so that we ensure they're sent after init related
    // messages that are sent once the process handle is available.  This is
    // because the queued messages may have dependencies on the init messages.
    std::queue<IPC::Message*> queued_messages_;
  
    // The globally-unique identifier for this RPH.
    int id_;
  
    BrowserContext* browser_context_;
  
    // Owned by |browser_context_|.
    StoragePartitionImpl* storage_partition_impl_;
  
    // True if the process can be shut down suddenly.  If this is true, then we're
    // sure that all the RenderViews in the process can be shutdown suddenly.  If
    // it's false, then specific RenderViews might still be allowed to be shutdown
    // suddenly by checking their SuddenTerminationAllowed() flag.  This can occur
    // if one WebContents has an unload event listener but another WebContents in
    // the same process doesn't.
    bool sudden_termination_allowed_;
  
    // Set to true if we shouldn't send input events.  We actually do the
    // filtering for this at the render widget level.
    bool ignore_input_events_;
  
    // Records the last time we regarded the child process active.
    base::TimeTicks child_process_activity_time_;
  
  #if defined(OS_ANDROID)
    // Android WebView needs to use a SyncChannel to block the browser process
    // for synchronous find-in-page API support. In that case the shutdown event
    // makes no sense as the Android port doesn't shutdown, but gets killed.
    // SyncChannel still expects a shutdown event, so create a dummy one that
    // will never will be signaled.
    base::WaitableEvent dummy_shutdown_event_;
  #endif
  
    // Indicates whether this is a RenderProcessHost that has permission to embed
    // Browser Plugins.
    bool supports_browser_plugin_;
  
    // Indicates whether this is a RenderProcessHost of a Browser Plugin guest
    // renderer.
    bool is_guest_;
  
    // Forwards messages between WebRTCInternals in the browser process
    // and PeerConnectionTracker in the renderer process.
    scoped_refptr<PeerConnectionTrackerHost> peer_connection_tracker_host_;
  
    DISALLOW_COPY_AND_ASSIGN(RenderProcessHostImpl);
  };
  
  }  // namespace content
  
  #endif  // CONTENT_BROWSER_RENDERER_HOST_BROWSER_RENDER_PROCESS_HOST_IMPL_H_
  