content/public/browser/render_process_host.h

// 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_PUBLIC_BROWSER_RENDER_PROCESS_HOST_H_
#define CONTENT_PUBLIC_BROWSER_RENDER_PROCESS_HOST_H_

#include <stddef.h>
#include <stdint.h>

#include <list>

#include "base/id_map.h"
#include "base/memory/ptr_util.h"
#include "base/process/kill.h"
#include "base/process/process_handle.h"
#include "base/supports_user_data.h"
#include "content/common/content_export.h"
#include "ipc/ipc_channel_proxy.h"
#include "ipc/ipc_sender.h"
#include "ui/gfx/native_widget_types.h"

class GURL;

namespace base {
class SharedPersistentMemoryAllocator;
class TimeDelta;
}

namespace media {
class AudioOutputController;
class MediaKeys;
}

namespace shell {
class Connection;
class InterfaceProvider;
}

namespace content {
class BrowserContext;
class BrowserMessageFilter;
class RenderProcessHostObserver;
class RenderWidgetHost;
class StoragePartition;
struct GlobalRequestID;

// Interface that represents the browser side of the browser <-> renderer
// communication channel. There will generally be one RenderProcessHost per
// renderer process.
class CONTENT_EXPORT RenderProcessHost : public IPC::Sender,
                                         public IPC::Listener,
                                         public base::SupportsUserData {
 public:
  typedef IDMap<RenderProcessHost>::iterator iterator;

  // Details for RENDERER_PROCESS_CLOSED notifications.
  struct RendererClosedDetails {
    RendererClosedDetails(base::TerminationStatus status,
                          int exit_code) {
      this->status = status;
      this->exit_code = exit_code;
    }
    base::TerminationStatus status;
    int exit_code;
  };

  // General functions ---------------------------------------------------------

  ~RenderProcessHost() override {}

  // Initialize the new renderer process, returning true on success. This must
  // be called once before the object can be used, but can be called after
  // that with no effect. Therefore, if the caller isn't sure about whether
  // the process has been created, it should just call Init().
  virtual bool Init() = 0;

  // Gets the next available routing id.
  virtual int GetNextRoutingID() = 0;

  // These methods add or remove listener for a specific message routing ID.
  // Used for refcounting, each holder of this object must AddRoute and
  // RemoveRoute. This object should be allocated on the heap; when no
  // listeners own it any more, it will delete itself.
  virtual void AddRoute(int32_t routing_id, IPC::Listener* listener) = 0;
  virtual void RemoveRoute(int32_t routing_id) = 0;

  // Add and remove observers for lifecycle events. The order in which
  // notifications are sent to observers is undefined. Observers must be sure to
  // remove the observer before they go away.
  virtual void AddObserver(RenderProcessHostObserver* observer) = 0;
  virtual void RemoveObserver(RenderProcessHostObserver* observer) = 0;

  // Called when a received message cannot be decoded. Terminates the renderer.
  // Most callers should not call this directly, but instead should call
  // bad_message::BadMessageReceived() or an equivalent method outside of the
  // content module.
  virtual void ShutdownForBadMessage() = 0;

  // Track the count of visible widgets. Called by listeners to register and
  // unregister visibility.
  virtual void WidgetRestored() = 0;
  virtual void WidgetHidden() = 0;
  virtual int VisibleWidgetCount() const = 0;

  // Called when the audio state changes for this render process host.
  virtual void AudioStateChanged() = 0;

  // Indicates whether the current RenderProcessHost is exclusively hosting
  // guest RenderFrames. Not all guest RenderFrames are created equal.  A guest,
  // as indicated by BrowserPluginGuest::IsGuest, may coexist with other
  // non-guest RenderFrames in the same process if IsForGuestsOnly() is false.
  virtual bool IsForGuestsOnly() const = 0;

  // Returns the storage partition associated with this process.
  virtual StoragePartition* GetStoragePartition() const = 0;

  // Try to shut down the associated renderer process without running unload
  // handlers, etc, giving it the specified exit code. If |wait| is true, wait
  // for the process to be actually terminated before returning.  Returns true
  // if it was able to shut down.  On Windows, this must not be called before
  // RenderProcessReady was called on a RenderProcessHostObserver, otherwise
  // RenderProcessExited may never be called.
  virtual bool Shutdown(int exit_code, bool wait) = 0;

  // Try to shut down the associated renderer process as fast as possible.
  // If this renderer has any RenderViews with unload handlers, then this
  // function does nothing.
  // Returns true if it was able to do fast shutdown.
  virtual bool FastShutdownIfPossible() = 0;

  // Returns true if fast shutdown was started for the renderer.
  virtual bool FastShutdownStarted() const = 0;

  // Returns the process object associated with the child process.  In certain
  // tests or single-process mode, this will actually represent the current
  // process.
  //
  // NOTE: this is not necessarily valid immediately after calling Init, as
  // Init starts the process asynchronously.  It's guaranteed to be valid after
  // the first IPC arrives or RenderProcessReady was called on a
  // RenderProcessHostObserver for this. At that point, IsReady() returns true.
  virtual base::ProcessHandle GetHandle() const = 0;

  // Returns whether the process is ready. The process is ready once both
  // conditions (which can happen in arbitrary order) are true:
  // 1- the launcher reported a succesful launch
  // 2- the channel is connected.
  //
  // After that point, GetHandle() is valid, and deferred messages have been
  // sent.
  virtual bool IsReady() const = 0;

  // Returns the user browser context associated with this renderer process.
  virtual content::BrowserContext* GetBrowserContext() const = 0;

  // Returns whether this process is using the same StoragePartition as
  // |partition|.
  virtual bool InSameStoragePartition(StoragePartition* partition) const = 0;

  // Returns the unique ID for this child process host. This can be used later
  // in a call to FromID() to get back to this object (this is used to avoid
  // sending non-threadsafe pointers to other threads).
  //
  // This ID will be unique across all child process hosts, including workers,
  // plugins, etc.
  //
  // This will never return ChildProcessHost::kInvalidUniqueID.
  virtual int GetID() const = 0;

  // Returns true iff channel_ has been set to non-nullptr. Use this for
  // checking if there is connection or not. Virtual for mocking out for tests.
  virtual bool HasConnection() const = 0;

  // Call this to allow queueing of IPC messages that are sent before the
  // process is launched.
  virtual void EnableSendQueue() = 0;

  // Returns the renderer channel.
  virtual IPC::ChannelProxy* GetChannel() = 0;

  // Adds a message filter to the IPC channel.
  virtual void AddFilter(BrowserMessageFilter* filter) = 0;

  // Try to shutdown the associated render process as fast as possible
  virtual bool FastShutdownForPageCount(size_t count) = 0;

  // TODO(ananta)
  // Revisit whether the virtual functions declared from here on need to be
  // part of the interface.
  virtual void SetIgnoreInputEvents(bool ignore_input_events) = 0;
  virtual bool IgnoreInputEvents() const = 0;

  // Schedules the host for deletion and removes it from the all_hosts list.
  virtual void Cleanup() = 0;

  // Track the count of pending views that are being swapped back in.  Called
  // by listeners to register and unregister pending views to prevent the
  // process from exiting.
  virtual void AddPendingView() = 0;
  virtual void RemovePendingView() = 0;

  // Sets a flag indicating that the process can be abnormally terminated.
  virtual void SetSuddenTerminationAllowed(bool allowed) = 0;
  // Returns true if the process can be abnormally terminated.
  virtual bool SuddenTerminationAllowed() const = 0;

  // Returns how long the child has been idle. The definition of idle
  // depends on when a derived class calls mark_child_process_activity_time().
  // This is a rough indicator and its resolution should not be better than
  // 10 milliseconds.
  virtual base::TimeDelta GetChildProcessIdleTime() const = 0;

  // Checks that the given renderer can request |url|, if not it sets it to
  // about:blank.
  // |empty_allowed| must be set to false for navigations for security reasons.
  virtual void FilterURL(bool empty_allowed, GURL* url) = 0;

#if defined(ENABLE_WEBRTC)
  virtual void EnableAudioDebugRecordings(const base::FilePath& file) = 0;
  virtual void DisableAudioDebugRecordings() = 0;

  // Starts a WebRTC event log for each peerconnection on the render process.
  // A base file_path can be supplied, which will be extended to include several
  // identifiers to ensure uniqueness. If a recording was already in progress,
  // this call will return false and have no other effect.
  virtual bool StartWebRTCEventLog(const base::FilePath& file_path) = 0;

  // Stops recording a WebRTC event log for each peerconnection on the render
  // process. If no recording was in progress, this call will return false.
  virtual bool StopWebRTCEventLog() = 0;

  // When set, |callback| receives log messages regarding, for example, media
  // devices (webcams, mics, etc) that were initially requested in the render
  // process associated with this RenderProcessHost.
  virtual void SetWebRtcLogMessageCallback(
      base::Callback<void(const std::string&)> callback) = 0;
  virtual void ClearWebRtcLogMessageCallback() = 0;

  typedef base::Callback<void(std::unique_ptr<uint8_t[]> packet_header,
                              size_t header_length,
                              size_t packet_length,
                              bool incoming)>
      WebRtcRtpPacketCallback;

  typedef base::Callback<void(bool incoming, bool outgoing)>
      WebRtcStopRtpDumpCallback;

  // Starts passing RTP packets to |packet_callback| and returns the callback
  // used to stop dumping.
  virtual WebRtcStopRtpDumpCallback StartRtpDump(
      bool incoming,
      bool outgoing,
      const WebRtcRtpPacketCallback& packet_callback) = 0;
#endif

  // Tells the ResourceDispatcherHost to resume a deferred navigation without
  // transferring it to a new renderer process.
  virtual void ResumeDeferredNavigation(const GlobalRequestID& request_id) = 0;

  // Notifies the renderer that the timezone configuration of the system might
  // have changed.
  virtual void NotifyTimezoneChange(const std::string& zone_id) = 0;

  // Returns the shell::InterfaceProvider the browser process can use to bind
  // interfaces exposed to it from the renderer.
  virtual shell::InterfaceProvider* GetRemoteInterfaces() = 0;

  // Extracts any persistent-memory-allocator used for renderer metrics.
  // Ownership is passed to the caller. To support sharing of histogram data
  // between the Renderer and the Browser, the allocator is created when the
  // process is created and later retrieved by the SubprocessMetricsProvider
  // for management.
  virtual std::unique_ptr<base::SharedPersistentMemoryAllocator>
  TakeMetricsAllocator() = 0;

  // PlzNavigate
  // Returns the time the first call to Init completed successfully (after a new
  // renderer process was created); further calls to Init won't change this
  // value.
  // Note: Do not use! Will disappear after PlzNavitate is completed.
  virtual const base::TimeTicks& GetInitTimeForNavigationMetrics() const = 0;

  // Retrieves the list of AudioOutputController objects associated
  // with this object and passes it to the callback you specify, on
  // the same thread on which you called the method.
  typedef std::list<scoped_refptr<media::AudioOutputController>>
      AudioOutputControllerList;
  typedef base::Callback<void(const AudioOutputControllerList&)>
      GetAudioOutputControllersCallback;
  virtual void GetAudioOutputControllers(
      const GetAudioOutputControllersCallback& callback) const = 0;

#if defined(ENABLE_BROWSER_CDMS)
  // Returns the CDM instance associated with |render_frame_id| and |cdm_id|,
  // or nullptr if not found.
  virtual scoped_refptr<media::MediaKeys> GetCdm(int render_frame_id,
                                                 int cdm_id) const = 0;
#endif

  // Returns true if this process currently has backgrounded priority.
  virtual bool IsProcessBackgrounded() const = 0;

  // Called when the existence of the other renderer process which is connected
  // to the Worker in this renderer process has changed.
  virtual void IncrementWorkerRefCount() = 0;
  virtual void DecrementWorkerRefCount() = 0;

  // Purges and suspends the renderer process.
  virtual void PurgeAndSuspend() = 0;

  // Returns the current number of active views in this process.  Excludes
  // any RenderViewHosts that are swapped out.
  size_t GetActiveViewCount();

  // Static management functions -----------------------------------------------

  // Flag to run the renderer in process.  This is primarily
  // for debugging purposes.  When running "in process", the
  // browser maintains a single RenderProcessHost which communicates
  // to a RenderProcess which is instantiated in the same process
  // with the Browser.  All IPC between the Browser and the
  // Renderer is the same, it's just not crossing a process boundary.

  static bool run_renderer_in_process();

  // This also calls out to ContentBrowserClient::GetApplicationLocale and
  // modifies the current process' command line.
  static void SetRunRendererInProcess(bool value);

  // Allows iteration over all the RenderProcessHosts in the browser. Note
  // that each host may not be active, and therefore may have nullptr channels.
  static iterator AllHostsIterator();

  // Returns the RenderProcessHost given its ID.  Returns nullptr if the ID does
  // not correspond to a live RenderProcessHost.
  static RenderProcessHost* FromID(int render_process_id);

  // 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(content::BrowserContext* browser_context,
                                      const GURL& url);

  // Returns true if the caller should attempt to use an existing
  // RenderProcessHost rather than creating a new one.
  static bool ShouldTryToUseExistingProcessHost(
      content::BrowserContext* browser_context, const GURL& site_url);

  // Get an existing RenderProcessHost associated with the given browser
  // context, if possible.  The renderer process is chosen randomly from
  // suitable renderers that share the same context and type (determined by the
  // site url).
  // Returns nullptr if no suitable renderer process is available, in which case
  // the caller is free to create a new renderer.
  static RenderProcessHost* GetExistingProcessHost(
      content::BrowserContext* browser_context, const GURL& site_url);

  // Overrides the default heuristic for limiting the max renderer process
  // count.  This is useful for unit testing process limit behaviors.  It is
  // also used to allow a command line parameter to configure the max number of
  // renderer processes and should only be called once during startup.
  // A value of zero means to use the default heuristic.
  static void SetMaxRendererProcessCount(size_t count);

  // Returns the current maximum number of renderer process hosts kept by the
  // content module.
  static size_t GetMaxRendererProcessCount();
};

}  // namespace content.

#endif  // CONTENT_PUBLIC_BROWSER_RENDER_PROCESS_HOST_H_