Keep NaCl plugins used in app background pages alive when active.

ppapi/proxy/plugin_globals.cc

 // 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 "ppapi/proxy/plugin_globals.h"
 
 #include "base/task_runner.h"
 #include "base/threading/thread.h"
 #include "ipc/ipc_message.h"
 #include "ipc/ipc_sender.h"
 #include "ppapi/proxy/plugin_dispatcher.h"
 #include "ppapi/proxy/plugin_proxy_delegate.h"
+#include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/proxy/ppb_message_loop_proxy.h"
 #include "ppapi/proxy/resource_reply_thread_registrar.h"
 #include "ppapi/shared_impl/proxy_lock.h"
 #include "ppapi/thunk/enter.h"
 
+namespace {
+
+const int kKeepaliveThrottleIntervalDefault = 5000;
+
+}  // namespace
+
 namespace ppapi {
 namespace proxy {
 
 // It performs necessary locking/unlocking of the proxy lock, and forwards all
 // messages to the underlying sender.
 class PluginGlobals::BrowserSender : public IPC::Sender {
  public:
   // |underlying_sender| must outlive this object.
   explicit BrowserSender(IPC::Sender* underlying_sender)
       : underlying_sender_(underlying_sender) {
@@ skipping 19 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(BrowserSender);
 };
 
 PluginGlobals* PluginGlobals::plugin_globals_ = NULL;
 
 PluginGlobals::PluginGlobals()
     : ppapi::PpapiGlobals(),
       plugin_proxy_delegate_(NULL),
       callback_tracker_(new CallbackTracker),
       resource_reply_thread_registrar_(
-          new ResourceReplyThreadRegistrar(GetMainThreadMessageLoop())) {
+          new ResourceReplyThreadRegistrar(GetMainThreadMessageLoop())),
+      plugin_recently_active_(false),
+      keepalive_throttle_interval_milliseconds_(
+          kKeepaliveThrottleIntervalDefault),
+      weak_factory_(this) {
   DCHECK(!plugin_globals_);
   plugin_globals_ = this;
 
   // ResourceTracker asserts that we have the lock when we add new resources,
   // so we lock when creating the MessageLoopResource even though there is no
   // chance of race conditions.
   ProxyAutoLock lock;
   loop_for_main_thread_ =
       new MessageLoopResource(MessageLoopResource::ForMainThread());
 }
 
 PluginGlobals::PluginGlobals(PerThreadForTest per_thread_for_test)
     : ppapi::PpapiGlobals(per_thread_for_test),
       plugin_proxy_delegate_(NULL),
       callback_tracker_(new CallbackTracker),
       resource_reply_thread_registrar_(
-          new ResourceReplyThreadRegistrar(GetMainThreadMessageLoop())) {
+          new ResourceReplyThreadRegistrar(GetMainThreadMessageLoop())),
+      plugin_recently_active_(false),
+      keepalive_throttle_interval_milliseconds_(
+          kKeepaliveThrottleIntervalDefault),
+      weak_factory_(this) {
   DCHECK(!plugin_globals_);
 }
 
 PluginGlobals::~PluginGlobals() {
   DCHECK(plugin_globals_ == this || !plugin_globals_);
   {
     ProxyAutoLock lock;
     // Release the main-thread message loop. We should have the last reference
     // count, so this will delete the MessageLoop resource. We do this before
     // we clear plugin_globals_, because the Resource destructor tries to access
@@ skipping 73 matching lines @@
 base::TaskRunner* PluginGlobals::GetFileTaskRunner() {
   if (!file_thread_.get()) {
     file_thread_.reset(new base::Thread("Plugin::File"));
     base::Thread::Options options;
     options.message_loop_type = base::MessageLoop::TYPE_IO;
     file_thread_->StartWithOptions(options);
   }
   return file_thread_->message_loop_proxy();
 }
 
+void PluginGlobals::MarkPluginIsActive() {
+  if (!plugin_recently_active_) {
+    plugin_recently_active_ = true;
+    if (!GetBrowserSender() || !base::MessageLoop::current())
+      return;
+    GetBrowserSender()->Send(new PpapiHostMsg_Keepalive());
+
+    base::MessageLoop::current()->PostDelayedTask(FROM_HERE,

[dmichael (off chromium), 2013/12/16 22:17:54]

MarkPluginIsActive can be called by any thread, including one that the plugin
created, which may not have a message loop. You should use the loop for the main
thread (GetMainThreadMessageLoop()).

[scheib, 2013/12/16 23:13:44]

Done.

+        base::Bind(&PluginGlobals::OnReleaseKeepaliveThrottle,

[dmichael (off chromium), 2013/12/16 22:17:54]

Are you able to use "RunWhileLocked" (from ppapi/proxy/proxy_lock.h) instead of
locking explicitly in OnReleaseKeepaliveThrottle?

[scheib, 2013/12/16 23:13:44]

Done.

+                   weak_factory_.GetWeakPtr()),
+        base::TimeDelta::FromMilliseconds(
+            keepalive_throttle_interval_milliseconds()));
+  }
+}
+
 IPC::Sender* PluginGlobals::GetBrowserSender() {
   if (!browser_sender_.get()) {
     browser_sender_.reset(
         new BrowserSender(plugin_proxy_delegate_->GetBrowserSender()));
   }
 
   return browser_sender_.get();
 }
 
 std::string PluginGlobals::GetUILanguage() {
@@ skipping 10 matching lines @@
     const PP_BrowserFont_Trusted_Description& desc,
     const ppapi::Preferences& prefs) {
   return plugin_proxy_delegate_->CreateBrowserFont(
       connection, instance, desc, prefs);
 }
 
 MessageLoopResource* PluginGlobals::loop_for_main_thread() {
   return loop_for_main_thread_.get();
 }
 
+int PluginGlobals::keepalive_throttle_interval_milliseconds() const {
+  return keepalive_throttle_interval_milliseconds_;
+}
+
+void PluginGlobals::set_keepalive_throttle_interval_milliseconds(int i) {
+  keepalive_throttle_interval_milliseconds_ = i;
+}
+
 bool PluginGlobals::IsPluginGlobals() const {
   return true;
 }
 
+void PluginGlobals::OnReleaseKeepaliveThrottle() {
+  ppapi::ProxyAutoLock lock;
+  plugin_recently_active_ = false;
+}
+
 }  // namespace proxy
 }  // namespace ppapi