Add GetFileThreadMessageLoop method to PpapiGlobals.

This is needed to implement performance critical FileIO functions
on the plugin side.

BUG=194304

Review URL: https://chromiumcodereview.appspot.com/18144004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@211019 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 41 insertions, 0 deletions

diff --git a/ppapi/proxy/plugin_globals.cc b/ppapi/proxy/plugin_globals.cc
index fba5b1f..e41cd5e 100644
--- a/ppapi/proxy/plugin_globals.cc
+++ b/ppapi/proxy/plugin_globals.cc
@@ -4,6 +4,8 @@
 
 #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"
@@ -152,6 +154,16 @@ MessageLoopShared* PluginGlobals::GetCurrentMessageLoop() {
   return MessageLoopResource::GetCurrent();
 }
 
+base::TaskRunner* PluginGlobals::GetFileTaskRunner(PP_Instance instance) {
+  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();
+}
+
 IPC::Sender* PluginGlobals::GetBrowserSender() {
   if (!browser_sender_.get()) {
     browser_sender_.reset(
diff --git a/ppapi/proxy/plugin_globals.h b/ppapi/proxy/plugin_globals.h
index 37fdc1a..014cb26 100644
--- a/ppapi/proxy/plugin_globals.h
+++ b/ppapi/proxy/plugin_globals.h
@@ -17,6 +17,9 @@
 #include "ppapi/shared_impl/callback_tracker.h"
 #include "ppapi/shared_impl/ppapi_globals.h"
 
+namespace base {
+class Thread;
+}
 namespace IPC {
 class Sender;
 }
@@ -65,6 +68,7 @@ class PPAPI_PROXY_EXPORT PluginGlobals : public PpapiGlobals {
                                       const std::string& source,
                                       const std::string& value) OVERRIDE;
   virtual MessageLoopShared* GetCurrentMessageLoop() OVERRIDE;
+  base::TaskRunner* GetFileTaskRunner(PP_Instance instance) OVERRIDE;
 
   // Returns the channel for sending to the browser.
   IPC::Sender* GetBrowserSender();
@@ -144,6 +148,10 @@ class PPAPI_PROXY_EXPORT PluginGlobals : public PpapiGlobals {
 
   scoped_ptr<BrowserSender> browser_sender_;
 
+  // Thread for performing potentially blocking file operations. It's created
+  // lazily, since it might not be needed.
+  scoped_ptr<base::Thread> file_thread_;
+
   DISALLOW_COPY_AND_ASSIGN(PluginGlobals);
 };
 
diff --git a/ppapi/shared_impl/ppapi_globals.h b/ppapi/shared_impl/ppapi_globals.h
index 4c094c1..66275e5 100644
--- a/ppapi/shared_impl/ppapi_globals.h
+++ b/ppapi/shared_impl/ppapi_globals.h
@@ -19,6 +19,7 @@
 namespace base {
 class Lock;
 class MessageLoopProxy;
+class TaskRunner;
 }
 
 namespace ppapi {
@@ -114,6 +115,11 @@ class PPAPI_SHARED_EXPORT PpapiGlobals {
   // supported.
   virtual MessageLoopShared* GetCurrentMessageLoop() = 0;
 
+  // Returns a task runner for file operations that may block.
+  // TODO(bbudge) Move this to PluginGlobals when we no longer support
+  // in-process plugins.
+  virtual base::TaskRunner* GetFileTaskRunner(PP_Instance instance) = 0;
+
   // Returns the command line for the process.
   virtual std::string GetCmdLine() = 0;
 
diff --git a/ppapi/shared_impl/test_globals.cc b/ppapi/shared_impl/test_globals.cc
index 6c6af5b..133b943 100644
--- a/ppapi/shared_impl/test_globals.cc
+++ b/ppapi/shared_impl/test_globals.cc
@@ -75,6 +75,10 @@ MessageLoopShared* TestGlobals::GetCurrentMessageLoop() {
   return NULL;
 }
 
+base::TaskRunner* TestGlobals::GetFileTaskRunner(PP_Instance instance) {
+  return NULL;
+}
+
 bool TestGlobals::IsHostGlobals() const {
   // Pretend to be the host-side, for code that expects one or the other.
   // TODO(dmichael): just make it settable which one we're pretending to be?
diff --git a/ppapi/shared_impl/test_globals.h b/ppapi/shared_impl/test_globals.h
index c4d4aa1..803cfe3 100644
--- a/ppapi/shared_impl/test_globals.h
+++ b/ppapi/shared_impl/test_globals.h
@@ -71,6 +71,7 @@ class TestGlobals : public PpapiGlobals {
                                       const std::string& source,
                                       const std::string& value) OVERRIDE;
   virtual MessageLoopShared* GetCurrentMessageLoop() OVERRIDE;
+  virtual base::TaskRunner* GetFileTaskRunner(PP_Instance instance) OVERRIDE;
 
   // PpapiGlobals overrides:
   virtual bool IsHostGlobals() const OVERRIDE;
diff --git a/webkit/plugins/ppapi/host_globals.cc b/webkit/plugins/ppapi/host_globals.cc
index 2572b16..c2b3331 100644
--- a/webkit/plugins/ppapi/host_globals.cc
+++ b/webkit/plugins/ppapi/host_globals.cc
@@ -10,6 +10,7 @@
 #include "base/logging.h"
 #include "base/rand_util.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/task_runner.h"
 #include "ppapi/shared_impl/api_id.h"
 #include "ppapi/shared_impl/id_assignment.h"
 #include "third_party/WebKit/public/platform/WebString.h"
@@ -183,6 +184,14 @@ void HostGlobals::BroadcastLogWithSource(PP_Module pp_module,
      (*i)->element().document().frame()->addMessageToConsole(message);
 }
 
+base::TaskRunner* HostGlobals::GetFileTaskRunner(PP_Instance instance) {
+  scoped_refptr<PluginInstance> plugin_instance = GetInstance(instance);
+  DCHECK(plugin_instance.get());
+  scoped_refptr<base::MessageLoopProxy> message_loop =
+      plugin_instance->delegate()->GetFileThreadMessageLoopProxy();
+  return message_loop.get();
+}
+
 ::ppapi::MessageLoopShared* HostGlobals::GetCurrentMessageLoop() {
   return NULL;
 }
diff --git a/webkit/plugins/ppapi/host_globals.h b/webkit/plugins/ppapi/host_globals.h
index 31c22ed..36cbc87 100644
--- a/webkit/plugins/ppapi/host_globals.h
+++ b/webkit/plugins/ppapi/host_globals.h
@@ -55,6 +55,7 @@ class HostGlobals : public ::ppapi::PpapiGlobals {
                                       const std::string& source,
                                       const std::string& value) OVERRIDE;
   virtual ::ppapi::MessageLoopShared* GetCurrentMessageLoop() OVERRIDE;
+  virtual base::TaskRunner* GetFileTaskRunner(PP_Instance instance) OVERRIDE;
 
   HostVarTracker* host_var_tracker() {
     return &host_var_tracker_;