Pepper: Use shared memory for ArrayBufferVar.

This change improves performance for sending ArrayBufferVars between the
plugin and the host. It copies the data from the var into a shared
memory region and sends the shared memory handle over IPC.

This required defining a new message for plugins to request the host to
create shared memory.

BUG=


Review URL: https://chromiumcodereview.appspot.com/11827059

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@189089 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 90 insertions, 1 deletions

diff --git a/ppapi/host/instance_message_filter.cc b/ppapi/host/instance_message_filter.cc
new file mode 100644
index 0000000..229235f
--- /dev/null
+++ b/ppapi/host/instance_message_filter.cc
@@ -0,0 +1,19 @@
+// 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/host/instance_message_filter.h"
+
+#include "ppapi/host/ppapi_host.h"
+
+namespace ppapi {
+namespace host {
+
+InstanceMessageFilter::InstanceMessageFilter(PpapiHost* host) : host_(host) {
+}
+
+InstanceMessageFilter::~InstanceMessageFilter() {
+}
+
+}  // namespace host
+}  // namespace ppapi
diff --git a/ppapi/host/instance_message_filter.h b/ppapi/host/instance_message_filter.h
new file mode 100644
index 0000000..2b072e9
--- /dev/null
+++ b/ppapi/host/instance_message_filter.h
@@ -0,0 +1,41 @@
+// 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 PPAPI_HOST_INSTANCE_MESSAGE_FILTER_H_
+#define PPAPI_HOST_INSTANCE_MESSAGE_FILTER_H_
+
+#include "base/basictypes.h"
+#include "ppapi/host/ppapi_host_export.h"
+
+namespace IPC {
+class Message;
+}
+
+namespace ppapi {
+namespace host {
+
+class PpapiHost;
+
+class PPAPI_HOST_EXPORT InstanceMessageFilter {
+ public:
+  explicit InstanceMessageFilter(PpapiHost* host);
+  virtual ~InstanceMessageFilter();
+
+  // Processes an instance message from the plugin process. Returns true if the
+  // message was handled. On false, the PpapiHost will forward the message to
+  // the next filter.
+  virtual bool OnInstanceMessageReceived(const IPC::Message& msg) = 0;
+
+  PpapiHost* host() { return host_; }
+
+ private:
+  PpapiHost* host_;
+
+  DISALLOW_COPY_AND_ASSIGN(InstanceMessageFilter);
+};
+
+}  // namespace host
+}  // namespace ppapi
+
+#endif  // PPAPI_HOST_INSTANCE_MESSAGE_FILTER_H_
diff --git a/ppapi/host/ppapi_host.cc b/ppapi/host/ppapi_host.cc
index 6423f1e..87dfb11 100644
--- a/ppapi/host/ppapi_host.cc
+++ b/ppapi/host/ppapi_host.cc
@@ -8,6 +8,7 @@
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/host/host_factory.h"
 #include "ppapi/host/host_message_context.h"
+#include "ppapi/host/instance_message_filter.h"
 #include "ppapi/host/resource_host.h"
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/proxy/resource_message_params.h"
@@ -33,8 +34,11 @@ PpapiHost::PpapiHost(IPC::Sender* sender,
 
 PpapiHost::~PpapiHost() {
   // Delete these explicitly before destruction since then the host is still
-  // technically alive in case one of the hosts accesses us from the
+  // technically alive in case one of the filters accesses us from the
   // destructor.
+  instance_message_filters_.clear();
+
+  // The resources may also want to use us in their destructors.
   resources_.clear();
   pending_resource_hosts_.clear();
 }
@@ -59,6 +63,15 @@ bool PpapiHost::OnMessageReceived(const IPC::Message& msg) {
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
+  if (!handled) {
+    for (size_t i = 0; i < instance_message_filters_.size(); i++) {
+      if (instance_message_filters_[i]->OnInstanceMessageReceived(msg)) {
+        handled = true;
+        break;
+      }
+    }
+  }
+
   return handled;
 }
 
@@ -94,6 +107,11 @@ void PpapiHost::AddHostFactoryFilter(scoped_ptr<HostFactory> filter) {
   host_factory_filters_.push_back(filter.release());
 }
 
+void PpapiHost::AddInstanceMessageFilter(
+    scoped_ptr<InstanceMessageFilter> filter) {
+  instance_message_filters_.push_back(filter.release());
+}
+
 void PpapiHost::OnHostMsgResourceCall(
     const proxy::ResourceMessageCallParams& params,
     const IPC::Message& nested_msg) {
diff --git a/ppapi/host/ppapi_host.h b/ppapi/host/ppapi_host.h
index 5e44d1a..c661a9b 100644
--- a/ppapi/host/ppapi_host.h
+++ b/ppapi/host/ppapi_host.h
@@ -30,6 +30,7 @@ namespace host {
 
 class HostFactory;
 struct HostMessageContext;
+class InstanceMessageFilter;
 struct ReplyMessageContext;
 class ResourceHost;
 
@@ -69,6 +70,10 @@ class PPAPI_HOST_EXPORT PpapiHost : public IPC::Sender, public IPC::Listener {
   // ownership of the pointer.
   void AddHostFactoryFilter(scoped_ptr<HostFactory> filter);
 
+  // Adds the given message filter to the host. The PpapiHost will take
+  // ownership of the pointer.
+  void AddInstanceMessageFilter(scoped_ptr<InstanceMessageFilter> filter);
+
   // Returns null if the resource doesn't exist.
   host::ResourceHost* GetResourceHost(PP_Resource resource) const;
 
@@ -104,6 +109,12 @@ class PPAPI_HOST_EXPORT PpapiHost : public IPC::Sender, public IPC::Listener {
   // an ObserverList.
   ScopedVector<HostFactory> host_factory_filters_;
 
+  // Filters for instance messages. Note that since we don't support deleting
+  // these dynamically we don't need to worry about modifications during
+  // iteration. If we add that capability, this should be replaced with an
+  // ObserverList.
+  ScopedVector<InstanceMessageFilter> instance_message_filters_;
+
   typedef std::map<PP_Resource, linked_ptr<ResourceHost> > ResourceMap;
   ResourceMap resources_;