Implement out-of-process proxy for PPB_Buffer_Dev.

ppapi/proxy/ppb_buffer_proxy.cc

 // Copyright (c) 2011 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/ppb_buffer_proxy.h"
 
 #include <vector>
 
 #include "base/logging.h"
 #include "build/build_config.h"
 #include "ppapi/c/pp_completion_callback.h"
+#include "ppapi/c/pp_errors.h"
 #include "ppapi/c/pp_resource.h"
 #include "ppapi/c/dev/ppb_buffer_dev.h"
+#include "ppapi/proxy/host_dispatcher.h"
 #include "ppapi/proxy/plugin_dispatcher.h"
 #include "ppapi/proxy/plugin_resource.h"
 #include "ppapi/proxy/ppapi_messages.h"
+#include "ppapi/thunk/enter.h"
 #include "ppapi/thunk/ppb_buffer_api.h"
+#include "ppapi/thunk/ppb_buffer_trusted_api.h"
 #include "ppapi/thunk/thunk.h"
 
 namespace pp {
 namespace proxy {
 
 namespace {
 
 InterfaceProxy* CreateBufferProxy(Dispatcher* dispatcher,
                                   const void* target_interface) {
   return new PPB_Buffer_Proxy(dispatcher, target_interface);
 }
 
 }  // namespace
 
 class Buffer : public ppapi::thunk::PPB_Buffer_API,
                public PluginResource {
  public:
   Buffer(const HostResource& resource,
-         int memory_handle,
+         const base::SharedMemoryHandle& shm_handle,
          uint32_t size);
   virtual ~Buffer();
 
   // Resource overrides.
   virtual Buffer* AsBuffer() OVERRIDE;
 
   // ResourceObjectBase overries.
   virtual ppapi::thunk::PPB_Buffer_API* AsPPB_Buffer_API() OVERRIDE;
 
   // PPB_Buffer_API implementation.
   virtual PP_Bool Describe(uint32_t* size_in_bytes) OVERRIDE;
   virtual PP_Bool IsMapped() OVERRIDE;
   virtual void* Map() OVERRIDE;
   virtual void Unmap() OVERRIDE;
 
  private:
-  int memory_handle_;
+  base::SharedMemory shm_;
   uint32_t size_;
-
   void* mapped_data_;
 
   DISALLOW_COPY_AND_ASSIGN(Buffer);
 };
 
 Buffer::Buffer(const HostResource& resource,
-               int memory_handle,
+               const base::SharedMemoryHandle& shm_handle,
                uint32_t size)
     : PluginResource(resource),
-      memory_handle_(memory_handle),
+      shm_(shm_handle, false),
       size_(size),
       mapped_data_(NULL) {
 }
 
 Buffer::~Buffer() {
   Unmap();
 }
 
 Buffer* Buffer::AsBuffer() {
   return this;
 }
 
 ppapi::thunk::PPB_Buffer_API* Buffer::AsPPB_Buffer_API() {
   return this;
 }
 
 PP_Bool Buffer::Describe(uint32_t* size_in_bytes) {
   *size_in_bytes = size_;
   return PP_TRUE;
 }
 
 PP_Bool Buffer::IsMapped() {
   return PP_FromBool(!!mapped_data_);
 }
 
 void* Buffer::Map() {
-  // TODO(brettw) implement this.
-  return mapped_data_;
+  if (!shm_.memory())
+    shm_.Map(size_);
+  return shm_.memory();
 }
 
 void Buffer::Unmap() {
-  // TODO(brettw) implement this.
+  shm_.Unmap();
 }
 
 PPB_Buffer_Proxy::PPB_Buffer_Proxy(Dispatcher* dispatcher,
                                    const void* target_interface)
     : InterfaceProxy(dispatcher, target_interface) {
 }
 
 PPB_Buffer_Proxy::~PPB_Buffer_Proxy() {
 }
 
@@ skipping 10 matching lines @@
 }
 
 // static
 PP_Resource PPB_Buffer_Proxy::CreateProxyResource(PP_Instance instance,
                                                   uint32_t size) {
   PluginDispatcher* dispatcher = PluginDispatcher::GetForInstance(instance);
   if (!dispatcher)
     return 0;
 
   HostResource result;
-  int32_t shm_handle = -1;
+  base::SharedMemoryHandle shm_handle = base::SharedMemory::NULLHandle();
   dispatcher->Send(new PpapiHostMsg_PPBBuffer_Create(
       INTERFACE_ID_PPB_BUFFER, instance, size,
       &result, &shm_handle));
-  if (result.is_null())
+  if (result.is_null() || !base::SharedMemory::IsHandleValid(shm_handle))
     return 0;
 
-  linked_ptr<Buffer> object(new Buffer(result,
-                                       static_cast<int>(shm_handle), size));
+  linked_ptr<Buffer> object(new Buffer(result, shm_handle, size));
   return PluginResourceTracker::GetInstance()->AddResource(object);
 }
 
 bool PPB_Buffer_Proxy::OnMessageReceived(const IPC::Message& msg) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(PPB_Buffer_Proxy, msg)
     IPC_MESSAGE_HANDLER(PpapiHostMsg_PPBBuffer_Create, OnMsgCreate)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   // TODO(brettw) handle bad messages!
   return handled;
 }
 
-void PPB_Buffer_Proxy::OnMsgCreate(PP_Instance instance,
-                                   uint32_t size,
-                                   HostResource* result_resource,
-                                   int* result_shm_handle) {
-  result_resource->SetHostResource(
-      instance,
-      ppb_buffer_target()->Create(instance, size));
-  // TODO(brettw) set the shm handle from a trusted interface.
-  *result_shm_handle = 0;
+void PPB_Buffer_Proxy::OnMsgCreate(
+    PP_Instance instance,
+    uint32_t size,
+    HostResource* result_resource,
+    base::SharedMemoryHandle* result_shm_handle) {
+  // Overwritten below on success.
+  *result_shm_handle = base::SharedMemory::NULLHandle();
+  HostDispatcher* dispatcher = HostDispatcher::GetForInstance(instance);
+  if (!dispatcher)
+    return;
+  PP_Resource local_buffer_resource =
+      ppb_buffer_target()->Create(instance, size);
+  if (local_buffer_resource == 0)
+    return;
+  ::ppapi::thunk::EnterResourceNoLock< ::ppapi::thunk::PPB_BufferTrusted_API>
+        trusted_buffer(local_buffer_resource, false);
+  if (trusted_buffer.failed())
+    return;
+  int local_fd;
+  if (trusted_buffer.object()->GetSharedMemory(&local_fd) != PP_OK)
+    return;
+
+  result_resource->SetHostResource(instance, local_buffer_resource);
+
+  // TODO(piman/brettw): Change trusted interface to return a PP_FileHandle,
+  // those casts are ugly.
+  base::PlatformFile platform_file =
+#if defined(OS_WIN)
+      reinterpret_cast<HANDLE>(static_cast<intptr_t>(local_fd));
+#elif defined(OS_POSIX)
+      local_fd;
+#else
+  #error Not implemented.
+#endif
+  *result_shm_handle = dispatcher->ShareHandleWithRemote(platform_file, false);
 }
 
 }  // namespace proxy
 }  // namespace pp