Add a Mojo EDK for Chrome that uses one OS pipe per message pipe.

mojo/edk/system/shared_buffer_dispatcher.cc

 // Copyright 2014 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 "mojo/edk/system/shared_buffer_dispatcher.h"
 
 #include <limits>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
+#include "mojo/edk/embedder/embedder_internal.h"
 #include "mojo/edk/embedder/platform_support.h"
-#include "mojo/edk/system/channel.h"
 #include "mojo/edk/system/configuration.h"
 #include "mojo/edk/system/memory.h"
 #include "mojo/edk/system/options_validation.h"
 #include "mojo/public/c/system/macros.h"
 
 namespace mojo {
 namespace system {
 
 namespace {
 
-struct SerializedSharedBufferDispatcher {
+struct MOJO_ALIGNAS(8) SerializedSharedBufferDispatcher {
   size_t num_bytes;
   size_t platform_handle_index;
 };
 
 }  // namespace
 
 // static
 const MojoCreateSharedBufferOptions
     SharedBufferDispatcher::kDefaultCreateOptions = {
         static_cast<uint32_t>(sizeof(MojoCreateSharedBufferOptions)),
@@ skipping 46 matching lines @@
   *result = CreateInternal(shared_buffer.Pass());
   return MOJO_RESULT_OK;
 }
 
 Dispatcher::Type SharedBufferDispatcher::GetType() const {
   return Type::SHARED_BUFFER;
 }
 
 // static
 scoped_refptr<SharedBufferDispatcher> SharedBufferDispatcher::Deserialize(
-    Channel* channel,
     const void* source,
     size_t size,
     embedder::PlatformHandleVector* platform_handles) {
-  DCHECK(channel);
 
   if (size != sizeof(SerializedSharedBufferDispatcher)) {
     LOG(ERROR) << "Invalid serialized shared buffer dispatcher (bad size)";
     return nullptr;
   }
 
   const SerializedSharedBufferDispatcher* serialization =
       static_cast<const SerializedSharedBufferDispatcher*>(source);
   size_t num_bytes = serialization->num_bytes;
   size_t platform_handle_index = serialization->platform_handle_index;
@@ skipping 12 matching lines @@
 
   // Starts off invalid, which is what we want.
   embedder::PlatformHandle platform_handle;
   // We take ownership of the handle, so we have to invalidate the one in
   // |platform_handles|.
   std::swap(platform_handle, (*platform_handles)[platform_handle_index]);
 
   // Wrapping |platform_handle| in a |ScopedPlatformHandle| means that it'll be
   // closed even if creation fails.
   scoped_refptr<embedder::PlatformSharedBuffer> shared_buffer(
-      channel->platform_support()->CreateSharedBufferFromHandle(
+      embedder::internal::g_platform_support->CreateSharedBufferFromHandle(
           num_bytes, embedder::ScopedPlatformHandle(platform_handle)));
   if (!shared_buffer) {
     LOG(ERROR)
         << "Invalid serialized shared buffer dispatcher (invalid num_bytes?)";
     return nullptr;
   }
 
   return CreateInternal(shared_buffer.Pass());
 }
 
@@ skipping 32 matching lines @@
   out_options->flags = reader.options().flags;
 
   // Checks for fields beyond |flags|:
 
   // (Nothing here yet.)
 
   return MOJO_RESULT_OK;
 }
 
 void SharedBufferDispatcher::CloseImplNoLock() {
-  mutex().AssertHeld();
+  lock().AssertAcquired();
   DCHECK(shared_buffer_);
   shared_buffer_ = nullptr;
 }
 
 scoped_refptr<Dispatcher>
 SharedBufferDispatcher::CreateEquivalentDispatcherAndCloseImplNoLock() {
-  mutex().AssertHeld();
+  lock().AssertAcquired();
   DCHECK(shared_buffer_);
   return CreateInternal(shared_buffer_.Pass());
 }
 
 MojoResult SharedBufferDispatcher::DuplicateBufferHandleImplNoLock(
     UserPointer<const MojoDuplicateBufferHandleOptions> options,
     scoped_refptr<Dispatcher>* new_dispatcher) {
-  mutex().AssertHeld();
+  lock().AssertAcquired();
 
   MojoDuplicateBufferHandleOptions validated_options;
   MojoResult result = ValidateDuplicateOptions(options, &validated_options);
   if (result != MOJO_RESULT_OK)
     return result;
 
   // Note: Since this is "duplicate", we keep our ref to |shared_buffer_|.
   *new_dispatcher = CreateInternal(shared_buffer_);
   return MOJO_RESULT_OK;
 }
 
 MojoResult SharedBufferDispatcher::MapBufferImplNoLock(
     uint64_t offset,
     uint64_t num_bytes,
     MojoMapBufferFlags flags,
     scoped_ptr<embedder::PlatformSharedBufferMapping>* mapping) {
-  mutex().AssertHeld();
+  lock().AssertAcquired();
   DCHECK(shared_buffer_);
 
   if (offset > static_cast<uint64_t>(std::numeric_limits<size_t>::max()))
     return MOJO_RESULT_INVALID_ARGUMENT;
   if (num_bytes > static_cast<uint64_t>(std::numeric_limits<size_t>::max()))
     return MOJO_RESULT_INVALID_ARGUMENT;
 
   if (!shared_buffer_->IsValidMap(static_cast<size_t>(offset),
                                   static_cast<size_t>(num_bytes)))
     return MOJO_RESULT_INVALID_ARGUMENT;
 
   DCHECK(mapping);
   *mapping = shared_buffer_->MapNoCheck(static_cast<size_t>(offset),
                                         static_cast<size_t>(num_bytes));
   if (!*mapping)
     return MOJO_RESULT_RESOURCE_EXHAUSTED;
 
   return MOJO_RESULT_OK;
 }
 
 void SharedBufferDispatcher::StartSerializeImplNoLock(
-    Channel* /*channel*/,
     size_t* max_size,
     size_t* max_platform_handles) {
   DCHECK(HasOneRef());  // Only one ref => no need to take the lock.
   *max_size = sizeof(SerializedSharedBufferDispatcher);
   *max_platform_handles = 1;
 }
 
 bool SharedBufferDispatcher::EndSerializeAndCloseImplNoLock(
-    Channel* /*channel*/,
     void* destination,
     size_t* actual_size,
     embedder::PlatformHandleVector* platform_handles) {
   DCHECK(HasOneRef());  // Only one ref => no need to take the lock.
   DCHECK(shared_buffer_);
 
   SerializedSharedBufferDispatcher* serialization =
       static_cast<SerializedSharedBufferDispatcher*>(destination);
   // If there's only one reference to |shared_buffer_|, then it's ours (and no
   // one else can make any more references to it), so we can just take its
   // handle.
   embedder::ScopedPlatformHandle platform_handle(
       shared_buffer_->HasOneRef() ? shared_buffer_->PassPlatformHandle()
                                   : shared_buffer_->DuplicatePlatformHandle());
   if (!platform_handle.is_valid()) {
     shared_buffer_ = nullptr;
     return false;
   }
 
   serialization->num_bytes = shared_buffer_->GetNumBytes();
   serialization->platform_handle_index = platform_handles->size();
   platform_handles->push_back(platform_handle.release());
   *actual_size = sizeof(SerializedSharedBufferDispatcher);
 
   shared_buffer_ = nullptr;
 
   return true;
 }
 
+
 }  // namespace system
 }  // namespace mojo