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

mojo/edk/system/core.cc

 // Copyright 2013 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/core.h"
 
 #include <vector>
 
 #include "base/logging.h"
 #include "base/time/time.h"
+#include "mojo/edk/embedder/platform_channel_pair.h"
 #include "mojo/edk/embedder/platform_shared_buffer.h"
 #include "mojo/edk/embedder/platform_support.h"
 #include "mojo/edk/system/async_waiter.h"
 #include "mojo/edk/system/configuration.h"
 #include "mojo/edk/system/data_pipe.h"
 #include "mojo/edk/system/data_pipe_consumer_dispatcher.h"
 #include "mojo/edk/system/data_pipe_producer_dispatcher.h"
 #include "mojo/edk/system/dispatcher.h"
 #include "mojo/edk/system/handle_signals_state.h"
 #include "mojo/edk/system/memory.h"
-#include "mojo/edk/system/message_pipe.h"
 #include "mojo/edk/system/message_pipe_dispatcher.h"
 #include "mojo/edk/system/shared_buffer_dispatcher.h"
 #include "mojo/edk/system/waiter.h"
 #include "mojo/public/c/system/macros.h"
 #include "mojo/public/cpp/system/macros.h"
 
 namespace mojo {
-namespace system {
+namespace edk {
 
 // Implementation notes
 //
 // Mojo primitives are implemented by the singleton |Core| object. Most calls
 // are for a "primary" handle (the first argument). |Core::GetDispatcher()| is
 // used to look up a |Dispatcher| object for a given handle. That object
 // implements most primitives for that object. The wait primitives are not
 // attached to objects and are implemented by |Core| itself.
 //
 // Some objects have multiple handles associated to them, e.g., message pipes
@@ skipping 31 matching lines @@
 //
 // Notes:
 //    - While holding a |Dispatcher| lock, you may not unconditionally attempt
 //      to take another |Dispatcher| lock. (This has consequences on the
 //      concurrency semantics of |MojoWriteMessage()| when passing handles.)
 //      Doing so would lead to deadlock.
 //    - Locks at the "INF" level may not have any locks taken while they are
 //      held.
 
 // TODO(vtl): This should take a |scoped_ptr<PlatformSupport>| as a parameter.
-Core::Core(embedder::PlatformSupport* platform_support)
+Core::Core(PlatformSupport* platform_support)
     : platform_support_(platform_support) {
 }
 
 Core::~Core() {
 }
 
 MojoHandle Core::AddDispatcher(const scoped_refptr<Dispatcher>& dispatcher) {
-  MutexLocker locker(&handle_table_mutex_);
+  base::AutoLock locker(handle_table_lock_);
   return handle_table_.AddDispatcher(dispatcher);
 }
 
 scoped_refptr<Dispatcher> Core::GetDispatcher(MojoHandle handle) {
   if (handle == MOJO_HANDLE_INVALID)
     return nullptr;
 
-  MutexLocker locker(&handle_table_mutex_);
+  base::AutoLock locker(handle_table_lock_);
   return handle_table_.GetDispatcher(handle);
 }
 
 MojoResult Core::GetAndRemoveDispatcher(MojoHandle handle,
                                         scoped_refptr<Dispatcher>* dispatcher) {
   if (handle == MOJO_HANDLE_INVALID)
     return MOJO_RESULT_INVALID_ARGUMENT;
 
-  MutexLocker locker(&handle_table_mutex_);
+  base::AutoLock locker(handle_table_lock_);
   return handle_table_.GetAndRemoveDispatcher(handle, dispatcher);
 }
 
 MojoResult Core::AsyncWait(MojoHandle handle,
                            MojoHandleSignals signals,
                            const base::Callback<void(MojoResult)>& callback) {
   scoped_refptr<Dispatcher> dispatcher = GetDispatcher(handle);
   DCHECK(dispatcher);
 
   scoped_ptr<AsyncWaiter> waiter = make_scoped_ptr(new AsyncWaiter(callback));
   MojoResult rv = dispatcher->AddAwakable(waiter.get(), signals, 0, nullptr);
   if (rv == MOJO_RESULT_OK)
     ignore_result(waiter.release());
   return rv;
 }
 
 MojoTimeTicks Core::GetTimeTicksNow() {
   return base::TimeTicks::Now().ToInternalValue();
 }
 
 MojoResult Core::Close(MojoHandle handle) {
   if (handle == MOJO_HANDLE_INVALID)
     return MOJO_RESULT_INVALID_ARGUMENT;
 
   scoped_refptr<Dispatcher> dispatcher;
   {
-    MutexLocker locker(&handle_table_mutex_);
+    base::AutoLock locker(handle_table_lock_);
     MojoResult result =
         handle_table_.GetAndRemoveDispatcher(handle, &dispatcher);
     if (result != MOJO_RESULT_OK)
       return result;
   }
 
   // The dispatcher doesn't have a say in being closed, but gets notified of it.
-  // Note: This is done outside of |handle_table_mutex_|. As a result, there's a
+  // Note: This is done outside of |handle_table_lock_|. As a result, there's a
   // race condition that the dispatcher must handle; see the comment in
   // |Dispatcher| in dispatcher.h.
   return dispatcher->Close();
 }
 
 MojoResult Core::Wait(MojoHandle handle,
                       MojoHandleSignals signals,
                       MojoDeadline deadline,
                       UserPointer<MojoHandleSignalsState> signals_state) {
   uint32_t unused = static_cast<uint32_t>(-1);
@@ skipping 52 matching lines @@
   if (result != MOJO_RESULT_OK)
     return result;
 
   scoped_refptr<MessagePipeDispatcher> dispatcher0 =
       MessagePipeDispatcher::Create(validated_options);
   scoped_refptr<MessagePipeDispatcher> dispatcher1 =
       MessagePipeDispatcher::Create(validated_options);
 
   std::pair<MojoHandle, MojoHandle> handle_pair;
   {
-    MutexLocker locker(&handle_table_mutex_);
+    base::AutoLock locker(handle_table_lock_);
     handle_pair = handle_table_.AddDispatcherPair(dispatcher0, dispatcher1);
   }
   if (handle_pair.first == MOJO_HANDLE_INVALID) {
     DCHECK_EQ(handle_pair.second, MOJO_HANDLE_INVALID);
     LOG(ERROR) << "Handle table full";
     dispatcher0->Close();
     dispatcher1->Close();
     return MOJO_RESULT_RESOURCE_EXHAUSTED;
   }
 
-  scoped_refptr<MessagePipe> message_pipe(MessagePipe::CreateLocalLocal());
-  dispatcher0->Init(message_pipe, 0);
-  dispatcher1->Init(message_pipe, 1);
+  PlatformChannelPair channel_pair;
+  dispatcher0->Init(channel_pair.PassServerHandle());
+  dispatcher1->Init(channel_pair.PassClientHandle());
 
   message_pipe_handle0.Put(handle_pair.first);
   message_pipe_handle1.Put(handle_pair.second);
   return MOJO_RESULT_OK;
 }
 
 // Implementation note: To properly cancel waiters and avoid other races, this
 // does not transfer dispatchers from one handle to another, even when sending a
 // message in-process. Instead, it must transfer the "contents" of the
 // dispatcher to a new dispatcher, and then close the old dispatcher. If this
@@ skipping 31 matching lines @@
   // |WriteMessage()| and also so that we can unlock their locks afterwards
   // without accessing the handle table. These can be dumb pointers, since their
   // entries in the handle table won't get removed (since they'll be marked as
   // busy).
   std::vector<DispatcherTransport> transports(num_handles);
 
   // When we pass handles, we have to try to take all their dispatchers' locks
   // and mark the handles as busy. If the call succeeds, we then remove the
   // handles from the handle table.
   {
-    MutexLocker locker(&handle_table_mutex_);
+    base::AutoLock locker(handle_table_lock_);
     MojoResult result = handle_table_.MarkBusyAndStartTransport(
         message_pipe_handle, handles_reader.GetPointer(), num_handles,
         &transports);
     if (result != MOJO_RESULT_OK)
       return result;
   }
 
   MojoResult rv =
       dispatcher->WriteMessage(bytes, num_bytes, &transports, flags);
 
   // We need to release the dispatcher locks before we take the handle table
   // lock.
   for (uint32_t i = 0; i < num_handles; i++)
     transports[i].End();
 
   {
-    MutexLocker locker(&handle_table_mutex_);
+    base::AutoLock locker(handle_table_lock_);
     if (rv == MOJO_RESULT_OK) {
       handle_table_.RemoveBusyHandles(handles_reader.GetPointer(), num_handles);
     } else {
       handle_table_.RestoreBusyHandles(handles_reader.GetPointer(),
                                        num_handles);
     }
   }
 
   return rv;
 }
@@ skipping 21 matching lines @@
                                  &num_handles_value, flags);
     if (!dispatchers.empty()) {
       DCHECK_EQ(rv, MOJO_RESULT_OK);
       DCHECK(!num_handles.IsNull());
       DCHECK_LE(dispatchers.size(), static_cast<size_t>(num_handles_value));
 
       bool success;
       UserPointer<MojoHandle>::Writer handles_writer(handles,
                                                      dispatchers.size());
       {
-        MutexLocker locker(&handle_table_mutex_);
+        base::AutoLock locker(handle_table_lock_);
         success = handle_table_.AddDispatcherVector(
             dispatchers, handles_writer.GetPointer());
       }
       if (success) {
         handles_writer.Commit();
       } else {
         LOG(ERROR) << "Received message with " << dispatchers.size()
                    << " handles, but handle table full";
         // Close dispatchers (outside the lock).
         for (size_t i = 0; i < dispatchers.size(); i++) {
@@ skipping 15 matching lines @@
     UserPointer<const MojoCreateDataPipeOptions> options,
     UserPointer<MojoHandle> data_pipe_producer_handle,
     UserPointer<MojoHandle> data_pipe_consumer_handle) {
   MojoCreateDataPipeOptions validated_options = {};
   MojoResult result =
       DataPipe::ValidateCreateOptions(options, &validated_options);
   if (result != MOJO_RESULT_OK)
     return result;
 
   scoped_refptr<DataPipeProducerDispatcher> producer_dispatcher =
-      DataPipeProducerDispatcher::Create();
+      DataPipeProducerDispatcher::Create(validated_options);
   scoped_refptr<DataPipeConsumerDispatcher> consumer_dispatcher =
-      DataPipeConsumerDispatcher::Create();
+      DataPipeConsumerDispatcher::Create(validated_options);
 
   std::pair<MojoHandle, MojoHandle> handle_pair;
   {
-    MutexLocker locker(&handle_table_mutex_);
+    base::AutoLock locker(handle_table_lock_);
     handle_pair = handle_table_.AddDispatcherPair(producer_dispatcher,
                                                   consumer_dispatcher);
   }
   if (handle_pair.first == MOJO_HANDLE_INVALID) {
     DCHECK_EQ(handle_pair.second, MOJO_HANDLE_INVALID);
     LOG(ERROR) << "Handle table full";
     producer_dispatcher->Close();
     consumer_dispatcher->Close();
     return MOJO_RESULT_RESOURCE_EXHAUSTED;
   }
   DCHECK_NE(handle_pair.second, MOJO_HANDLE_INVALID);
 
-  scoped_refptr<DataPipe> data_pipe(DataPipe::CreateLocal(validated_options));
-  producer_dispatcher->Init(data_pipe);
-  consumer_dispatcher->Init(data_pipe);
+  PlatformChannelPair channel_pair;
+  producer_dispatcher->Init(channel_pair.PassServerHandle());
+  consumer_dispatcher->Init(channel_pair.PassClientHandle());
 
   data_pipe_producer_handle.Put(handle_pair.first);
   data_pipe_consumer_handle.Put(handle_pair.second);
   return MOJO_RESULT_OK;
 }
 
 MojoResult Core::WriteData(MojoHandle data_pipe_producer_handle,
                            UserPointer<const void> elements,
                            UserPointer<uint32_t> num_bytes,
                            MojoWriteDataFlags flags) {
@@ skipping 118 matching lines @@
 
 MojoResult Core::MapBuffer(MojoHandle buffer_handle,
                            uint64_t offset,
                            uint64_t num_bytes,
                            UserPointer<void*> buffer,
                            MojoMapBufferFlags flags) {
   scoped_refptr<Dispatcher> dispatcher(GetDispatcher(buffer_handle));
   if (!dispatcher)
     return MOJO_RESULT_INVALID_ARGUMENT;
 
-  scoped_ptr<embedder::PlatformSharedBufferMapping> mapping;
+  scoped_ptr<PlatformSharedBufferMapping> mapping;
   MojoResult result = dispatcher->MapBuffer(offset, num_bytes, flags, &mapping);
   if (result != MOJO_RESULT_OK)
     return result;
 
   DCHECK(mapping);
   void* address = mapping->GetBase();
   {
-    MutexLocker locker(&mapping_table_mutex_);
+    base::AutoLock locker(mapping_table_lock_);
     result = mapping_table_.AddMapping(mapping.Pass());
   }
   if (result != MOJO_RESULT_OK)
     return result;
 
   buffer.Put(address);
   return MOJO_RESULT_OK;
 }
 
 MojoResult Core::UnmapBuffer(UserPointer<void> buffer) {
-  MutexLocker locker(&mapping_table_mutex_);
+  base::AutoLock locker(mapping_table_lock_);
   return mapping_table_.RemoveMapping(buffer.GetPointerValue());
 }
 
 // Note: We allow |handles| to repeat the same handle multiple times, since
 // different flags may be specified.
 // TODO(vtl): This incurs a performance cost in |Remove()|. Analyze this
 // more carefully and address it if necessary.
 MojoResult Core::WaitManyInternal(const MojoHandle* handles,
                                   const MojoHandleSignals* signals,
                                   uint32_t num_handles,
@@ skipping 43 matching lines @@
         &waiter, signals_states ? &signals_states[i] : nullptr);
   }
   if (signals_states) {
     for (; i < num_handles; i++)
       signals_states[i] = dispatchers[i]->GetHandleSignalsState();
   }
 
   return rv;
 }
 
-}  // namespace system
+}  // namespace edk
 }  // namespace mojo