Revert 113479 - Revert "Revert 113250 - Add CommandBuffer::SetGetBuffer"

gpu/command_buffer/service/command_buffer_service.cc

Index: gpu/command_buffer/service/command_buffer_service.cc
===================================================================
--- gpu/command_buffer/service/command_buffer_service.cc	(revision 113511)
+++ gpu/command_buffer/service/command_buffer_service.cc	(working copy)
@@ -14,8 +14,7 @@
 namespace gpu {
 
 CommandBufferService::CommandBufferService()
-    : ring_buffer_id_(-1),
-      num_entries_(0),
+    : num_entries_(0),
       get_offset_(0),
       put_offset_(0),
       token_(0),
@@ -26,16 +25,71 @@
 }
 
 CommandBufferService::~CommandBufferService() {
+  delete ring_buffer_.shared_memory;
+
   for (size_t i = 0; i < registered_objects_.size(); ++i) {
     if (registered_objects_[i].shared_memory)
       delete registered_objects_[i].shared_memory;
   }
 }
 
-bool CommandBufferService::Initialize() {
+bool CommandBufferService::Initialize(int32 size) {
+  // Fail if already initialized.
+  if (ring_buffer_.shared_memory) {
+    LOG(ERROR) << "Failed because already initialized.";
+    return false;
+  }
+
+  if (size <= 0 || size > kMaxCommandBufferSize) {
+    LOG(ERROR) << "Failed because command buffer size was invalid.";
+    return false;
+  }
+
+  num_entries_ = size / sizeof(CommandBufferEntry);
+
+  SharedMemory shared_memory;
+  if (!shared_memory.CreateAnonymous(size)) {
+    LOG(ERROR) << "Failed to create shared memory for command buffer.";
+    return true;
+  }
+
+  return Initialize(&shared_memory, size);
+}
+
+bool CommandBufferService::Initialize(base::SharedMemory* buffer, int32 size) {
+  // Fail if already initialized.
+  if (ring_buffer_.shared_memory) {
+    LOG(ERROR) << "Failed because already initialized.";
+    return false;
+  }
+
+  base::SharedMemoryHandle shared_memory_handle;
+  if (!buffer->ShareToProcess(base::GetCurrentProcessHandle(),
+                              &shared_memory_handle)) {
+    LOG(ERROR) << "Failed to duplicate command buffer shared memory handle.";
+    return false;
+  }
+
+  ring_buffer_.shared_memory = new base::SharedMemory(shared_memory_handle,
+                                                      false);
+  if (!ring_buffer_.shared_memory->Map(size)) {
+    LOG(ERROR) << "Failed because ring buffer could not be created or mapped ";
+    delete ring_buffer_.shared_memory;
+    ring_buffer_.shared_memory = NULL;
+    return false;
+  }
+
+  ring_buffer_.ptr = ring_buffer_.shared_memory->memory();
+  ring_buffer_.size = size;
+  num_entries_ = size / sizeof(CommandBufferEntry);
+
   return true;
 }
 
+Buffer CommandBufferService::GetRingBuffer() {
+  return ring_buffer_;
+}
+
 CommandBufferService::State CommandBufferService::GetState() {
   State state;
   state.num_entries = num_entries_;
@@ -80,20 +134,6 @@
     put_offset_change_callback_.Run();
 }
 
-void CommandBufferService::SetGetBuffer(int32 transfer_buffer_id) {
-  DCHECK_EQ(-1, ring_buffer_id_);
-  DCHECK_EQ(put_offset_, get_offset_);  // Only if it's empty.
-  ring_buffer_ = GetTransferBuffer(transfer_buffer_id);
-  DCHECK(ring_buffer_.ptr);
-  ring_buffer_id_ = transfer_buffer_id;
-  num_entries_ = ring_buffer_.size / sizeof(CommandBufferEntry);
-  put_offset_ = 0;
-  SetGetOffset(0);
-  if (!get_buffer_change_callback_.is_null()) {
-    get_buffer_change_callback_.Run(ring_buffer_id_);
-  }
-}
-
 void CommandBufferService::SetGetOffset(int32 get_offset) {
   DCHECK(get_offset >= 0 && get_offset < num_entries_);
   get_offset_ = get_offset;
@@ -183,14 +223,6 @@
   registered_objects_[handle] = Buffer();
   unused_registered_object_elements_.insert(handle);
 
-  if (handle == ring_buffer_id_) {
-    ring_buffer_id_ = -1;
-    ring_buffer_ = Buffer();
-    num_entries_ = 0;
-    get_offset_ = 0;
-    put_offset_ = 0;
-  }
-
   // Remove all null objects from the end of the vector. This allows the vector
   // to shrink when, for example, all objects are unregistered. Note that this
   // loop never removes element zero, which is always NULL.
@@ -234,11 +266,6 @@
   put_offset_change_callback_ = callback;
 }
 
-void CommandBufferService::SetGetBufferChangeCallback(
-    const GetBufferChangedCallback& callback) {
-  get_buffer_change_callback_ = callback;
-}
-
 void CommandBufferService::SetParseErrorCallback(
     const base::Closure& callback) {
   parse_error_callback_ = callback;