command_buffer: Table based command dispatch for Common commands

gpu/command_buffer/service/common_decoder.cc

 // 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 "gpu/command_buffer/service/common_decoder.h"
 #include "gpu/command_buffer/service/cmd_buffer_engine.h"
 
 namespace gpu {
 
+const CommonDecoder::CommandInfo CommonDecoder::command_info[] = {
+#define COMMON_COMMAND_BUFFER_CMD_OP(name)                       \
+  {                                                              \
+    &CommonDecoder::Handle##name, cmd::name::kArgFlags,          \
+        cmd::name::cmd_flags,                                    \
+        sizeof(cmd::name) / sizeof(CommandBufferEntry) - 1,      \
+  }                                                              \
+  ,  /* NOLINT */
+  COMMON_COMMAND_BUFFER_CMDS(COMMON_COMMAND_BUFFER_CMD_OP)
+  #undef COMMON_COMMAND_BUFFER_CMD_OP
+};
+
+
 CommonDecoder::Bucket::Bucket() : size_(0) {}
 
 CommonDecoder::Bucket::~Bucket() {}
 
 void* CommonDecoder::Bucket::GetData(size_t offset, size_t size) const {
   if (OffsetSizeValid(offset, size)) {
     return data_.get() + offset;
   }
   return NULL;
 }
@@ skipping 81 matching lines @@
 const void* AddressAfterStruct(const T& pod) {
   return reinterpret_cast<const uint8*>(&pod) + sizeof(pod);
 }
 
 // Returns the address of the frst byte after the struct.
 template <typename RETURN_TYPE, typename COMMAND_TYPE>
 RETURN_TYPE GetImmediateDataAs(const COMMAND_TYPE& pod) {
   return static_cast<RETURN_TYPE>(const_cast<void*>(AddressAfterStruct(pod)));
 }
 
-// TODO(vmiura): Looks like this g_command_info is duplicated in
-// common_decoder.cc
-// and gles2_cmd_decoder.cc.  Fix it!
-
-// A struct to hold info about each command.
-struct CommandInfo {
-  uint8 arg_flags;   // How to handle the arguments for this command
-  uint8 cmd_flags;   // How to handle this command
-  uint16 arg_count;  // How many arguments are expected for this command.
-};
-
-// A table of CommandInfo for all the commands.
-const CommandInfo g_command_info[] = {
-  #define COMMON_COMMAND_BUFFER_CMD_OP(name) {                           \
-    cmd::name::kArgFlags,                                                \
-    cmd::name::cmd_flags,                                                \
-    sizeof(cmd::name) / sizeof(CommandBufferEntry) - 1, },  /* NOLINT */
-
-  COMMON_COMMAND_BUFFER_CMDS(COMMON_COMMAND_BUFFER_CMD_OP)
-
-  #undef COMMON_COMMAND_BUFFER_CMD_OP
-};
-
 }  // anonymous namespace.
 
 // Decode command with its arguments, and call the corresponding method.
 // Note: args is a pointer to the command buffer. As such, it could be changed
 // by a (malicious) client at any time, so if validation has to happen, it
 // should operate on a copy of them.
 error::Error CommonDecoder::DoCommonCommand(
     unsigned int command,
     unsigned int arg_count,
     const void* cmd_data) {
-  if (command < arraysize(g_command_info)) {
-    const CommandInfo& info = g_command_info[command];
+  if (command < arraysize(command_info)) {
+    const CommandInfo& info = command_info[command];
     unsigned int info_arg_count = static_cast<unsigned int>(info.arg_count);
     if ((info.arg_flags == cmd::kFixed && arg_count == info_arg_count) ||
         (info.arg_flags == cmd::kAtLeastN && arg_count >= info_arg_count)) {
       uint32 immediate_data_size =
           (arg_count - info_arg_count) * sizeof(CommandBufferEntry);  // NOLINT
-      switch (command) {
-        #define COMMON_COMMAND_BUFFER_CMD_OP(name)                      \
-          case cmd::name::kCmdId:                                       \
-            return Handle ## name(                                      \
-                immediate_data_size,                                    \
-                *static_cast<const cmd::name*>(cmd_data));              \
-
-        COMMON_COMMAND_BUFFER_CMDS(COMMON_COMMAND_BUFFER_CMD_OP)
-
-        #undef COMMON_COMMAND_BUFFER_CMD_OP
-      }
+      return (this->*info.cmd_handler)(immediate_data_size, cmd_data);
     } else {
       return error::kInvalidArguments;
     }
   }
   return error::kUnknownCommand;
 }
 
 error::Error CommonDecoder::HandleNoop(
     uint32 immediate_data_size,
-    const cmd::Noop& args) {
+    const void* cmd_data) {
   return error::kNoError;
 }
 
 error::Error CommonDecoder::HandleSetToken(
     uint32 immediate_data_size,
-    const cmd::SetToken& args) {
+    const void* cmd_data) {
+  const cmd::SetToken& args = *static_cast<const cmd::SetToken*>(cmd_data);
   engine_->set_token(args.token);
   return error::kNoError;
 }
 
 error::Error CommonDecoder::HandleSetBucketSize(
     uint32 immediate_data_size,
-    const cmd::SetBucketSize& args) {
+    const void* cmd_data) {
+  const cmd::SetBucketSize& args =
+      *static_cast<const cmd::SetBucketSize*>(cmd_data);
   uint32 bucket_id = args.bucket_id;
   uint32 size = args.size;
 
   Bucket* bucket = CreateBucket(bucket_id);
   bucket->SetSize(size);
   return error::kNoError;
 }
 
 error::Error CommonDecoder::HandleSetBucketData(
     uint32 immediate_data_size,
-    const cmd::SetBucketData& args) {
+    const void* cmd_data) {
+  const cmd::SetBucketData& args =
+      *static_cast<const cmd::SetBucketData*>(cmd_data);
   uint32 bucket_id = args.bucket_id;
   uint32 offset = args.offset;
   uint32 size = args.size;
   const void* data = GetSharedMemoryAs<const void*>(
       args.shared_memory_id, args.shared_memory_offset, size);
   if (!data) {
     return error::kInvalidArguments;
   }
   Bucket* bucket = GetBucket(bucket_id);
   if (!bucket) {
     return error::kInvalidArguments;
   }
   if (!bucket->SetData(data, offset, size)) {
     return error::kInvalidArguments;
   }
 
   return error::kNoError;
 }
 
 error::Error CommonDecoder::HandleSetBucketDataImmediate(
     uint32 immediate_data_size,
-    const cmd::SetBucketDataImmediate& args) {
+    const void* cmd_data) {
+  const cmd::SetBucketDataImmediate& args =
+      *static_cast<const cmd::SetBucketDataImmediate*>(cmd_data);
   const void* data = GetImmediateDataAs<const void*>(args);
   uint32 bucket_id = args.bucket_id;
   uint32 offset = args.offset;
   uint32 size = args.size;
   if (size > immediate_data_size) {
     return error::kInvalidArguments;
   }
   Bucket* bucket = GetBucket(bucket_id);
   if (!bucket) {
     return error::kInvalidArguments;
   }
   if (!bucket->SetData(data, offset, size)) {
     return error::kInvalidArguments;
   }
   return error::kNoError;
 }
 
 error::Error CommonDecoder::HandleGetBucketStart(
     uint32 immediate_data_size,
-    const cmd::GetBucketStart& args) {
+    const void* cmd_data) {
+  const cmd::GetBucketStart& args =
+      *static_cast<const cmd::GetBucketStart*>(cmd_data);
   uint32 bucket_id = args.bucket_id;
   uint32* result = GetSharedMemoryAs<uint32*>(
       args.result_memory_id, args.result_memory_offset, sizeof(*result));
   int32 data_memory_id = args.data_memory_id;
   uint32 data_memory_offset = args.data_memory_offset;
   uint32 data_memory_size = args.data_memory_size;
   uint8* data = NULL;
   if (data_memory_size != 0 || data_memory_id != 0 || data_memory_offset != 0) {
     data = GetSharedMemoryAs<uint8*>(
         args.data_memory_id, args.data_memory_offset, args.data_memory_size);
@@ skipping 16 matching lines @@
   *result = bucket_size;
   if (data) {
     uint32 size = std::min(data_memory_size, bucket_size);
     memcpy(data, bucket->GetData(0, size), size);
   }
   return error::kNoError;
 }
 
 error::Error CommonDecoder::HandleGetBucketData(
     uint32 immediate_data_size,
-    const cmd::GetBucketData& args) {
+    const void* cmd_data) {
+  const cmd::GetBucketData& args =
+      *static_cast<const cmd::GetBucketData*>(cmd_data);
   uint32 bucket_id = args.bucket_id;
   uint32 offset = args.offset;
   uint32 size = args.size;
   void* data = GetSharedMemoryAs<void*>(
       args.shared_memory_id, args.shared_memory_offset, size);
   if (!data) {
     return error::kInvalidArguments;
   }
   Bucket* bucket = GetBucket(bucket_id);
   if (!bucket) {
     return error::kInvalidArguments;
   }
   const void* src = bucket->GetData(offset, size);
   if (!src) {
       return error::kInvalidArguments;
   }
   memcpy(data, src, size);
   return error::kNoError;
 }
 
 }  // namespace gpu