1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 // This file contains the command parser class. 6 7 #ifndef GPU_COMMAND_BUFFER_SERVICE_CMD_PARSER_H_ 8 #define GPU_COMMAND_BUFFER_SERVICE_CMD_PARSER_H_ 9 10 #include "gpu/command_buffer/common/constants.h" 11 #include "gpu/command_buffer/common/cmd_buffer_common.h" 12 #include "gpu/gpu_export.h" 13 14 namespace gpu { 15 16 class AsyncAPIInterface; 17 18 // Command parser class. This class parses commands from a shared memory 19 // buffer, to implement some asynchronous RPC mechanism. 20 class GPU_EXPORT CommandParser { 21 public: 22 static const int kParseCommandsSlice = 20; 23 24 explicit CommandParser(AsyncAPIInterface* handler); 25 26 // Sets the buffer to read commands from. 27 void SetBuffer( 28 void* shm_address, 29 size_t shm_size, 30 ptrdiff_t offset, 31 size_t size); 32 33 // Gets the "get" pointer. The get pointer is an index into the command 34 // buffer considered as an array of CommandBufferEntry. get()35 CommandBufferOffset get() const { return get_; } 36 37 // Sets the "get" pointer. The get pointer is an index into the command buffer 38 // considered as an array of CommandBufferEntry. set_get(CommandBufferOffset get)39 bool set_get(CommandBufferOffset get) { 40 if (get >= 0 && get < entry_count_) { 41 get_ = get; 42 return true; 43 } 44 return false; 45 } 46 47 // Sets the "put" pointer. The put pointer is an index into the command 48 // buffer considered as an array of CommandBufferEntry. set_put(CommandBufferOffset put)49 void set_put(CommandBufferOffset put) { put_ = put; } 50 51 // Gets the "put" pointer. The put pointer is an index into the command 52 // buffer considered as an array of CommandBufferEntry. put()53 CommandBufferOffset put() const { return put_; } 54 55 // Checks whether there are commands to process. IsEmpty()56 bool IsEmpty() const { return put_ == get_; } 57 58 // Processes one command, updating the get pointer. This will return an error 59 // if there are no commands in the buffer. 60 error::Error ProcessCommands(int num_commands); 61 62 // Processes all commands until get == put. 63 error::Error ProcessAllCommands(); 64 65 private: 66 CommandBufferOffset get_; 67 CommandBufferOffset put_; 68 CommandBufferEntry* buffer_; 69 int32 entry_count_; 70 AsyncAPIInterface* handler_; 71 }; 72 73 // This class defines the interface for an asynchronous API handler, that 74 // is responsible for de-multiplexing commands and their arguments. 75 class GPU_EXPORT AsyncAPIInterface { 76 public: AsyncAPIInterface()77 AsyncAPIInterface() {} ~AsyncAPIInterface()78 virtual ~AsyncAPIInterface() {} 79 80 // Executes a single command. 81 // Parameters: 82 // command: the command index. 83 // arg_count: the number of CommandBufferEntry arguments. 84 // cmd_data: the command data. 85 // Returns: 86 // error::kNoError if no error was found, one of 87 // error::Error otherwise. 88 virtual error::Error DoCommand( 89 unsigned int command, 90 unsigned int arg_count, 91 const void* cmd_data) = 0; 92 93 // Executes multiple commands. 94 // Parameters: 95 // num_commands: maximum number of commands to execute from buffer. 96 // buffer: pointer to first command entry to process. 97 // num_entries: number of sequential command buffer entries in buffer. 98 // entries_processed: if not 0, is set to the number of entries processed. 99 virtual error::Error DoCommands(unsigned int num_commands, 100 const void* buffer, 101 int num_entries, 102 int* entries_processed); 103 104 // Returns a name for a command. Useful for logging / debuging. 105 virtual const char* GetCommandName(unsigned int command_id) const = 0; 106 }; 107 108 } // namespace gpu 109 110 #endif // GPU_COMMAND_BUFFER_SERVICE_CMD_PARSER_H_ 111