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.
5 // This file contains the command buffer helper class.
7 #ifndef GPU_COMMAND_BUFFER_CLIENT_CMD_BUFFER_HELPER_H_
8 #define GPU_COMMAND_BUFFER_CLIENT_CMD_BUFFER_HELPER_H_
13 #include "gpu/command_buffer/common/cmd_buffer_common.h"
14 #include "gpu/command_buffer/common/command_buffer.h"
15 #include "gpu/command_buffer/common/constants.h"
16 #include "gpu/command_buffer/common/logging.h"
17 #include "gpu/gpu_export.h"
21 // Command buffer helper class. This class simplifies ring buffer management:
22 // it will allocate the buffer, give it to the buffer interface, and let the
23 // user add commands to it, while taking care of the synchronization (put and
24 // get). It also provides a way to ensure commands have been executed, through
25 // the token mechanism:
27 // helper.AddCommand(...);
28 // helper.AddCommand(...);
29 // int32 token = helper.InsertToken();
30 // helper.AddCommand(...);
31 // helper.AddCommand(...);
34 // helper.WaitForToken(token); // this doesn't return until the first two
35 // // commands have been executed.
36 class GPU_EXPORT CommandBufferHelper {
38 explicit CommandBufferHelper(CommandBuffer* command_buffer);
39 virtual ~CommandBufferHelper();
41 // Initializes the CommandBufferHelper.
43 // ring_buffer_size: The size of the ring buffer portion of the command
45 bool Initialize(int32 ring_buffer_size);
47 // Sets whether the command buffer should automatically flush periodically
48 // to try to increase performance. Defaults to true.
49 void SetAutomaticFlushes(bool enabled);
51 // True if the context is lost.
54 // Asynchronously flushes the commands, setting the put pointer to let the
55 // buffer interface know that new commands have been added. After a flush
56 // returns, the command buffer service is aware of all pending commands.
59 // Flushes the commands, setting the put pointer to let the buffer interface
60 // know that new commands have been added. After a flush returns, the command
61 // buffer service is aware of all pending commands and it is guaranteed to
62 // have made some progress in processing them. Returns whether the flush was
63 // successful. The flush will fail if the command buffer service has
67 // Waits until all the commands have been executed. Returns whether it
68 // was successful. The function will fail if the command buffer service has
72 // Waits until a given number of available entries are available.
74 // count: number of entries needed. This value must be at most
75 // the size of the buffer minus one.
76 void WaitForAvailableEntries(int32 count);
78 // Inserts a new token into the command buffer. This token either has a value
79 // different from previously inserted tokens, or ensures that previously
80 // inserted tokens with that value have already passed through the command
83 // the value of the new token or -1 if the command buffer reader has
87 // Waits until the token of a particular value has passed through the command
88 // stream (i.e. commands inserted before that token have been executed).
89 // NOTE: This will call Flush if it needs to block.
91 // the value of the token to wait for.
92 void WaitForToken(int32 token);
94 // Called prior to each command being issued. Waits for a certain amount of
95 // space to be available. Returns address of space.
96 CommandBufferEntry* GetSpace(uint32 entries);
98 // Typed version of GetSpace. Gets enough room for the given type and returns
100 template <typename T>
102 COMPILE_ASSERT(T::kArgFlags == cmd::kFixed, Cmd_kArgFlags_not_kFixed);
103 uint32 space_needed = ComputeNumEntries(sizeof(T));
104 void* data = GetSpace(space_needed);
105 return reinterpret_cast<T*>(data);
108 // Typed version of GetSpace for immediate commands.
109 template <typename T>
110 T* GetImmediateCmdSpace(size_t data_space) {
111 COMPILE_ASSERT(T::kArgFlags == cmd::kAtLeastN, Cmd_kArgFlags_not_kAtLeastN);
112 uint32 space_needed = ComputeNumEntries(sizeof(T) + data_space);
113 void* data = GetSpace(space_needed);
114 return reinterpret_cast<T*>(data);
117 // Typed version of GetSpace for immediate commands.
118 template <typename T>
119 T* GetImmediateCmdSpaceTotalSize(size_t total_space) {
120 COMPILE_ASSERT(T::kArgFlags == cmd::kAtLeastN, Cmd_kArgFlags_not_kAtLeastN);
121 uint32 space_needed = ComputeNumEntries(total_space);
122 void* data = GetSpace(space_needed);
123 return reinterpret_cast<T*>(data);
126 int32 last_token_read() const {
127 return command_buffer_->GetLastToken();
130 int32 get_offset() const {
131 return command_buffer_->GetLastState().get_offset;
135 void Noop(uint32 skip_count) {
136 cmd::Noop* cmd = GetImmediateCmdSpace<cmd::Noop>(
137 (skip_count - 1) * sizeof(CommandBufferEntry));
139 cmd->Init(skip_count);
143 void SetToken(uint32 token) {
144 cmd::SetToken* cmd = GetCmdSpace<cmd::SetToken>();
150 void SetBucketSize(uint32 bucket_id, uint32 size) {
151 cmd::SetBucketSize* cmd = GetCmdSpace<cmd::SetBucketSize>();
153 cmd->Init(bucket_id, size);
157 void SetBucketData(uint32 bucket_id,
160 uint32 shared_memory_id,
161 uint32 shared_memory_offset) {
162 cmd::SetBucketData* cmd = GetCmdSpace<cmd::SetBucketData>();
168 shared_memory_offset);
172 void SetBucketDataImmediate(
173 uint32 bucket_id, uint32 offset, const void* data, uint32 size) {
174 cmd::SetBucketDataImmediate* cmd =
175 GetImmediateCmdSpace<cmd::SetBucketDataImmediate>(size);
177 cmd->Init(bucket_id, offset, size);
178 memcpy(ImmediateDataAddress(cmd), data, size);
182 void GetBucketStart(uint32 bucket_id,
183 uint32 result_memory_id,
184 uint32 result_memory_offset,
185 uint32 data_memory_size,
186 uint32 data_memory_id,
187 uint32 data_memory_offset) {
188 cmd::GetBucketStart* cmd = GetCmdSpace<cmd::GetBucketStart>();
192 result_memory_offset,
199 void GetBucketData(uint32 bucket_id,
202 uint32 shared_memory_id,
203 uint32 shared_memory_offset) {
204 cmd::GetBucketData* cmd = GetCmdSpace<cmd::GetBucketData>();
210 shared_memory_offset);
214 CommandBuffer* command_buffer() const {
215 return command_buffer_;
218 Buffer get_ring_buffer() const {
222 void FreeRingBuffer();
224 bool HaveRingBuffer() const {
225 return ring_buffer_id_ != -1;
228 bool usable () const {
237 // Waits until get changes, updating the value of get_.
238 void WaitForGetChange();
240 // Returns the number of available entries (they may not be contiguous).
241 int32 AvailableEntries() {
242 return (get_offset() - put_ - 1 + total_entry_count_) % total_entry_count_;
245 bool AllocateRingBuffer();
246 void FreeResources();
248 CommandBuffer* command_buffer_;
249 int32 ring_buffer_id_;
250 int32 ring_buffer_size_;
252 CommandBufferEntry* entries_;
253 int32 total_entry_count_; // the total number of entries
256 int32 last_put_sent_;
257 int commands_issued_;
260 bool flush_automatically_;
262 // Using C runtime instead of base because this file cannot depend on base.
263 clock_t last_flush_time_;
265 friend class CommandBufferHelperTest;
266 DISALLOW_COPY_AND_ASSIGN(CommandBufferHelper);
271 #endif // GPU_COMMAND_BUFFER_CLIENT_CMD_BUFFER_HELPER_H_