xref: /aosp_15_r20/external/skia/src/gpu/graphite/BufferManager.h (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2021 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #ifndef skgpu_graphite_BufferManager_DEFINED
9 #define skgpu_graphite_BufferManager_DEFINED
10 
11 #include "include/core/SkRefCnt.h"
12 #include "include/private/base/SkTArray.h"
13 #include "src/gpu/BufferWriter.h"
14 #include "src/gpu/graphite/Buffer.h"
15 #include "src/gpu/graphite/DrawTypes.h"
16 #include "src/gpu/graphite/ResourceTypes.h"
17 #include "src/gpu/graphite/UploadBufferManager.h"
18 
19 #include <array>
20 #include <tuple>
21 
22 namespace skgpu::graphite {
23 
24 class Caps;
25 class Context;
26 class DrawBufferManager;
27 class GlobalCache;
28 class QueueManager;
29 class Recording;
30 class ResourceProvider;
31 
32 /**
33  * ScratchBuffer represents a GPU buffer object that is allowed to be reused across strictly
34  * sequential tasks within a Recording. It can be used to sub-allocate multiple bindings.
35  * When a ScratchBuffer gets deallocated, the underlying GPU buffer gets returned to the
36  * originating DrawBufferManager for reuse.
37  */
38 class ScratchBuffer final {
39 public:
40     // The default constructor creates an invalid ScratchBuffer that cannot be used for
41     // suballocations.
42     ScratchBuffer() = default;
43 
44     // The destructor returns the underlying buffer back to the reuse pool, if the ScratchBuffer is
45     // valid.
46     ~ScratchBuffer();
47 
48     // Disallow copy
49     ScratchBuffer(const ScratchBuffer&) = delete;
50     ScratchBuffer& operator=(const ScratchBuffer&) = delete;
51 
52     // Allow move
53     ScratchBuffer(ScratchBuffer&&) = default;
54     ScratchBuffer& operator=(ScratchBuffer&&) = default;
55 
56     // Returns false if the underlying buffer has been returned to the reuse pool.
isValid()57     bool isValid() const { return static_cast<bool>(fBuffer); }
58 
59     // Convenience wrapper for checking the validity of a buffer.
60     explicit operator bool() { return this->isValid(); }
61 
62     // Logical size of the initially requested allocation.
63     //
64     // NOTE: This number may be different from the size of the underlying GPU buffer but it is
65     // guaranteed to be less than or equal to it.
size()66     uint32_t size() const { return fSize; }
67 
68     // Sub-allocate a slice within the scratch buffer object. Fails and returns a NULL pointer if
69     // the buffer doesn't have enough space remaining for `requiredBytes`.
70     // TODO(b/330743233): Currently the suballocations use the alignment for the BufferInfo that was
71     // assigned by the DrawBufferManager based on the ScratchBuffer's buffer type. One way to
72     // generalize this across different buffer usages/types is to have this function accept an
73     // additional alignment parameter. That should happen after we loosen the coupling between
74     // DrawBufferManager's BufferInfos and ScratchBuffer reuse pools.
75     BindBufferInfo suballocate(size_t requiredBytes);
76 
77     // Returns the underlying buffer object back to the pool and invalidates this ScratchBuffer.
78     void returnToPool();
79 
80 private:
81     friend class DrawBufferManager;
82 
83     ScratchBuffer(uint32_t size, uint32_t alignment, sk_sp<Buffer>, DrawBufferManager*);
84 
85     uint32_t fSize;
86     uint32_t fAlignment;
87     sk_sp<Buffer> fBuffer;
88     uint32_t fOffset = 0;
89 
90     DrawBufferManager* fOwner = nullptr;
91 };
92 
93 /**
94  * DrawBufferManager controls writing to buffer data ranges within larger, cacheable Buffers and
95  * automatically handles either mapping or copying via transfer buffer depending on what the GPU
96  * hardware supports for the requested buffer type and use case. It is intended for repeatedly
97  * uploading dynamic data to the GPU.
98 */
99 class DrawBufferManager {
100 public:
101     DrawBufferManager(ResourceProvider*, const Caps*, UploadBufferManager*);
102     ~DrawBufferManager();
103 
104     // Let possible users check if the manager is already in a bad mapping state and skip any extra
105     // work that will be wasted because the next Recording snap will fail.
hasMappingFailed()106     bool hasMappingFailed() const { return fMappingFailed; }
107 
108     // These writers automatically calculate the required bytes based on count and stride. If a
109     // valid writer is returned, the byte count will fit in a uint32_t.
110     std::pair<VertexWriter, BindBufferInfo> getVertexWriter(size_t count, size_t stride);
111     std::pair<IndexWriter, BindBufferInfo> getIndexWriter(size_t count, size_t stride);
112     std::pair<UniformWriter, BindBufferInfo> getUniformWriter(size_t count, size_t stride);
113 
114     // Return an SSBO writer that is aligned for binding, per the requirements in fCurrentBuffers.
115     std::pair<UniformWriter, BindBufferInfo> getSsboWriter(size_t count, size_t stride);
116     // Return an SSBO writer that is aligned for indexing from the shader, per the provided stride.
117     std::pair<UniformWriter, BindBufferInfo> getAlignedSsboWriter(size_t count, size_t stride);
118 
119     // The remaining writers and buffer allocator functions assume that byte counts are safely
120     // calculated by the caller (e.g. Vello or ).
121 
122     // Return a pointer to a mapped storage buffer suballocation without a specific data writer.
123     std::pair<void* /* mappedPtr */, BindBufferInfo> getUniformPointer(size_t requiredBytes);
124     std::pair<void* /* mappedPtr */, BindBufferInfo> getStoragePointer(size_t requiredBytes);
125 
126     // Utilities that return an unmapped buffer suballocation for a particular usage. These buffers
127     // are intended to be only accessed by the GPU and are not intended for CPU data uploads.
128     BindBufferInfo getStorage(size_t requiredBytes, ClearBuffer cleared = ClearBuffer::kNo);
129     BindBufferInfo getVertexStorage(size_t requiredBytes);
130     BindBufferInfo getIndexStorage(size_t requiredBytes);
131     BindBufferInfo getIndirectStorage(size_t requiredBytes, ClearBuffer cleared = ClearBuffer::kNo);
132 
133     // Returns an entire storage buffer object that is large enough to fit `requiredBytes`. The
134     // returned ScratchBuffer can be used to sub-allocate one or more storage buffer bindings that
135     // reference the same buffer object.
136     //
137     // When the ScratchBuffer goes out of scope, the buffer object gets added to an internal pool
138     // and is available for immediate reuse. getScratchStorage() returns buffers from this pool if
139     // possible. A ScratchBuffer can be explicitly returned to the pool by calling `returnToPool()`.
140     //
141     // Returning a ScratchBuffer back to the buffer too early can result in validation failures
142     // and/or data races. It is the callers responsibility to manage reuse within a Recording and
143     // guarantee synchronized access to buffer bindings.
144     //
145     // This type of usage is currently limited to GPU-only storage buffers.
146     //
147     // TODO(b/330743233): Generalize the underlying pool to other buffer types, including mapped
148     //                    ones.
149     ScratchBuffer getScratchStorage(size_t requiredBytes);
150 
151     // Returns the last 'unusedBytes' from the last call to getVertexWriter(). Assumes that
152     // 'unusedBytes' is less than the 'count*stride' to the original allocation.
153     void returnVertexBytes(size_t unusedBytes);
154 
155     // Finalizes all buffers and transfers ownership of them to a Recording. Returns true on success
156     // and false if a mapping had previously failed.
157     //
158     // Regardless of success or failure, the DrawBufferManager is reset to a valid initial state
159     // for recording buffer data for the next Recording.
160     [[nodiscard]] bool transferToRecording(Recording*);
161 
162 private:
163     friend class ScratchBuffer;
164 
165     struct BufferInfo {
166         BufferInfo(BufferType type, uint32_t minBlockSize, uint32_t maxBlockSize, const Caps* caps);
167 
168         const BufferType fType;
169         const uint32_t fStartAlignment;
170         const uint32_t fMinBlockSize;
171         const uint32_t fMaxBlockSize;
172         sk_sp<Buffer> fBuffer;
173         // The fTransferBuffer can be null, if draw buffer cannot be mapped,
174         // see Caps::drawBufferCanBeMapped() for detail.
175         BindBufferInfo fTransferBuffer{};
176         void* fTransferMapPtr = nullptr;
177         uint32_t fOffset = 0;
178 
179         // Block size to use when creating new buffers; between fMinBlockSize and fMaxBlockSize.
180         uint32_t fCurBlockSize = 0;
181         // How many bytes have been used for for this buffer type since the last Recording snap.
182         uint32_t fUsedSize = 0;
183     };
184     std::pair<void* /*mappedPtr*/, BindBufferInfo> prepareMappedBindBuffer(
185             BufferInfo* info,
186             std::string_view label,
187             uint32_t requiredBytes,
188             uint32_t requiredAlignment = 0);
189     BindBufferInfo prepareBindBuffer(BufferInfo* info,
190                                      std::string_view label,
191                                      uint32_t requiredBytes,
192                                      uint32_t requiredAlignment = 0,
193                                      bool supportCpuUpload = false,
194                                      ClearBuffer cleared = ClearBuffer::kNo);
195 
196     // Helper method for public getSsboWriter methods.
197     std::pair<UniformWriter, BindBufferInfo> getSsboWriter(size_t count,
198                                                            size_t stride,
199                                                            size_t alignment);
200 
201     sk_sp<Buffer> findReusableSbo(size_t bufferSize);
202 
203     // Marks manager in a failed state, unmaps any previously collected buffers.
204     void onFailedBuffer();
205 
206     ResourceProvider* const fResourceProvider;
207     const Caps* const fCaps;
208     UploadBufferManager* fUploadManager;
209 
210     static constexpr size_t kVertexBufferIndex          = 0;
211     static constexpr size_t kIndexBufferIndex           = 1;
212     static constexpr size_t kUniformBufferIndex         = 2;
213     static constexpr size_t kStorageBufferIndex         = 3;
214     static constexpr size_t kGpuOnlyStorageBufferIndex  = 4;
215     static constexpr size_t kVertexStorageBufferIndex   = 5;
216     static constexpr size_t kIndexStorageBufferIndex    = 6;
217     static constexpr size_t kIndirectStorageBufferIndex = 7;
218     std::array<BufferInfo, 8> fCurrentBuffers;
219 
220     // Vector of buffer and transfer buffer pairs.
221     skia_private::TArray<std::pair<sk_sp<Buffer>, BindBufferInfo>> fUsedBuffers;
222 
223     // List of buffer regions that were requested to be cleared at the time of allocation.
224     skia_private::TArray<BindBufferInfo> fClearList;
225 
226     // TODO(b/330744081): These should probably be maintained in a sorted data structure that
227     // supports fast insertion and lookup doesn't waste buffers (e.g. by vending out large buffers
228     // for small buffer sizes).
229     // TODO(b/330743233): We may want this pool to contain buffers with mixed usages (such as
230     // VERTEX|INDEX|UNIFORM|STORAGE) to reduce buffer usage on platforms like Dawn where
231     // host-written data always go through a copy via transfer buffer.
232     skia_private::TArray<sk_sp<Buffer>> fReusableScratchStorageBuffers;
233 
234     // If mapping failed on Buffers created/managed by this DrawBufferManager or by the mapped
235     // transfer buffers from the UploadManager, remember so that the next Recording will fail.
236     bool fMappingFailed = false;
237 };
238 
239 /**
240  * The StaticBufferManager is the one-time-only analog to DrawBufferManager and provides "static"
241  * Buffers to RenderSteps and other Context-lifetime-tied objects, where the Buffers' contents will
242  * not change and can benefit from prioritizing GPU reads. The assumed use case is that they remain
243  * read-only on the GPU as well, so a single static buffer can be shared by all Recorders.
244  *
245  * Unlike DrawBufferManager's getXWriter() functions that return both a Writer and a BindBufferInfo,
246  * StaticBufferManager returns only a Writer and accepts a BindBufferInfo* as an argument. This will
247  * be re-written with the final binding info for the GPU-private data once that can be determined
248  * after *all* static buffers have been requested.
249  */
250 class StaticBufferManager {
251 public:
252     StaticBufferManager(ResourceProvider*, const Caps*);
253     ~StaticBufferManager();
254 
255     // The passed in BindBufferInfos are updated when finalize() is later called, to point to the
256     // packed, GPU-private buffer at the appropriate offset. The data written to the returned Writer
257     // is copied to the private buffer at that offset. 'binding' must live until finalize() returns.
258     VertexWriter getVertexWriter(size_t size, BindBufferInfo* binding);
259     // TODO: Update the tessellation index buffer generation functions to use an IndexWriter so this
260     // can return an IndexWriter vs. a VertexWriter that happens to just write uint16s...
261     VertexWriter getIndexWriter(size_t size, BindBufferInfo* binding);
262 
263     enum class FinishResult : int {
264         kFailure, // Unable to create or copy static buffers
265         kSuccess, // Successfully created static buffers and added GPU tasks to the queue
266         kNoWork   // No static buffers required, no GPU tasks add to the queue
267     };
268 
269     // Finalizes all buffers and records a copy task to compact and privatize static data. The
270     // final static buffers will become owned by the Context's GlobalCache.
271     FinishResult finalize(Context*, QueueManager*, GlobalCache*);
272 
273 private:
274     struct CopyRange {
275         BindBufferInfo  fSource; // The CPU-to-GPU buffer and offset for the source of the copy
276         BindBufferInfo* fTarget; // The late-assigned destination of the copy
277     };
278     struct BufferInfo {
279         BufferInfo(BufferType type, const Caps* caps);
280 
281         bool createAndUpdateBindings(ResourceProvider*,
282                                      Context*,
283                                      QueueManager*,
284                                      GlobalCache*,
285                                      std::string_view label) const;
resetBufferInfo286         void reset() {
287             fData.clear();
288             fTotalRequiredBytes = 0;
289         }
290 
291         const BufferType fBufferType;
292         const uint32_t   fAlignment;
293 
294         skia_private::TArray<CopyRange> fData;
295         uint32_t fTotalRequiredBytes;
296     };
297 
298     void* prepareStaticData(BufferInfo* info, size_t requiredBytes, BindBufferInfo* target);
299 
300     ResourceProvider* const fResourceProvider;
301     UploadBufferManager fUploadManager;
302     const uint32_t fRequiredTransferAlignment;
303 
304     // The source data that's copied into a final GPU-private buffer
305     BufferInfo fVertexBufferInfo;
306     BufferInfo fIndexBufferInfo;
307 
308     // If mapping failed on Buffers created/managed by this StaticBufferManager or by the mapped
309     // transfer buffers from the UploadManager, remember so that finalize() will fail.
310     bool fMappingFailed = false;
311 };
312 
313 } // namespace skgpu::graphite
314 
315 #endif // skgpu_graphite_BufferManager_DEFINED
316