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* Copyright 2017 Google Inc.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
#ifndef GrDeferredUpload_DEFINED
#define GrDeferredUpload_DEFINED
#include <functional>
#include "include/gpu/GrTypes.h"
#include "include/private/GrTypesPriv.h"
class GrTextureProxy;
* A word about deferred uploads and tokens: Ops should usually schedule their uploads to occur at
* the beginning of a frame whenever possible. These are called ASAP uploads. Of course, this
* requires that there are no draws that have yet to be flushed that rely on the old texture
* contents. In that case the ASAP upload would happen prior to the draw and therefore the draw
* would read the new (wrong) texture data. When this read-before-write data hazard exists they
* should schedule an inline upload.
* Ops, in conjunction with helpers such as GrDrawOpAtlas, use upload tokens to know what the most
* recent draw was that referenced a resource (or portion of a resource). Each draw is assigned a
* token. A resource (or portion thereof) can be tagged with the most recent reading draw's token.
* The deferred uploads target provides a facility for testing whether the draw corresponding to the
* token has been flushed. If it has not been flushed then the op must perform an inline upload
* instead so that the upload occurs after the draw depending on the old contents and before the
* draw depending on the updated contents. When scheduling an inline upload the op provides the
* token of the draw that the upload must occur before.
* GrDeferredUploadToken is used to sequence the uploads relative to each other and to draws.
class GrDeferredUploadToken {
static GrDeferredUploadToken AlreadyFlushedToken() { return GrDeferredUploadToken(0); }
GrDeferredUploadToken(const GrDeferredUploadToken&) = default;
GrDeferredUploadToken& operator=(const GrDeferredUploadToken&) = default;
bool operator==(const GrDeferredUploadToken& that) const {
return fSequenceNumber == that.fSequenceNumber;
bool operator!=(const GrDeferredUploadToken& that) const { return !(*this == that); }
bool operator<(const GrDeferredUploadToken that) const {
return fSequenceNumber < that.fSequenceNumber;
bool operator<=(const GrDeferredUploadToken that) const {
return fSequenceNumber <= that.fSequenceNumber;
bool operator>(const GrDeferredUploadToken that) const {
return fSequenceNumber > that.fSequenceNumber;
bool operator>=(const GrDeferredUploadToken that) const {
return fSequenceNumber >= that.fSequenceNumber;
GrDeferredUploadToken& operator++() {
return *this;
GrDeferredUploadToken operator++(int) {
auto old = fSequenceNumber;
return GrDeferredUploadToken(old);
GrDeferredUploadToken next() const { return GrDeferredUploadToken(fSequenceNumber + 1); }
/** Is this token in the [start, end] inclusive interval? */
bool inInterval(const GrDeferredUploadToken& start, const GrDeferredUploadToken& end) {
return *this >= start && *this <= end;
GrDeferredUploadToken() = delete;
explicit GrDeferredUploadToken(uint64_t sequenceNumber) : fSequenceNumber(sequenceNumber) {}
uint64_t fSequenceNumber;
* The GrTokenTracker encapsulates the incrementing and distribution of tokens.
class GrTokenTracker {
/** Gets the token one beyond the last token that has been flushed. */
GrDeferredUploadToken nextTokenToFlush() const { return; }
/** Gets the next draw token that will be issued by this target. This can be used by an op
to record that the next draw it issues will use a resource (e.g. texture) while preparing
that draw. */
GrDeferredUploadToken nextDrawToken() const { return; }
// Only these three classes get to increment the token counters
friend class SkInternalAtlasTextContext;
friend class GrOpFlushState;
friend class TestingUploadTarget;
/** Issues the next token for a draw. */
GrDeferredUploadToken issueDrawToken() { return ++fLastIssuedToken; }
/** Advances the last flushed token by one. */
GrDeferredUploadToken flushToken() { return ++fLastFlushedToken; }
GrDeferredUploadToken fLastIssuedToken = GrDeferredUploadToken::AlreadyFlushedToken();
GrDeferredUploadToken fLastFlushedToken = GrDeferredUploadToken::AlreadyFlushedToken();
* Passed to a deferred upload when it is executed, this method allows the deferred upload to
* actually write its pixel data into a texture.
using GrDeferredTextureUploadWritePixelsFn =
std::function<bool(GrTextureProxy*, int left, int top, int width, int height,
GrColorType colorType, const void* buffer, size_t rowBytes)>;
* A deferred texture upload is simply a std::function that takes a
* GrDeferredTextureUploadWritePixelsFn as a parameter. It is called when it should perform its
* upload as the draw/upload sequence is executed.
using GrDeferredTextureUploadFn = std::function<void(GrDeferredTextureUploadWritePixelsFn&)>;
* An interface for scheduling deferred uploads. It accepts asap and deferred inline uploads.
class GrDeferredUploadTarget {
virtual ~GrDeferredUploadTarget() {}
virtual const GrTokenTracker* tokenTracker() = 0;
/** Returns the token of the draw that this upload will occur before. */
virtual GrDeferredUploadToken addInlineUpload(GrDeferredTextureUploadFn&&) = 0;
/** Returns the token of the draw that this upload will occur before. Since ASAP uploads
are done first during a flush, this will be the first token since the most recent
flush. */
virtual GrDeferredUploadToken addASAPUpload(GrDeferredTextureUploadFn&& upload) = 0;