/*
 * Copyright 2015 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "GrDrawingManager.h"

#include "GrBackendSemaphore.h"
#include "GrContextPriv.h"
#include "GrGpu.h"
#include "GrMemoryPool.h"
#include "GrOnFlushResourceProvider.h"
#include "GrOpList.h"
#include "GrRecordingContext.h"
#include "GrRecordingContextPriv.h"
#include "GrRenderTargetContext.h"
#include "GrRenderTargetProxy.h"
#include "GrResourceAllocator.h"
#include "GrResourceProvider.h"
#include "GrSoftwarePathRenderer.h"
#include "GrSurfaceProxyPriv.h"
#include "GrTexture.h"
#include "GrTextureContext.h"
#include "GrTextureOpList.h"
#include "GrTexturePriv.h"
#include "GrTextureProxy.h"
#include "GrTextureProxyPriv.h"
#include "GrTracing.h"
#include "SkDeferredDisplayList.h"
#include "SkSurface_Gpu.h"
#include "SkTTopoSort.h"
#include "ccpr/GrCoverageCountingPathRenderer.h"
#include "text/GrTextContext.h"

GrDrawingManager::OpListDAG::OpListDAG(bool explicitlyAllocating, bool sortOpLists)
        : fSortOpLists(sortOpLists) {
    SkASSERT(!sortOpLists || explicitlyAllocating);
}

GrDrawingManager::OpListDAG::~OpListDAG() {}

void GrDrawingManager::OpListDAG::gatherIDs(SkSTArray<8, uint32_t, true>* idArray) const {
    idArray->reset(fOpLists.count());
    for (int i = 0; i < fOpLists.count(); ++i) {
        if (fOpLists[i]) {
            (*idArray)[i] = fOpLists[i]->uniqueID();
        }
    }
}

void GrDrawingManager::OpListDAG::reset() {
    fOpLists.reset();
}

void GrDrawingManager::OpListDAG::removeOpList(int index) {
    if (!fOpLists[index]->unique()) {
        // TODO: Eventually this should be guaranteed unique: http://skbug.com/7111
        fOpLists[index]->endFlush();
    }

    fOpLists[index] = nullptr;
}

void GrDrawingManager::OpListDAG::removeOpLists(int startIndex, int stopIndex) {
    for (int i = startIndex; i < stopIndex; ++i) {
        if (!fOpLists[i]) {
            continue;
        }
        this->removeOpList(i);
    }
}

void GrDrawingManager::OpListDAG::add(sk_sp<GrOpList> opList) {
    fOpLists.emplace_back(std::move(opList));
}

void GrDrawingManager::OpListDAG::add(const SkTArray<sk_sp<GrOpList>>& opLists) {
    fOpLists.push_back_n(opLists.count(), opLists.begin());
}

void GrDrawingManager::OpListDAG::swap(SkTArray<sk_sp<GrOpList>>* opLists) {
    SkASSERT(opLists->empty());
    opLists->swap(fOpLists);
}

void GrDrawingManager::OpListDAG::prepForFlush() {
    if (fSortOpLists) {
        SkDEBUGCODE(bool result =) SkTTopoSort<GrOpList, GrOpList::TopoSortTraits>(&fOpLists);
        SkASSERT(result);
    }

#ifdef SK_DEBUG
    // This block checks for any unnecessary splits in the opLists. If two sequential opLists
    // share the same backing GrSurfaceProxy it means the opList was artificially split.
    if (fOpLists.count()) {
        GrRenderTargetOpList* prevOpList = fOpLists[0]->asRenderTargetOpList();
        for (int i = 1; i < fOpLists.count(); ++i) {
            GrRenderTargetOpList* curOpList = fOpLists[i]->asRenderTargetOpList();

            if (prevOpList && curOpList) {
                SkASSERT(prevOpList->fTarget.get() != curOpList->fTarget.get());
            }

            prevOpList = curOpList;
        }
    }
#endif
}

void GrDrawingManager::OpListDAG::closeAll(const GrCaps* caps) {
    for (int i = 0; i < fOpLists.count(); ++i) {
        if (fOpLists[i]) {
            fOpLists[i]->makeClosed(*caps);
        }
    }
}

void GrDrawingManager::OpListDAG::cleanup(const GrCaps* caps) {
    for (int i = 0; i < fOpLists.count(); ++i) {
        if (!fOpLists[i]) {
            continue;
        }

        // no opList should receive a new command after this
        fOpLists[i]->makeClosed(*caps);

        // We shouldn't need to do this, but it turns out some clients still hold onto opLists
        // after a cleanup.
        // MDB TODO: is this still true?
        if (!fOpLists[i]->unique()) {
            // TODO: Eventually this should be guaranteed unique.
            // https://bugs.chromium.org/p/skia/issues/detail?id=7111
            fOpLists[i]->endFlush();
        }
    }

    fOpLists.reset();
}

///////////////////////////////////////////////////////////////////////////////////////////////////
GrDrawingManager::GrDrawingManager(GrRecordingContext* context,
                                   const GrPathRendererChain::Options& optionsForPathRendererChain,
                                   const GrTextContext::Options& optionsForTextContext,
                                   bool explicitlyAllocating,
                                   bool sortOpLists,
                                   GrContextOptions::Enable reduceOpListSplitting)
        : fContext(context)
        , fOptionsForPathRendererChain(optionsForPathRendererChain)
        , fOptionsForTextContext(optionsForTextContext)
        , fDAG(explicitlyAllocating, sortOpLists)
        , fTextContext(nullptr)
        , fPathRendererChain(nullptr)
        , fSoftwarePathRenderer(nullptr)
        , fFlushing(false) {
    if (GrContextOptions::Enable::kNo == reduceOpListSplitting) {
        fReduceOpListSplitting = false;
    } else if (GrContextOptions::Enable::kYes == reduceOpListSplitting) {
        fReduceOpListSplitting = true;
    } else {
        // For now, this is only turned on when explicitly enabled. Once mini-flushes are
        // implemented it should be enabled whenever sorting is enabled.
        fReduceOpListSplitting = false; // sortOpLists
    }
}

void GrDrawingManager::cleanup() {
    fDAG.cleanup(fContext->priv().caps());

    fPathRendererChain = nullptr;
    fSoftwarePathRenderer = nullptr;

    fOnFlushCBObjects.reset();
}

GrDrawingManager::~GrDrawingManager() {
    this->cleanup();
}

bool GrDrawingManager::wasAbandoned() const {
    return fContext->priv().abandoned();
}

void GrDrawingManager::freeGpuResources() {
    for (int i = fOnFlushCBObjects.count() - 1; i >= 0; --i) {
        if (!fOnFlushCBObjects[i]->retainOnFreeGpuResources()) {
            // it's safe to just do this because we're iterating in reverse
            fOnFlushCBObjects.removeShuffle(i);
        }
    }

    // a path renderer may be holding onto resources
    fPathRendererChain = nullptr;
    fSoftwarePathRenderer = nullptr;
}

// MDB TODO: make use of the 'proxy' parameter.
GrSemaphoresSubmitted GrDrawingManager::flush(GrSurfaceProxy* proxy,
                                              SkSurface::BackendSurfaceAccess access,
                                              SkSurface::FlushFlags flags,
                                              int numSemaphores,
                                              GrBackendSemaphore backendSemaphores[]) {
    GR_CREATE_TRACE_MARKER_CONTEXT("GrDrawingManager", "flush", fContext);

    if (fFlushing || this->wasAbandoned()) {
        return GrSemaphoresSubmitted::kNo;
    }
    SkDEBUGCODE(this->validate());

    auto direct = fContext->priv().asDirectContext();
    if (!direct) {
        return GrSemaphoresSubmitted::kNo; // Can't flush while DDL recording
    }

    GrGpu* gpu = direct->priv().getGpu();
    if (!gpu) {
        return GrSemaphoresSubmitted::kNo; // Can't flush while DDL recording
    }
    fFlushing = true;

    auto resourceProvider = direct->priv().resourceProvider();
    auto resourceCache = direct->priv().getResourceCache();

    // Semi-usually the GrOpLists are already closed at this point, but sometimes Ganesh
    // needs to flush mid-draw. In that case, the SkGpuDevice's GrOpLists won't be closed
    // but need to be flushed anyway. Closing such GrOpLists here will mean new
    // GrOpLists will be created to replace them if the SkGpuDevice(s) write to them again.
    fDAG.closeAll(fContext->priv().caps());
    fActiveOpList = nullptr;

    fDAG.prepForFlush();
    if (!fCpuBufferCache) {
        // We cache more buffers when the backend is using client side arrays. Otherwise, we
        // expect each pool will use a CPU buffer as a staging buffer before uploading to a GPU
        // buffer object. Each pool only requires one staging buffer at a time.
        int maxCachedBuffers = fContext->priv().caps()->preferClientSideDynamicBuffers() ? 2 : 6;
        fCpuBufferCache = GrBufferAllocPool::CpuBufferCache::Make(maxCachedBuffers);
    }

    GrOpFlushState flushState(gpu, resourceProvider, &fTokenTracker, fCpuBufferCache);

    GrOnFlushResourceProvider onFlushProvider(this);
    // TODO: AFAICT the only reason fFlushState is on GrDrawingManager rather than on the
    // stack here is to preserve the flush tokens.

    // Prepare any onFlush op lists (e.g. atlases).
    if (!fOnFlushCBObjects.empty()) {
        fDAG.gatherIDs(&fFlushingOpListIDs);

        SkSTArray<4, sk_sp<GrRenderTargetContext>> renderTargetContexts;
        for (GrOnFlushCallbackObject* onFlushCBObject : fOnFlushCBObjects) {
            onFlushCBObject->preFlush(&onFlushProvider,
                                      fFlushingOpListIDs.begin(), fFlushingOpListIDs.count(),
                                      &renderTargetContexts);
            for (const sk_sp<GrRenderTargetContext>& rtc : renderTargetContexts) {
                sk_sp<GrRenderTargetOpList> onFlushOpList = sk_ref_sp(rtc->getRTOpList());
                if (!onFlushOpList) {
                    continue;   // Odd - but not a big deal
                }
#ifdef SK_DEBUG
                // OnFlush callbacks are already invoked during flush, and are therefore expected to
                // handle resource allocation & usage on their own. (No deferred or lazy proxies!)
                onFlushOpList->visitProxies_debugOnly([](GrSurfaceProxy* p) {
                    SkASSERT(!p->asTextureProxy() || !p->asTextureProxy()->texPriv().isDeferred());
                    SkASSERT(GrSurfaceProxy::LazyState::kNot == p->lazyInstantiationState());
                });
#endif
                onFlushOpList->makeClosed(*fContext->priv().caps());
                onFlushOpList->prepare(&flushState);
                fOnFlushCBOpLists.push_back(std::move(onFlushOpList));
            }
            renderTargetContexts.reset();
        }
    }

#if 0
    // Enable this to print out verbose GrOp information
    for (int i = 0; i < fOpLists.count(); ++i) {
        SkDEBUGCODE(fOpLists[i]->dump();)
    }
#endif

    int startIndex, stopIndex;
    bool flushed = false;

    {
        GrResourceAllocator alloc(resourceProvider, flushState.deinstantiateProxyTracker()
                                  SkDEBUGCODE(, fDAG.numOpLists()));
        for (int i = 0; i < fDAG.numOpLists(); ++i) {
            if (fDAG.opList(i)) {
                fDAG.opList(i)->gatherProxyIntervals(&alloc);
            }
            alloc.markEndOfOpList(i);
        }

        GrResourceAllocator::AssignError error = GrResourceAllocator::AssignError::kNoError;
        int numOpListsExecuted = 0;
        while (alloc.assign(&startIndex, &stopIndex, &error)) {
            if (GrResourceAllocator::AssignError::kFailedProxyInstantiation == error) {
                for (int i = startIndex; i < stopIndex; ++i) {
                    if (fDAG.opList(i) && !fDAG.opList(i)->isFullyInstantiated()) {
                        // If the backing surface wasn't allocated drop the entire opList.
                        fDAG.removeOpList(i);
                    }
                    if (fDAG.opList(i)) {
                        fDAG.opList(i)->purgeOpsWithUninstantiatedProxies();
                    }
                }
            }

            if (this->executeOpLists(startIndex, stopIndex, &flushState, &numOpListsExecuted)) {
                flushed = true;
            }
        }
    }

#ifdef SK_DEBUG
    for (int i = 0; i < fDAG.numOpLists(); ++i) {
        // If there are any remaining opLists at this point, make sure they will not survive the
        // flush. Otherwise we need to call endFlush() on them.
        // http://skbug.com/7111
        SkASSERT(!fDAG.opList(i) || fDAG.opList(i)->unique());
    }
#endif
    fDAG.reset();

#ifdef SK_DEBUG
    // In non-DDL mode this checks that all the flushed ops have been freed from the memory pool.
    // When we move to partial flushes this assert will no longer be valid.
    // In DDL mode this check is somewhat superfluous since the memory for most of the ops/opLists
    // will be stored in the DDL's GrOpMemoryPools.
    GrOpMemoryPool* opMemoryPool = fContext->priv().opMemoryPool();
    opMemoryPool->isEmpty();
#endif

    GrSemaphoresSubmitted result = gpu->finishFlush(proxy, access, flags, numSemaphores,
                                                    backendSemaphores);

    flushState.deinstantiateProxyTracker()->deinstantiateAllProxies();

    // Give the cache a chance to purge resources that become purgeable due to flushing.
    if (flushed) {
        resourceCache->purgeAsNeeded();
        flushed = false;
    }
    for (GrOnFlushCallbackObject* onFlushCBObject : fOnFlushCBObjects) {
        onFlushCBObject->postFlush(fTokenTracker.nextTokenToFlush(), fFlushingOpListIDs.begin(),
                                   fFlushingOpListIDs.count());
        flushed = true;
    }
    if (flushed) {
        resourceCache->purgeAsNeeded();
    }
    fFlushingOpListIDs.reset();
    fFlushing = false;

    return result;
}

bool GrDrawingManager::executeOpLists(int startIndex, int stopIndex, GrOpFlushState* flushState,
                                      int* numOpListsExecuted) {
    SkASSERT(startIndex <= stopIndex && stopIndex <= fDAG.numOpLists());

#if GR_FLUSH_TIME_OP_SPEW
    SkDebugf("Flushing opLists: %d to %d out of [%d, %d]\n",
                            startIndex, stopIndex, 0, fDAG.numOpLists());
    for (int i = startIndex; i < stopIndex; ++i) {
        if (fDAG.opList(i)) {
            fDAG.opList(i)->dump(true);
        }
    }
#endif

    auto direct = fContext->priv().asDirectContext();
    if (!direct) {
        return false;
    }

    auto resourceProvider = direct->priv().resourceProvider();
    bool anyOpListsExecuted = false;

    for (int i = startIndex; i < stopIndex; ++i) {
        if (!fDAG.opList(i)) {
             continue;
        }

        GrOpList* opList = fDAG.opList(i);

        if (resourceProvider->explicitlyAllocateGPUResources()) {
            if (!opList->isFullyInstantiated()) {
                // If the backing surface wasn't allocated drop the draw of the entire opList.
                fDAG.removeOpList(i);
                continue;
            }
        } else {
            if (!opList->instantiate(resourceProvider)) {
                fDAG.removeOpList(i);
                continue;
            }
        }

        // TODO: handle this instantiation via lazy surface proxies?
        // Instantiate all deferred proxies (being built on worker threads) so we can upload them
        opList->instantiateDeferredProxies(resourceProvider);
        opList->prepare(flushState);
    }

    // Upload all data to the GPU
    flushState->preExecuteDraws();

    // For Vulkan, if we have too many oplists to be flushed we end up allocating a lot of resources
    // for each command buffer associated with the oplists. If this gets too large we can cause the
    // devices to go OOM. In practice we usually only hit this case in our tests, but to be safe we
    // put a cap on the number of oplists we will execute before flushing to the GPU to relieve some
    // memory pressure.
    static constexpr int kMaxOpListsBeforeFlush = 100;

    // Execute the onFlush op lists first, if any.
    for (sk_sp<GrOpList>& onFlushOpList : fOnFlushCBOpLists) {
        if (!onFlushOpList->execute(flushState)) {
            SkDebugf("WARNING: onFlushOpList failed to execute.\n");
        }
        SkASSERT(onFlushOpList->unique());
        onFlushOpList = nullptr;
        (*numOpListsExecuted)++;
        if (*numOpListsExecuted >= kMaxOpListsBeforeFlush) {
            flushState->gpu()->finishFlush(nullptr, SkSurface::BackendSurfaceAccess::kNoAccess,
                                           SkSurface::kNone_FlushFlags, 0, nullptr);
            *numOpListsExecuted = 0;
        }
    }
    fOnFlushCBOpLists.reset();

    // Execute the normal op lists.
    for (int i = startIndex; i < stopIndex; ++i) {
        if (!fDAG.opList(i)) {
            continue;
        }

        if (fDAG.opList(i)->execute(flushState)) {
            anyOpListsExecuted = true;
        }
        (*numOpListsExecuted)++;
        if (*numOpListsExecuted >= kMaxOpListsBeforeFlush) {
            flushState->gpu()->finishFlush(nullptr, SkSurface::BackendSurfaceAccess::kNoAccess,
                                           SkSurface::kNone_FlushFlags, 0, nullptr);
            *numOpListsExecuted = 0;
        }
    }

    SkASSERT(!flushState->commandBuffer());
    SkASSERT(fTokenTracker.nextDrawToken() == fTokenTracker.nextTokenToFlush());

    // We reset the flush state before the OpLists so that the last resources to be freed are those
    // that are written to in the OpLists. This helps to make sure the most recently used resources
    // are the last to be purged by the resource cache.
    flushState->reset();

    fDAG.removeOpLists(startIndex, stopIndex);

    return anyOpListsExecuted;
}

GrSemaphoresSubmitted GrDrawingManager::prepareSurfaceForExternalIO(
        GrSurfaceProxy* proxy, SkSurface::BackendSurfaceAccess access, SkSurface::FlushFlags flags,
        int numSemaphores, GrBackendSemaphore backendSemaphores[]) {
    if (this->wasAbandoned()) {
        return GrSemaphoresSubmitted::kNo;
    }
    SkDEBUGCODE(this->validate());
    SkASSERT(proxy);

    auto direct = fContext->priv().asDirectContext();
    if (!direct) {
        return GrSemaphoresSubmitted::kNo; // Can't flush while DDL recording
    }

    GrGpu* gpu = direct->priv().getGpu();
    if (!gpu) {
        return GrSemaphoresSubmitted::kNo; // Can't flush while DDL recording
    }

    auto resourceProvider = direct->priv().resourceProvider();

    GrSemaphoresSubmitted result = GrSemaphoresSubmitted::kNo;
    if (proxy->priv().hasPendingIO() || numSemaphores ||
        SkToBool(flags & SkSurface::kSyncCpu_FlushFlag)) {
        result = this->flush(proxy, access, flags, numSemaphores, backendSemaphores);
    }

    if (!proxy->instantiate(resourceProvider)) {
        return result;
    }

    GrSurface* surface = proxy->peekSurface();
    if (auto* rt = surface->asRenderTarget()) {
        gpu->resolveRenderTarget(rt);
    }
    if (auto* tex = surface->asTexture()) {
        if (tex->texturePriv().mipMapped() == GrMipMapped::kYes &&
            tex->texturePriv().mipMapsAreDirty()) {
            gpu->regenerateMipMapLevels(tex);
        }
    }

    SkDEBUGCODE(this->validate());
    return result;
}

void GrDrawingManager::addOnFlushCallbackObject(GrOnFlushCallbackObject* onFlushCBObject) {
    fOnFlushCBObjects.push_back(onFlushCBObject);
}

#if GR_TEST_UTILS
void GrDrawingManager::testingOnly_removeOnFlushCallbackObject(GrOnFlushCallbackObject* cb) {
    int n = std::find(fOnFlushCBObjects.begin(), fOnFlushCBObjects.end(), cb) -
            fOnFlushCBObjects.begin();
    SkASSERT(n < fOnFlushCBObjects.count());
    fOnFlushCBObjects.removeShuffle(n);
}
#endif

void GrDrawingManager::moveOpListsToDDL(SkDeferredDisplayList* ddl) {
    SkDEBUGCODE(this->validate());

    // no opList should receive a new command after this
    fDAG.closeAll(fContext->priv().caps());
    fActiveOpList = nullptr;

    fDAG.swap(&ddl->fOpLists);

    if (fPathRendererChain) {
        if (auto ccpr = fPathRendererChain->getCoverageCountingPathRenderer()) {
            ddl->fPendingPaths = ccpr->detachPendingPaths();
        }
    }

    SkDEBUGCODE(this->validate());
}

void GrDrawingManager::copyOpListsFromDDL(const SkDeferredDisplayList* ddl,
                                          GrRenderTargetProxy* newDest) {
    SkDEBUGCODE(this->validate());

    if (fActiveOpList) {
        // This is  a temporary fix for the partial-MDB world. In that world we're not
        // reordering so ops that (in the single opList world) would've just glommed onto the
        // end of the single opList but referred to a far earlier RT need to appear in their
        // own opList.
        fActiveOpList->makeClosed(*fContext->priv().caps());
        fActiveOpList = nullptr;
    }

    // Here we jam the proxy that backs the current replay SkSurface into the LazyProxyData.
    // The lazy proxy that references it (in the copied opLists) will steal its GrTexture.
    ddl->fLazyProxyData->fReplayDest = newDest;

    if (ddl->fPendingPaths.size()) {
        GrCoverageCountingPathRenderer* ccpr = this->getCoverageCountingPathRenderer();

        ccpr->mergePendingPaths(ddl->fPendingPaths);
    }

    fDAG.add(ddl->fOpLists);

    SkDEBUGCODE(this->validate());
}

#ifdef SK_DEBUG
void GrDrawingManager::validate() const {
    if (fDAG.sortingOpLists() && fReduceOpListSplitting) {
        SkASSERT(!fActiveOpList);
    } else {
        if (fActiveOpList) {
            SkASSERT(!fDAG.empty());
            SkASSERT(!fActiveOpList->isClosed());
            SkASSERT(fActiveOpList == fDAG.back());
        }

        for (int i = 0; i < fDAG.numOpLists(); ++i) {
            if (fActiveOpList != fDAG.opList(i)) {
                SkASSERT(fDAG.opList(i)->isClosed());
            }
        }

        if (!fDAG.empty() && !fDAG.back()->isClosed()) {
            SkASSERT(fActiveOpList == fDAG.back());
        }
    }
}
#endif

sk_sp<GrRenderTargetOpList> GrDrawingManager::newRTOpList(GrRenderTargetProxy* rtp,
                                                          bool managedOpList) {
    SkDEBUGCODE(this->validate());
    SkASSERT(fContext);

    if (fDAG.sortingOpLists() && fReduceOpListSplitting) {
        // In this case we need to close all the opLists that rely on the current contents of
        // 'rtp'. That is bc we're going to update the content of the proxy so they need to be
        // split in case they use both the old and new content. (This is a bit of an overkill:
        // they really only need to be split if they ever reference proxy's contents again but
        // that is hard to predict/handle).
        if (GrOpList* lastOpList = rtp->getLastOpList()) {
            lastOpList->closeThoseWhoDependOnMe(*fContext->priv().caps());
        }
    } else if (fActiveOpList) {
        // This is  a temporary fix for the partial-MDB world. In that world we're not
        // reordering so ops that (in the single opList world) would've just glommed onto the
        // end of the single opList but referred to a far earlier RT need to appear in their
        // own opList.
        fActiveOpList->makeClosed(*fContext->priv().caps());
        fActiveOpList = nullptr;
    }

    // MDB TODO: this is unfortunate. GrOpList only needs the resourceProvider here so that, when
    // not explicitly allocating resources, it can immediately instantiate 'rtp' so that the use
    // order matches the allocation order (see the comment in GrOpList's ctor).
    GrResourceProvider* resourceProvider = nullptr;
    if (fContext->priv().asDirectContext()) {
        resourceProvider = fContext->priv().asDirectContext()->priv().resourceProvider();
    }

    sk_sp<GrRenderTargetOpList> opList(new GrRenderTargetOpList(
                                                        resourceProvider,
                                                        fContext->priv().refOpMemoryPool(),
                                                        rtp,
                                                        fContext->priv().auditTrail()));
    SkASSERT(rtp->getLastOpList() == opList.get());

    if (managedOpList) {
        fDAG.add(opList);

        if (!fDAG.sortingOpLists() || !fReduceOpListSplitting) {
            fActiveOpList = opList.get();
        }
    }

    SkDEBUGCODE(this->validate());
    return opList;
}

sk_sp<GrTextureOpList> GrDrawingManager::newTextureOpList(GrTextureProxy* textureProxy) {
    SkDEBUGCODE(this->validate());
    SkASSERT(fContext);

    if (fDAG.sortingOpLists() && fReduceOpListSplitting) {
        // In this case we need to close all the opLists that rely on the current contents of
        // 'texture'. That is bc we're going to update the content of the proxy so they need to
        // be split in case they use both the old and new content. (This is a bit of an
        // overkill: they really only need to be split if they ever reference proxy's contents
        // again but that is hard to predict/handle).
        if (GrOpList* lastOpList = textureProxy->getLastOpList()) {
            lastOpList->closeThoseWhoDependOnMe(*fContext->priv().caps());
        }
    } else if (fActiveOpList) {
        // This is  a temporary fix for the partial-MDB world. In that world we're not
        // reordering so ops that (in the single opList world) would've just glommed onto the
        // end of the single opList but referred to a far earlier RT need to appear in their
        // own opList.
        fActiveOpList->makeClosed(*fContext->priv().caps());
        fActiveOpList = nullptr;
    }

    // MDB TODO: this is unfortunate. GrOpList only needs the resourceProvider here so that, when
    // not explicitly allocating resources, it can immediately instantiate 'texureProxy' so that
    // the use order matches the allocation order (see the comment in GrOpList's ctor).
    GrResourceProvider* resourceProvider = nullptr;
    if (fContext->priv().asDirectContext()) {
        resourceProvider = fContext->priv().asDirectContext()->priv().resourceProvider();
    }

    sk_sp<GrTextureOpList> opList(new GrTextureOpList(resourceProvider,
                                                      fContext->priv().refOpMemoryPool(),
                                                      textureProxy,
                                                      fContext->priv().auditTrail()));

    SkASSERT(textureProxy->getLastOpList() == opList.get());

    fDAG.add(opList);
    if (!fDAG.sortingOpLists() || !fReduceOpListSplitting) {
        fActiveOpList = opList.get();
    }

    SkDEBUGCODE(this->validate());
    return opList;
}

GrTextContext* GrDrawingManager::getTextContext() {
    if (!fTextContext) {
        fTextContext = GrTextContext::Make(fOptionsForTextContext);
    }

    return fTextContext.get();
}

/*
 * This method finds a path renderer that can draw the specified path on
 * the provided target.
 * Due to its expense, the software path renderer has split out so it can
 * can be individually allowed/disallowed via the "allowSW" boolean.
 */
GrPathRenderer* GrDrawingManager::getPathRenderer(const GrPathRenderer::CanDrawPathArgs& args,
                                                  bool allowSW,
                                                  GrPathRendererChain::DrawType drawType,
                                                  GrPathRenderer::StencilSupport* stencilSupport) {

    if (!fPathRendererChain) {
        fPathRendererChain.reset(new GrPathRendererChain(fContext, fOptionsForPathRendererChain));
    }

    GrPathRenderer* pr = fPathRendererChain->getPathRenderer(args, drawType, stencilSupport);
    if (!pr && allowSW) {
        auto swPR = this->getSoftwarePathRenderer();
        if (GrPathRenderer::CanDrawPath::kNo != swPR->canDrawPath(args)) {
            pr = swPR;
        }
    }

    return pr;
}

GrPathRenderer* GrDrawingManager::getSoftwarePathRenderer() {
    if (!fSoftwarePathRenderer) {
        fSoftwarePathRenderer.reset(
                new GrSoftwarePathRenderer(fContext->priv().proxyProvider(),
                                           fOptionsForPathRendererChain.fAllowPathMaskCaching));
    }
    return fSoftwarePathRenderer.get();
}

GrCoverageCountingPathRenderer* GrDrawingManager::getCoverageCountingPathRenderer() {
    if (!fPathRendererChain) {
        fPathRendererChain.reset(new GrPathRendererChain(fContext, fOptionsForPathRendererChain));
    }
    return fPathRendererChain->getCoverageCountingPathRenderer();
}

void GrDrawingManager::flushIfNecessary() {
    auto direct = fContext->priv().asDirectContext();
    if (!direct) {
        return;
    }

    auto resourceCache = direct->priv().getResourceCache();
    if (resourceCache && resourceCache->requestsFlush()) {
        this->flush(nullptr, SkSurface::BackendSurfaceAccess::kNoAccess,
                    SkSurface::kNone_FlushFlags, 0, nullptr);
        resourceCache->purgeAsNeeded();
    }
}

sk_sp<GrRenderTargetContext> GrDrawingManager::makeRenderTargetContext(
                                                            sk_sp<GrSurfaceProxy> sProxy,
                                                            sk_sp<SkColorSpace> colorSpace,
                                                            const SkSurfaceProps* surfaceProps,
                                                            bool managedOpList) {
    if (this->wasAbandoned() || !sProxy->asRenderTargetProxy()) {
        return nullptr;
    }

    // SkSurface catches bad color space usage at creation. This check handles anything that slips
    // by, including internal usage.
    if (!SkSurface_Gpu::Valid(fContext->priv().caps(), sProxy->config(), colorSpace.get())) {
        SkDEBUGFAIL("Invalid config and colorspace combination");
        return nullptr;
    }

    sk_sp<GrRenderTargetProxy> renderTargetProxy(sk_ref_sp(sProxy->asRenderTargetProxy()));

    return sk_sp<GrRenderTargetContext>(new GrRenderTargetContext(fContext,
                                                                  std::move(renderTargetProxy),
                                                                  std::move(colorSpace),
                                                                  surfaceProps,
                                                                  managedOpList));
}

sk_sp<GrTextureContext> GrDrawingManager::makeTextureContext(sk_sp<GrSurfaceProxy> sProxy,
                                                             sk_sp<SkColorSpace> colorSpace) {
    if (this->wasAbandoned() || !sProxy->asTextureProxy()) {
        return nullptr;
    }

    // SkSurface catches bad color space usage at creation. This check handles anything that slips
    // by, including internal usage.
    if (!SkSurface_Gpu::Valid(fContext->priv().caps(), sProxy->config(), colorSpace.get())) {
        SkDEBUGFAIL("Invalid config and colorspace combination");
        return nullptr;
    }

    // GrTextureRenderTargets should always be using a GrRenderTargetContext
    SkASSERT(!sProxy->asRenderTargetProxy());

    sk_sp<GrTextureProxy> textureProxy(sk_ref_sp(sProxy->asTextureProxy()));

    return sk_sp<GrTextureContext>(new GrTextureContext(fContext,
                                                        std::move(textureProxy),
                                                        std::move(colorSpace)));
}