// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "gpu/command_buffer/service/gr_cache_controller.h"

#include <chrono>

#include "base/feature_list.h"
#include "base/functional/bind.h"
#include "base/task/single_thread_task_runner.h"
#include "build/build_config.h"
#include "gpu/command_buffer/service/shared_context_state.h"
#include "gpu/command_buffer/service/skia_utils.h"
#include "gpu/config/gpu_finch_features.h"
#include "gpu/ipc/common/gpu_client_ids.h"
#include "ui/gl/gl_bindings.h"
#include "ui/gl/gl_context.h"

namespace gpu {
namespace raster {

GrCacheController::GrCacheController(SharedContextState* context_state)
    : context_state_(context_state),
      task_runner_(base::SingleThreadTaskRunner::HasCurrentDefault()
                       ? base::SingleThreadTaskRunner::GetCurrentDefault()
                       : nullptr) {}

GrCacheController::GrCacheController(
    SharedContextState* context_state,
    scoped_refptr<base::SingleThreadTaskRunner> task_runner)
    : context_state_(context_state), task_runner_(std::move(task_runner)) {}

GrCacheController::~GrCacheController() = default;

void GrCacheController::ScheduleGrContextCleanup() {
  DCHECK(context_state_->IsCurrent(nullptr));

  if (!context_state_->gr_context())
    return;

  if (!task_runner_) {
    // No way to estimate idle. Just periodically call PerformDeferredCleanup.
    PerformDeferredCleanupThrottled();
    return;
  }

  DCHECK(task_runner_->BelongsToCurrentThread());

  current_idle_id_++;
  if (!purge_gr_cache_cb_.IsCancelled())
    return;

  PerformDeferredCleanup();

  constexpr int kIdleCleanupDelaySeconds = 1;
  purge_gr_cache_cb_.Reset(base::BindOnce(&GrCacheController::PurgeGrCache,
                                          base::Unretained(this),
                                          current_idle_id_));
  task_runner_->PostDelayedTask(FROM_HERE, purge_gr_cache_cb_.callback(),
                                base::Seconds(kIdleCleanupDelaySeconds));
}

void GrCacheController::PerformDeferredCleanupThrottled() {
  constexpr base::TimeDelta kTimeout = base::Seconds(1);
  base::TimeTicks now = base::TimeTicks::Now();
  if (now - last_cleanup_timestamp_ < kTimeout) {
    return;
  }
  last_cleanup_timestamp_ = now;
  PerformDeferredCleanup();
}

void GrCacheController::PerformDeferredCleanup() {
#if BUILDFLAG(IS_MAC)
  constexpr int kOldResourceDelaySeconds = 5;
#else
  constexpr int kOldResourceDelaySeconds = 1;
#endif
  // Here we ask GrContext to free any resources that haven't been used in
  // a long while even if it is under budget. Below we set a call back to
  // purge all possible GrContext resources if the context itself is not being
  // used.
  context_state_->set_need_context_state_reset(true);
  context_state_->gr_context()->performDeferredCleanup(
      std::chrono::seconds(kOldResourceDelaySeconds));
}

void GrCacheController::PurgeGrCache(uint64_t idle_id) {
  purge_gr_cache_cb_.Cancel();

  // We don't care which surface is current. This improves
  // performance. https://crbug.com/457431
  if (!context_state_->MakeCurrent(nullptr))
    return;

  // If the idle id changed, the context was used after this callback was
  // posted. Schedule another one.
  if (idle_id != current_idle_id_) {
    ScheduleGrContextCleanup();
    return;
  }

  context_state_->set_need_context_state_reset(true);

  // Force Skia to check fences to determine what can be freed.
  context_state_->gr_context()->checkAsyncWorkCompletion();
  {
    std::optional<gpu::raster::GrShaderCache::ScopedCacheUse> cache_use;
    // ScopedCacheUse is to avoid the empty/invalid client id DCHECKS caused
    // while accessing GrShaderCache. Note that since the actual client_id here
    // does not matter, we are using gpu::kDisplayCompositorClientId.
    context_state_->UseShaderCache(cache_use, gpu::kDisplayCompositorClientId);
    context_state_->gr_context()->freeGpuResources();
  }

  // Skia may have released resources, but the driver may not process that
  // without a flush.
  if (features::EnablePruneOldTransferCacheEntries()) {
    GrFlushInfo flush_info;
    gpu::AddVulkanCleanupTaskForSkiaFlush(context_state_->vk_context_provider(),
                                          &flush_info);
    context_state_->gr_context()->flush(flush_info);
    context_state_->gr_context()->submit();
  }
  if (context_state_->GrContextIsGL()) {
    auto* api = gl::g_current_gl_context;
    api->glFlushFn();
  }

  // Skia store VkPipeline cache only on demand. We do it when we're idle idle
  // as it might take time.
  context_state_->StoreVkPipelineCacheIfNeeded();
}

}  // namespace raster
}  // namespace gpu