renderer/src/metal/background_shader_compiler.h

/*
 * Copyright 2023 Rive
 */

#pragma once

#include "rive/renderer/gpu.hpp"
#include "rive/renderer/metal/render_context_metal_impl.h"

#include <queue>
#include <thread>

#import <Metal/Metal.h>

namespace rive::gpu
{
// Defines a job to compile a "draw" shader, with a specific set of features
// enabled.
struct BackgroundCompileJob
{
  gpu::DrawType drawType;
  gpu::ShaderFeatures shaderFeatures;
  gpu::InterlockMode interlockMode;
  gpu::ShaderMiscFlags shaderMiscFlags;
  id<MTLLibrary> compiledLibrary = nil;
#ifdef WITH_RIVE_TOOLS
  gpu::SynthesizedFailureType
      synthesizedFailureType = gpu::SynthesizedFailureType::none;
#endif
};

// Compiles "draw" shaders in a background thread, with a specific set of
// features enabled.
class BackgroundShaderCompiler
{
public:
  using AtomicBarrierType = RenderContextMetalImpl::AtomicBarrierType;
  using MetalFeatures = RenderContextMetalImpl::MetalFeatures;

  BackgroundShaderCompiler(id<MTLDevice> gpu, MetalFeatures metalFeatures)
      : m_gpu(gpu)
      , m_metalFeatures(metalFeatures)
  {}

  ~BackgroundShaderCompiler();

  void pushJob(const BackgroundCompileJob&);
  bool popFinishedJob(BackgroundCompileJob* job, bool wait);

private:
  void threadMain();

  const id<MTLDevice> m_gpu;
  const MetalFeatures m_metalFeatures;
  std::queue<BackgroundCompileJob> m_pendingJobs;
  std::vector<BackgroundCompileJob> m_finishedJobs;
  std::mutex m_mutex;
  std::condition_variable m_workAddedCondition;
  std::condition_variable m_workFinishedCondition;
  bool m_shouldQuit = false;
  std::thread m_compilerThread;
};
} // namespace rive::gpu