src/ui/scenic/lib/scheduling/tests/fuzzers/frame_scheduler_fuzztest.cc

// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <lib/async-testing/test_loop.h>
#include <lib/async/default.h>

#include <fuzzer/FuzzedDataProvider.h>
#include <gtest/gtest.h>

#include "src/ui/scenic/lib/scheduling/constant_frame_predictor.h"
#include "src/ui/scenic/lib/scheduling/default_frame_scheduler.h"
#include "src/ui/scenic/lib/scheduling/tests/mocks/frame_scheduler_mocks.h"

namespace scheduling {
namespace test {

extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
  // Fuzz FrameScheduler against fuzz timing input. The expectation is that all
  // tasks can be posted to the loop and run, and the FrameScheduler will not crash.
  FuzzedDataProvider fuzzed_data(Data, Size);

  async::TestLoop test_loop;
  async_set_default_dispatcher(test_loop.dispatcher());
  // Sanity check the default dispatcher has been set.
  EXPECT_EQ(async_get_default_dispatcher(), test_loop.dispatcher());

  // Fuzz vsync and prediction times.
  zx::time last_vsync_time = zx::time(fuzzed_data.ConsumeIntegral<zx_time_t>());
  zx::duration vsync_interval = zx::msec(fuzzed_data.ConsumeIntegral<zx_time_t>());

  // Negative values here indicates programming or driver bug and are not interesting to fuzz.
  if (last_vsync_time.get() < 0 || vsync_interval.get() < 0)
    return 0;

  zx::duration constant_prediction_offset = zx::msec(fuzzed_data.ConsumeIntegral<zx_time_t>());
  zx::time schedule_present_time = zx::time(fuzzed_data.ConsumeIntegral<zx_time_t>());

  // Set up DefaultFrameScheduler.
  auto vsync_timing = std::make_shared<VsyncTiming>();
  vsync_timing->set_vsync_interval(vsync_interval);
  vsync_timing->set_last_vsync_time(last_vsync_time);

  MockSessionUpdater updater;
  MockFrameRenderer renderer;

  auto frame_scheduler = std::make_unique<DefaultFrameScheduler>(
      vsync_timing, std::make_unique<ConstantFramePredictor>(constant_prediction_offset));
  frame_scheduler->SetFrameRenderer(renderer.GetWeakPtr());
  frame_scheduler->AddSessionUpdater(updater.GetWeakPtr());

  const SessionId client_id = 5;
  frame_scheduler->ScheduleUpdateForSession(schedule_present_time, {client_id, 1});

  test_loop.RunUntilIdle();

  EXPECT_EQ(1u, updater.update_sessions_call_count());
  EXPECT_EQ(1u, renderer.render_frame_call_count());
  return 0;
}

}  // namespace test
}  // namespace scheduling