gecko-dev/gfx/tests/gtest/TestJobScheduler.cpp

/* vim:set ts=2 sw=2 sts=2 et: */
/* Any copyright is dedicated to the Public Domain.
 * http://creativecommons.org/publicdomain/zero/1.0/
 */

#include "gtest/gtest.h"
#include "gmock/gmock.h"

#include "mozilla/gfx/JobScheduler.h"

#ifndef WIN32
#  include <pthread.h>
#  include <sched.h>
#endif

#include <stdlib.h>
#include <time.h>

namespace test_scheduler {

using namespace mozilla::gfx;
using namespace mozilla;
using mozilla::gfx::SyncObject;

// Artificially cause threads to yield randomly in an attempt to make racy
// things more apparent (if any).
static void MaybeYieldThread() {
#ifndef WIN32
  if (rand() % 5 == 0) {
    sched_yield();
  }
#endif
}

/// Used by the TestCommand to check that tasks are processed in the right
/// order.
struct SanityChecker {
  std::vector<uint64_t> mAdvancements;
  mozilla::gfx::CriticalSection mSection;

  explicit SanityChecker(uint64_t aNumCmdBuffers) {
    for (uint32_t i = 0; i < aNumCmdBuffers; ++i) {
      mAdvancements.push_back(0);
    }
  }

  virtual void Check(uint64_t aJobId, uint64_t aCmdId) {
    MaybeYieldThread();
    CriticalSectionAutoEnter lock(&mSection);
    MOZ_RELEASE_ASSERT(mAdvancements[aJobId] == aCmdId - 1);
    mAdvancements[aJobId] = aCmdId;
  }
};

/// Run checks that are specific to TestSchulerJoin.
struct JoinTestSanityCheck : public SanityChecker {
  bool mSpecialJobHasRun;

  explicit JoinTestSanityCheck(uint64_t aNumCmdBuffers)
      : SanityChecker(aNumCmdBuffers), mSpecialJobHasRun(false) {}

  virtual void Check(uint64_t aJobId, uint64_t aCmdId) override {
    // Job 0 is the special task executed when everything is joined after task 1
    if (aCmdId == 0) {
      MOZ_RELEASE_ASSERT(!mSpecialJobHasRun,
                         "GFX: A special task has been executed.");
      mSpecialJobHasRun = true;
      for (auto advancement : mAdvancements) {
        // Because of the synchronization point (beforeFilter), all
        // task buffers should have run task 1 when task 0 is run.
        MOZ_RELEASE_ASSERT(advancement == 1,
                           "GFX: task buffer has not run task 1.");
      }
    } else {
      // This check does not apply to task 0.
      SanityChecker::Check(aJobId, aCmdId);
    }

    if (aCmdId == 2) {
      MOZ_RELEASE_ASSERT(mSpecialJobHasRun, "GFX: Special job has not run.");
    }
  }
};

class TestJob : public Job {
 public:
  TestJob(uint64_t aCmdId, uint64_t aJobId, SanityChecker* aChecker,
          SyncObject* aStart, SyncObject* aCompletion)
      : Job(aStart, aCompletion, nullptr),
        mCmdId(aCmdId),
        mCmdBufferId(aJobId),
        mSanityChecker(aChecker) {}

  JobStatus Run() {
    MaybeYieldThread();
    mSanityChecker->Check(mCmdBufferId, mCmdId);
    MaybeYieldThread();
    return JobStatus::Complete;
  }

  uint64_t mCmdId;
  uint64_t mCmdBufferId;
  SanityChecker* mSanityChecker;
};

/// This test creates aNumCmdBuffers task buffers with sync objects set up
/// so that all tasks will join after command 5 before a task buffer runs
/// a special task (task 0) after which all task buffers fork again.
/// This simulates the kind of scenario where all tiles must join at
/// a certain point to execute, say, a filter, and fork again after the filter
/// has been processed.
/// The main thread is only blocked when waiting for the completion of the
/// entire task stream (it doesn't have to wait at the filter's sync points to
/// orchestrate it).
static void TestSchedulerJoin(uint32_t aNumThreads, uint32_t aNumCmdBuffers) {
  JoinTestSanityCheck check(aNumCmdBuffers);

  RefPtr<SyncObject> beforeFilter = new SyncObject(aNumCmdBuffers);
  RefPtr<SyncObject> afterFilter = new SyncObject();
  RefPtr<SyncObject> completion = new SyncObject(aNumCmdBuffers);

  for (uint32_t i = 0; i < aNumCmdBuffers; ++i) {
    Job* t1 = new TestJob(1, i, &check, nullptr, beforeFilter);
    JobScheduler::SubmitJob(t1);
    MaybeYieldThread();
  }
  beforeFilter->FreezePrerequisites();

  // This task buffer is executed when all other tasks have joined after task 1
  JobScheduler::SubmitJob(new TestJob(0, 0, &check, beforeFilter, afterFilter));
  afterFilter->FreezePrerequisites();

  for (uint32_t i = 0; i < aNumCmdBuffers; ++i) {
    Job* t2 = new TestJob(2, i, &check, afterFilter, completion);
    JobScheduler::SubmitJob(t2);
    MaybeYieldThread();
  }
  completion->FreezePrerequisites();

  JobScheduler::Join(completion);

  MaybeYieldThread();

  for (auto advancement : check.mAdvancements) {
    EXPECT_TRUE(advancement == 2);
  }
}

/// This test creates several chains of 10 task, tasks of a given chain are
/// executed sequentially, and chains are exectuted in parallel. This simulates
/// the typical scenario where we want to process sequences of drawing commands
/// for several tiles in parallel.
static void TestSchedulerChain(uint32_t aNumThreads, uint32_t aNumCmdBuffers) {
  SanityChecker check(aNumCmdBuffers);

  RefPtr<SyncObject> completion = new SyncObject(aNumCmdBuffers);

  uint32_t numJobs = 10;

  for (uint32_t i = 0; i < aNumCmdBuffers; ++i) {
    std::vector<RefPtr<SyncObject>> syncs;
    std::vector<Job*> tasks;
    syncs.reserve(numJobs);
    tasks.reserve(numJobs);

    for (uint32_t t = 0; t < numJobs - 1; ++t) {
      syncs.push_back(new SyncObject());
      tasks.push_back(new TestJob(
          t + 1, i, &check, t == 0 ? nullptr : syncs[t - 1].get(), syncs[t]));
      syncs.back()->FreezePrerequisites();
    }

    tasks.push_back(new TestJob(numJobs, i, &check, syncs.back(), completion));

    if (i % 2 == 0) {
      // submit half of the tasks in order
      for (Job* task : tasks) {
        JobScheduler::SubmitJob(task);
        MaybeYieldThread();
      }
    } else {
      // ... and submit the other half in reverse order
      for (int32_t reverse = numJobs - 1; reverse >= 0; --reverse) {
        JobScheduler::SubmitJob(tasks[reverse]);
        MaybeYieldThread();
      }
    }
  }
  completion->FreezePrerequisites();

  JobScheduler::Join(completion);

  for (auto advancement : check.mAdvancements) {
    EXPECT_TRUE(advancement == numJobs);
  }
}

}  // namespace test_scheduler

#if !defined(MOZ_CODE_COVERAGE) || !defined(XP_WIN)
TEST(Moz2D, JobScheduler_Shutdown)
{
  srand(time(nullptr));
  for (uint32_t threads = 1; threads < 16; ++threads) {
    for (uint32_t i = 1; i < 1000; ++i) {
      mozilla::gfx::JobScheduler::Init(threads, threads);
      mozilla::gfx::JobScheduler::ShutDown();
    }
  }
}
#endif

TEST(Moz2D, JobScheduler_Join)
{
  srand(time(nullptr));
  for (uint32_t threads = 1; threads < 8; ++threads) {
    for (uint32_t queues = 1; queues < threads; ++queues) {
      for (uint32_t buffers = 1; buffers < 100; buffers += 3) {
        mozilla::gfx::JobScheduler::Init(threads, queues);
        test_scheduler::TestSchedulerJoin(threads, buffers);
        mozilla::gfx::JobScheduler::ShutDown();
      }
    }
  }
}

TEST(Moz2D, JobScheduler_Chain)
{
  srand(time(nullptr));
  for (uint32_t threads = 1; threads < 8; ++threads) {
    for (uint32_t queues = 1; queues < threads; ++queues) {
      for (uint32_t buffers = 1; buffers < 100; buffers += 3) {
        mozilla::gfx::JobScheduler::Init(threads, queues);
        test_scheduler::TestSchedulerChain(threads, buffers);
        mozilla::gfx::JobScheduler::ShutDown();
      }
    }
  }
}