CacheLocalityTest.cpp File Reference

#include <folly/concurrency/CacheLocality.h>
#include <folly/portability/GTest.h>
#include <glog/logging.h>
#include <memory>
#include <thread>
#include <unordered_map>

Go to the source code of this file.

Functions
	TEST (CacheLocality, FakeSysfs)
	TEST (ThreadId, SimplePthread)
	TEST (AccessSpreader, Simple)
	TEST (AccessSpreader, SimpleCached)
	TEST (AccessSpreader, ConcurrentAccessCached)

Variables
static std::unordered_map< std::string, std::string >	fakeSysfsTree
static const CacheLocality	nonUniformExampleLocality
	This is the expected CacheLocality structure for fakeSysfsTree. More...

Function Documentation

TEST	(	CacheLocality	,
		FakeSysfs
	)

Definition at line 312 of file CacheLocalityTest.cpp.

References EXPECT_EQ, EXPECT_TRUE, name, nonUniformExampleLocality, folly::Getcpu::resolveVdsoFunc(), string, and folly::TEST().

                               {
  auto parsed = CacheLocality::readFromSysfsTree([](std::string name) {
    auto iter = fakeSysfsTree.find(name);
    return iter == fakeSysfsTree.end() ? std::string() : iter->second;
  });

  auto& expected = nonUniformExampleLocality;
  EXPECT_EQ(expected.numCpus, parsed.numCpus);
  EXPECT_EQ(expected.numCachesByLevel, parsed.numCachesByLevel);
  EXPECT_EQ(expected.localityIndexByCpu, parsed.localityIndexByCpu);
}

TEST	(	ThreadId	,
		SimplePthread
	)

Definition at line 347 of file CacheLocalityTest.cpp.

References EXPECT_EQ, EXPECT_TRUE, and folly::FallbackGetcpu< ThreadId >::getcpu().

                              {
  unsigned cpu = 0;
  auto rv =
      folly::FallbackGetcpu<HashingThreadId>::getcpu(&cpu, nullptr, nullptr);
  EXPECT_EQ(rv, 0);
  EXPECT_TRUE(cpu > 0);
  unsigned again;
  folly::FallbackGetcpu<HashingThreadId>::getcpu(&again, nullptr, nullptr);
  EXPECT_EQ(cpu, again);
}

TEST	(	AccessSpreader	,
		Simple
	)

Definition at line 372 of file CacheLocalityTest.cpp.

References EXPECT_LT, and s.

                             {
  for (size_t s = 1; s < 200; ++s) {
    EXPECT_LT(AccessSpreader<>::current(s), s);
  }
}

TEST	(	AccessSpreader	,
		SimpleCached
	)

Definition at line 378 of file CacheLocalityTest.cpp.

References EXPECT_LT, and s.

                                   {
  for (size_t s = 1; s < 200; ++s) {
    EXPECT_LT(AccessSpreader<>::cachedCurrent(s), s);
  }
}

TEST	(	AccessSpreader	,
		ConcurrentAccessCached
	)

Definition at line 384 of file CacheLocalityTest.cpp.

References a, c, folly::AccessSpreader< Atom >::current(), DECLARE_SPREADER_TAG, EXPECT_EQ, EXPECT_LT, EXPECT_TRUE, folly::CoreRawAllocator< Stripes >::get(), i, s, folly::TEST(), threads, folly::CacheLocality::uniform(), and folly::fibers::yield().

                                             {
  std::vector<std::thread> threads;
  for (size_t i = 0; i < 4; ++i) {
    threads.emplace_back([]() {
      for (size_t s : {16, 32, 64}) {
        for (size_t j = 1; j < 200; ++j) {
          EXPECT_LT(AccessSpreader<>::cachedCurrent(s), s);
          EXPECT_LT(AccessSpreader<>::cachedCurrent(s), s);
        }
        std::this_thread::yield();
      }
    });
  }
  for (auto& thread : threads) {
    thread.join();
  }
}

Variable Documentation

std::unordered_map<std::string, std::string> fakeSysfsTree

static

This is the relevant nodes from a production box's sysfs tree. If you think this map is ugly you should see the version of this test that used a real directory tree. To reduce the chance of testing error I haven't tried to remove the common prefix

Definition at line 32 of file CacheLocalityTest.cpp.

const CacheLocality nonUniformExampleLocality

static

Initial value:

= {
    32,
    {16, 16, 2},
    {0,  2, 4, 6, 8, 10, 11, 12, 14, 16, 18, 20, 22, 24, 26, 28,
     30, 1, 3, 5, 7, 9,  13, 15, 17, 19, 21, 23, 25, 27, 29, 31}}

This is the expected CacheLocality structure for fakeSysfsTree.

Definition at line 306 of file CacheLocalityTest.cpp.

Referenced by TEST().