/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * Copyright (C) 2020, Google Inc. * * Test the buffer cache different operation modes */ #include <iostream> #include <random> #include <vector> #include <libcamera/formats.h> #include <libcamera/stream.h> #include "buffer_source.h" #include "test.h" using namespace libcamera; namespace { class BufferCacheTest : public Test { public: /* * Test that a cache with the same size as there are buffers results in * a sequential run over; 0, 1, 2, 3, 4, 0, 1, 2, 3, 4, ... * * The test is only valid when the cache size is as least as big as the * number of buffers. */ int testSequential(V4L2BufferCache *cache, const std::vector<std::unique_ptr<FrameBuffer>> &buffers) { for (unsigned int i = 0; i < buffers.size() * 100; i++) { int nBuffer = i % buffers.size(); int index = cache->get(*buffers[nBuffer].get()); if (index != nBuffer) { std::cout << "Expected index " << nBuffer << " got " << index << std::endl; return TestFail; } cache->put(index); } return TestPass; } /* * Test that randomly putting buffers to the cache always results in a * valid index. */ int testRandom(V4L2BufferCache *cache, const std::vector<std::unique_ptr<FrameBuffer>> &buffers) { std::uniform_int_distribution<> dist(0, buffers.size() - 1); for (unsigned int i = 0; i < buffers.size() * 100; i++) { int nBuffer = dist(generator_); int index = cache->get(*buffers[nBuffer].get()); if (index < 0) { std::cout << "Failed lookup from cache" << std::endl; return TestFail; } cache->put(index); } return TestPass; } /* * Test that using a buffer more frequently keeps it hot in the cache at * all times. */ int testHot(V4L2BufferCache *cache, const std::vector<std::unique_ptr<FrameBuffer>> &buffers, unsigned int hotFrequency) { /* Run the random test on the cache to make it messy. */ if (testRandom(cache, buffers) != TestPass) return TestFail; std::uniform_int_distribution<> dist(0, buffers.size() - 1); /* Pick a hot buffer at random and store its index. */ int hotBuffer = dist(generator_); int hotIndex = cache->get(*buffers[hotBuffer].get()); cache->put(hotIndex); /* * Queue hot buffer at the requested frequency and make sure * it stays hot. */ for (unsigned int i = 0; i < buffers.size() * 100; i++) { int nBuffer, index; bool hotQueue = i % hotFrequency == 0; if (hotQueue) nBuffer = hotBuffer; else nBuffer = dist(generator_); index = cache->get(*buffers[nBuffer].get()); if (index < 0) { std::cout << "Failed lookup from cache" << std::endl; return TestFail; } if (hotQueue && index != hotIndex) { std::cout << "Hot buffer got cold" << std::endl; return TestFail; } cache->put(index); } return TestPass; } int init() override { std::random_device rd; unsigned int seed = rd(); std::cout << "Random seed is " << seed << std::endl; generator_.seed(seed); return TestPass; } int run() override { const unsigned int numBuffers = 8; StreamConfiguration cfg; cfg.pixelFormat = formats::YUYV; cfg.size = Size(600, 800); cfg.bufferCount = numBuffers; BufferSource source; int ret = source.allocate(cfg); if (ret != TestPass) return ret; const std::vector<std::unique_ptr<FrameBuffer>> &buffers = source.buffers(); if (buffers.size() != numBuffers) { std::cout << "Got " << buffers.size() << " buffers, expected " << numBuffers << std::endl; return TestFail; } /* * Test cache of same size as there are buffers, the cache is * created from a list of buffers and will be pre-populated. */ V4L2BufferCache cacheFromBuffers(buffers); if (testSequential(&cacheFromBuffers, buffers) != TestPass) return TestFail; if (testRandom(&cacheFromBuffers, buffers) != TestPass) return TestFail; if (testHot(&cacheFromBuffers, buffers, numBuffers) != TestPass) return TestFail; /* * Test cache of same size as there are buffers, the cache is * not pre-populated. */ V4L2BufferCache cacheFromNumbers(numBuffers); if (testSequential(&cacheFromNumbers, buffers) != TestPass) return TestFail; if (testRandom(&cacheFromNumbers, buffers) != TestPass) return TestFail; if (testHot(&cacheFromNumbers, buffers, numBuffers) != TestPass) return TestFail; /* * Test cache half the size of number of buffers used, the cache * is not pre-populated. */ V4L2BufferCache cacheHalf(numBuffers / 2); if (testRandom(&cacheHalf, buffers) != TestPass) return TestFail; if (testHot(&cacheHalf, buffers, numBuffers / 2) != TestPass) return TestFail; return TestPass; } private: std::mt19937 generator_; }; } /* namespace */ TEST_REGISTER(BufferCacheTest);