Files
scylladb/test/boost/cached_file_test.cc
Avi Kivity 0770b328c7 test: fix some mismatched signed/unsigned comparisons
gcc likes to complain about sized/unsigned compares as they
can yield surprising results. The fixes are trivial, so apply
them.
2023-03-21 13:15:12 +02:00

437 lines
15 KiB
C++

/*
* Copyright (C) 2020-present ScyllaDB
*/
/*
* SPDX-License-Identifier: AGPL-3.0-or-later
*/
#include <boost/range/irange.hpp>
#include "test/lib/scylla_test_case.hh"
#include <seastar/testing/thread_test_case.hh>
#include <seastar/core/iostream.hh>
#include <seastar/core/when_all.hh>
#include <seastar/core/fstream.hh>
#include <seastar/core/file.hh>
#include <seastar/core/reactor.hh>
#include <seastar/util/defer.hh>
#include "test/lib/random_utils.hh"
#include "test/lib/log.hh"
#include "test/lib/tmpdir.hh"
#include "utils/cached_file.hh"
using namespace seastar;
static lru cf_lru;
static sstring read_to_string(cached_file::stream& s, size_t limit = std::numeric_limits<size_t>::max()) {
sstring b;
while (auto buf = s.next().get0()) {
b += sstring(buf.get(), buf.size());
if (b.size() >= limit) {
break;
}
}
return b.substr(0, limit);
}
static void read_to_void(cached_file::stream& s, size_t limit = std::numeric_limits<size_t>::max()) {
while (auto buf = s.next().get0()) {
if (buf.size() >= limit) {
break;
}
limit -= buf.size();
}
}
static sstring read_to_string(file& f, size_t start, size_t len) {
file_input_stream_options opt;
auto in = make_file_input_stream(f, start, len, opt);
auto buf = in.read_exactly(len).get0();
return sstring(buf.get(), buf.size());
}
static sstring read_to_string(cached_file& cf, size_t off, size_t limit = std::numeric_limits<size_t>::max()) {
auto s = cf.read(off, default_priority_class(), std::nullopt);
return read_to_string(s, limit);
}
[[gnu::unused]]
static void read_to_void(cached_file& cf, size_t off, size_t limit = std::numeric_limits<size_t>::max()) {
auto s = cf.read(off, default_priority_class(), std::nullopt);
read_to_void(s, limit);
}
struct test_file {
tmpdir dir;
file f;
sstring contents;
~test_file() {
f.close().get();
}
};
test_file make_test_file(size_t size) {
tmpdir dir;
auto contents = tests::random::get_sstring(size);
auto path = dir.path() / "file";
file f = open_file_dma(path.c_str(), open_flags::create | open_flags::rw).get0();
testlog.debug("file contents: {}", contents);
output_stream<char> out = make_file_output_stream(f).get0();
auto close_out = defer([&] { out.close().get(); });
out.write(contents.begin(), contents.size()).get();
out.flush().get();
f = open_file_dma(path.c_str(), open_flags::ro).get0();
return test_file{
.dir = std::move(dir),
.f = std::move(f),
.contents = std::move(contents)
};
}
SEASTAR_THREAD_TEST_CASE(test_file_wrapper) {
auto page_size = cached_file::page_size;
cached_file::metrics metrics;
test_file tf = make_test_file(page_size * 3);
logalloc::region region;
cached_file cf(tf.f, metrics, cf_lru, region, page_size * 3);
seastar::file f = make_cached_seastar_file(cf);
BOOST_REQUIRE_EQUAL(tf.contents.substr(0, 1),
read_to_string(f, 0, 1));
BOOST_REQUIRE_EQUAL(tf.contents.substr(page_size - 1, 10),
read_to_string(f, page_size - 1, 10));
BOOST_REQUIRE_EQUAL(tf.contents.substr(page_size - 1, cf.size() - (page_size - 1)),
read_to_string(f, page_size - 1, cf.size() - (page_size - 1)));
BOOST_REQUIRE_EQUAL(tf.contents.substr(0, cf.size()),
read_to_string(f, 0, cf.size()));
BOOST_CHECK_THROW(read_to_string(f, 0, cf.size() + 1), seastar::file::eof_error);
}
SEASTAR_THREAD_TEST_CASE(test_concurrent_population) {
auto page_size = cached_file::page_size;
cached_file::metrics metrics;
test_file tf = make_test_file(page_size * 3);
logalloc::region region;
cached_file cf(tf.f, metrics, cf_lru, region, page_size * 3);
seastar::file f = make_cached_seastar_file(cf);
seastar::when_all(
seastar::async([&] {
BOOST_REQUIRE_EQUAL(tf.contents.substr(0, 1), read_to_string(f, 0, 1));
}),
seastar::async([&] {
BOOST_REQUIRE_EQUAL(tf.contents.substr(0, 1), read_to_string(f, 0, 1));
})
).get();
BOOST_REQUIRE_EQUAL(page_size, metrics.cached_bytes);
BOOST_REQUIRE_EQUAL(2, metrics.page_misses);
BOOST_REQUIRE_EQUAL(0, metrics.page_evictions);
BOOST_REQUIRE_EQUAL(0, metrics.page_hits);
BOOST_REQUIRE_EQUAL(1, metrics.page_populations);
}
SEASTAR_THREAD_TEST_CASE(test_reading_from_small_file) {
test_file tf = make_test_file(1024);
{
cached_file::metrics metrics;
logalloc::region region;
cached_file cf(tf.f, metrics, cf_lru, region, tf.contents.size());
{
BOOST_REQUIRE_EQUAL(tf.contents, read_to_string(cf, 0));
BOOST_REQUIRE_EQUAL(cached_file::page_size, metrics.cached_bytes);
BOOST_REQUIRE_EQUAL(1, metrics.page_misses);
BOOST_REQUIRE_EQUAL(0, metrics.page_evictions);
BOOST_REQUIRE_EQUAL(0, metrics.page_hits);
BOOST_REQUIRE_EQUAL(1, metrics.page_populations);
}
{
BOOST_REQUIRE_EQUAL(tf.contents.substr(2), read_to_string(cf, 2));
BOOST_REQUIRE_EQUAL(cached_file::page_size, metrics.cached_bytes);
BOOST_REQUIRE_EQUAL(1, metrics.page_misses);
BOOST_REQUIRE_EQUAL(0, metrics.page_evictions);
BOOST_REQUIRE_EQUAL(1, metrics.page_hits); // change here
BOOST_REQUIRE_EQUAL(1, metrics.page_populations);
}
{
BOOST_REQUIRE_EQUAL(sstring(), read_to_string(cf, 3000));
// no change
BOOST_REQUIRE_EQUAL(cached_file::page_size, metrics.cached_bytes);
BOOST_REQUIRE_EQUAL(1, metrics.page_misses);
BOOST_REQUIRE_EQUAL(0, metrics.page_evictions);
BOOST_REQUIRE_EQUAL(1, metrics.page_hits);
BOOST_REQUIRE_EQUAL(1, metrics.page_populations);
}
}
}
SEASTAR_THREAD_TEST_CASE(test_eviction_via_lru) {
auto page = cached_file::page_size;
auto file_size = page * 2 + 12;
test_file tf = make_test_file(file_size);
{
cached_file::metrics metrics;
logalloc::region region;
cached_file cf(tf.f, metrics, cf_lru, region, tf.contents.size());
{
BOOST_REQUIRE_EQUAL(tf.contents, read_to_string(cf, 0));
BOOST_REQUIRE_EQUAL(page * 3, metrics.cached_bytes);
BOOST_REQUIRE_EQUAL(page * 3, cf.cached_bytes());
BOOST_REQUIRE_EQUAL(3, metrics.page_misses);
BOOST_REQUIRE_EQUAL(0, metrics.page_evictions);
BOOST_REQUIRE_EQUAL(0, metrics.page_hits);
BOOST_REQUIRE_EQUAL(3, metrics.page_populations);
}
{
with_allocator(region.allocator(), [] {
cf_lru.evict_all();
});
BOOST_REQUIRE_EQUAL(0, metrics.cached_bytes); // change here
BOOST_REQUIRE_EQUAL(0, cf.cached_bytes()); // change here
BOOST_REQUIRE_EQUAL(3, metrics.page_misses);
BOOST_REQUIRE_EQUAL(3, metrics.page_evictions); // change here
BOOST_REQUIRE_EQUAL(0, metrics.page_hits);
BOOST_REQUIRE_EQUAL(3, metrics.page_populations);
BOOST_REQUIRE_EQUAL(region.occupancy().used_space(), 0);
}
{
BOOST_REQUIRE_EQUAL(tf.contents, read_to_string(cf, 0));
BOOST_REQUIRE_EQUAL(page * 3, metrics.cached_bytes); // change here
BOOST_REQUIRE_EQUAL(page * 3, cf.cached_bytes());
BOOST_REQUIRE_EQUAL(6, metrics.page_misses); // change here
BOOST_REQUIRE_EQUAL(3, metrics.page_evictions);
BOOST_REQUIRE_EQUAL(0, metrics.page_hits);
BOOST_REQUIRE_EQUAL(6, metrics.page_populations); // change here
}
{
// Test that the page which is touched is evicted last
BOOST_REQUIRE_EQUAL(tf.contents.substr(page, 1), read_to_string(cf, page, 1)); // hit page 1
BOOST_REQUIRE_EQUAL(6, metrics.page_misses);
BOOST_REQUIRE_EQUAL(3, metrics.page_evictions);
BOOST_REQUIRE_EQUAL(1, metrics.page_hits);
BOOST_REQUIRE_EQUAL(6, metrics.page_populations);
cf_lru.evict();
BOOST_REQUIRE_EQUAL(tf.contents.substr(page, 1), read_to_string(cf, page, 1)); // hit page 1
BOOST_REQUIRE_EQUAL(6, metrics.page_misses);
BOOST_REQUIRE_EQUAL(4, metrics.page_evictions); // change
BOOST_REQUIRE_EQUAL(2, metrics.page_hits); // change
BOOST_REQUIRE_EQUAL(6, metrics.page_populations);
cf_lru.evict();
BOOST_REQUIRE_EQUAL(tf.contents.substr(page, 1), read_to_string(cf, page, 1)); // hit page 1
BOOST_REQUIRE_EQUAL(6, metrics.page_misses);
BOOST_REQUIRE_EQUAL(5, metrics.page_evictions); // change
BOOST_REQUIRE_EQUAL(3, metrics.page_hits); // change
BOOST_REQUIRE_EQUAL(6, metrics.page_populations);
}
}
}
// A file which serves garbage but is very fast.
class garbage_file_impl : public file_impl {
private:
[[noreturn]] void unsupported() {
throw_with_backtrace<std::logic_error>("unsupported operation");
}
public:
// unsupported
virtual future<size_t> write_dma(uint64_t pos, const void* buffer, size_t len, const io_priority_class& pc) override { unsupported(); }
virtual future<size_t> write_dma(uint64_t pos, std::vector<iovec> iov, const io_priority_class& pc) override { unsupported(); }
virtual future<> flush(void) override { unsupported(); }
virtual future<> truncate(uint64_t length) override { unsupported(); }
virtual future<> discard(uint64_t offset, uint64_t length) override { unsupported(); }
virtual future<> allocate(uint64_t position, uint64_t length) override { unsupported(); }
virtual subscription<directory_entry> list_directory(std::function<future<>(directory_entry)>) override { unsupported(); }
virtual future<struct stat> stat(void) override { unsupported(); }
virtual future<uint64_t> size(void) override { unsupported(); }
virtual std::unique_ptr<seastar::file_handle_impl> dup() override { unsupported(); }
virtual future<> close() override { return make_ready_future<>(); }
virtual future<temporary_buffer<uint8_t>> dma_read_bulk(uint64_t offset, size_t size, const io_priority_class& pc) override {
return make_ready_future<temporary_buffer<uint8_t>>(temporary_buffer<uint8_t>(size));
}
virtual future<size_t> read_dma(uint64_t pos, void* buffer, size_t len, const io_priority_class& pc) override {
unsupported(); // FIXME
}
virtual future<size_t> read_dma(uint64_t pos, std::vector<iovec> iov, const io_priority_class& pc) override {
unsupported(); // FIXME
}
};
#ifndef SEASTAR_DEFAULT_ALLOCATOR // Eviction works only with the seastar allocator
SEASTAR_THREAD_TEST_CASE(test_stress_eviction) {
auto page_size = cached_file::page_size;
auto n_pages = 8'000'000 / page_size;
auto file_size = page_size * n_pages;
auto cached_size = 4'000'000;
cached_file::metrics metrics;
logalloc::region region;
auto f = file(make_shared<garbage_file_impl>());
cached_file cf(f, metrics, cf_lru, region, file_size);
region.make_evictable([&] {
testlog.trace("Evicting");
cf.invalidate_at_most_front(file_size / 2);
return cf_lru.evict();
});
for (size_t i = 0; i < (cached_size / page_size); ++i) {
read_to_string(cf, page_size * i, page_size);
}
testlog.debug("Saturating memory...");
// Disable background reclaiming which will prevent bugs from reproducing
// We want reclamation to happen synchronously with page cache population in read_to_void()
seastar::memory::set_min_free_pages(0);
// Saturate std memory
chunked_fifo<bytes> blobs;
auto rc = region.reclaim_counter();
while (region.reclaim_counter() == rc) {
blobs.emplace_back(bytes(bytes::initialized_later(), 1024));
}
testlog.debug("Memory: allocated={}, free={}", seastar::memory::stats().allocated_memory(), seastar::memory::stats().free_memory());
testlog.debug("Starting test...");
for (size_t j = 0; j < n_pages * 16; ++j) {
testlog.trace("Allocating");
auto stride = tests::random::get_int(1, 20);
auto page_idx = tests::random::get_int(n_pages - stride);
read_to_void(cf, page_idx * page_size, page_size * stride);
}
}
#endif
SEASTAR_THREAD_TEST_CASE(test_invalidation) {
auto page_size = cached_file::page_size;
test_file tf = make_test_file(page_size * 2);
cached_file::metrics metrics;
logalloc::region region;
cached_file cf(tf.f, metrics, cf_lru, region, page_size * 2);
// Reads one page, half of the first page and half of the second page.
auto read = [&] {
BOOST_REQUIRE_EQUAL(
tf.contents.substr(page_size / 2, page_size),
read_to_string(cf, page_size / 2, page_size));
};
read();
BOOST_REQUIRE_EQUAL(2, metrics.page_populations);
BOOST_REQUIRE_EQUAL(2, metrics.page_misses);
metrics = {};
read();
BOOST_REQUIRE_EQUAL(0, metrics.page_misses);
BOOST_REQUIRE_EQUAL(2, metrics.page_hits);
metrics = {};
cf.invalidate_at_most(0, page_size / 2);
BOOST_REQUIRE_EQUAL(0, metrics.page_evictions);
read();
BOOST_REQUIRE_EQUAL(0, metrics.page_misses);
BOOST_REQUIRE_EQUAL(2, metrics.page_hits);
metrics = {};
cf.invalidate_at_most(0, page_size - 1);
BOOST_REQUIRE_EQUAL(0, metrics.page_evictions);
read();
BOOST_REQUIRE_EQUAL(0, metrics.page_misses);
BOOST_REQUIRE_EQUAL(2, metrics.page_hits);
metrics = {};
cf.invalidate_at_most(0, page_size);
BOOST_REQUIRE_EQUAL(1, metrics.page_evictions);
read();
BOOST_REQUIRE_EQUAL(1, metrics.page_misses);
BOOST_REQUIRE_EQUAL(1, metrics.page_populations);
BOOST_REQUIRE_EQUAL(1, metrics.page_hits);
metrics = {};
cf.invalidate_at_most(page_size, page_size + 1);
BOOST_REQUIRE_EQUAL(0, metrics.page_evictions);
read();
BOOST_REQUIRE_EQUAL(0, metrics.page_misses);
BOOST_REQUIRE_EQUAL(2, metrics.page_hits);
metrics = {};
cf.invalidate_at_most(page_size, page_size + page_size);
BOOST_REQUIRE_EQUAL(1, metrics.page_evictions);
read();
BOOST_REQUIRE_EQUAL(1, metrics.page_misses);
BOOST_REQUIRE_EQUAL(1, metrics.page_populations);
BOOST_REQUIRE_EQUAL(1, metrics.page_hits);
metrics = {};
cf.invalidate_at_most(0, page_size * 3);
BOOST_REQUIRE_EQUAL(2, metrics.page_evictions);
read();
BOOST_REQUIRE_EQUAL(2, metrics.page_misses);
BOOST_REQUIRE_EQUAL(2, metrics.page_populations);
BOOST_REQUIRE_EQUAL(0, metrics.page_hits);
metrics = {};
cf.invalidate_at_most_front(0);
BOOST_REQUIRE_EQUAL(0, metrics.page_evictions);
metrics = {};
cf.invalidate_at_most_front(1);
BOOST_REQUIRE_EQUAL(0, metrics.page_evictions);
metrics = {};
cf.invalidate_at_most_front(page_size);
BOOST_REQUIRE_EQUAL(1, metrics.page_evictions);
metrics = {};
cf.invalidate_at_most_front(page_size * 2);
BOOST_REQUIRE_EQUAL(1, metrics.page_evictions);
read();
BOOST_REQUIRE_EQUAL(2, metrics.page_misses);
BOOST_REQUIRE_EQUAL(2, metrics.page_populations);
BOOST_REQUIRE_EQUAL(0, metrics.page_hits);
}