rocksdb/port/lang.h
Peter Dillinger efd035164b Meta-internal folly integration with F14FastMap (#9546)
Summary:
Especially after updating to C++17, I don't see a compelling case for
*requiring* any folly components in RocksDB. I was able to purge the existing
hard dependencies, and it can be quite difficult to strip out non-trivial components
from folly for use in RocksDB. (The prospect of doing that on F14 has changed
my mind on the best approach here.)

But this change creates an optional integration where we can plug in
components from folly at compile time, starting here with F14FastMap to replace
std::unordered_map when possible (probably no public APIs for example). I have
replaced the biggest CPU users of std::unordered_map with compile-time
pluggable UnorderedMap which will use F14FastMap when USE_FOLLY is set.
USE_FOLLY is always set in the Meta-internal buck build, and a simulation of
that is in the Makefile for public CI testing. A full folly build is not needed, but
checking out the full folly repo is much simpler for getting the dependency,
and anything else we might want to optionally integrate in the future.

Some picky details:
* I don't think the distributed mutex stuff is actually used, so it was easy to remove.
* I implemented an alternative to `folly::constexpr_log2` (which is much easier
in C++17 than C++11) so that I could pull out the hard dependencies on
`ConstexprMath.h`
* I had to add noexcept move constructors/operators to some types to make
F14's complainUnlessNothrowMoveAndDestroy check happy, and I added a
macro to make that easier in some common cases.
* Updated Meta-internal buck build to use folly F14Map (always)

No updates to HISTORY.md nor INSTALL.md as this is not (yet?) considered a
production integration for open source users.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9546

Test Plan:
CircleCI tests updated so that a couple of them use folly.

Most internal unit & stress/crash tests updated to use Meta-internal latest folly.
(Note: they should probably use buck but they currently use Makefile.)

Example performance improvement: when filter partitions are pinned in cache,
they are tracked by PartitionedFilterBlockReader::filter_map_ and we can build
a test that exercises that heavily. Build DB with

```
TEST_TMPDIR=/dev/shm/rocksdb ./db_bench -benchmarks=fillrandom -num=10000000 -disable_wal=1 -write_buffer_size=30000000 -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -partition_index_and_filters
```

and test with (simultaneous runs with & without folly, ~20 times each to see
convergence)

```
TEST_TMPDIR=/dev/shm/rocksdb ./db_bench_folly -readonly -use_existing_db -benchmarks=readrandom -num=10000000 -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -partition_index_and_filters -duration=40 -pin_l0_filter_and_index_blocks_in_cache
```

Average ops/s no folly: 26229.2
Average ops/s with folly: 26853.3 (+2.4%)

Reviewed By: ajkr

Differential Revision: D34181736

Pulled By: pdillinger

fbshipit-source-id: ffa6ad5104c2880321d8a1aa7187e00ab0d02e94
2022-04-13 07:34:01 -07:00

69 lines
2.2 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#pragma once
#ifndef FALLTHROUGH_INTENDED
#if defined(__clang__)
#define FALLTHROUGH_INTENDED [[clang::fallthrough]]
#elif defined(__GNUC__) && __GNUC__ >= 7
#define FALLTHROUGH_INTENDED [[gnu::fallthrough]]
#else
#define FALLTHROUGH_INTENDED do {} while (0)
#endif
#endif
#define DECLARE_DEFAULT_MOVES(Name) \
Name(Name&&) noexcept = default; \
Name& operator=(Name&&) = default
// ASAN (Address sanitizer)
#if defined(__clang__)
#if defined(__has_feature)
#if __has_feature(address_sanitizer)
#define MUST_FREE_HEAP_ALLOCATIONS 1
#endif // __has_feature(address_sanitizer)
#endif // defined(__has_feature)
#else // __clang__
#ifdef __SANITIZE_ADDRESS__
#define MUST_FREE_HEAP_ALLOCATIONS 1
#endif // __SANITIZE_ADDRESS__
#endif // __clang__
#ifdef ROCKSDB_VALGRIND_RUN
#define MUST_FREE_HEAP_ALLOCATIONS 1
#endif // ROCKSDB_VALGRIND_RUN
// Coding guidelines say to avoid static objects with non-trivial destructors,
// because it's easy to cause trouble (UB) in static destruction. This
// macro makes it easier to define static objects that are normally never
// destructed, except are destructed when running under ASAN. This should
// avoid unexpected, unnecessary destruction behavior in production.
// Note that constructor arguments can be provided as in
// STATIC_AVOID_DESTRUCTION(Foo, foo)(arg1, arg2);
#ifdef MUST_FREE_HEAP_ALLOCATIONS
#define STATIC_AVOID_DESTRUCTION(Type, name) static Type name
constexpr bool kMustFreeHeapAllocations = true;
#else
#define STATIC_AVOID_DESTRUCTION(Type, name) static Type& name = *new Type
constexpr bool kMustFreeHeapAllocations = false;
#endif
// TSAN (Thread sanitizer)
// For simplicity, standardize on the GCC define
#if defined(__clang__)
#if defined(__has_feature) && __has_feature(thread_sanitizer)
#define __SANITIZE_THREAD__ 1
#endif // __has_feature(thread_sanitizer)
#endif // __clang__
#ifdef __SANITIZE_THREAD__
#define TSAN_SUPPRESSION __attribute__((no_sanitize("thread")))
#else
#define TSAN_SUPPRESSION
#endif // TSAN_SUPPRESSION