Summary:
The following are risks associated with pointer-to-pointer reinterpret_cast:
* Can produce the "wrong result" (crash or memory corruption). IIRC, in theory this can happen for any up-cast or down-cast for a non-standard-layout type, though in practice would only happen for multiple inheritance cases (where the base class pointer might be "inside" the derived object). We don't use multiple inheritance a lot, but we do.
* Can mask useful compiler errors upon code change, including converting between unrelated pointer types that you are expecting to be related, and converting between pointer and scalar types unintentionally.
I can only think of some obscure cases where static_cast could be troublesome when it compiles as a replacement:
* Going through `void*` could plausibly cause unnecessary or broken pointer arithmetic. Suppose we have
`struct Derived: public Base1, public Base2`. If we have `Derived*` -> `void*` -> `Base2*` -> `Derived*` through reinterpret casts, this could plausibly work (though technical UB) assuming the `Base2*` is not dereferenced. Changing to static cast could introduce breaking pointer arithmetic.
* Unnecessary (but safe) pointer arithmetic could arise in a case like `Derived*` -> `Base2*` -> `Derived*` where before the Base2 pointer might not have been dereferenced. This could potentially affect performance.
With some light scripting, I tried replacing pointer-to-pointer reinterpret_casts with static_cast and kept the cases that still compile. Most occurrences of reinterpret_cast have successfully been changed (except for java/ and third-party/). 294 changed, 257 remain.
A couple of related interventions included here:
* Previously Cache::Handle was not actually derived from in the implementations and just used as a `void*` stand-in with reinterpret_cast. Now there is a relationship to allow static_cast. In theory, this could introduce pointer arithmetic (as described above) but is unlikely without multiple inheritance AND non-empty Cache::Handle.
* Remove some unnecessary casts to void* as this is allowed to be implicit (for better or worse).
Most of the remaining reinterpret_casts are for converting to/from raw bytes of objects. We could consider better idioms for these patterns in follow-up work.
I wish there were a way to implement a template variant of static_cast that would only compile if no pointer arithmetic is generated, but best I can tell, this is not possible. AFAIK the best you could do is a dynamic check that the void* conversion after the static cast is unchanged.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12308
Test Plan: existing tests, CI
Reviewed By: ltamasi
Differential Revision: D53204947
Pulled By: pdillinger
fbshipit-source-id: 9de23e618263b0d5b9820f4e15966876888a16e2
Summary:
when I use g++-13 to exec the `make all` command, the output throws the warnings.
```
db/compaction/compaction_job_test.cc: In member function ‘void rocksdb::CompactionJobTestBase::AddMockFile(const rocksdb::mock::KVVector&, int)’:
db/compaction/compaction_job_test.cc:376:57: error: redundant move in initialization [-Werror=redundant-move]
376 | env_, GenerateFileName(file_number), std::move(contents)));
| ~~~~~~~~~^~~~~~~~~~
db/compaction/compaction_job_test.cc:375:7: note: in expansion of macro ‘EXPECT_OK’
375 | EXPECT_OK(mock_table_factory_->CreateMockTable(
| ^~~~~~~~~
db/compaction/compaction_job_test.cc:376:57: note: remove ‘std::move’ call
376 | env_, GenerateFileName(file_number), std::move(contents)));
| ~~~~~~~~~^~~~~~~~~~
db/compaction/compaction_job_test.cc:375:7: note: in expansion of macro ‘EXPECT_OK’
375 | EXPECT_OK(mock_table_factory_->CreateMockTable(
| ^~~~~~~~~
cc1plus: all warnings being treated as errors
make: *** [Makefile:2507: db/compaction/compaction_job_test.o] Error 1
```
and I also add some `(void)unused_variable` statements because of the cmake argument `-Wunused-but-set-variable -Wunused-but-set-variable`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11418
Reviewed By: akankshamahajan15
Differential Revision: D45528223
Pulled By: ajkr
fbshipit-source-id: fee1a77c30039a56b481de953f0a834cc788abbc
Summary:
Instead of existing calls to ps from gnu_parallel, call a new wrapper that does ps, looks for unit test like processes, and uses pstack or gdb to print thread stack traces. Also, using `ps -wwf` instead of `ps -wf` ensures output is not cut off.
For security, CircleCI runs with security restrictions on ptrace (/proc/sys/kernel/yama/ptrace_scope = 1), and this change adds a work-around to `InstallStackTraceHandler()` (only used by testing tools) to allow any process from the same user to debug it. (I've also touched >100 files to ensure all the unit tests call this function.)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10828
Test Plan: local manual + temporary infinite loop in a unit test to observe in CircleCI
Reviewed By: hx235
Differential Revision: D40447634
Pulled By: pdillinger
fbshipit-source-id: 718a4c4a5b54fa0f9af2d01a446162b45e5e84e1
Summary:
Old typedef syntax is confusing
Most but not all changes with
perl -pi -e 's/typedef (.*) ([a-zA-Z0-9_]+);/using $2 = $1;/g' list_of_files
make format
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8751
Test Plan: existing
Reviewed By: zhichao-cao
Differential Revision: D30745277
Pulled By: pdillinger
fbshipit-source-id: 6f65f0631c3563382d43347896020413cc2366d9
Summary:
Various tests had disabled valgrind due to it slowing down and timing
out (as is the case right now) the CI runs. Where a test was disabled with no comment,
I assumed slowness was the cause. For these tests that were slow under
valgrind, as well as the ones identified in https://github.com/facebook/rocksdb/issues/8352, this PR moves them
behind the compiler flag `-DROCKSDB_FULL_VALGRIND_RUN`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8475
Test Plan: running `make full_valgrind_test`, `make valgrind_test`, `make check`; will verify they appear working correctly
Reviewed By: jay-zhuang
Differential Revision: D29504843
Pulled By: ajkr
fbshipit-source-id: 2aac90749cfbd30d5ce11cb29a07a1b9314eeea7
Summary:
When dynamically linking two binaries together, different builds of RocksDB from two sources might cause errors. To provide a tool for user to solve the problem, the RocksDB namespace is changed to a flag which can be overridden in build time.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6433
Test Plan: Build release, all and jtest. Try to build with ROCKSDB_NAMESPACE with another flag.
Differential Revision: D19977691
fbshipit-source-id: aa7f2d0972e1c31d75339ac48478f34f6cfcfb3e
Summary:
There are too many types of files under util/. Some test related files don't belong to there or just are just loosely related. Mo
ve them to a new directory test_util/, so that util/ is cleaner.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5377
Differential Revision: D15551366
Pulled By: siying
fbshipit-source-id: 0f5c8653832354ef8caa31749c0143815d719e2c
Summary:
In order to make valgrind check test to pass in a day, remove some tests that run prohibitively slow under valgrind.
Closes https://github.com/facebook/rocksdb/pull/3924
Differential Revision: D8210184
Pulled By: siying
fbshipit-source-id: 5b06fb08f3cf57571d422d05a0dbddc9f9376f7a
Summary:
Summary
========
`InlineSkipList<>::Insert` takes the `key` parameter as a C-string. Then, it performs multiple comparisons with it requiring the `GetLengthPrefixedSlice()` to be spawn in `MemTable::KeyComparator::operator()(const char* prefix_len_key1, const char* prefix_len_key2)` on the same data over and over. The patch tries to optimize that.
Rough performance comparison
=====
Big keys, no compression.
```
$ ./db_bench --writes 20000000 --benchmarks="fillrandom" --compression_type none -key_size 256
(...)
fillrandom : 4.222 micros/op 236836 ops/sec; 80.4 MB/s
```
```
$ ./db_bench --writes 20000000 --benchmarks="fillrandom" --compression_type none -key_size 256
(...)
fillrandom : 4.064 micros/op 246059 ops/sec; 83.5 MB/s
```
TODO
======
In ~~a separated~~ this PR:
- [x] Go outside the write path. Maybe even eradicate the C-string-taking variant of `KeyIsAfterNode` entirely.
- [x] Try to cache the transformations applied by `KeyComparator` & friends in situations where we havy many comparisons with the same key.
Closes https://github.com/facebook/rocksdb/pull/3516
Differential Revision: D7059300
Pulled By: ajkr
fbshipit-source-id: 6f027dbb619a488129f79f79b5f7dbe566fb2dbb
Summary:
Currently DB does not accept duplicate keys (keys with the same user key and the same sequence number). If Memtable returns false when receiving such keys, we can benefit from this signal to properly increase the sequence number in the rare cases when we have a duplicate key in the write batch written to DB under WritePrepared transactions.
Closes https://github.com/facebook/rocksdb/pull/3418
Differential Revision: D6822412
Pulled By: maysamyabandeh
fbshipit-source-id: adea3ce5073131cd38ed52b16bea0673b1a19e77
Summary:
When we had a single thread pool for compactions, a thread could be busy for a long time (minutes) executing a compaction involving the bottom level. In multi-instance setups, the entire thread pool could be consumed by such bottom-level compactions. Then, top-level compactions (e.g., a few L0 files) would be blocked for a long time ("head-of-line blocking"). Such top-level compactions are critical to prevent compaction stalls as they can quickly reduce number of L0 files / sorted runs.
This diff introduces a bottom-priority queue for universal compactions including the bottom level. This alleviates the head-of-line blocking situation for fast, top-level compactions.
- Added `Env::Priority::BOTTOM` thread pool. This feature is only enabled if user explicitly configures it to have a positive number of threads.
- Changed `ThreadPoolImpl`'s default thread limit from one to zero. This change is invisible to users as we call `IncBackgroundThreadsIfNeeded` on the low-pri/high-pri pools during `DB::Open` with values of at least one. It is necessary, though, for bottom-pri to start with zero threads so the feature is disabled by default.
- Separated `ManualCompaction` into two parts in `PrepickedCompaction`. `PrepickedCompaction` is used for any compaction that's picked outside of its execution thread, either manual or automatic.
- Forward universal compactions involving last level to the bottom pool (worker thread's entry point is `BGWorkBottomCompaction`).
- Track `bg_bottom_compaction_scheduled_` so we can wait for bottom-level compactions to finish. We don't count them against the background jobs limits. So users of this feature will get an extra compaction for free.
Closes https://github.com/facebook/rocksdb/pull/2580
Differential Revision: D5422916
Pulled By: ajkr
fbshipit-source-id: a74bd11f1ea4933df3739b16808bb21fcd512333
