181191a1e4
Summary:
Add a counter for collecting the wait time on db mutex.
Also add MutexWrapper and CondVarWrapper for measuring wait time.
Test Plan:
./db_test
export ROCKSDB_TESTS=MutexWaitStats
./db_test
verify stats output using db_bench
make clean
make release
./db_bench --statistics=1 --benchmarks=fillseq,readwhilewriting --num=10000 --threads=10
Sample output:
rocksdb.db.mutex.wait.micros COUNT : 7546866
Reviewers: MarkCallaghan, rven, sdong, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D32787
82 lines
2.6 KiB
C++
82 lines
2.6 KiB
C++
// Copyright (c) 2013, Facebook, Inc. All rights reserved.
|
|
// This source code is licensed under the BSD-style license found in the
|
|
// LICENSE file in the root directory of this source tree. An additional grant
|
|
// of patent rights can be found in the PATENTS file in the same directory.
|
|
|
|
#pragma once
|
|
|
|
#include <stdint.h>
|
|
#include <deque>
|
|
#include <limits>
|
|
#include "rocksdb/status.h"
|
|
#include "db/write_batch_internal.h"
|
|
#include "util/autovector.h"
|
|
#include "port/port.h"
|
|
#include "util/instrumented_mutex.h"
|
|
|
|
namespace rocksdb {
|
|
|
|
class WriteThread {
|
|
public:
|
|
static const uint64_t kNoTimeOut = std::numeric_limits<uint64_t>::max();
|
|
// Information kept for every waiting writer
|
|
struct Writer {
|
|
Status status;
|
|
WriteBatch* batch;
|
|
bool sync;
|
|
bool disableWAL;
|
|
bool in_batch_group;
|
|
bool done;
|
|
uint64_t timeout_hint_us;
|
|
InstrumentedCondVar cv;
|
|
|
|
explicit Writer(InstrumentedMutex* mu)
|
|
: batch(nullptr),
|
|
sync(false),
|
|
disableWAL(false),
|
|
in_batch_group(false),
|
|
done(false),
|
|
timeout_hint_us(kNoTimeOut),
|
|
cv(mu) {}
|
|
};
|
|
|
|
WriteThread() = default;
|
|
~WriteThread() = default;
|
|
|
|
// Before applying write operation (such as DBImpl::Write, DBImpl::Flush)
|
|
// thread should grab the mutex_ and be the first on writers queue.
|
|
// EnterWriteThread is used for it.
|
|
// Be aware! Writer's job can be done by other thread (see DBImpl::Write
|
|
// for examples), so check it via w.done before applying changes.
|
|
//
|
|
// Writer* w: writer to be placed in the queue
|
|
// uint64_t expiration_time: maximum time to be in the queue
|
|
// See also: ExitWriteThread
|
|
// REQUIRES: db mutex held
|
|
Status EnterWriteThread(Writer* w, uint64_t expiration_time);
|
|
|
|
// After doing write job, we need to remove already used writers from
|
|
// writers_ queue and notify head of the queue about it.
|
|
// ExitWriteThread is used for this.
|
|
//
|
|
// Writer* w: Writer, that was added by EnterWriteThread function
|
|
// Writer* last_writer: Since we can join a few Writers (as DBImpl::Write
|
|
// does)
|
|
// we should pass last_writer as a parameter to
|
|
// ExitWriteThread
|
|
// (if you don't touch other writers, just pass w)
|
|
// Status status: Status of write operation
|
|
// See also: EnterWriteThread
|
|
// REQUIRES: db mutex held
|
|
void ExitWriteThread(Writer* w, Writer* last_writer, Status status);
|
|
|
|
void BuildBatchGroup(Writer** last_writer,
|
|
autovector<WriteBatch*>* write_batch_group);
|
|
|
|
private:
|
|
// Queue of writers.
|
|
std::deque<Writer*> writers_;
|
|
};
|
|
|
|
} // namespace rocksdb
|