rocksdb/db/flush_scheduler.h
storagezhang d9be6556aa Include C++ standard library headers instead of C compatibility headers (#8068)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8068

Reviewed By: zhichao-cao

Differential Revision: D27147685

Pulled By: riversand963

fbshipit-source-id: 5428b1c0142ecae17c977fba31a6d49b52983d1c
2021-03-19 12:09:47 -07:00

56 lines
1.6 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
#include <atomic>
#include <cstdint>
#include <mutex>
#include <set>
#include "util/autovector.h"
namespace ROCKSDB_NAMESPACE {
class ColumnFamilyData;
// FlushScheduler keeps track of all column families whose memtable may
// be full and require flushing. Unless otherwise noted, all methods on
// FlushScheduler should be called only with the DB mutex held or from
// a single-threaded recovery context.
class FlushScheduler {
public:
FlushScheduler() : head_(nullptr) {}
// May be called from multiple threads at once, but not concurrent with
// any other method calls on this instance
void ScheduleWork(ColumnFamilyData* cfd);
// Removes and returns Ref()-ed column family. Client needs to Unref().
// Filters column families that have been dropped.
ColumnFamilyData* TakeNextColumnFamily();
// This can be called concurrently with ScheduleWork but it would miss all
// the scheduled flushes after the last synchronization. This would result
// into less precise enforcement of memtable sizes but should not matter much.
bool Empty();
void Clear();
private:
struct Node {
ColumnFamilyData* column_family;
Node* next;
};
std::atomic<Node*> head_;
#ifndef NDEBUG
std::mutex checking_mutex_;
std::set<ColumnFamilyData*> checking_set_;
#endif // NDEBUG
};
} // namespace ROCKSDB_NAMESPACE