rocksdb/include/rocksdb/concurrent_task_limiter.h

52 lines
1.7 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).
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#pragma once
#include <stdint.h>
#include <string>
#include "rocksdb/rocksdb_namespace.h"
namespace ROCKSDB_NAMESPACE {
// This is NOT an extensible interface but a public interface for result of
// NewConcurrentTaskLimiter. Any derived classes must be RocksDB internal.
class ConcurrentTaskLimiter {
public:
virtual ~ConcurrentTaskLimiter() {}
// Returns a name that identifies this concurrent task limiter.
virtual const std::string& GetName() const = 0;
// Set max concurrent tasks.
// limit = 0 means no new task allowed.
// limit < 0 means no limitation.
virtual void SetMaxOutstandingTask(int32_t limit) = 0;
// Reset to unlimited max concurrent task.
virtual void ResetMaxOutstandingTask() = 0;
// Returns current outstanding task count.
virtual int32_t GetOutstandingTask() const = 0;
};
// Create a ConcurrentTaskLimiter that can be shared with multiple CFs
// across RocksDB instances to control concurrent tasks.
//
// @param name: Name of the limiter.
// @param limit: max concurrent tasks.
// limit = 0 means no new task allowed.
// limit < 0 means no limitation.
ConcurrentTaskLimiter* NewConcurrentTaskLimiter(const std::string& name,
int32_t limit);
} // namespace ROCKSDB_NAMESPACE