rocksdb/include/rocksdb/concurrent_task_limiter.h
sdong fdf882ded2 Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433)
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
2020-02-20 12:09:57 -08:00

47 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).
//
// 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 "rocksdb/env.h"
#include "rocksdb/statistics.h"
namespace ROCKSDB_NAMESPACE {
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 mulitple 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.
extern ConcurrentTaskLimiter* NewConcurrentTaskLimiter(const std::string& name,
int32_t limit);
} // namespace ROCKSDB_NAMESPACE