mirror of https://github.com/facebook/rocksdb.git
68 lines
2.2 KiB
C++
68 lines
2.2 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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//
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// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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#include "util/concurrent_task_limiter_impl.h"
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#include "rocksdb/concurrent_task_limiter.h"
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namespace rocksdb {
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ConcurrentTaskLimiterImpl::ConcurrentTaskLimiterImpl(
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const std::string& name, int32_t max_outstanding_task)
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: name_(name),
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max_outstanding_tasks_{max_outstanding_task},
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outstanding_tasks_{0} {
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}
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ConcurrentTaskLimiterImpl::~ConcurrentTaskLimiterImpl() {
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assert(outstanding_tasks_ == 0);
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}
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const std::string& ConcurrentTaskLimiterImpl::GetName() const {
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return name_;
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}
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void ConcurrentTaskLimiterImpl::SetMaxOutstandingTask(int32_t limit) {
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max_outstanding_tasks_.store(limit, std::memory_order_relaxed);
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}
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void ConcurrentTaskLimiterImpl::ResetMaxOutstandingTask() {
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max_outstanding_tasks_.store(-1, std::memory_order_relaxed);
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}
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int32_t ConcurrentTaskLimiterImpl::GetOutstandingTask() const {
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return outstanding_tasks_.load(std::memory_order_relaxed);
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}
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std::unique_ptr<TaskLimiterToken> ConcurrentTaskLimiterImpl::GetToken(
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bool force) {
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int32_t limit = max_outstanding_tasks_.load(std::memory_order_relaxed);
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int32_t tasks = outstanding_tasks_.load(std::memory_order_relaxed);
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// force = true, bypass the throttle.
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// limit < 0 means unlimited tasks.
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while (force || limit < 0 || tasks < limit) {
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if (outstanding_tasks_.compare_exchange_weak(tasks, tasks + 1)) {
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return std::unique_ptr<TaskLimiterToken>(new TaskLimiterToken(this));
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}
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}
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return nullptr;
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}
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ConcurrentTaskLimiter* NewConcurrentTaskLimiter(
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const std::string& name, int32_t limit) {
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return new ConcurrentTaskLimiterImpl(name, limit);
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}
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TaskLimiterToken::~TaskLimiterToken() {
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--limiter_->outstanding_tasks_;
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assert(limiter_->outstanding_tasks_ >= 0);
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}
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} // namespace rocksdb
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