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Diffstat (limited to 'src/rocksdb/db/periodic_task_scheduler.h')
-rw-r--r-- | src/rocksdb/db/periodic_task_scheduler.h | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/src/rocksdb/db/periodic_task_scheduler.h b/src/rocksdb/db/periodic_task_scheduler.h new file mode 100644 index 000000000..f45b80c4d --- /dev/null +++ b/src/rocksdb/db/periodic_task_scheduler.h @@ -0,0 +1,110 @@ +// Copyright (c) Meta Platforms, Inc. and affiliates. +// +// 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 + +#ifndef ROCKSDB_LITE + +#include "util/timer.h" + +namespace ROCKSDB_NAMESPACE { +class SystemClock; + +using PeriodicTaskFunc = std::function<void()>; + +constexpr uint64_t kInvalidPeriodSec = 0; + +// List of task types +enum class PeriodicTaskType : uint8_t { + kDumpStats = 0, + kPersistStats, + kFlushInfoLog, + kRecordSeqnoTime, + kMax, +}; + +// PeriodicTaskScheduler contains the periodic task scheduled from the DB +// instance. It's used to schedule/unschedule DumpStats(), PersistStats(), +// FlushInfoLog(), etc. Each type of the task can only have one instance, +// re-register the same task type would only update the repeat period. +// +// Internally, it uses a global single threaded timer object to run the periodic +// task functions. Timer thread will always be started since the info log +// flushing cannot be disabled. +class PeriodicTaskScheduler { + public: + explicit PeriodicTaskScheduler() = default; + + PeriodicTaskScheduler(const PeriodicTaskScheduler&) = delete; + PeriodicTaskScheduler(PeriodicTaskScheduler&&) = delete; + PeriodicTaskScheduler& operator=(const PeriodicTaskScheduler&) = delete; + PeriodicTaskScheduler& operator=(PeriodicTaskScheduler&&) = delete; + + // Register a task with its default repeat period + Status Register(PeriodicTaskType task_type, const PeriodicTaskFunc& fn); + + // Register a task with specified repeat period. 0 is an invalid argument + // (kInvalidPeriodSec). To stop the task, please use Unregister() specifically + Status Register(PeriodicTaskType task_type, const PeriodicTaskFunc& fn, + uint64_t repeat_period_seconds); + + // Unregister the task + Status Unregister(PeriodicTaskType task_type); + +#ifndef NDEBUG + // Override the timer for the unittest + void TEST_OverrideTimer(SystemClock* clock); + + // Call Timer TEST_WaitForRun() which wait until Timer starting waiting. + void TEST_WaitForRun(const std::function<void()>& callback) const { + if (timer_ != nullptr) { + timer_->TEST_WaitForRun(callback); + } + } + + // Get global valid task number in the Timer + size_t TEST_GetValidTaskNum() const { + if (timer_ != nullptr) { + return timer_->TEST_GetPendingTaskNum(); + } + return 0; + } + + // If it has the specified task type registered + bool TEST_HasTask(PeriodicTaskType task_type) const { + auto it = tasks_map_.find(task_type); + return it != tasks_map_.end(); + } +#endif // NDEBUG + + private: + // default global Timer instance + static Timer* Default(); + + // Internal structure to store task information + struct TaskInfo { + TaskInfo(std::string _name, uint64_t _repeat_every_sec) + : name(std::move(_name)), repeat_every_sec(_repeat_every_sec) {} + std::string name; + uint64_t repeat_every_sec; + }; + + // Internal tasks map + std::map<PeriodicTaskType, TaskInfo> tasks_map_; + + // Global timer pointer, which doesn't support synchronous add/cancel tasks + // so having a global `timer_mutex` for add/cancel task. + Timer* timer_ = Default(); + + // Global task id, protected by the global `timer_mutex` + inline static uint64_t id_; + + static constexpr uint64_t kMicrosInSecond = 1000U * 1000U; +}; + +} // namespace ROCKSDB_NAMESPACE + +#endif // ROCKSDB_LITE |