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rocksdb/db/periodic_task_scheduler.cc

113 lines
3.8 KiB

// 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).
#include "db/periodic_task_scheduler.h"
#include "rocksdb/system_clock.h"
#ifndef ROCKSDB_LITE
namespace ROCKSDB_NAMESPACE {
// `timer_mutex` is a global mutex serves 3 purposes currently:
// (1) to ensure calls to `Start()` and `Shutdown()` are serialized, as
// they are currently not implemented in a thread-safe way; and
// (2) to ensure the `Timer::Add()`s and `Timer::Start()` run atomically, and
// the `Timer::Cancel()`s and `Timer::Shutdown()` run atomically.
// (3) protect tasks_map_ in PeriodicTaskScheduler
// Note: It's not efficient to have a static global mutex, for
// PeriodicTaskScheduler it should be okay, as the operations are called
// infrequently.
static port::Mutex timer_mutex;
static const std::map<PeriodicTaskType, uint64_t> kDefaultPeriodSeconds = {
{PeriodicTaskType::kDumpStats, kInvalidPeriodSec},
{PeriodicTaskType::kPersistStats, kInvalidPeriodSec},
{PeriodicTaskType::kFlushInfoLog, 10},
{PeriodicTaskType::kRecordSeqnoTime, kInvalidPeriodSec},
};
static const std::map<PeriodicTaskType, std::string> kPeriodicTaskTypeNames = {
{PeriodicTaskType::kDumpStats, "dump_st"},
{PeriodicTaskType::kPersistStats, "pst_st"},
{PeriodicTaskType::kFlushInfoLog, "flush_info_log"},
{PeriodicTaskType::kRecordSeqnoTime, "record_seq_time"},
};
Status PeriodicTaskScheduler::Register(PeriodicTaskType task_type,
const PeriodicTaskFunc& fn) {
return Register(task_type, fn, kDefaultPeriodSeconds.at(task_type));
}
Status PeriodicTaskScheduler::Register(PeriodicTaskType task_type,
const PeriodicTaskFunc& fn,
uint64_t repeat_period_seconds) {
MutexLock l(&timer_mutex);
static std::atomic<uint64_t> initial_delay(0);
if (repeat_period_seconds == kInvalidPeriodSec) {
return Status::InvalidArgument("Invalid task repeat period");
}
auto it = tasks_map_.find(task_type);
if (it != tasks_map_.end()) {
// the task already exists and it's the same, no update needed
if (it->second.repeat_every_sec == repeat_period_seconds) {
return Status::OK();
}
// cancel the existing one before register new one
timer_->Cancel(it->second.name);
tasks_map_.erase(it);
}
timer_->Start();
// put task type name as prefix, for easy debug
std::string unique_id =
kPeriodicTaskTypeNames.at(task_type) + std::to_string(id_++);
bool succeeded = timer_->Add(
fn, unique_id,
(initial_delay.fetch_add(1) % repeat_period_seconds) * kMicrosInSecond,
repeat_period_seconds * kMicrosInSecond);
if (!succeeded) {
return Status::Aborted("Failed to register periodic task");
}
auto result = tasks_map_.try_emplace(
task_type, TaskInfo{unique_id, repeat_period_seconds});
if (!result.second) {
return Status::Aborted("Failed to add periodic task");
};
return Status::OK();
}
Status PeriodicTaskScheduler::Unregister(PeriodicTaskType task_type) {
MutexLock l(&timer_mutex);
auto it = tasks_map_.find(task_type);
if (it != tasks_map_.end()) {
timer_->Cancel(it->second.name);
tasks_map_.erase(it);
}
if (!timer_->HasPendingTask()) {
timer_->Shutdown();
}
return Status::OK();
}
Timer* PeriodicTaskScheduler::Default() {
static Timer timer(SystemClock::Default().get());
return &timer;
}
#ifndef NDEBUG
void PeriodicTaskScheduler::TEST_OverrideTimer(SystemClock* clock) {
static Timer test_timer(clock);
test_timer.TEST_OverrideTimer(clock);
MutexLock l(&timer_mutex);
timer_ = &test_timer;
}
#endif // NDEBUG
} // namespace ROCKSDB_NAMESPACE
#endif // ROCKSDB_LITE