statistics_monitor.h

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#ifndef MYSQL_SCHEDULER_STATISTICS_MONITOR_H
#define MYSQL_SCHEDULER_STATISTICS_MONITOR_H
 
#include <array>
#include <atomic>
#include <chrono>
#include <memory>
#include <new>
#include <optional>
#include <unordered_map>
#include "mysql/concurrency/condition_variable.h"
#include "mysql/concurrency/mutex.h"
#include "mysql/scheduler/constants.h"
#include "mysql/scheduler/sharded_counter.h"
#include "mysql/scheduler/statistics_instance_monitor.h"
 
namespace mysql::scheduler {
 
/// @brief Singleton Statistics Monitor for all of the registered "instances".
/// We typically track statistics separately for user-defined channels
class Statistics_monitor {
 public:
  using Mutex = concurrency::Mutex;
  using Mutex_key = concurrency::Mutex_key;
 
  static Statistics_instance_monitor &get(std::size_t instance_id);
  static void clear(std::size_t instance_id);
 
 protected:
  /// @brief This initialization function is called by "get" if needed
  static void init();
  Statistics_monitor() = default;
  using Statistics_instance_monitor_ptr =
      std::unique_ptr<Statistics_instance_monitor>;
  using Instances_map =
      std::array<Statistics_instance_monitor, Constants::max_instances>;
  static Instances_map &instances();
  static std::atomic<bool> m_init;
  static std::atomic<bool> m_ready;
};
 
}  // namespace mysql::scheduler
 
#endif  // MYSQL_SCHEDULER_STATISTICS_MONITOR_H