module.h

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#ifndef MYSQL_CSA_MODULE_H
#define MYSQL_CSA_MODULE_H
 
#include <mysql/psi/mysql_mutex.h>
#include <mysql/psi/mysql_rwlock.h>
#include "my_sys.h"
#include "mysql/service_mysql_alloc.h"
 
#include "mysql/scheduler/logger_stream.h"
#include "sql/changestreams/apply/psi/psi.h"
#include "sql/changestreams/apply/util/initable.h"
#include "sql/changestreams/apply/util/lock_guard_object.h"
 
namespace mysql::csa {
 
/// @brief Represents a lockable module
class Module : public Initable {
 public:
  /// @brief Enum defining possible states of the module
  enum class State { off = 0, on, start, stop };
 
  friend class Lock_guard_object<Module>;
  using Lock_guard = Lock_guard_object<Module>;
 
  /// @brief Constructs the module
  /// @param mutex_key PSI mutex key
  /// @param rwlock_key PSI rwlock key
  Module(PSI_mutex_key mutex_key, PSI_rwlock_key rwlock_key);
 
  /// @brief Destructor
  virtual ~Module() override;
 
  /// @brief Initializes internal locking
  void init_locking();
 
  /// @brief Initializes the module
  /// @return True on error, false on success
  bool init() override;
 
  /// @brief Acquires a read lock on this object
  /// @return Scope guard that unlocks at the end of the scope
  [[nodiscard]] Lock_guard rdlock();
 
  /// @brief Acquires a write lock on this object
  /// @return Scope guard that unlocks at the end of the scope
  [[nodiscard]] Lock_guard wrlock();
 
  /// @brief Deinitializes the module
  /// @return True on error, false on success
  bool deinit() override;
 
  /// @brief Checks if the module is initialized
  /// @return True if initialized, false otherwise
  bool is_inited();
 
 protected:
  /// @brief Unlocks this module
  void unlock();
 
  /// @brief Initialization hook for derived classes
  /// @return True on error, false on success
  virtual bool do_init();
  /// @brief Deinitialization hook for derived classes
  /// @return True on error, false on success
  virtual bool do_deinit();
 
 private:
  /// @brief PSI key for the read-write lock
  PSI_rwlock_key m_rwlock_key;
  /// @brief Read-write lock for the module
  mysql_rwlock_t m_rwlock;
  /// @brief State of the module
  std::atomic<State> m_inited{State::off};
};
 
}  // namespace mysql::csa
 
#endif