MySQL  8.0.18
Source Code Documentation
MDL_deadlock_discovery_repair_handler Class Reference

An error handler to mark transaction to rollback on DEADLOCK error during DISCOVER / REPAIR. More...

Inheritance diagram for MDL_deadlock_discovery_repair_handler:
Internal_error_handler

Public Member Functions

virtual bool handle_condition (THD *thd, uint sql_errno, const char *, Sql_condition::enum_severity_level *, const char *)
 Handle a sql condition. More...
 

Additional Inherited Members

- Protected Member Functions inherited from Internal_error_handler
 Internal_error_handler ()
 
Internal_error_handlerprev_internal_handler () const
 
virtual ~Internal_error_handler ()
 

Detailed Description

An error handler to mark transaction to rollback on DEADLOCK error during DISCOVER / REPAIR.

Member Function Documentation

◆ handle_condition()

virtual bool MDL_deadlock_discovery_repair_handler::handle_condition ( THD thd,
uint  sql_errno,
const char *  sqlstate,
Sql_condition::enum_severity_level level,
const char *  msg 
)
inlinevirtual

Handle a sql condition.

This method can be implemented by a subclass to achieve any of the following:

  • mask a warning/error internally, prevent exposing it to the user,
  • mask a warning/error and throw another one instead. When this method returns true, the sql condition is considered 'handled', and will not be propagated to upper layers. It is the responsibility of the code installing an internal handler to then check for trapped conditions, and implement logic to recover from the anticipated conditions trapped during runtime.

This mechanism is similar to C++ try/throw/catch:

  • 'try' correspond to THD::push_internal_handler(),
  • 'throw' correspond to my_error(), which invokes my_message_sql(),
  • 'catch' correspond to checking how/if an internal handler was invoked, before removing it from the exception stack with THD::pop_internal_handler().
Parameters
thdthe calling thread
sql_errnothe error number for the condition raised.
sqlstatethe SQLSTATE for the condition raised.
levelthe severity level for the condition raised.
msgthe error message for the condition raised.
Returns
true if the condition is handled

Implements Internal_error_handler.


The documentation for this class was generated from the following file: