MDL_wait_for_graph_visitor Class Reference

An abstract class for inspection of a connected subgraph of the wait-for graph. More...

#include <mdl.h>

Inheritance diagram for MDL_wait_for_graph_visitor:

Public Member Functions
virtual bool	enter_node (MDL_context *node)=0
virtual void	leave_node (MDL_context *node)=0
virtual bool	inspect_edge (MDL_context *dest)=0
virtual	~MDL_wait_for_graph_visitor ()
	MDL_wait_for_graph_visitor ()

Public Attributes
uint	m_lock_open_count
	XXX, hack: During deadlock search, we may need to inspect TABLE_SHAREs and acquire LOCK_open. More...

Detailed Description

An abstract class for inspection of a connected subgraph of the wait-for graph.

Constructor & Destructor Documentation

~MDL_wait_for_graph_visitor()

MDL_wait_for_graph_visitor::~MDL_wait_for_graph_visitor ( )

virtualdefault

MDL_wait_for_graph_visitor()

MDL_wait_for_graph_visitor::MDL_wait_for_graph_visitor ( )

inline

Member Function Documentation

enter_node()

virtual bool MDL_wait_for_graph_visitor::enter_node ( MDL_context *  node )

pure virtual

Implemented in Deadlock_detection_visitor.

inspect_edge()

virtual bool MDL_wait_for_graph_visitor::inspect_edge ( MDL_context *  dest )

pure virtual

Implemented in Deadlock_detection_visitor.

leave_node()

virtual void MDL_wait_for_graph_visitor::leave_node ( MDL_context *  node )

pure virtual

Implemented in Deadlock_detection_visitor.

Member Data Documentation

m_lock_open_count

uint MDL_wait_for_graph_visitor::m_lock_open_count

XXX, hack: During deadlock search, we may need to inspect TABLE_SHAREs and acquire LOCK_open.

Since LOCK_open is not a recursive mutex, count here how many times we "took" it (but only take and release once). Not using a native recursive mutex or rwlock in 5.5 for LOCK_open since it has significant performance impacts.

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

• sql/mdl.h
• sql/mdl.cc