A RAII helper which latches the mutexes protecting specified shards for the duration of its scope. More...

#include <lock0guards.h>

Public Member Functions
	Shard_naked_latches_guard (const buf_block_t &block_a, const buf_block_t &block_b)

	~Shard_naked_latches_guard ()

Private Member Functions
	Shard_naked_latches_guard (Lock_mutex &shard_mutex_a, Lock_mutex &shard_mutex_b)

Private Attributes
Lock_mutex &	m_shard_mutex_1
	The "smallest" of the two shards' mutexes in the latching order. More...

Lock_mutex &	m_shard_mutex_2
	The "largest" of the two shards' mutexes in the latching order. More...

Static Private Attributes
static constexpr std::less< Lock_mutex * >	MUTEX_ORDER {}
	The ordering on shard mutexes used to avoid deadlocks. More...

Detailed Description

A RAII helper which latches the mutexes protecting specified shards for the duration of its scope.

It makes sure to take the latches in correct order and handles the case where both pages are in the same shard correctly. You quite probably don't want to use this class, which only takes a shard's latch, without acquiring global_latch - which gives no protection from threads which latch only the global_latch exclusively to prevent any activity. You should use it in combination with Global_shared_latch_guard, so that you first obtain an s-latch on the global_latch, or simply use the Shard_latches_guard class which already combines the two for you.

Constructor & Destructor Documentation

◆ Shard_naked_latches_guard() [1/2]

locksys::Shard_naked_latches_guard::Shard_naked_latches_guard	(	Lock_mutex &	shard_mutex_a,
		Lock_mutex &	shard_mutex_b
	)

explicitprivate

◆ Shard_naked_latches_guard() [2/2]

locksys::Shard_naked_latches_guard::Shard_naked_latches_guard	(	const buf_block_t &	block_a,
		const buf_block_t &	block_b
	)

explicit

◆ ~Shard_naked_latches_guard()

locksys::Shard_naked_latches_guard::~Shard_naked_latches_guard ( )

Member Data Documentation

◆ m_shard_mutex_1

Lock_mutex& locksys::Shard_naked_latches_guard::m_shard_mutex_1

private

The "smallest" of the two shards' mutexes in the latching order.

◆ m_shard_mutex_2

Lock_mutex& locksys::Shard_naked_latches_guard::m_shard_mutex_2

private

The "largest" of the two shards' mutexes in the latching order.

◆ MUTEX_ORDER

constexpr std::less<Lock_mutex *> locksys::Shard_naked_latches_guard::MUTEX_ORDER {}

staticconstexprprivate

The ordering on shard mutexes used to avoid deadlocks.

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

storage/innobase/include/lock0guards.h
storage/innobase/lock/lock0guards.cc

Public Member Functions

Private Member Functions

Private Attributes

Static Private Attributes