This is a helper class that helps managing reader and writer locks claimed from reader_writer_mutex. More...

#include <reader_writer_lock.hpp>

Collaboration diagram for m::reader_writer_lock:

Public Member Functions
	reader_writer_lock (reader_writer_mutex &rw_mutex)

	reader_writer_lock (const reader_writer_lock &)=delete

	reader_writer_lock (reader_writer_lock &&other)

	~reader_writer_lock ()

reader_writer_lock &	operator= (reader_writer_lock &&other)=default

bool	owns_read_lock () const

bool	owns_write_lock () const

void	lock_read ()
	Acquire a read lock.

void	lock_write ()
	Acquire the write lock.

bool	upgrade ()
	Tries to upgrade a held read lock to the write lock.

void	unlock ()

Private Types
enum	{ LOCK_NONE , LOCK_READ , LOCK_WRITE }

Private Attributes
std::reference_wrapper< reader_writer_mutex >	rw_mutex_

enum m::reader_writer_lock:: { ... }	LOCK_NONE

Detailed Description

This is a helper class that helps managing reader and writer locks claimed from reader_writer_mutex.

Its main purpose is to automatically unlock on destruction.

Definition at line 241 of file reader_writer_lock.hpp.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

private

Enumerator
LOCK_NONE	holds no lock
LOCK_READ	holds a read (shared) lock
LOCK_WRITE	holds a write (exclusive) lock

Definition at line 245 of file reader_writer_lock.hpp.

Constructor & Destructor Documentation

◆ reader_writer_lock() [1/3]

m::reader_writer_lock::reader_writer_lock ( reader_writer_mutex & rw_mutex )

inlineexplicit

Definition at line 252 of file reader_writer_lock.hpp.

◆ reader_writer_lock() [2/3]

m::reader_writer_lock::reader_writer_lock ( const reader_writer_lock & )

delete

◆ reader_writer_lock() [3/3]

m::reader_writer_lock::reader_writer_lock ( reader_writer_lock && other )

inline

Definition at line 254 of file reader_writer_lock.hpp.

◆ ~reader_writer_lock()

m::reader_writer_lock::~reader_writer_lock ( )

inline

Definition at line 259 of file reader_writer_lock.hpp.

References LOCK_NONE, and unlock().

Member Function Documentation

◆ lock_read()

void m::reader_writer_lock::lock_read ( )

inline

Acquire a read lock.

This call blocks the calling thread until a read lock was acquired.

Definition at line 270 of file reader_writer_lock.hpp.

References LOCK_READ, and rw_mutex_.

Referenced by m::PODPool< T, Hash, KeyEqual, Copy, ThreadSafe >::operator()(), and m::Pool< T, Hash, KeyEqual, ThreadSafe >::operator()().

◆ lock_write()

void m::reader_writer_lock::lock_write ( )

inline

Acquire the write lock.

This call blocks the calling thread until the write lock was acquired.

Definition at line 276 of file reader_writer_lock.hpp.

References LOCK_WRITE, and rw_mutex_.

◆ operator=()

reader_writer_lock & m::reader_writer_lock::operator= ( reader_writer_lock && other )

default

◆ owns_read_lock()

bool m::reader_writer_lock::owns_read_lock ( ) const

inline

Definition at line 266 of file reader_writer_lock.hpp.

References LOCK_READ.

◆ owns_write_lock()

bool m::reader_writer_lock::owns_write_lock ( ) const

inline

Definition at line 267 of file reader_writer_lock.hpp.

References LOCK_WRITE.

◆ unlock()

void m::reader_writer_lock::unlock ( )

inline

Definition at line 301 of file reader_writer_lock.hpp.

References LOCK_NONE, LOCK_READ, LOCK_WRITE, M_insist, M_unreachable, and rw_mutex_.

Referenced by upgrade(), and ~reader_writer_lock().

◆ upgrade()

bool m::reader_writer_lock::upgrade ( )

inline

Tries to upgrade a held read lock to the write lock.

If this call succeeds, it blocks until the write lock was acquired. If this call fails, immediatly unlocks the held read lock to prevent deadlocks and returns.

NOTE: On failure, the held read lock is unlocked to prevent deadlocks.

As a consequence, a reader that wants to upgrade and fails takes no precedence over other waiting readers or writers. Contrary, a reader that succeeds to upgrade takes precedence over other waiting readers.

Definition at line 290 of file reader_writer_lock.hpp.

References LOCK_READ, LOCK_WRITE, M_insist, rw_mutex_, and unlock().