cds::sync::pool_monitor< LockPool, BackOff, Stat > Class Template Reference

Monitor that allocates node's lock when needed More...

#include <cds/sync/pool_monitor.h>

Data Structures
struct	node_injection
	Node injection. More...

Public Types
typedef LockPool	pool_type
	Pool type.
typedef pool_type::value_type	lock_type
	node lock type
typedef std::conditional< std::is_same< BackOff, cds::opt::none >::value, cds::backoff::yield, BackOff >::type	back_off
	back-off strategy for spinning
typedef uint32_t	refspin_type
	Reference counter + spin-lock bit.
typedef std::conditional< Stat, typename pool_monitor_traits::stat<>, typename pool_monitor_traits::empty_stat >::type	internal_stat
	Internal statistics.
template<typename Node >
using	scoped_lock = monitor_scoped_lock< pool_monitor, Node >
	Scoped lock.

Public Member Functions
	pool_monitor ()
	Initializes the pool of 256 preallocated mutexes.
	pool_monitor (size_t nPoolCapacity)
	Initializes the pool of nPoolCapacity preallocated mutexes.
template<typename Node >
void	lock (Node const &p) const
	Makes exclusive access to node p.
template<typename Node >
void	unlock (Node const &p) const
	Unlocks the node p.
internal_stat const &	statistics () const
	Returns the reference to internal statistics. More...

Static Public Attributes
static constexpr size_t const	c_nDefaultCapacity = 256
	Pool's default capacity.

Detailed Description

template<class LockPool, typename BackOff = cds::backoff::Default, bool Stat = false>
class cds::sync::pool_monitor< LockPool, BackOff, Stat >

Monitor that allocates node's lock when needed

The monitor is intended for reducing the number of system mutexes for huge containers like a tree. The monitor allocates the mutex from the pool LockPool only when container's node should be locked. Lifetime of node's mutex is managed by reference counter. When the reference counter to node's mutex becomes zero, the mutex is given back to the pool.

The monitor is blocked: the access to node's mutex is performed under the spin-lock. However, node locking/unlocking is performed beyond the spin-lock.

Template arguments:

• LockPool - the pool type. The pool must maintain the objects of type std::mutex or similar. The access to the pool is not synchronized.
• BackOff - back-off strategy for spinning, default is cds::backoff::Default
• Stat - enable (true) or disable (false, the default) monitor's internal statistics.

How to use

typedef cds::memory::vyukov_queue_pool< std::mutex > pool_type;
typedef cds::sync::pool_monitor< pool_type > sync_monitor;

Member Function Documentation

statistics()

template<class LockPool , typename BackOff = cds::backoff::Default, bool Stat = false>

internal_stat const& cds::sync::pool_monitor< LockPool, BackOff, Stat >::statistics ( ) const

inline

Returns the reference to internal statistics.

If class' template argument Stat is false, the function returns dummy statistics. Otherwise, it returns the reference to monitor's internal statistics of type pool_monitor_traits::stat.

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

• cds/sync/pool_monitor.h