Class template monitor_shared_lock
poet::monitor_shared_lock — shared_lock with monitor object access
Synopsis
template<typename MonitorType> class monitor_shared_lock { public: // types typedef MonitorType monitor_type; typedef MonitorType::element_type element_type; // will additionally be const-qualified if MonitorType is "const monitor<T>" // construct/copy/destruct explicit monitor_shared_lock(MonitorType &); template<typename T> monitor_shared_lock(MonitorType &, const T &); monitor_shared_lock(boost::detail::thread_move_t<monitor_shared_lock>); monitor_shared_lock(boost::detail::thread_move_t<monitor_upgrade_lock<MonitorType> >); monitor_shared_lock(boost::detail::thread_move_t<monitor_unique_lock<MonitorType> >); monitor_shared_lock(); ~monitor_shared_lock(); // public boost::shared_lock interface void lock(); boost::detail::thread_move_t<monitor_shared_lock> move(); MonitorType * mutex() const; monitor_shared_lock & operator=(boost::detail::thread_move_t<monitor_shared_lock>); monitor_shared_lock & operator=(boost::detail::thread_move_t<monitor_upgrade_lock>); monitor_shared_lock & operator=(boost::detail::thread_move_t<monitor_unique_lock>); bool operator!() const; operator boost::detail::thread_move_t<monitor_shared_lock>(); operator unspecified_bool_type() const; bool owns_lock() const; MonitorType * release(); void swap(monitor_shared_lock &); template<typename Timeout> bool timed_lock(const Timeout &); bool try_lock(); void unlock(); // public member functions const element_type * operator->() const; const element_type & operator*() const; private: // construct/copy/destruct monitor_shared_lock(monitor_shared_lock &); monitor_shared_lock& operator=(monitor_shared_lock &); }; // free functions template<typename Monitor> boost::detail::thread_move_t<monitor_shared_lock<Monitor> > move(monitor_shared_lock<Monitor> &); template<typename Monitor> void swap(monitor_shared_lock<Monitor> &, monitor_shared_lock<Monitor> &);
Description
monitor_shared_lock
is an extension of boost::shared_lock
from the
Boost.Thread
library. It extends the interface of
boost::shared_lock by adding operator->
and operator* methods, which permit access to
the object protected by the lock's associated monitor. This tight
coupling of locking with access helps insure
the monitor's mutex is always locked when the object it is protecting
is accessed.
Unlike monitor_unique_lock, the operator->
and operator* of monitor_shared_lock
only permit const
access to the associated object. This helps prevent unintended
modification of the object while only holding a shared_lock.
The MonitorType
template type parameter may be one of the monitor
or monitor_ptr types.
See the documentation of boost::shared_lock in the Boost.Thread library for more information about the shared_lock interface.
monitor_shared_lock
public construct/copy/destruct
-
explicit monitor_shared_lock(MonitorType & mon);
Calls lock(), acquiring shared ownership of
mon
(in the sense of a lock having ownership of a mutex).Internally, the monitor_shared_lock stores a
monitor_ptr
to use as a reference to the object protected by themon
argument. Thus the monitor_shared_lock shares ownership (in theshared_ptr
sense) and may safely outlive themon
object. -
template<typename T> monitor_shared_lock(MonitorType & mon, const T & arg);
This constructor corresponds to all the 2 argument constructors of boost::shared_lock. The second argument may thus be of type
boost::adopt_lock_t
,boost::defer_lock_t
,boost::try_to_lock_t
, orboost::system_time
. -
monitor_shared_lock(boost::detail::thread_move_t<monitor_shared_lock> other);
Move constructor.
-
monitor_shared_lock(boost::detail::thread_move_t<monitor_upgrade_lock<MonitorType> > other);
Move constructor.
-
monitor_shared_lock(boost::detail::thread_move_t<monitor_unique_lock<MonitorType> > other);
Move constructor. The unique_lock is downgraded to a shared_lock as it is moved into
*this
. -
monitor_shared_lock();
The default constructor creates an empty lock that is not associated with any monitor object. The empty lock can only be made useful by moving another another lock into it.
-
~monitor_shared_lock();
If
owns_lock()
, callsunlock()
.
monitor_shared_lock
public boost::shared_lock interface
-
void lock();
-
boost::detail::thread_move_t<monitor_shared_lock> move();
-
MonitorType * mutex() const;
-
monitor_shared_lock & operator=(boost::detail::thread_move_t<monitor_shared_lock>);
-
monitor_shared_lock & operator=(boost::detail::thread_move_t<monitor_upgrade_lock>);
-
monitor_shared_lock & operator=(boost::detail::thread_move_t<monitor_unique_lock>);
-
bool operator!() const;
-
operator boost::detail::thread_move_t<monitor_shared_lock>();
-
operator unspecified_bool_type() const;
-
bool owns_lock() const;
-
MonitorType * release();
-
void swap(monitor_shared_lock & other);
-
template<typename Timeout> bool timed_lock(const Timeout & t);
-
bool try_lock();
-
void unlock();
monitor_shared_lock
public member functions
-
const element_type * operator->() const;
Provides
const
access to the members of the object protected by the lock's associated monitor.Throws:
boost::lock_error if
owns_lock() != true
. -
const element_type & operator*() const;
Provides
const
access to the object protected by the lock's associated monitor.Throws:
boost::lock_error if
owns_lock() != true
.
monitor_shared_lock
free functions
-
template<typename Monitor> boost::detail::thread_move_t<monitor_shared_lock<Monitor> > move(monitor_shared_lock<Monitor> & lock);
Returns:
lock.move()
-
template<typename Monitor> void swap(monitor_shared_lock<Monitor> & lock_a, monitor_shared_lock<Monitor> & lock_b);
Effects:
lock_a.swap(lock_b)