pmem::obj::timed_mutex Class Reference

Persistent memory resident timed_mutex implementation. More...

#include <libpmemobj++/timed_mutex.hpp>

Public Types
typedef PMEMmutex *	native_handle_type
	Implementation defined handle to the native type.

Public Member Functions
	timed_mutex ()
	Default constructor. More...
	~timed_mutex ()=default
	Defaulted destructor.
void	lock ()
	Locks the mutex, blocks if already locked. More...
bool	try_lock ()
	Tries to lock the mutex, returns regardless if the lock succeeds. More...
template<typename Clock , typename Duration >
bool	try_lock_until (const std::chrono::time_point< Clock, Duration > &timeout_time)
	Makes the current thread block until the lock is acquired or a specific time is reached. More...
template<typename Rep , typename Period >
bool	try_lock_for (const std::chrono::duration< Rep, Period > &timeout_duration)
	Makes the current thread block until the lock is acquired or a specified amount of time passes. More...
void	unlock ()
	Unlocks a previously locked mutex. More...
native_handle_type	native_handle () noexcept
	Access a native handle to this condition variable. More...
timed_mutex &	operator= (const timed_mutex &)=delete
	Deleted assignment operator.
	timed_mutex (const timed_mutex &)=delete
	Deleted copy constructor.

Private Member Functions
template<typename Clock , typename Duration >
bool	timedlock_impl (const std::chrono::time_point< Clock, Duration > &abs_time)
	Internal implementation of the timed lock call.

Private Attributes
PMEMmutex	plock
	A POSIX style PMEM-resident timed_mutex.

Detailed Description

Persistent memory resident timed_mutex implementation.

This class is an implementation of a PMEM-resident timed_mutex which mimics in behavior the C++11 std::timed_mutex. This class satisfies all requirements of the TimedMutex and StandardLayoutType concepts. The typical usage example would be:

#include <chrono>
#include <libpmemobj++/persistent_ptr.hpp>
#include <libpmemobj++/pool.hpp>
#include <libpmemobj++/timed_mutex.hpp>
 
namespace nvobj = pmem::obj;
 
void
timed_mutex_example()
{
    /* pool root structure */
    struct root {
        nvobj::timed_mutex pmutex;
    };
 
    /* create a pmemobj pool */
    auto pop = nvobj::pool<root>::create("poolfile", "layout",
                         PMEMOBJ_MIN_POOL);
    auto proot = pop.root();
 
    const auto timeout = std::chrono::milliseconds(100);
 
    /* typical usage schemes */
    proot->pmutex.try_lock_for(timeout);
 
    proot->pmutex.try_lock_until(std::chrono::steady_clock::now() +
                     timeout);
}

Constructor & Destructor Documentation

timed_mutex()

pmem::obj::timed_mutex::timed_mutex ( )

inline

Default constructor.

Exceptions

lock_error

when the timed_mutex is not from persistent memory.

Member Function Documentation

lock()

void pmem::obj::timed_mutex::lock ( )

inline

Locks the mutex, blocks if already locked.

If a different thread already locked this mutex, the calling thread will block. If the same thread tries to lock a mutex it already owns, the behavior is undefined.

Exceptions

lock_error

when an error occurs, this includes all system related errors with the underlying implementation of the mutex.

native_handle()

native_handle_type pmem::obj::timed_mutex::native_handle ( )

inlinenoexcept

Access a native handle to this condition variable.

Returns

a pointer to PMEMmutex.

try_lock()

bool pmem::obj::timed_mutex::try_lock ( )

inline

Tries to lock the mutex, returns regardless if the lock succeeds.

If the same thread tries to lock a mutex it already owns, the behavior is undefined.

Returns

true on successful lock acquisition, false otherwise.

Exceptions

lock_error

when an error occurs, this includes all system related errors with the underlying implementation of the mutex.

try_lock_for()

template<typename Rep , typename Period >

bool pmem::obj::timed_mutex::try_lock_for ( const std::chrono::duration< Rep, Period > &  timeout_duration )

inline

Makes the current thread block until the lock is acquired or a specified amount of time passes.

If the same thread tries to lock a mutex it already owns, the behavior is undefined.

Parameters

[in]

timeout_duration

a specific duration, which when expired unblocks the thread.

Returns

true on successful lock acquisition, false otherwise.

Exceptions

lock_error

when an error occurs, this includes all system related errors with the underlying implementation of the mutex.

try_lock_until()

template<typename Clock , typename Duration >

bool pmem::obj::timed_mutex::try_lock_until ( const std::chrono::time_point< Clock, Duration > &  timeout_time )

inline

Makes the current thread block until the lock is acquired or a specific time is reached.

If the same thread tries to lock a mutex it already owns, the behavior is undefined.

Parameters

[in]

timeout_time

a specific point in time, which when reached unblocks the thread.

Returns

true on successful lock acquisition, false otherwise.

Exceptions

lock_error

when an error occurs, this includes all system related errors with the underlying implementation of the mutex.

unlock()

void pmem::obj::timed_mutex::unlock ( )

inline

Unlocks a previously locked mutex.

Unlocking a mutex that has not been locked by the current thread results in undefined behavior. Unlocking a mutex that has not been lock also results in undefined behavior.

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

• libpmemobj++/timed_mutex.hpp