ucommon::MappedReuse Class Reference

Map a reusable allocator over a named shared memory segment. More...

#include <mapped.h>

Inheritance diagram for ucommon::MappedReuse:

Collaboration diagram for ucommon::MappedReuse:

Public Member Functions
bool	avail (void) const
	Check whether there are objects available to be allocated.
ReusableObject *	get (void)
	Request a reusable object from the free list or mapped space.
ReusableObject *	getLocked (void)
	Used to get an object from the reuse pool when the mutex lock is already held.
ReusableObject *	getTimed (timeout_t timeout)
	Request a reusable object from the free list or mapped space.
	MappedReuse (const char *name, size_t size, unsigned count)
	Construct a named memory segment for use with managed fixed size reusable objects.
void	removeLocked (ReusableObject *object)
	Used to return an object to the reuse pool when the mutex lock is already held.
ReusableObject *	request (void)
	Request a reusable object from the free list or mapped space.

Protected Member Functions
void	create (const char *fname, unsigned count)
	MappedReuse (size_t osize)
Protected Member Functions inherited from ucommon::ReusableAllocator
ReusableObject *	next (ReusableObject *object)
	Get next reusable object in the pool.
void	release (ReusableObject *object)
	Release resuable object.
	ReusableAllocator ()
	Initialize reusable allocator through a conditional.
Protected Member Functions inherited from ucommon::Conditional
void	broadcast (void)
	Signal the conditional to release all waiting threads.
	Conditional ()
	Initialize and construct conditional.
void	signal (void)
	Signal the conditional to release one waiting thread.
bool	wait (struct timespec *timeout)
	Conditional wait for signal on timespec timeout.
bool	wait (timeout_t timeout)
	Conditional wait for signal on millisecond timeout.
void	wait (void)
	Wait (block) until signalled.
	~Conditional ()
	Destroy conditional, release any blocked threads.
Protected Member Functions inherited from ucommon::ConditionMutex
	ConditionMutex ()
	Initialize and construct conditional.
void	lock (void)
	Lock the conditional's supporting mutex.
void	unlock (void)
	Unlock the conditional's supporting mutex.
	~ConditionMutex ()
	Destroy conditional, release any blocked threads.
Protected Member Functions inherited from ucommon::MappedMemory
void	create (const char *name, size_t size=(size_t) 0)
	Supporting function to construct a new or access an existing shared memory segment.
caddr_t	addr (void)
	Get starting address of mapped segment.
bool	copy (size_t offset, void *buffer, size_t size) const
	Copy memory from specific offset within the mapped memory segment.
size_t	len (void) const
	Get size of mapped segment.
	MappedMemory (const char *name)
	Provide read-only mapped access to an existing named shared memory segment.
	MappedMemory (const char *name, size_t size)
	Construct a read/write access mapped shared segment of memory of a known size.
void *	offset (size_t offset) const
	Get memory from a specific offset within the mapped memory segment.
	operator bool () const
	Test if map active.
bool	operator! () const
	Test if map is inactive.
void	release (void)
	Unmap memory segment.
void *	sbrk (size_t size)
	Extend size of managed heap on shared memory segment.
virtual	~MappedMemory ()
	Unmap memory segment.

Additional Inherited Members
Static Protected Member Functions inherited from ucommon::Conditional
static pthread_condattr_t *	initializer (void)
	Support function for getting conditional attributes for realtime scheduling.
static void	set (struct timespec *hires, timeout_t timeout)
	Convert a millisecond timeout into use for high resolution conditional timers.
Static Protected Member Functions inherited from ucommon::MappedMemory
static void	disable (void)
	An API that allows "disabling" of publishing shared memory maps.
static void	remove (const char *name)
	Destroy a previously existing memory segment under the specified name.
Protected Attributes inherited from ucommon::ReusableAllocator
ReusableObject *	freelist
unsigned	waiting
Protected Attributes inherited from ucommon::Conditional
pthread_cond_t	cond
Protected Attributes inherited from ucommon::ConditionMutex
pthread_mutex_t	mutex
Protected Attributes inherited from ucommon::MappedMemory
bool	erase
char	idname [65]
size_t	size
size_t	used
Static Protected Attributes inherited from ucommon::Conditional
static attribute	attr

Detailed Description

Map a reusable allocator over a named shared memory segment.

This may be used to form a resource bound fixed size managed heap in shared memory. The request can either be fulfilled from the object reuse pool or from a new section of memory, and if all memory in the segment has been exhausted, it can wait until more objects are returned by another thread to the reuse pool.

Author

David Sugar dyfet.nosp@m.@gnu.nosp@m.telep.nosp@m.hony.nosp@m..org

Definition at line 191 of file mapped.h.

Constructor & Destructor Documentation

MappedReuse()

ucommon::MappedReuse::MappedReuse	(	const char *	name,
		size_t	size,
		unsigned	count )

Construct a named memory segment for use with managed fixed size reusable objects.

The segment is created as writable. There is no read-only version of mapped reuse since the mapped segment can be read by another process directly as a mapped read-only vector. The actual mapped type will be derived from ReusableObject to meet the needs of the reusable allocator. The template version should be used to assure type correctness rather than using this class directly.

Parameters

name	of shared memory segment.
size	of the object type being mapped.
count	of the maximum number of active mapped objects.

Member Function Documentation

avail()

bool ucommon::MappedReuse::avail

(

void

)

const

Check whether there are objects available to be allocated.

Returns

true if objects are available.

create()

void ucommon::MappedReuse::create ( const char * fname, unsigned count )

inlineprotected

Definition at line 203 of file mapped.h.

get()

ReusableObject * ucommon::MappedReuse::get

(

void

)

Request a reusable object from the free list or mapped space.

This method blocks until an object becomes available.

Returns

free object.

getLocked()

ReusableObject * ucommon::MappedReuse::getLocked

(

void

)

Used to get an object from the reuse pool when the mutex lock is already held.

Returns

object from pool or NULL if exhausted.

getTimed()

ReusableObject * ucommon::MappedReuse::getTimed

(

timeout_t

timeout

)

Request a reusable object from the free list or mapped space.

This method blocks until an object becomes available or the timeout has expired.

Parameters

timeout

to wait in milliseconds.

Returns

free object or NULL if timeout.

removeLocked()

void ucommon::MappedReuse::removeLocked

(

ReusableObject *

object

)

Used to return an object to the reuse pool when the mutex lock is already held.

Parameters

object

being returned.

request()

ReusableObject * ucommon::MappedReuse::request

(

void

)

Request a reusable object from the free list or mapped space.

Returns

free object or NULL if pool is exhausted.

---

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

• /builddir/build/BUILD/ucommon-7.0.0-build/ucommon-7.0.0/inc/ucommon/mapped.h