ACE_MMAP_Memory_Pool Class Reference

Make a memory pool that is based on mmap(2). This implementation allows memory to be shared between processes. More...

#include <MMAP_Memory_Pool.h>

Inheritance diagram for ACE_MMAP_Memory_Pool:

Collaboration diagram for ACE_MMAP_Memory_Pool:

Public Types
typedef ACE_MMAP_Memory_Pool_Options	OPTIONS
Public Types inherited from ACE_Event_Handler
enum	{   LO_PRIORITY = 0 , HI_PRIORITY = 10 , NULL_MASK = 0 , READ_MASK = (1 << 0) ,   WRITE_MASK = (1 << 1) , EXCEPT_MASK = (1 << 2) , ACCEPT_MASK = (1 << 3) , CONNECT_MASK = (1 << 4) ,   TIMER_MASK = (1 << 5) , QOS_MASK = (1 << 6) , GROUP_QOS_MASK = (1 << 7) , SIGNAL_MASK = (1 << 8) ,   ALL_EVENTS_MASK , RWE_MASK , DONT_CALL = (1 << 9) }
enum	{ ACE_EVENT_HANDLER_NOT_RESUMED = -1 , ACE_REACTOR_RESUMES_HANDLER = 0 , ACE_APPLICATION_RESUMES_HANDLER }
typedef long	Reference_Count
	Reference count type.

Public Member Functions
	ACE_MMAP_Memory_Pool (const ACE_TCHAR *backing_store_name=0, const OPTIONS *options=0)
	Initialize the pool.
virtual	~ACE_MMAP_Memory_Pool ()
	Destructor.
virtual void *	init_acquire (size_t nbytes, size_t &rounded_bytes, int &first_time)
	Ask system for initial chunk of shared memory.
virtual void *	acquire (size_t nbytes, size_t &rounded_bytes)
virtual int	release (int destroy=1)
	Instruct the memory pool to release all of its resources.
virtual int	sync (size_t len, int flags=MS_SYNC)
virtual int	sync (int flags=MS_SYNC)
virtual int	sync (void *addr, size_t len, int flags=MS_SYNC)
	Sync the memory region to the backing store starting at addr.
virtual int	protect (size_t len, int prot=PROT_RDWR)
virtual int	protect (int prot=PROT_RDWR)
virtual int	protect (void *addr, size_t len, int prot=PROT_RDWR)
virtual int	seh_selector (void *)
virtual int	remap (void *addr)
virtual void *	base_addr () const
	Return the base address of this memory pool.
virtual void	dump () const
	Dump the state of an object.
ACE_Mem_Map const &	mmap () const
	Get reference to underlying ACE_Mem_Map object.
ACE_Mem_Map &	mmap ()
	Get reference to underlying ACE_Mem_Map object.
Public Member Functions inherited from ACE_Event_Handler
virtual	~ACE_Event_Handler ()=default
	Destructor is virtual to enable proper cleanup.
virtual ACE_HANDLE	get_handle () const
	Get the I/O handle.
virtual void	set_handle (ACE_HANDLE)
	Set the I/O handle.
virtual int	priority () const
virtual void	priority (int priority)
	Set the priority of the Event_Handler.
virtual int	handle_input (ACE_HANDLE fd=ACE_INVALID_HANDLE)
	Called when input events occur (e.g., connection or data).
virtual int	handle_output (ACE_HANDLE fd=ACE_INVALID_HANDLE)
virtual int	handle_exception (ACE_HANDLE fd=ACE_INVALID_HANDLE)
	Called when an exceptional events occur (e.g., SIGURG).
virtual int	handle_timeout (const ACE_Time_Value &current_time, const void *act=0)
virtual int	handle_exit (ACE_Process *)
	Called when a process exits.
virtual int	handle_close (ACE_HANDLE handle, ACE_Reactor_Mask close_mask)
virtual int	handle_signal (int signum, siginfo_t *=0, ucontext_t *=0)
virtual int	resume_handler ()
virtual int	handle_qos (ACE_HANDLE=ACE_INVALID_HANDLE)
virtual int	handle_group_qos (ACE_HANDLE=ACE_INVALID_HANDLE)
virtual void	reactor (ACE_Reactor *reactor)
	Set the event demultiplexors.
virtual ACE_Reactor *	reactor () const
	Get the event demultiplexors.
virtual ACE_Reactor_Timer_Interface *	reactor_timer_interface () const
	Get only the reactor's timer related interface.
virtual Reference_Count	add_reference ()
	Increment reference count on the handler.
virtual Reference_Count	remove_reference ()
	Decrement reference count on the handler.
Reference_Counting_Policy &	reference_counting_policy ()
	Current Reference_Counting_Policy.

Public Attributes
	ACE_ALLOC_HOOK_DECLARE
	Declare the dynamic allocation hooks.

Protected Member Functions
virtual size_t	round_up (size_t nbytes)
virtual int	commit_backing_store_name (size_t rounded_bytes, size_t &map_size)
virtual int	map_file (size_t map_size)
	Memory map the file up to map_size bytes.
Protected Member Functions inherited from ACE_Event_Handler
	ACE_Event_Handler (ACE_Reactor *=nullptr, int priority=ACE_Event_Handler::LO_PRIORITY)
	Force ACE_Event_Handler to be an abstract base class.

Protected Attributes
ACE_Mem_Map	mmap_
	Memory-mapping object.
void *	base_addr_
int	use_fixed_addr_
	Must we use the base_addr_ or can we let mmap(2) select it?
int	flags_
	Flags passed into ACE_OS::mmap().
bool	write_each_page_
size_t	minimum_bytes_
	What the minimum bytes of the initial segment should be.
ACE_TCHAR	backing_store_name_ [MAXPATHLEN+1]
	Name of the backing store where the shared memory pool is kept.
bool	guess_on_fault_
LPSECURITY_ATTRIBUTES	sa_
	Security attributes object, only used on NT.
mode_t	file_mode_
	Protection mode for mmaped file.
bool	install_signal_handler_
	Should we install a signal handler.
Protected Attributes inherited from ACE_Event_Handler
Atomic_Reference_Count	reference_count_
	Reference count.

Additional Inherited Members
Static Public Member Functions inherited from ACE_Event_Handler
static ACE_THR_FUNC_RETURN	read_adapter (void *event_handler)
static int	register_stdin_handler (ACE_Event_Handler *eh, ACE_Reactor *reactor, ACE_Thread_Manager *thr_mgr, int flags=THR_DETACHED)
static int	remove_stdin_handler (ACE_Reactor *reactor, ACE_Thread_Manager *thr_mgr)
	Performs the inverse of the register_stdin_handler() method.
Protected Types inherited from ACE_Event_Handler
typedef std::atomic< Reference_Count >	Atomic_Reference_Count
	Typedef for implementation of reference counting.

Detailed Description

Make a memory pool that is based on mmap(2). This implementation allows memory to be shared between processes.

Member Typedef Documentation

OPTIONS

typedef ACE_MMAP_Memory_Pool_Options ACE_MMAP_Memory_Pool::OPTIONS

Constructor & Destructor Documentation

ACE_MMAP_Memory_Pool()

ACE_MMAP_Memory_Pool::ACE_MMAP_Memory_Pool	(	const ACE_TCHAR *	backing_store_name = 0,
		const OPTIONS *	options = 0 )

Initialize the pool.

~ACE_MMAP_Memory_Pool()

ACE_MMAP_Memory_Pool::~ACE_MMAP_Memory_Pool ( )

virtual

Destructor.

Member Function Documentation

acquire()

void * ACE_MMAP_Memory_Pool::acquire ( size_t nbytes, size_t & rounded_bytes )

virtual

Acquire at least nbytes from the memory pool. rounded_bytes is the actual number of bytes allocated. Also acquires an internal semaphore that ensures proper serialization of ACE_MMAP_Memory_Pool initialization across processes.

base_addr()

void * ACE_MMAP_Memory_Pool::base_addr ( ) const

virtual

Return the base address of this memory pool.

commit_backing_store_name()

int ACE_MMAP_Memory_Pool::commit_backing_store_name ( size_t rounded_bytes, size_t & map_size )

protectedvirtual

Compute the new map_size of the backing store and commit the memory.

dump()

void ACE_MMAP_Memory_Pool::dump ( ) const

virtual

Dump the state of an object.

init_acquire()

void * ACE_MMAP_Memory_Pool::init_acquire ( size_t nbytes, size_t & rounded_bytes, int & first_time )

virtual

Ask system for initial chunk of shared memory.

map_file()

int ACE_MMAP_Memory_Pool::map_file ( size_t map_size )

protectedvirtual

Memory map the file up to map_size bytes.

mmap() [1/2]

ACE_Mem_Map & ACE_MMAP_Memory_Pool::mmap ( )

inline

Get reference to underlying ACE_Mem_Map object.

mmap() [2/2]

ACE_Mem_Map const & ACE_MMAP_Memory_Pool::mmap ( ) const

inline

Get reference to underlying ACE_Mem_Map object.

protect() [1/3]

int ACE_MMAP_Memory_Pool::protect ( int prot = PROT_RDWR )

virtual

Change the protection of all the pages of the mapped region to prot starting at this->base_addr_.

protect() [2/3]

int ACE_MMAP_Memory_Pool::protect ( size_t len, int prot = PROT_RDWR )

virtual

Change the protection of the pages of the mapped region to prot starting at this->base_addr_ up to len bytes. If len == -1 then change protection of all pages in the mapped region.

protect() [3/3]

int ACE_MMAP_Memory_Pool::protect ( void * addr, size_t len, int prot = PROT_RDWR )

virtual

Change the protection of the pages of the mapped region to prot starting at addr up to len bytes.

release()

int ACE_MMAP_Memory_Pool::release ( int destroy = 1 )

virtual

Instruct the memory pool to release all of its resources.

remap()

int ACE_MMAP_Memory_Pool::remap ( void * addr )

virtual

Try to extend the virtual address space so that addr is now covered by the address mapping. The method succeeds and returns 0 if the backing store has adequate memory to cover this address. Otherwise, it returns -1. This method is typically called by a UNIX signal handler for SIGSEGV or a Win32 structured exception when another process has grown the backing store (and its mapping) and our process now incurs a fault because our mapping isn't in range (yet).

round_up()

size_t ACE_MMAP_Memory_Pool::round_up ( size_t nbytes )

protectedvirtual

Implement the algorithm for rounding up the request to an appropriate chunksize.

seh_selector()

int ACE_MMAP_Memory_Pool::seh_selector ( void * ep )

virtual

Win32 Structural exception selector. The return value decides how to handle memory pool related structural exceptions. Returns 1, 0, or , -1.

sync() [1/3]

int ACE_MMAP_Memory_Pool::sync ( int flags = MS_SYNC )

virtual

Sync the memory region to the backing store starting at this->base_addr_. Will sync as much as the backing file allows.

Reimplemented in ACE_Lite_MMAP_Memory_Pool.

sync() [2/3]

int ACE_MMAP_Memory_Pool::sync ( size_t len, int flags = MS_SYNC )

virtual

Sync the memory region to the backing store starting at this->base_addr_.

Reimplemented in ACE_Lite_MMAP_Memory_Pool.

sync() [3/3]

int ACE_MMAP_Memory_Pool::sync ( void * addr, size_t len, int flags = MS_SYNC )

virtual

Sync the memory region to the backing store starting at addr.

Sync len bytes of the memory region to the backing store starting at <addr_>.

Reimplemented in ACE_Lite_MMAP_Memory_Pool.

Member Data Documentation

ACE_ALLOC_HOOK_DECLARE

ACE_MMAP_Memory_Pool::ACE_ALLOC_HOOK_DECLARE

Declare the dynamic allocation hooks.

backing_store_name_

ACE_TCHAR ACE_MMAP_Memory_Pool::backing_store_name_[MAXPATHLEN+1]

protected

Name of the backing store where the shared memory pool is kept.

base_addr_

void* ACE_MMAP_Memory_Pool::base_addr_

protected

Base of mapped region. If this has the value of 0 then the OS is free to select any address to map the file, otherwise this value is what the OS must try to use to mmap the file.

file_mode_

mode_t ACE_MMAP_Memory_Pool::file_mode_

protected

Protection mode for mmaped file.

flags_

int ACE_MMAP_Memory_Pool::flags_

protected

Flags passed into ACE_OS::mmap().

guess_on_fault_

bool ACE_MMAP_Memory_Pool::guess_on_fault_

protected

Try to remap without knowing the faulting address. This parameter is ignored on platforms that know the faulting address (UNIX with SI_ADDR and Win32).

install_signal_handler_

bool ACE_MMAP_Memory_Pool::install_signal_handler_

protected

Should we install a signal handler.

minimum_bytes_

size_t ACE_MMAP_Memory_Pool::minimum_bytes_

protected

What the minimum bytes of the initial segment should be.

mmap_

ACE_Mem_Map ACE_MMAP_Memory_Pool::mmap_

protected

Memory-mapping object.

sa_

LPSECURITY_ATTRIBUTES ACE_MMAP_Memory_Pool::sa_

protected

Security attributes object, only used on NT.

use_fixed_addr_

int ACE_MMAP_Memory_Pool::use_fixed_addr_

protected

Must we use the base_addr_ or can we let mmap(2) select it?

write_each_page_

bool ACE_MMAP_Memory_Pool::write_each_page_

protected

Should we write a byte to each page to forceably allocate memory for this backing store?

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

• MMAP_Memory_Pool.h
• MMAP_Memory_Pool.cpp
• MMAP_Memory_Pool.inl