aio_buffer_pool Class Reference

A buffer pool for use with async readers/writers. More...

#include <aio.hpp>

Inheritance diagram for aio_buffer_pool:

Collaboration diagram for aio_buffer_pool:

Public Types
typedef void *	shm_handle

Public Member Functions
	aio_buffer_pool (logger_interface &logger, size_t buffer_count=1, size_t buffer_size=0, bool use_shm=false, std::string_view application_group_id={})
	operator bool () const
buffer_lease	get_buffer (aio_waiter &h)
buffer_lease	get_buffer (event_handler &h)
logger_interface &	logger () const
std::tuple< shm_handle, uint8_t const *, size_t >	shared_memory_info () const
size_t	buffer_count () const
Public Member Functions inherited from aio_waitable
void	remove_waiter (aio_waiter &h)
void	remove_waiter (event_handler &h)

Static Public Attributes
static shm_handle const	shm_handle_default

Friends
class	buffer_lease

Additional Inherited Members
Protected Member Functions inherited from aio_waitable
void	remove_waiters ()
	Call in destructor of most-derived class.
void	add_waiter (aio_waiter &h)
void	add_waiter (event_handler &h)
void	signal_availibility ()

Detailed Description

A buffer pool for use with async readers/writers.

Can use shared memory, see shared_memory_info()

Examples

aio.cpp, and https.cpp.

Member Function Documentation

get_buffer()

buffer_lease get_buffer

(

aio_waiter &

h

)

/brief Returns either a buffer lease, or records the passed waiter/handler as waiting.

If waiting, do not call get_buffer again until after waiter/handler got signalled.

If a buffer becomes available and there are multiple waiters, the order in waiters are signaled is undefined.

shared_memory_info()

std::tuple<shm_handle, uint8_t const*, size_t> shared_memory_info

(

)

const

Returns a tuple with information on the mapping

• A file descriptor or handle backing the memory
• The base address of the mapping
• Total size of the memory mapping

To pass buffer leases to a child process:

• Pass the fd/handle and total size to the child
• Create mapping in the child, obtaining its own base address
• If parent gets a buffer lease, parent calculates offset to the base address, passes offset and buffer size to child
• Child computes actuall address from offset and its own base address
• Parent keeps lease until the child signals that it's done with that buffer

Warning

The child has write access to the mapping, do not pass the fd/handle to untrusted children

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

• aio.hpp