ivykis(3)						    ivykis programmer's manual							 ivykis(3)

NAME

       ivykis - library for asynchronous I/O readiness notification

DESCRIPTION

       ivykis  is  a  library  for  asynchronous I/O readiness notification.  It is a thin, portable wrapper around OS-provided mechanisms such as
       epoll_create(2), kqueue(2), poll(2), poll(7d) (/dev/poll), port_create(3C) and select(2).

       ivykis was mainly designed for building high-performance network applications, but can be used in any event-driven  application	that  uses
       poll(2)able file descriptors as its event sources.

       While  some  programming  models  dictate using blocking I/O and starting a thread per event source, programs written to the ivykis API are
       generally single-threaded (or use only a small number of threads), and never block on I/O.  All input and output is done in  a  nonblocking
       fashion, with I/O readiness notifications delivered via callback functions.

       The  two  main  event  sources  in ivykis are file descriptors and timers.  File descriptors generate an event when they become readable or
       writable or trigger an error condition, while timers generate an event when the system time increments past a certain pre-set time.  Events
       associated with file descriptors are level-triggered -- a callback function set up to handle a certain file descriptor event will be called
       repeatedly until the condition generating the event has been cleared.

       As mentioned, applications using ivykis are generally single-threaded.  Event callbacks are strictly serialised within a thread,  and  non-
       preemptible.  This mostly removes the need for locking of shared data, and generally simplifies writing applications.

       Each thread that uses ivykis has its own file descriptors and timers, and runs a separate event loop.

       In  ivykis, all code that is not initialization code runs from callback functions.  Callback functions are not allowed to block.  If a par-
       ticular piece of code wants to perform a certain operation that can block, it either has to schedule it to run in a separate thread, or	it
       has  to perform the operation in a nonblocking fashion instead.	For example, registering an input callback function instead of blocking on
       a read, registering a timer instead of calling sleep(2), etc.

       In case of an internal error, ivykis will use iv_fatal(3) to report the error.  The application can provide a custom fatal error handler by
       calling iv_set_fatal_msg_handler(3).

SEE ALSO

       iv_examples(3), iv_fatal(3), iv_fd(3), iv_timer(3), iv_task(3), iv_init(3), iv_main(3), iv_time(3)

ivykis								    2010-08-15								 ivykis(3)