io_wait(3) [debian man page]

io_wait(3)						     Library Functions Manual							io_wait(3)

NAME

       io_wait - wait for events

SYNTAX

       #include <io.h>

       void io_wait();

DESCRIPTION

       io_wait()  checks  the  descriptors  that  the  program	is  interested in to see whether any of them are ready. If none of them are ready,
       io_wait() tries to pause until one of them is ready, so that it does not take time away from other programs running on the same computer.

       io_wait pays attention to timeouts: if a descriptor reaches its timeout, and the program is interested in reading or writing that  descrip-
       tor, io_wait will return promptly.

       Under  some  circumstances,  io_wait will return even though no interesting descriptors are ready. Do not assume that a descriptor is ready
       merely because io_wait has returned.

       io_wait is not interrupted by the delivery of a signal. Programs that expect interruption are unreliable: they will block if the same  sig-
       nal is delivered a moment before io_wait. The correct way to handle signals is with the self-pipe trick.

SEE ALSO

       io_waituntil(3), io_check(3), io_wantread(3), io_wantwrite(3), io_fd(3)

																	io_wait(3)

iob_write(3)						     Library Functions Manual						      iob_write(3)

NAME

       iob_write - send I/O batch through callback

SYNTAX

       #include <iob.h>

       typedef int64 (*io_write_callback)(int64 s,const void* buf,uint64 n);

       int64 iob_write(int64 s,io_batch* b,io_write_callback cb);

DESCRIPTION

       iob_write sends the (rest of) b through the callback cb, passing s as first argument.  cb is expected to behave like io_trywrite(2).

       This  interface	is intended to send an I/O batch through a filter, for example to encrypt or compress it.  If you just want to send an I/O
       batch to a socket, use iob_send instead.

       iob_write returns the number of bytes written, 0 if there were no more bytes to be written in the batch, -1 for EAGAIN, or -3 for a  perma-
       nent error (for example "connection reset by peer").

       The normal usage pattern is using io_wait to know when a descriptor is writable, and then calling iob_write until it returns 0, -1 or -3.

       If  it  returns	0,  terminate  the  loop (everything was written OK).  If it returns -1, call io_wait again.  If it returned -3, signal an
       error.

NOTE

       iob_write will continue to call your callback until it returns an error.  So if you are in a state machine, for example a web server  using
       this  for  SSL  support,  make  sure  to  write at most n bytes at a time (e.g. 64k) and the next time you are called return -1.  Otherwise
       iob_write might not return until the whole file is served.

SEE ALSO

       iob_send(3)

																      iob_write(3)