82 lines
2.1 KiB
Text
82 lines
2.1 KiB
Text
|
Overview of the filedescriptor subsystem
|
||
|
|
Adrian Chadd <adrian@creative.net.au>
|
||
|
|
|
||
|
|
$Id: fd-management.txt 6 2005-09-10 01:02:21Z nenolod $
|
||
|
|
|
||
|
|
|
||
|
|
Filedescriptor lists
|
||
|
|
--------------------
|
||
|
|
|
||
|
|
The filedescriptor list is managed through the routines in fdlist.c .
|
||
|
|
These include:
|
||
|
|
|
||
|
|
fd_open() - tag an FD as "open" and active
|
||
|
|
fd_close() - tag an FD as "closed" and close() the filedescriptor
|
||
|
|
fd_note() - update the filedescriptor tag
|
||
|
|
|
||
|
|
You can get the current list of open filedescriptors through /stats F as
|
||
|
|
an oper.
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
FD lists
|
||
|
|
--------
|
||
|
|
|
||
|
|
The FD list support is very alpha. There are a few lists defined:
|
||
|
|
|
||
|
|
typedef enum fdlist_t {
|
||
|
|
FDLIST_NONE,
|
||
|
|
FDLIST_SERVICE,
|
||
|
|
FDLIST_SERVER,
|
||
|
|
FDLIST_IDLECLIENT,
|
||
|
|
FDLIST_BUSYCLIENT,
|
||
|
|
FDLIST_MAX
|
||
|
|
} fdlist_t;
|
||
|
|
|
||
|
|
FDLIST_NONE Not on any list (ie close()d)
|
||
|
|
FDLIST_SERVICE A service - listen() sockets, resolver, etc
|
||
|
|
FDLIST_SERVER Server connections
|
||
|
|
FDLIST_IDLECLIENT An idle client
|
||
|
|
FDLIST_BUSYCLIENT A busy client
|
||
|
|
FDLIST_MAX Used for bounds checking
|
||
|
|
|
||
|
|
The idea is that the SERVICE sockets need polling frequently, the SERVER
|
||
|
|
sockets also need polling frequently, BUSYCLIENT is for busy clients
|
||
|
|
which need frequent polling (eg we're trying to write to them), and
|
||
|
|
IDLECLIENT is for clients which we don't need to poll frequently.
|
||
|
|
THIS hasn't been decided upon yet.
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
File operations
|
||
|
|
---------------
|
||
|
|
|
||
|
|
The file operations are also wrapped through file_open() and file_close()
|
||
|
|
which handle calling fd_open() / fd_close() and tracking the filedescriptors
|
||
|
|
correctly. fbopen() / fbclose() use file_open() / file_close() too.
|
||
|
|
|
||
|
|
fileio.c defines the functions:
|
||
|
|
|
||
|
|
int
|
||
|
|
file_open(const char *filename, int mode, int fmode)
|
||
|
|
|
||
|
|
A wrapper around open(filename, flags, mode). Read the open manpage for
|
||
|
|
information. file_open() enforces filedescriptor limits and tags the FD
|
||
|
|
through fd_open().
|
||
|
|
|
||
|
|
void
|
||
|
|
file_close(int fd)
|
||
|
|
|
||
|
|
A wrapper around close() for files. close() handles fd_close()ing the fd.
|
||
|
|
|
||
|
|
|
||
|
|
FBFILE *
|
||
|
|
fbopen(const char *filename, const char *mode)
|
||
|
|
|
||
|
|
void
|
||
|
|
fbclose(FBFILE *fb)
|
||
|
|
|
||
|
|
These are the 'buffered disk IO' routines. You can read the code yourself.
|
||
|
|
Note that these routines use file_open() and file_close().
|
||
|
|
|