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/* fd.c */
/* NOTICE
*
* Copyright (c) 1990,1992,1993 Britt Yenne. All rights reserved.
*
* This software is provided AS-IS. The author gives no warranty,
* real or assumed, and takes no responsibility whatsoever for any
* use or misuse of this software, or any damage created by its use
* or misuse.
*
* This software may be freely copied and distributed provided that
* no part of this NOTICE is deleted or edited in any manner.
*
*/
/* Mail comments or questions to ytalk@austin.eds.com */
#include "header.h"
#include "menu.h"
#include <sys/time.h>
#include <signal.h>
#ifdef _AIX
# include <sys/select.h>
#endif
static fd_set fdset; /* descriptors to select on */
static fd_set fdtmp; /* descriptors to select on (input_loop) */
static fd_set sel; /* currently readable descriptors */
static int high_fd = 0; /* highest fd so far */
int input_flag = 0; /* flag: waiting for user input */
int user_winch = 0; /* flag: user window/status changed */
struct fd_func {
void (*func)(); /* user function */
};
static struct fd_func tag[MAX_FILES]; /* one function per file descriptor */
/* Initialize fdset data.
*/
void
init_fd()
{
FD_ZERO(&fdset);
}
/* Add a file descriptor to the current checklist. The supplied
* function will be called whenever the file descriptor has input
* waiting.
*/
void
add_fd(fd, user_func)
int fd;
void (*user_func)();
{
if(fd < 0 || fd >= MAX_FILES)
{
show_error("add_fd: descriptor out of range");
return;
}
FD_SET(fd, &fdset);
tag[fd].func = user_func;
if(fd >= high_fd)
high_fd = fd + 1;
}
/* Remove a file descriptor from the checklist.
*/
void
remove_fd(fd)
int fd;
{
if(fd < 0 || fd >= MAX_FILES)
{
show_error("remove_fd: descriptor out of range");
return;
}
FD_CLR(fd, &fdset);
FD_CLR(fd, &fdtmp);
FD_CLR(fd, &sel);
}
/* Read an entire length of data.
* Returns 0 on success, -1 on error.
*/
int
full_read(fd, buf, len)
int fd;
register char *buf;
register int len;
{
register int rc;
while(len > 0)
{
if((rc = read(fd, buf, len)) <= 0)
return -1;
buf += rc;
len -= rc;
}
return 0;
}
/* -- MAIN LOOPS -- */
static ylong lastping, curtime;
void
main_loop()
{
register int fd, rc;
struct timeval tv;
#ifndef Y_USE_SIGHOLD
int mask, old_mask;
#endif
/* Some signals need to be blocked while doing internal
* processing, else some craziness might occur.
*/
#ifndef Y_USE_SIGHOLD
mask = 0;
# ifdef SIGWINCH
mask |= sigmask(SIGWINCH);
# endif
#endif
#if defined(SIGCHLD)
signal(SIGCHLD, SIG_IGN);
#else
# if defined(SIGCLD)
signal(SIGCLD, SIG_IGN);
# endif
#endif
/* For housecleaning to occur every CLEAN_INTERVAL seconds, we make
* our own little timer system. SIGALRM is nice; in fact it's so
* useful that we'll be using it in other parts of YTalk. Since
* we therefore can't use it here, we affect the timer manually.
*/
house_clean();
curtime = lastping = (ylong)time(NULL);
for(;;)
{
/* check if we're done */
if(connect_list == NULL
&& wait_list == NULL
&& menu_ptr == NULL
&& running_process == 0)
bail(0);
/* select */
sel = fdset;
if(curtime > lastping + CLEAN_INTERVAL)
tv.tv_sec = 0;
else
tv.tv_sec = (lastping + CLEAN_INTERVAL) - curtime;
tv.tv_usec = 0;
if((rc = select(high_fd, &sel, 0, 0, &tv)) < 0)
if(errno != EINTR)
show_error("main_loop: select failed");
/* block signals while doing internal processing */
#ifdef Y_USE_SIGHOLD
# ifdef SIGWINCH
sighold(SIGWINCH);
# endif
#else
old_mask = sigblock(mask);
#endif
/* process file descriptors with input waiting */
if(rc > 0)
for(fd = 0; fd < high_fd; fd++)
if(FD_ISSET(fd, &sel))
{
errno = 0;
tag[fd].func(fd);
if(--rc <= 0)
break;
}
/* check timer */
curtime = (ylong)time(NULL);
if(curtime - lastping >= CLEAN_INTERVAL)
{
house_clean();
lastping = (ylong)time(NULL);
}
/* re-allow signals */
#ifdef Y_USE_SIGHOLD
# ifdef SIGWINCH
sigrelse(SIGWINCH);
# endif
#else
sigsetmask(old_mask);
#endif
if(user_winch)
{
/* This is a cute hack that updates a user menu
* dynamically as information changes. So I had
* some free time. there.
*/
user_winch = 0;
update_user_menu();
}
}
}
/* Input loop. This loop keeps everything except user input going until
* input is received from <me>. This is necessary for answering pressing
* questions without needing to add a getch_term() function to the terminal
* definition library. Hack? maybe. Fun, tho.
*/
void
input_loop()
{
register int fd, rc;
struct timeval tv;
static int left_loop;
left_loop = 0;
fdtmp = fdset;
while(io_len <= 0)
{
/* select */
sel = fdtmp;
if(curtime > lastping + CLEAN_INTERVAL)
tv.tv_sec = 0;
else
tv.tv_sec = (lastping + CLEAN_INTERVAL) - curtime;
tv.tv_usec = 0;
if((rc = select(high_fd, &sel, 0, 0, &tv)) < 0)
if(errno != EINTR)
show_error("input_loop: select failed");
/* process file descriptors with input waiting */
if(rc > 0)
for(fd = 0; fd < high_fd; fd++)
if(FD_ISSET(fd, &sel))
{
/* Here the hack begins. Any function that takes user
* input should clear "input_flag" and return. This
* tells us to ignore this function for now. Any
* function which receives input from <me> should leave
* my input in io_ptr/io_len.
*/
errno = 0;
input_flag = 1;
tag[fd].func(fd);
if(left_loop) /* recursive input_loop()s. argh! */
return; /* let my parent function re-call me */
if(input_flag == 0)
{
/* don't check this descriptor anymore */
FD_CLR(fd, &fdtmp);
}
if(--rc <= 0)
break;
}
/* check timer */
curtime = (ylong)time(NULL);
if(curtime - lastping >= CLEAN_INTERVAL)
{
input_flag = 1;
house_clean();
lastping = (ylong)time(NULL);
}
}
input_flag = 0;
left_loop = 1;
}
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.