macssh/lsh/src/jpoll.c

69 lines
1.7 KiB
C
Executable File

/* jpoll.c
*
* This code emulates a minimal poll function, and can be used as a drop-in
* replacement for the SVID3 implementation. Note that at this time it only
* emulates the POLLIN and POLLOUT events.
*
* $id:$ */
/*
* AUTHOR: Sean Reifschneider <jafo@tummy.com>
* DATE: 1998-10-10
* COPYING: Free for unlimited use. No warranty expressed or implied.
* If it breaks, you get to keep both parts.
*/
#include "jpoll.h"
#include <sys/time.h>
#include <sys/types.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
int poll(struct pollfd *fdlist, nfds_t count, int timeoutInMS)
{
struct timeval timeout, *to;
fd_set readfdset, writefdset;
nfds_t i;
int ret, fdcount = 0;
int tsize = getdtablesize();
if (timeoutInMS < 0)
to = NULL;
else {
to = &timeout;
timeout.tv_sec = timeoutInMS / 1000;
timeout.tv_usec = (timeoutInMS % 1000) * 1000;
}
FD_ZERO(&readfdset);
FD_ZERO(&writefdset);
for (i = 0; i < count; i++) {
if (fdlist[i].fd < 0) continue;
if (fdlist[i].events & POLLIN) FD_SET(fdlist[i].fd, &readfdset);
if (fdlist[i].events & POLLOUT) FD_SET(fdlist[i].fd, &writefdset);
fdcount++;
}
/* spec says that if all FDs are negative, then *ONLY* return zero */
if (fdcount == 0)
return(0);
/* clear all events */
for (i = 0; i < count; i++) fdlist[i].revents = 0;
if ((ret = select(tsize, &readfdset, &writefdset, NULL, to)) == -1)
return(-1);
for (i = 0; i < count; i++) {
if (FD_ISSET(fdlist[i].fd, &readfdset)) fdlist[i].revents |= POLLIN;
if (FD_ISSET(fdlist[i].fd, &writefdset)) fdlist[i].revents |= POLLOUT;
/*trace("jpoll.c: Set FD %i = %i\n", i, fdlist[i].revents);*/
}
/*trace("jpoll.c: Returning %i\n", ret);*/
return(ret);
}