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/*
Poll() doesn't work when RLIMIT_NOFILE is set to 0;
Imitate poll() using select().
warning: poll() handle EBADF in different way
*/
#include <poll.h>
#include <sys/select.h>
#include "log.h"
#include "jail.h"
int jail_poll(struct pollfd *x, nfds_t len, int millisecs) {
struct timeval *tvp = 0;
struct timeval tv;
fd_set rfds;
fd_set wfds;
nfds_t nfds;
int fd, r;
nfds_t i;
log_t5("jail_poll(len = ", lognum(len), ", millisecs = ", lognum(millisecs),
")");
for (i = 0; i < len; ++i) x[i].revents = 0;
FD_ZERO(&rfds);
FD_ZERO(&wfds);
nfds = 1;
for (i = 0; i < len; ++i) {
fd = x[i].fd;
if (fd < 0) continue;
if (fd >= (int) (8 * sizeof(fd_set))) continue;
if ((unsigned int) fd >= nfds) nfds = fd + 1;
if (x[i].events & POLLIN) FD_SET(fd, &rfds);
if (x[i].events & POLLOUT) FD_SET(fd, &wfds);
}
if (millisecs >= 0) {
tv.tv_sec = millisecs / 1000;
tv.tv_usec = 1000 * (millisecs % 1000);
tvp = &tv;
}
r = select(nfds, &rfds, &wfds, (fd_set *) 0, tvp);
if (r <= 0) goto cleanup;
r = 0;
for (i = 0; i < len; ++i) {
fd = x[i].fd;
if (fd < 0) continue;
if (fd >= (int) (8 * sizeof(fd_set))) continue;
if (x[i].events & POLLIN) {
if (FD_ISSET(fd, &rfds)) {
x[i].revents |= POLLIN;
++r;
}
}
if (x[i].events & POLLOUT) {
if (FD_ISSET(fd, &wfds)) {
x[i].revents |= POLLOUT;
++r;
}
}
}
cleanup:
log_t6("jail_poll(len = ", lognum(len), ", millisecs = ", lognum(millisecs),
") = ", lognum(r));
return r;
}
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