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/* Copyright (C) 2009 Intel Corporation
Author: Andi Kleen
Event loop for mcelog daemon mode.
mcelog is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public
License as published by the Free Software Foundation; version
2.
mcelog is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should find a copy of v2 of the GNU General Public License somewhere
on your Linux system; if not, write to the Free Software Foundation,
Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#define _GNU_SOURCE 1
#include <assert.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <sys/fcntl.h>
#include <signal.h>
#include "mcelog.h"
#include "eventloop.h"
#define MAX_POLLFD 10
static int max_pollfd;
struct pollcb {
poll_cb_t cb;
int fd;
void *data;
};
static struct pollfd pollfds[MAX_POLLFD];
static struct pollcb pollcbs[MAX_POLLFD];
static sigset_t event_sigs;
static int closeonexec(int fd)
{
int flags = fcntl(fd, F_GETFD);
if (flags < 0 || fcntl(fd, F_SETFD, flags | FD_CLOEXEC) < 0) {
SYSERRprintf("Cannot set FD_CLOEXEC flag on fd");
return -1;
}
return 0;
}
int register_pollcb(int fd, int events, poll_cb_t cb, void *data)
{
int i = max_pollfd;
if (closeonexec(fd) < 0)
return -1;
if (i >= MAX_POLLFD) {
Eprintf("poll table overflow");
return -1;
}
max_pollfd++;
pollfds[i].fd = fd;
pollfds[i].events = events;
pollcbs[i].cb = cb;
pollcbs[i].data = data;
return 0;
}
/* Could mark free and put into a free list */
void unregister_pollcb(struct pollfd *pfd)
{
int i = pfd - pollfds;
assert(i >= 0 && i < max_pollfd);
memmove(pollfds + i, pollfds + i + 1,
(max_pollfd - i - 1) * sizeof(struct pollfd));
memmove(pollcbs + i, pollcbs + i + 1,
(max_pollfd - i - 1) * sizeof(struct pollcb));
max_pollfd--;
}
static void poll_callbacks(int n)
{
int k;
for (k = 0; k < max_pollfd && n > 0; k++) {
struct pollfd *f = pollfds + k;
if (f->revents) {
struct pollcb *c = pollcbs + k;
c->cb(f, c->data);
n--;
}
}
}
/* Run signal handler only directly after event loop */
int event_signal(int sig)
{
static int first = 1;
sigset_t mask;
if (first && sigprocmask(SIG_BLOCK, NULL, &event_sigs) < 0)
return -1;
first = 0;
if (sigprocmask(SIG_BLOCK, NULL, &mask) < 0)
return -1;
sigaddset(&mask, sig);
if (sigprocmask(SIG_BLOCK, &mask, NULL) < 0)
return -1;
return 0;
}
/* Handle old glibc without ppoll. */
static int ppoll_fallback(struct pollfd *pfd, nfds_t nfds,
const struct timespec *ts, const sigset_t *ss)
{
sigset_t origmask;
int ready;
sigprocmask(SIG_SETMASK, ss, &origmask);
ready = poll(pfd, nfds, ts ? ts->tv_sec : -1);
sigprocmask(SIG_SETMASK, &origmask, NULL);
return ready;
}
static int (*ppoll_vec)(struct pollfd *, nfds_t, const struct timespec
*, const sigset_t *);
void eventloop(void)
{
#if __GLIBC__ == 2 && __GLIBC_MINOR__ >= 5 || __GLIBC__ > 2
ppoll_vec = ppoll;
#endif
if (!ppoll_vec)
ppoll_vec = ppoll_fallback;
for (;;) {
int n = ppoll_vec(pollfds, max_pollfd, NULL, &event_sigs);
if (n <= 0) {
if (n < 0 && errno != EINTR)
SYSERRprintf("poll error");
continue;
}
poll_callbacks(n);
}
}
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