select.c

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/*
   +----------------------------------------------------------------------+
   | Copyright (c) The PHP Group                                          |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | https://www.php.net/license/3_01.txt                                 |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | Authors: Jerome Loyet <jerome@loyet.net>                             |
   +----------------------------------------------------------------------+
*/
 
#include "../fpm_config.h"
#include "../fpm_events.h"
#include "../fpm.h"
#include "../zlog.h"
 
#ifdef HAVE_SELECT
 
/* According to POSIX.1-2001 */
#include <sys/select.h>
 
/* According to earlier standards */
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
 
#include <errno.h>
 
static int fpm_event_select_init(int max);
static int fpm_event_select_wait(struct fpm_event_queue_s *queue, unsigned long int timeout);
static int fpm_event_select_add(struct fpm_event_s *ev);
static int fpm_event_select_remove(struct fpm_event_s *ev);
 
static struct fpm_event_module_s select_module = {
    .name = "select",
    .support_edge_trigger = 0,
    .init = fpm_event_select_init,
    .clean = NULL,
    .wait = fpm_event_select_wait,
    .add = fpm_event_select_add,
    .remove = fpm_event_select_remove,
};
 
static fd_set fds;
 
#endif /* HAVE_SELECT */
 
/*
 * return the module configuration
 */
struct fpm_event_module_s *fpm_event_select_module(void)
{
#ifdef HAVE_SELECT
    return &select_module;
#else
    return NULL;
#endif /* HAVE_SELECT */
}
 
#ifdef HAVE_SELECT
 
/*
 * Init the module
 */
static int fpm_event_select_init(int max) /* {{{ */
{
    FD_ZERO(&fds);
    return 0;
}
/* }}} */
 
 
/*
 * wait for events or timeout
 */
static int fpm_event_select_wait(struct fpm_event_queue_s *queue, unsigned long int timeout) /* {{{ */
{
    int ret;
    struct fpm_event_queue_s *q;
    fd_set current_fds;
    struct timeval t;
 
    /* copy fds because select() alters it */
    current_fds = fds;
 
    /* fill struct timeval with timeout */
    t.tv_sec = timeout / 1000;
    t.tv_usec = (timeout % 1000) * 1000;
 
    /* wait for incoming event or timeout */
    ret = select(FD_SETSIZE, &current_fds, NULL, NULL, &t);
    if (ret == -1) {
 
        /* trigger error unless signal interrupt */
        if (errno != EINTR) {
            zlog(ZLOG_WARNING, "poll() returns %d", errno);
            return -1;
        }
    }
 
    /* events have been triggered */
    if (ret > 0) {
 
        /* trigger POLLIN events */
        q = queue;
        while (q) {
            if (q->ev) { /* sanity check */
 
                /* check if the event has been triggered */
                if (FD_ISSET(q->ev->fd, &current_fds)) {
 
                    /* fire the event */
                    fpm_event_fire(q->ev);
 
                    /* sanity check */
                    if (fpm_globals.parent_pid != getpid()) {
                        return -2;
                    }
                }
            }
            q = q->next; /* iterate */
        }
    }
    return ret;
 
}
/* }}} */
 
/*
 * Add a FD to the fd set
 */
static int fpm_event_select_add(struct fpm_event_s *ev) /* {{{ */
{
    /* check size limitation */
    if (ev->fd >= FD_SETSIZE) {
        zlog(ZLOG_ERROR, "select: not enough space in the select fd list (max = %d). Please consider using another event mechanism.", FD_SETSIZE);
        return -1;
    }
 
    /* add the FD if not already in */
    if (!FD_ISSET(ev->fd, &fds)) {
        FD_SET(ev->fd, &fds);
        ev->index = ev->fd;
    }
 
    return 0;
}
/* }}} */
 
/*
 * Remove a FD from the fd set
 */
static int fpm_event_select_remove(struct fpm_event_s *ev) /* {{{ */
{
    /* remove the fd if it's in */
    if (FD_ISSET(ev->fd, &fds)) {
        FD_CLR(ev->fd, &fds);
        ev->index = -1;
    }
 
    return 0;
}
/* }}} */
 
#endif /* HAVE_SELECT */