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/*
This file is part of libmicrohttpd
Copyright (C) 2018 Christian Grothoff (and other contributing authors)
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file suspend_resume_epoll.c
* @brief example for how to use libmicrohttpd with epoll() and
* resume a suspended connection
* @author Robert D Kocisko
* @author Christian Grothoff
*/
#include "platform.h"
#include <microhttpd.h>
#include <sys/epoll.h>
#include <sys/timerfd.h>
#include <limits.h>
#define TIMEOUT_INFINITE -1
struct Request
{
struct MHD_Connection *connection;
int timerfd;
};
static int epfd;
static struct epoll_event evt;
static enum MHD_Result
ahc_echo (void *cls,
struct MHD_Connection *connection,
const char *url,
const char *method,
const char *version,
const char *upload_data, size_t *upload_data_size, void **req_cls)
{
struct MHD_Response *response;
enum MHD_Result ret;
struct Request *req;
struct itimerspec ts;
(void) cls;
(void) url; /* Unused. Silence compiler warning. */
(void) method;
(void) version; /* Unused. Silence compiler warning. */
(void) upload_data; /* Unused. Silence compiler warning. */
(void) upload_data_size; /* Unused. Silence compiler warning. */
req = *req_cls;
if (NULL == req)
{
req = malloc (sizeof(struct Request));
if (NULL == req)
return MHD_NO;
req->connection = connection;
req->timerfd = -1;
*req_cls = req;
return MHD_YES;
}
if (-1 != req->timerfd)
{
/* send response (echo request url) */
response = MHD_create_response_from_buffer (strlen (url),
(void *) url,
MHD_RESPMEM_MUST_COPY);
if (NULL == response)
return MHD_NO;
ret = MHD_queue_response (connection,
MHD_HTTP_OK,
response);
MHD_destroy_response (response);
return ret;
}
/* create timer and suspend connection */
req->timerfd = timerfd_create (CLOCK_MONOTONIC, TFD_NONBLOCK);
if (-1 == req->timerfd)
{
printf ("timerfd_create: %s", strerror (errno));
return MHD_NO;
}
evt.events = EPOLLIN;
evt.data.ptr = req;
if (-1 == epoll_ctl (epfd, EPOLL_CTL_ADD, req->timerfd, &evt))
{
printf ("epoll_ctl: %s", strerror (errno));
return MHD_NO;
}
ts.it_value.tv_sec = 1;
ts.it_value.tv_nsec = 0;
ts.it_interval.tv_sec = 0;
ts.it_interval.tv_nsec = 0;
if (-1 == timerfd_settime (req->timerfd, 0, &ts, NULL))
{
printf ("timerfd_settime: %s", strerror (errno));
return MHD_NO;
}
MHD_suspend_connection (connection);
return MHD_YES;
}
static void
connection_done (void *cls,
struct MHD_Connection *connection,
void **req_cls,
enum MHD_RequestTerminationCode toe)
{
struct Request *req = *req_cls;
(void) cls;
(void) connection;
(void) toe;
if (-1 != req->timerfd)
if (0 != close (req->timerfd))
abort ();
free (req);
}
int
main (int argc,
char *const *argv)
{
struct MHD_Daemon *d;
const union MHD_DaemonInfo *info;
int current_event_count;
struct epoll_event events_list[1];
struct Request *req;
uint64_t timer_expirations;
if (argc != 2)
{
printf ("%s PORT\n", argv[0]);
return 1;
}
d = MHD_start_daemon (MHD_USE_EPOLL | MHD_ALLOW_SUSPEND_RESUME,
atoi (argv[1]),
NULL, NULL, &ahc_echo, NULL,
MHD_OPTION_NOTIFY_COMPLETED, &connection_done, NULL,
MHD_OPTION_END);
if (d == NULL)
return 1;
info = MHD_get_daemon_info (d, MHD_DAEMON_INFO_EPOLL_FD);
if (info == NULL)
return 1;
epfd = epoll_create1 (EPOLL_CLOEXEC);
if (-1 == epfd)
return 1;
evt.events = EPOLLIN;
evt.data.ptr = NULL;
if (-1 == epoll_ctl (epfd, EPOLL_CTL_ADD, info->epoll_fd, &evt))
return 1;
while (1)
{
int timeout;
MHD_UNSIGNED_LONG_LONG to;
if (MHD_YES !=
MHD_get_timeout (d,
&to))
timeout = TIMEOUT_INFINITE;
else
timeout = (to < INT_MAX - 1) ? (int) to : (INT_MAX - 1);
current_event_count = epoll_wait (epfd, events_list, 1, timeout);
if (1 == current_event_count)
{
if (events_list[0].data.ptr)
{
/* A timer has timed out */
req = events_list[0].data.ptr;
/* read from the fd so the system knows we heard the notice */
if (-1 == read (req->timerfd, &timer_expirations,
sizeof(timer_expirations)))
{
return 1;
}
/* Now resume the connection */
MHD_resume_connection (req->connection);
}
}
else if (0 == current_event_count)
{
/* no events: continue */
}
else
{
/* error */
return 1;
}
if (! MHD_run (d))
return 1;
}
return 0;
}
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