getdns/src/extension/select_eventloop.c

316 lines
9.2 KiB
C

/*
* Copyright (c) 2013, NLNet Labs, Verisign, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the names of the copyright holders nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL Verisign, Inc. BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "debug.h"
#include "types-internal.h"
#include "platform.h"
#include "extension/select_eventloop.h"
static uint64_t get_now_plus(uint64_t amount)
{
struct timeval tv;
uint64_t now;
if (gettimeofday(&tv, NULL)) {
_getdns_perror("gettimeofday() failed");
exit(EXIT_FAILURE);
}
now = tv.tv_sec * 1000000 + tv.tv_usec;
return (now + amount * 1000) >= now
? now + amount * 1000 : TIMEOUT_FOREVER;
}
static getdns_return_t
select_eventloop_schedule(getdns_eventloop *loop,
int fd, uint64_t timeout, getdns_eventloop_event *event)
{
_getdns_select_eventloop *select_loop = (_getdns_select_eventloop *)loop;
size_t i;
DEBUG_SCHED( "%s(loop: %p, fd: %d, timeout: %"PRIu64", event: %p, FD_SETSIZE: %d)\n"
, __FUNC__, (void *)loop, fd, timeout, (void *)event, FD_SETSIZE);
if (!loop || !event)
return GETDNS_RETURN_INVALID_PARAMETER;
if (fd >= (int)FD_SETSIZE) {
DEBUG_SCHED( "ERROR: fd %d >= FD_SETSIZE: %d!\n"
, fd, FD_SETSIZE);
return GETDNS_RETURN_GENERIC_ERROR;
}
if (fd >= 0 && !(event->read_cb || event->write_cb)) {
DEBUG_SCHED("WARNING: fd event without "
"read or write cb!\n");
fd = -1;
}
if (fd >= 0) {
#if defined(SCHED_DEBUG) && SCHED_DEBUG
if (select_loop->fd_events[fd]) {
if (select_loop->fd_events[fd] == event) {
DEBUG_SCHED("WARNING: Event %p not cleared "
"before being rescheduled!\n"
, (void *)select_loop->fd_events[fd]);
} else {
DEBUG_SCHED("ERROR: A different event is "
"already present at fd slot: %p!\n"
, (void *)select_loop->fd_events[fd]);
}
}
#endif
select_loop->fd_events[fd] = event;
select_loop->fd_timeout_times[fd] = get_now_plus(timeout);
event->ev = (void *)(intptr_t)(fd + 1);
DEBUG_SCHED( "scheduled read/write at %d\n", fd);
return GETDNS_RETURN_GOOD;
}
if (!event->timeout_cb) {
DEBUG_SCHED("ERROR: fd < 0 without timeout_cb!\n");
return GETDNS_RETURN_GENERIC_ERROR;
}
if (event->read_cb) {
DEBUG_SCHED("ERROR: timeout event with read_cb! Clearing.\n");
event->read_cb = NULL;
}
if (event->write_cb) {
DEBUG_SCHED("ERROR: timeout event with write_cb! Clearing.\n");
event->write_cb = NULL;
}
for (i = 0; i < MAX_TIMEOUTS; i++) {
if (select_loop->timeout_events[i] == NULL) {
select_loop->timeout_events[i] = event;
select_loop->timeout_times[i] = get_now_plus(timeout);
event->ev = (void *)(intptr_t)(i + 1);
DEBUG_SCHED( "scheduled timeout at %d\n", (int)i);
return GETDNS_RETURN_GOOD;
}
}
DEBUG_SCHED("ERROR: Out of timeout slots!\n");
return GETDNS_RETURN_GENERIC_ERROR;
}
static getdns_return_t
select_eventloop_clear(getdns_eventloop *loop, getdns_eventloop_event *event)
{
_getdns_select_eventloop *select_loop = (_getdns_select_eventloop *)loop;
ssize_t i;
if (!loop || !event)
return GETDNS_RETURN_INVALID_PARAMETER;
DEBUG_SCHED( "%s(loop: %p, event: %p)\n", __FUNC__, (void *)loop, (void *)event);
i = (intptr_t)event->ev - 1;
if (i < 0 || i >= FD_SETSIZE) {
return GETDNS_RETURN_GENERIC_ERROR;
}
if (event->timeout_cb && !event->read_cb && !event->write_cb) {
#if defined(SCHED_DEBUG) && SCHED_DEBUG
if (select_loop->timeout_events[i] != event)
DEBUG_SCHED( "ERROR: Different/wrong event present at "
"timeout slot: %p!\n"
, (void *)select_loop->timeout_events[i]);
#endif
select_loop->timeout_events[i] = NULL;
} else {
#if defined(SCHED_DEBUG) && SCHED_DEBUG
if (select_loop->fd_events[i] != event)
DEBUG_SCHED( "ERROR: Different/wrong event present at "
"fd slot: %p!\n"
, (void *)select_loop->fd_events[i]);
#endif
select_loop->fd_events[i] = NULL;
}
event->ev = NULL;
return GETDNS_RETURN_GOOD;
}
static void
select_eventloop_cleanup(getdns_eventloop *loop)
{
(void)loop;
}
static void
select_read_cb(int fd, getdns_eventloop_event *event)
{
#if !defined(SCHED_DEBUG) || !SCHED_DEBUG
(void)fd;
#endif
DEBUG_SCHED( "%s(fd: %d, event: %p)\n", __FUNC__, fd, (void *)event);
event->read_cb(event->userarg);
}
static void
select_write_cb(int fd, getdns_eventloop_event *event)
{
#if !defined(SCHED_DEBUG) || !SCHED_DEBUG
(void)fd;
#endif
DEBUG_SCHED( "%s(fd: %d, event: %p)\n", __FUNC__, fd, (void *)event);
event->write_cb(event->userarg);
}
static void
select_timeout_cb(int fd, getdns_eventloop_event *event)
{
#if !defined(SCHED_DEBUG) || !SCHED_DEBUG
(void)fd;
#endif
DEBUG_SCHED( "%s(fd: %d, event: %p)\n", __FUNC__, fd, (void *)event);
event->timeout_cb(event->userarg);
}
static void
select_eventloop_run_once(getdns_eventloop *loop, int blocking)
{
_getdns_select_eventloop *select_loop = (_getdns_select_eventloop *)loop;
fd_set readfds, writefds;
int fd, max_fd = -1;
uint64_t now, timeout = TIMEOUT_FOREVER;
size_t i;
struct timeval tv;
if (!loop)
return;
FD_ZERO(&readfds);
FD_ZERO(&writefds);
now = get_now_plus(0);
for (i = 0; i < MAX_TIMEOUTS; i++) {
if (!select_loop->timeout_events[i])
continue;
if (now > select_loop->timeout_times[i])
select_timeout_cb(-1, select_loop->timeout_events[i]);
else if (select_loop->timeout_times[i] < timeout)
timeout = select_loop->timeout_times[i];
}
for (fd = 0; fd < (int)FD_SETSIZE; fd++) {
if (!select_loop->fd_events[fd])
continue;
if (select_loop->fd_events[fd]->read_cb)
FD_SET(fd, &readfds);
if (select_loop->fd_events[fd]->write_cb)
FD_SET(fd, &writefds);
if (fd > max_fd)
max_fd = fd;
if (select_loop->fd_timeout_times[fd] < timeout)
timeout = select_loop->fd_timeout_times[fd];
}
if (max_fd == -1 && timeout == TIMEOUT_FOREVER)
return;
if (! blocking || now > timeout) {
tv.tv_sec = 0;
tv.tv_usec = 0;
} else {
tv.tv_sec = (long)((timeout - now) / 1000000);
tv.tv_usec = (long)((timeout - now) % 1000000);
}
#ifdef USE_WINSOCK
if (max_fd == -1) {
if (timeout != TIMEOUT_FOREVER) {
uint32_t timeout_ms = (tv.tv_usec / 1000) + (tv.tv_sec * 1000);
Sleep(timeout_ms);
}
} else {
#endif
if (select(max_fd + 1, &readfds, &writefds, NULL,
(timeout == TIMEOUT_FOREVER ? NULL : &tv)) < 0) {
if (_getdns_socketerror_wants_retry())
return;
DEBUG_SCHED("I/O error with select(): %s\n", _getdns_errnostr());
return;
}
#ifdef USE_WINSOCK
}
#endif
now = get_now_plus(0);
for (fd = 0; fd < (int)FD_SETSIZE; fd++) {
if (select_loop->fd_events[fd] &&
select_loop->fd_events[fd]->read_cb &&
FD_ISSET(fd, &readfds))
select_read_cb(fd, select_loop->fd_events[fd]);
if (select_loop->fd_events[fd] &&
select_loop->fd_events[fd]->write_cb &&
FD_ISSET(fd, &writefds))
select_write_cb(fd, select_loop->fd_events[fd]);
if (select_loop->fd_events[fd] &&
select_loop->fd_events[fd]->timeout_cb &&
now > select_loop->fd_timeout_times[fd])
select_timeout_cb(fd, select_loop->fd_events[fd]);
i = fd;
if (select_loop->timeout_events[i] &&
select_loop->timeout_events[i]->timeout_cb &&
now > select_loop->timeout_times[i])
select_timeout_cb(-1, select_loop->timeout_events[i]);
}
}
static void
select_eventloop_run(getdns_eventloop *loop)
{
_getdns_select_eventloop *select_loop = (_getdns_select_eventloop *)loop;
size_t i;
if (!loop)
return;
i = 0;
while (i < MAX_TIMEOUTS) {
if (select_loop->fd_events[i] || select_loop->timeout_events[i]) {
select_eventloop_run_once(loop, 1);
i = 0;
} else {
i++;
}
}
}
void
_getdns_select_eventloop_init(struct mem_funcs *mf, _getdns_select_eventloop *loop)
{
static getdns_eventloop_vmt select_eventloop_vmt = {
select_eventloop_cleanup,
select_eventloop_schedule,
select_eventloop_clear,
select_eventloop_run,
select_eventloop_run_once
};
(void) mf;
(void) memset(loop, 0, sizeof(_getdns_select_eventloop));
loop->loop.vmt = &select_eventloop_vmt;
}