gstreamer/gst/tcp/gstfdset.c
Thomas Vander Stichele 29569738a6 first stab at documenting elements
Original commit message from CVS:
first stab at documenting elements
2005-08-05 17:13:10 +00:00

532 lines
11 KiB
C

/* GStreamer
* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
* Copyright (C) <2004> Wim Taymans <wim@fluendo.com>
*
* gsttcpfdset.h: fdset datastructure
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#define MIN_POLLFDS 32
#define INIT_POLLFDS MIN_POLLFDS
#include <sys/poll.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
/* OS/X needs this because of bad headers */
#include <string.h>
#include "gstfdset.h"
GType
gst_fdset_mode_get_type (void)
{
static GType fdset_mode_type = 0;
static GEnumValue fdset_mode[] = {
{GST_FDSET_MODE_SELECT, "GST_FDSET_MODE_SELECT", "Select"},
{GST_FDSET_MODE_POLL, "GST_FDSET_MODE_POLL", "Poll"},
{GST_FDSET_MODE_EPOLL, "GST_FDSET_MODE_EPOLL", "EPoll"},
{0, NULL, NULL},
};
if (!fdset_mode_type) {
fdset_mode_type = g_enum_register_static ("GstFDSetMode", fdset_mode);
}
return fdset_mode_type;
}
struct _GstFDSet
{
GstFDSetMode mode;
/* for poll */
struct pollfd *testpollfds;
gint last_testpollfds;
gint testsize;
struct pollfd *pollfds;
gint size;
gint free;
gint last_pollfds;
GMutex *poll_lock;
/* for select */
fd_set readfds, writefds; /* input */
fd_set testreadfds, testwritefds; /* output */
};
static gint
nearest_pow (gint num)
{
/* hacker's delight page 48 */
num -= 1;
num |= num >> 1;
num |= num >> 2;
num |= num >> 4;
num |= num >> 8;
num |= num >> 16;
return num + 1;
}
/* resize a given pollfd array from old_size number of items
* to new_size number of items. Also initializes the new elements
* with the default values. */
static struct pollfd *
resize (struct pollfd *fds, gint old_size, gint new_size)
{
struct pollfd *res;
gint i;
res = g_realloc (fds, new_size * sizeof (struct pollfd));
for (i = old_size; i < new_size; i++) {
res[i].fd = -1;
res[i].events = 0;
res[i].revents = 0;
}
return res;
}
static void
ensure_size (GstFDSet * set, gint len)
{
if (len > set->size) {
len = nearest_pow (len);
len = MAX (len, MIN_POLLFDS);
set->pollfds = resize (set->pollfds, set->size, len);
set->size = len;
}
}
GstFDSet *
gst_fdset_new (GstFDSetMode mode)
{
GstFDSet *nset;
nset = g_new0 (GstFDSet, 1);
nset->mode = mode;
switch (mode) {
case GST_FDSET_MODE_SELECT:
FD_ZERO (&nset->readfds);
FD_ZERO (&nset->writefds);
break;
case GST_FDSET_MODE_POLL:
nset->pollfds = NULL;
nset->testpollfds = NULL;
nset->free = 0;
nset->last_pollfds = 0;
nset->poll_lock = g_mutex_new ();
ensure_size (nset, MIN_POLLFDS);
break;
case GST_FDSET_MODE_EPOLL:
g_warning ("implement EPOLL mode in GstFDSet");
break;
default:
break;
}
return nset;
}
void
gst_fdset_free (GstFDSet * set)
{
g_return_if_fail (set != NULL);
switch (set->mode) {
case GST_FDSET_MODE_SELECT:
break;
case GST_FDSET_MODE_POLL:
g_free (set->testpollfds);
g_free (set->pollfds);
g_mutex_free (set->poll_lock);
break;
case GST_FDSET_MODE_EPOLL:
g_warning ("implement EPOLL mode in GstFDSet");
break;
default:
break;
}
g_free (set);
}
void
gst_fdset_set_mode (GstFDSet * set, GstFDSetMode mode)
{
g_return_if_fail (set != NULL);
g_warning ("implement set_mode in GstFDSet");
}
GstFDSetMode
gst_fdset_get_mode (GstFDSet * set)
{
g_return_val_if_fail (set != NULL, FALSE);
return set->mode;
}
gboolean
gst_fdset_add_fd (GstFDSet * set, GstFD * fd)
{
gboolean res = FALSE;
g_return_val_if_fail (set != NULL, FALSE);
g_return_val_if_fail (fd != NULL, FALSE);
switch (set->mode) {
case GST_FDSET_MODE_SELECT:
res = TRUE;
break;
case GST_FDSET_MODE_POLL:
{
struct pollfd *nfd;
gint idx;
g_mutex_lock (set->poll_lock);
ensure_size (set, set->last_pollfds + 1);
idx = set->free;
if (idx == -1) {
/* find free space */
while (idx < set->last_pollfds) {
idx++;
if (set->pollfds[idx].fd == -1)
break;
}
}
nfd = &set->pollfds[idx];
nfd->fd = fd->fd;
nfd->events = POLLERR | POLLNVAL | POLLHUP;
nfd->revents = 0;
/* see if we have one fd more */
set->last_pollfds = MAX (idx + 1, set->last_pollfds);
fd->idx = idx;
set->free = -1;
g_mutex_unlock (set->poll_lock);
res = TRUE;
break;
}
case GST_FDSET_MODE_EPOLL:
break;
}
return res;
}
gboolean
gst_fdset_remove_fd (GstFDSet * set, GstFD * fd)
{
gboolean res = FALSE;
g_return_val_if_fail (set != NULL, FALSE);
g_return_val_if_fail (fd != NULL, FALSE);
switch (set->mode) {
case GST_FDSET_MODE_SELECT:
/* nothing */
FD_CLR (fd->fd, &set->writefds);
FD_CLR (fd->fd, &set->readfds);
res = TRUE;
break;
case GST_FDSET_MODE_POLL:
{
g_mutex_lock (set->poll_lock);
/* FIXME on some platforms poll doesn't ignore the fd
* when set to -1 */
set->pollfds[fd->idx].fd = -1;
set->pollfds[fd->idx].events = 0;
set->pollfds[fd->idx].revents = 0;
/* if we removed the last fd, we can lower the last_pollfds */
if (fd->idx + 1 == set->last_pollfds) {
set->last_pollfds--;
}
fd->idx = -1;
if (set->free == -1) {
set->free = fd->idx;
} else {
set->free = MIN (set->free, fd->idx);
}
g_mutex_unlock (set->poll_lock);
res = TRUE;
break;
}
case GST_FDSET_MODE_EPOLL:
break;
}
return res;
}
void
gst_fdset_fd_ctl_write (GstFDSet * set, GstFD * fd, gboolean active)
{
g_return_if_fail (set != NULL);
g_return_if_fail (fd != NULL);
switch (set->mode) {
case GST_FDSET_MODE_SELECT:
if (active)
FD_SET (fd->fd, &set->writefds);
else
FD_CLR (fd->fd, &set->writefds);
break;
case GST_FDSET_MODE_POLL:
{
gint idx;
g_mutex_lock (set->poll_lock);
idx = fd->idx;
if (idx >= 0) {
gint events = set->pollfds[idx].events;
if (active)
events |= POLLOUT;
else
events &= ~POLLOUT;
set->pollfds[idx].events = events;
}
g_mutex_unlock (set->poll_lock);
break;
}
case GST_FDSET_MODE_EPOLL:
break;
}
}
void
gst_fdset_fd_ctl_read (GstFDSet * set, GstFD * fd, gboolean active)
{
g_return_if_fail (set != NULL);
g_return_if_fail (fd != NULL);
switch (set->mode) {
case GST_FDSET_MODE_SELECT:
if (active)
FD_SET (fd->fd, &set->readfds);
else
FD_CLR (fd->fd, &set->readfds);
break;
case GST_FDSET_MODE_POLL:
{
gint idx;
g_mutex_lock (set->poll_lock);
idx = fd->idx;
if (idx >= 0) {
gint events = set->pollfds[idx].events;
if (active)
events |= (POLLIN | POLLPRI);
else
events &= ~(POLLIN | POLLPRI);
set->pollfds[idx].events = events;
}
g_mutex_unlock (set->poll_lock);
break;
}
case GST_FDSET_MODE_EPOLL:
break;
}
}
gboolean
gst_fdset_fd_has_closed (GstFDSet * set, GstFD * fd)
{
gboolean res = FALSE;
g_return_val_if_fail (set != NULL, FALSE);
g_return_val_if_fail (fd != NULL, FALSE);
switch (set->mode) {
case GST_FDSET_MODE_SELECT:
res = FALSE;
break;
case GST_FDSET_MODE_POLL:
{
gint idx;
g_mutex_lock (set->poll_lock);
idx = fd->idx;
if (idx >= 0 && idx < set->last_testpollfds) {
res = (set->testpollfds[idx].revents & POLLHUP) != 0;
}
g_mutex_unlock (set->poll_lock);
break;
}
case GST_FDSET_MODE_EPOLL:
break;
}
return res;
}
gboolean
gst_fdset_fd_has_error (GstFDSet * set, GstFD * fd)
{
gboolean res = FALSE;
g_return_val_if_fail (set != NULL, FALSE);
g_return_val_if_fail (fd != NULL, FALSE);
switch (set->mode) {
case GST_FDSET_MODE_SELECT:
res = FALSE;
break;
case GST_FDSET_MODE_POLL:
{
gint idx;
g_mutex_lock (set->poll_lock);
idx = fd->idx;
if (idx >= 0 && idx < set->last_testpollfds) {
res = (set->testpollfds[idx].revents & (POLLERR | POLLNVAL)) != 0;
}
g_mutex_unlock (set->poll_lock);
break;
}
case GST_FDSET_MODE_EPOLL:
break;
}
return res;
}
gboolean
gst_fdset_fd_can_read (GstFDSet * set, GstFD * fd)
{
gboolean res = FALSE;
g_return_val_if_fail (set != NULL, FALSE);
g_return_val_if_fail (fd != NULL, FALSE);
switch (set->mode) {
case GST_FDSET_MODE_SELECT:
res = FD_ISSET (fd->fd, &set->testreadfds);
break;
case GST_FDSET_MODE_POLL:
{
gint idx;
g_mutex_lock (set->poll_lock);
idx = fd->idx;
if (idx >= 0 && idx < set->last_testpollfds) {
res = (set->testpollfds[idx].revents & (POLLIN | POLLPRI)) != 0;
}
g_mutex_unlock (set->poll_lock);
break;
}
case GST_FDSET_MODE_EPOLL:
break;
}
return res;
}
gboolean
gst_fdset_fd_can_write (GstFDSet * set, GstFD * fd)
{
gboolean res = FALSE;
g_return_val_if_fail (set != NULL, FALSE);
g_return_val_if_fail (fd != NULL, FALSE);
switch (set->mode) {
case GST_FDSET_MODE_SELECT:
res = FD_ISSET (fd->fd, &set->testwritefds);
break;
case GST_FDSET_MODE_POLL:
{
gint idx;
g_mutex_lock (set->poll_lock);
idx = fd->idx;
if (idx >= 0 && idx < set->last_testpollfds) {
res = (set->testpollfds[idx].revents & POLLOUT) != 0;
}
g_mutex_unlock (set->poll_lock);
break;
}
case GST_FDSET_MODE_EPOLL:
break;
}
return res;
}
gint
gst_fdset_wait (GstFDSet * set, int timeout)
{
int res = -1;
g_return_val_if_fail (set != NULL, -1);
switch (set->mode) {
case GST_FDSET_MODE_SELECT:
{
struct timeval tv;
struct timeval *tvptr;
set->testreadfds = set->readfds;
set->testwritefds = set->writefds;
if (timeout > 0) {
tv.tv_sec = timeout / 1000;
tv.tv_usec = timeout % 1000;
tvptr = &tv;
} else {
tvptr = NULL;
}
res =
select (FD_SETSIZE, &set->testreadfds, &set->testwritefds,
(fd_set *) 0, tvptr);
break;
}
case GST_FDSET_MODE_POLL:
{
g_mutex_lock (set->poll_lock);
if (set->testsize != set->size) {
set->testpollfds = resize (set->testpollfds, set->testsize, set->size);
set->testsize = set->size;
}
set->last_testpollfds = set->last_pollfds;
memcpy (set->testpollfds, set->pollfds,
sizeof (struct pollfd) * set->last_testpollfds);
g_mutex_unlock (set->poll_lock);
res = poll (set->testpollfds, set->last_testpollfds, timeout);
break;
}
case GST_FDSET_MODE_EPOLL:
break;
}
return res;
}