mutter/clutter/clutter-timeout-pool.c
Emmanuele Bassi d3d29b194e 2008-09-23 Emmanuele Bassi <ebassi@linux.intel.com>
* clutter/clutter-timeout-pool.c: Reword previous commit.
2008-09-23 13:25:31 +00:00

546 lines
15 KiB
C

/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Authored By Matthew Allum <mallum@openedhand.com>
*
* Copyright (C) 2006 OpenedHand
*
* 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 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
* ClutterTimeoutPool: pool of timeout functions using the same slice of
* the GLib main loop
*
* Author: Emmanuele Bassi <ebassi@openedhand.com>
*
* Based on similar code by Tristan van Berkom
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "clutter-debug.h"
#include "clutter-timeout-pool.h"
typedef struct _ClutterTimeout ClutterTimeout;
typedef enum {
CLUTTER_TIMEOUT_NONE = 0,
CLUTTER_TIMEOUT_READY = 1 << 1
} ClutterTimeoutFlags;
struct _ClutterTimeout
{
guint id;
ClutterTimeoutFlags flags;
gint refcount;
guint interval;
guint last_time;
GSourceFunc func;
gpointer data;
GDestroyNotify notify;
};
struct _ClutterTimeoutPool
{
GSource source;
guint next_id;
GTimeVal start_time;
GList *timeouts, *dispatched_timeouts;
gint ready;
guint id;
};
#define TIMEOUT_READY(timeout) (timeout->flags & CLUTTER_TIMEOUT_READY)
static gboolean clutter_timeout_pool_prepare (GSource *source,
gint *next_timeout);
static gboolean clutter_timeout_pool_check (GSource *source);
static gboolean clutter_timeout_pool_dispatch (GSource *source,
GSourceFunc callback,
gpointer data);
static void clutter_timeout_pool_finalize (GSource *source);
static GSourceFuncs clutter_timeout_pool_funcs =
{
clutter_timeout_pool_prepare,
clutter_timeout_pool_check,
clutter_timeout_pool_dispatch,
clutter_timeout_pool_finalize
};
static gint
clutter_timeout_sort (gconstpointer a,
gconstpointer b)
{
const ClutterTimeout *t_a = a;
const ClutterTimeout *t_b = b;
gint comparison;
/* Keep 'ready' timeouts at the front */
if (TIMEOUT_READY (t_a))
return -1;
if (TIMEOUT_READY (t_b))
return 1;
/* Otherwise sort by expiration time */
comparison = (t_a->last_time + t_a->interval)
- (t_b->last_time + t_b->interval);
if (comparison < 0)
return -1;
if (comparison > 0)
return 1;
return 0;
}
static gint
clutter_timeout_find_by_id (gconstpointer a,
gconstpointer b)
{
const ClutterTimeout *t_a = a;
return t_a->id == GPOINTER_TO_UINT (b) ? 0 : 1;
}
static guint
clutter_timeout_pool_get_ticks (ClutterTimeoutPool *pool)
{
GTimeVal time_now;
g_source_get_current_time ((GSource *) pool, &time_now);
return (time_now.tv_sec - pool->start_time.tv_sec) * 1000
+ (time_now.tv_usec - pool->start_time.tv_usec) / 1000;
}
static gboolean
clutter_timeout_prepare (ClutterTimeoutPool *pool,
ClutterTimeout *timeout,
gint *next_timeout)
{
guint now = clutter_timeout_pool_get_ticks (pool);
/* If time has gone backwards or the time since the last frame is
greater than the two frames worth then reset the time and do a
frame now */
if (timeout->last_time > now || now - timeout->last_time
> timeout->interval * 2)
{
timeout->last_time = now - timeout->interval;
if (next_timeout)
*next_timeout = 0;
return TRUE;
}
else if (now - timeout->last_time >= timeout->interval)
{
if (next_timeout)
*next_timeout = 0;
return TRUE;
}
else
{
if (next_timeout)
*next_timeout = timeout->interval + timeout->last_time - now;
return FALSE;
}
}
static gboolean
clutter_timeout_dispatch (GSource *source,
ClutterTimeout *timeout)
{
gboolean retval = FALSE;
if (G_UNLIKELY (!timeout->func))
{
g_warning ("Timeout dispatched without a callback.");
return FALSE;
}
if (timeout->func (timeout->data))
{
timeout->last_time += timeout->interval;
retval = TRUE;
}
return retval;
}
static ClutterTimeout *
clutter_timeout_new (guint interval)
{
ClutterTimeout *timeout;
timeout = g_slice_new0 (ClutterTimeout);
timeout->interval = interval;
timeout->flags = CLUTTER_TIMEOUT_NONE;
timeout->refcount = 1;
return timeout;
}
/* ref and unref are always called under the main Clutter lock, so there
* is not need for us to use g_atomic_int_* API.
*/
static ClutterTimeout *
clutter_timeout_ref (ClutterTimeout *timeout)
{
g_return_val_if_fail (timeout != NULL, timeout);
g_return_val_if_fail (timeout->refcount > 0, timeout);
timeout->refcount += 1;
return timeout;
}
static void
clutter_timeout_unref (ClutterTimeout *timeout)
{
g_return_if_fail (timeout != NULL);
g_return_if_fail (timeout->refcount > 0);
timeout->refcount -= 1;
if (timeout->refcount == 0)
{
if (timeout->notify)
timeout->notify (timeout->data);
g_slice_free (ClutterTimeout, timeout);
}
}
static void
clutter_timeout_free (ClutterTimeout *timeout)
{
if (G_LIKELY (timeout))
{
if (timeout->notify)
timeout->notify (timeout->data);
g_slice_free (ClutterTimeout, timeout);
}
}
static gboolean
clutter_timeout_pool_prepare (GSource *source,
gint *next_timeout)
{
ClutterTimeoutPool *pool = (ClutterTimeoutPool *) source;
GList *l = pool->timeouts;
/* the pool is ready if the first timeout is ready */
if (l && l->data)
{
ClutterTimeout *timeout = l->data;
return clutter_timeout_prepare (pool, timeout, next_timeout);
}
else
{
*next_timeout = -1;
return FALSE;
}
}
static gboolean
clutter_timeout_pool_check (GSource *source)
{
ClutterTimeoutPool *pool = (ClutterTimeoutPool *) source;
GList *l = pool->timeouts;
clutter_threads_enter ();
for (l = pool->timeouts; l; l = l->next)
{
ClutterTimeout *timeout = l->data;
/* since the timeouts are sorted by expiration, as soon
* as we get a check returning FALSE we know that the
* following timeouts are not expiring, so we break as
* soon as possible
*/
if (clutter_timeout_prepare (pool, timeout, NULL))
{
timeout->flags |= CLUTTER_TIMEOUT_READY;
pool->ready += 1;
}
else
break;
}
clutter_threads_leave ();
return (pool->ready > 0);
}
static gboolean
clutter_timeout_pool_dispatch (GSource *source,
GSourceFunc func,
gpointer data)
{
ClutterTimeoutPool *pool = (ClutterTimeoutPool *) source;
GList *dispatched_timeouts;
/* the main loop might have predicted this, so we repeat the
* check for ready timeouts.
*/
if (!pool->ready)
clutter_timeout_pool_check (source);
clutter_threads_enter ();
/* Iterate by moving the actual start of the list along so that it
* can cope with adds and removes while a timeout is being dispatched
*/
while (pool->timeouts && pool->timeouts->data && pool->ready-- > 0)
{
ClutterTimeout *timeout = pool->timeouts->data;
GList *l;
/* One of the ready timeouts may have been removed during dispatch,
* in which case pool->ready will be wrong, but the ready timeouts
* are always kept at the start of the list so we can stop once
* we've reached the first non-ready timeout
*/
if (!(TIMEOUT_READY (timeout)))
break;
/* Add a reference to the timeout so it can't disappear
* while it's being dispatched
*/
clutter_timeout_ref (timeout);
timeout->flags &= ~CLUTTER_TIMEOUT_READY;
/* Move the list node to a list of dispatched timeouts */
l = pool->timeouts;
if (l->next)
l->next->prev = NULL;
pool->timeouts = l->next;
if (pool->dispatched_timeouts)
pool->dispatched_timeouts->prev = l;
l->prev = NULL;
l->next = pool->dispatched_timeouts;
pool->dispatched_timeouts = l;
if (!clutter_timeout_dispatch (source, timeout))
{
/* The timeout may have already been removed, but nothing
* can be added to the dispatched_timeout list except in this
* function so it will always either be at the head of the
* dispatched list or have been removed
*/
if (pool->dispatched_timeouts &&
pool->dispatched_timeouts->data == timeout)
{
pool->dispatched_timeouts =
g_list_delete_link (pool->dispatched_timeouts,
pool->dispatched_timeouts);
/* Remove the reference that was held by it being in the list */
clutter_timeout_unref (timeout);
}
}
clutter_timeout_unref (timeout);
}
/* Re-insert the dispatched timeouts in sorted order */
dispatched_timeouts = pool->dispatched_timeouts;
while (dispatched_timeouts)
{
ClutterTimeout *timeout = dispatched_timeouts->data;
GList *next = dispatched_timeouts->next;
if (timeout)
pool->timeouts = g_list_insert_sorted (pool->timeouts, timeout,
clutter_timeout_sort);
dispatched_timeouts = next;
}
g_list_free (pool->dispatched_timeouts);
pool->dispatched_timeouts = NULL;
pool->ready = 0;
clutter_threads_leave ();
return TRUE;
}
static void
clutter_timeout_pool_finalize (GSource *source)
{
ClutterTimeoutPool *pool = (ClutterTimeoutPool *) source;
/* force destruction */
g_list_foreach (pool->timeouts, (GFunc) clutter_timeout_free, NULL);
g_list_free (pool->timeouts);
}
/**
* clutter_timeout_pool_new:
* @priority: the priority of the timeout pool. Typically this will
* be #G_PRIORITY_DEFAULT
*
* Creates a new timeout pool source. A timeout pool should be used when
* multiple timeout functions, running at the same priority, are needed and
* the g_timeout_add() API might lead to starvation of the time slice of
* the main loop. A timeout pool allocates a single time slice of the main
* loop and runs every timeout function inside it. The timeout pool is
* always sorted, so that the extraction of the next timeout function is
* a constant time operation.
*
* Inside Clutter, every #ClutterTimeline share the same timeout pool, unless
* the CLUTTER_TIMELINE=no-pool environment variable is set.
*
* #ClutterTimeoutPool is part of the #ClutterTimeline implementation
* and should not be used by application developers.
*
* Return value: the newly created #ClutterTimeoutPool. The created pool
* is owned by the GLib default context and will be automatically
* destroyed when the context is destroyed. It is possible to force
* the destruction of the timeout pool using g_source_destroy()
*
* Since: 0.4
*/
ClutterTimeoutPool *
clutter_timeout_pool_new (gint priority)
{
ClutterTimeoutPool *pool;
GSource *source;
source = g_source_new (&clutter_timeout_pool_funcs,
sizeof (ClutterTimeoutPool));
if (!source)
return NULL;
if (priority != G_PRIORITY_DEFAULT)
g_source_set_priority (source, priority);
pool = (ClutterTimeoutPool *) source;
g_get_current_time (&pool->start_time);
pool->next_id = 1;
pool->id = g_source_attach (source, NULL);
/* let the default GLib context manage the pool */
g_source_unref (source);
return pool;
}
/**
* clutter_timeout_pool_add:
* @pool: a #ClutterTimeoutPool
* @interval: the time between calls to the function, in milliseconds
* @func: function to call
* @data: data to pass to the function, or %NULL
* @notify: function to call when the timeout is removed, or %NULL
*
* Sets a function to be called at regular intervals, and puts it inside
* the @pool. The function is repeatedly called until it returns %FALSE,
* at which point the timeout is automatically destroyed and the function
* won't be called again. If @notify is not %NULL, the @notify function
* will be called. The first call to @func will be at the end of @interval.
*
* Since version 0.8 this will try to compensate for delays. For
* example, if @func takes half the interval time to execute then the
* function will be called again half the interval time after it
* finished. Before version 0.8 it would not fire until a full
* interval after the function completes so the delay between calls
* would be @interval * 1.5. This function does not however try to
* invoke the function multiple times to catch up missing frames if
* @func takes more than @interval ms to execute.
*
* Return value: the ID (greater than 0) of the timeout inside the pool.
* Use clutter_timeout_pool_remove() to stop the timeout.
*
* Since: 0.4
*/
guint
clutter_timeout_pool_add (ClutterTimeoutPool *pool,
guint interval,
GSourceFunc func,
gpointer data,
GDestroyNotify notify)
{
ClutterTimeout *timeout;
guint retval = 0;
timeout = clutter_timeout_new (interval);
retval = timeout->id = pool->next_id++;
timeout->last_time = clutter_timeout_pool_get_ticks (pool);
timeout->func = func;
timeout->data = data;
timeout->notify = notify;
pool->timeouts = g_list_insert_sorted (pool->timeouts, timeout,
clutter_timeout_sort);
return retval;
}
/**
* clutter_timeout_pool_remove:
* @pool: a #ClutterTimeoutPool
* @id: the id of the timeout to remove
*
* Removes a timeout function with @id from the timeout pool. The id
* is the same returned when adding a function to the timeout pool with
* clutter_timeout_pool_add().
*
* Since: 0.4
*/
void
clutter_timeout_pool_remove (ClutterTimeoutPool *pool,
guint id)
{
GList *l;
if ((l = g_list_find_custom (pool->timeouts, GUINT_TO_POINTER (id),
clutter_timeout_find_by_id)))
{
clutter_timeout_unref (l->data);
pool->timeouts = g_list_delete_link (pool->timeouts, l);
}
else if ((l = g_list_find_custom (pool->dispatched_timeouts,
GUINT_TO_POINTER (id),
clutter_timeout_find_by_id)))
{
clutter_timeout_unref (l->data);
pool->dispatched_timeouts
= g_list_delete_link (pool->dispatched_timeouts, l);
}
}