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2007-06-14 Emmanuele Bassi <ebassi@openedhand.com>

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* clutter/clutter-timeout-pool.c: Make ClutterTimeoutPool
	more thread-safe, using a static lock.

	(clutter_timeout_pool_dispatch), (clutter_timeout_pool_remove): Fix
	a race condition-turned-in-memory corruption bug, triggered by
	removing a timeout from the pool while still spinning the pool
	source.
This commit is contained in:
Emmanuele Bassi 2007-06-14 12:00:31 +00:00
parent 358269be3e
commit ba0fa9d4be
2 changed files with 82 additions and 9 deletions
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12
ChangeLog
View File

@ -1,4 +1,14 @@
2007-06-07 Emmanuele Bassi <ebassi@openedhand.com>
2007-06-14 Emmanuele Bassi <ebassi@openedhand.com>
* clutter/clutter-timeout-pool.c: Make ClutterTimeoutPool
more thread-safe, using a static lock.
(clutter_timeout_pool_dispatch), (clutter_timeout_pool_remove): Fix
a race condition-turned-in-memory corruption bug, triggered by
removing a timeout from the pool while still spinning the pool
source.
2007-06-14 Emmanuele Bassi <ebassi@openedhand.com>
* configure.ac:
* doc/manual/Makefile.am: Find xmlto and jw in the path and

75
clutter/clutter-timeout-pool.c
View File

@ -36,10 +36,16 @@
#include "clutter-timeout-pool.h"
typedef struct _ClutterTimeout ClutterTimeout;
typedef enum {
CLUTTER_TIMEOUT_NONE = 0,
CLUTTER_TIMEOUT_ACTIVE = 1 << 0,
CLUTTER_TIMEOUT_READY = 1 << 1
} ClutterTimeoutFlags;
struct _ClutterTimeout
{
guint id;
ClutterTimeoutFlags flags;
guint interval;
@ -54,6 +60,7 @@ struct _ClutterTimeoutPool
{
GSource source;
GStaticMutex mutex;
guint next_id;
GList *timeouts;
@ -62,6 +69,12 @@ struct _ClutterTimeoutPool
guint id;
};
#define LOCK_POOL(pool) g_static_mutex_lock (&pool->mutex);
#define UNLOCK_POOL(pool) g_static_mutex_unlock (&pool->mutex);
#define TIMEOUT_REMOVED(timeout) ((timeout->flags & CLUTTER_TIMEOUT_ACTIVE) == 0)
#define TIMEOUT_READY(timeout) ((timeout->flags & CLUTTER_TIMEOUT_READY) == 1)
static gboolean clutter_timeout_pool_prepare (GSource *source,
gint *next_timeout);
static gboolean clutter_timeout_pool_check (GSource *source);
@ -201,6 +214,7 @@ clutter_timeout_new (guint interval)
timeout = g_slice_new0 (ClutterTimeout);
timeout->interval = interval;
timeout->flags = CLUTTER_TIMEOUT_NONE;
g_get_current_time (&current_time);
clutter_timeout_set_expiration (timeout, &current_time);
@ -227,7 +241,8 @@ clutter_timeout_pool_prepare (GSource *source,
ClutterTimeoutPool *pool = (ClutterTimeoutPool *) source;
GList *l = pool->timeouts;
if (l)
/* the pool is ready if the first timeout is ready */
if (l && l->data)
{
ClutterTimeout *timeout = l->data;
return clutter_timeout_prepare (source, timeout, next_timeout);
@ -245,13 +260,27 @@ clutter_timeout_pool_check (GSource *source)
ClutterTimeoutPool *pool = (ClutterTimeoutPool *) source;
GList *l = pool->timeouts;
LOCK_POOL (pool);
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_check (source, timeout))
{
timeout->flags |= CLUTTER_TIMEOUT_READY;
pool->ready += 1;
}
else
break;
}
UNLOCK_POOL (pool);
return (pool->ready > 0);
}
@ -265,22 +294,40 @@ clutter_timeout_pool_dispatch (GSource *source,
GList *l = pool->timeouts;
gboolean sort_needed = FALSE;
LOCK_POOL (pool);
/* the main loop might have predicted this, so we repeat the
* check for ready timeouts.
*/
if (!pool->ready)
{
UNLOCK_POOL (pool);
clutter_timeout_pool_check (source);
LOCK_POOL (pool);
}
while (l && l->data && (pool->ready-- > 0))
{
ClutterTimeout *timeout = l->data;
GList *next = l->next;
gboolean needs_removing = FALSE;
if (clutter_timeout_dispatch (source, timeout))
timeout->flags &= ~CLUTTER_TIMEOUT_READY;
if (!TIMEOUT_REMOVED (timeout))
{
sort_needed = TRUE;
needs_removing = !clutter_timeout_dispatch (source, timeout);
sort_needed = needs_removing;
}
else
needs_removing = TRUE;
if (needs_removing)
{
pool->timeouts = g_list_delete_link (pool->timeouts, l);
pool->timeouts = g_list_remove_link (pool->timeouts, l);
clutter_timeout_free (timeout);
g_list_free1 (l);
}
l = next;
@ -291,6 +338,8 @@ clutter_timeout_pool_dispatch (GSource *source,
pool->ready = 0;
UNLOCK_POOL (pool);
return TRUE;
}
@ -299,6 +348,8 @@ clutter_timeout_pool_finalize (GSource *source)
{
ClutterTimeoutPool *pool = (ClutterTimeoutPool *) source;
g_static_mutex_free (&pool->mutex);
g_list_foreach (pool->timeouts, (GFunc) clutter_timeout_free, NULL);
g_list_free (pool->timeouts);
}
@ -337,6 +388,7 @@ clutter_timeout_pool_new (gint priority)
g_source_set_priority (source, priority);
pool = (ClutterTimeoutPool *) source;
g_static_mutex_init (&pool->mutex);
pool->next_id = 1;
pool->id = g_source_attach (source, NULL);
g_source_unref (source);
@ -379,7 +431,11 @@ clutter_timeout_pool_add (ClutterTimeoutPool *pool,
ClutterTimeout *timeout;
guint retval = 0;
LOCK_POOL (pool);
timeout = clutter_timeout_new (interval);
timeout->flags |= CLUTTER_TIMEOUT_ACTIVE;
retval = timeout->id = pool->next_id++;
timeout->func = func;
@ -389,6 +445,8 @@ clutter_timeout_pool_add (ClutterTimeoutPool *pool,
pool->timeouts = g_list_insert_sorted (pool->timeouts, timeout,
clutter_timeout_sort);
UNLOCK_POOL (pool);
return retval;
}
@ -409,11 +467,16 @@ clutter_timeout_pool_remove (ClutterTimeoutPool *pool,
{
GList *l;
LOCK_POOL (pool);
l = g_list_find_custom (pool->timeouts, GUINT_TO_POINTER (id),
clutter_timeout_find_by_id);
if (l)
{
clutter_timeout_free (l->data);
pool->timeouts = g_list_delete_link (pool->timeouts, l);
ClutterTimeout *timeout = l->data;
timeout->flags &= ~CLUTTER_TIMEOUT_ACTIVE;
}
UNLOCK_POOL (pool);
}