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Make refcounting threadsafe by using atomic operations. (#166020, Wim

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2005-07-15  Matthias Clasen  <mclasen@redhat.com>

	Make refcounting threadsafe by using atomic
	operations.  (#166020, Wim Taymans)

	* gobject.c: Use a recursive lock to protect the
	notify queue.
	(g_object_unref): Get rid of g_object_last_unref and
	do the last unref handling in g_object_unref.
	(g_object_ref, g_object_unref): Use atomic operations.

	* gsignal.c (struct _HandlerMatch): Use a full integer
	for the ref_count field.
	(handler_ref, handler_unref_R): Use atomic operations.

	* gparam.c (g_param_spec_ref, g_param_spec_unref):
	Use atomic operations instead of a lock to make the
	refcounting threadsafe.

	* gclosure.c (g_closure_ref, g_closure_unref): Use atomic
	operations. This is more complicated here, since the
	refcount is stored in a bitfield, so we also have
	to access all other bitfield members atomically.

	* gsignal.c (handlers_find): Read the meta_marshal flag
	of the closure atomically.

	* tests/Makefile.am (SUBDIRS): Add tests/refcount

	* configure.in: Add tests/refcount

	* tests/refcount/properties.c: Test property changes
	from multiple threads.

	* tests/refcount/signals.c: Test signal emission from
	multiple threads.

	* tests/refcount/objects.c: Test refcounting from
	multiple threads.

	* tests/refcount/objects2.c:
	* tests/refcount/properties2.c: Tests to measure the
	overhead of threadsafe refcounting.

	* glib/giochannel.c (g_io_channel_ref, g_io_channel_unref):
	Use atomic operations to make refcounting
	threadsafe.  (#166020, Wim Taymans)
This commit is contained in:
Matthias Clasen
2005-07-15 16:51:10 +00:00
committed by Matthias Clasen
parent 58729b464b
commit 39ea11ce6b
18 changed files with 1576 additions and 242 deletions
Download Patch File Download Diff File Expand all files Collapse all files

94
gobject/gsignal.c
View File

@@ -222,8 +222,7 @@ struct _Handler
Handler *next;
Handler *prev;
GQuark detail;
guint ref_count : 16;
#define HANDLER_MAX_REF_COUNT (1 << 16)
guint ref_count; /* ABI change, was 16 bits but since it's internal... */
guint block_count : 12;
#define HANDLER_MAX_BLOCK_COUNT (1 << 12)
guint after : 1;
@@ -455,6 +454,17 @@ handler_match_free1_R (HandlerMatch *node,
return next;
}
/* copy of gclosure.c code here to make the first 32 bits of the closure
* atomic. */
typedef union
{
GClosure bits;
gint atomic;
} GAtomicClosureBits;
#define BITS_AS_INT(b) (((GAtomicClosureBits*)(b))->atomic)
#define CLOSURE_READ_BITS(cl,bits) (BITS_AS_INT(bits) = g_atomic_int_get ((gint*)(cl)))
static HandlerMatch*
handlers_find (gpointer instance,
GSignalMatchType mask,
@@ -481,20 +491,26 @@ handlers_find (gpointer instance,
}
mask = ~mask;
for (handler = hlist ? hlist->handlers : NULL; handler; handler = handler->next)
if (handler->sequential_number &&
((mask & G_SIGNAL_MATCH_DETAIL) || handler->detail == detail) &&
((mask & G_SIGNAL_MATCH_CLOSURE) || handler->closure == closure) &&
((mask & G_SIGNAL_MATCH_DATA) || handler->closure->data == data) &&
((mask & G_SIGNAL_MATCH_UNBLOCKED) || handler->block_count == 0) &&
((mask & G_SIGNAL_MATCH_FUNC) || (handler->closure->marshal == node->c_marshaller &&
handler->closure->meta_marshal == 0 &&
((GCClosure*) handler->closure)->callback == func)))
{
mlist = handler_match_prepend (mlist, handler, signal_id);
if (one_and_only)
return mlist;
}
for (handler = hlist ? hlist->handlers : NULL; handler; handler = handler->next)
{
GClosure bits;
CLOSURE_READ_BITS (handler->closure, &bits);
if (handler->sequential_number &&
((mask & G_SIGNAL_MATCH_DETAIL) || handler->detail == detail) &&
((mask & G_SIGNAL_MATCH_CLOSURE) || handler->closure == closure) &&
((mask & G_SIGNAL_MATCH_DATA) || handler->closure->data == data) &&
((mask & G_SIGNAL_MATCH_UNBLOCKED) || handler->block_count == 0) &&
((mask & G_SIGNAL_MATCH_FUNC) || (handler->closure->marshal == node->c_marshaller &&
bits.meta_marshal == 0 &&
((GCClosure*) handler->closure)->callback == func)))
{
mlist = handler_match_prepend (mlist, handler, signal_id);
if (one_and_only)
return mlist;
}
}
}
else
{
@@ -519,19 +535,25 @@ handlers_find (gpointer instance,
}
for (handler = hlist->handlers; handler; handler = handler->next)
if (handler->sequential_number &&
((mask & G_SIGNAL_MATCH_DETAIL) || handler->detail == detail) &&
((mask & G_SIGNAL_MATCH_CLOSURE) || handler->closure == closure) &&
((mask & G_SIGNAL_MATCH_DATA) || handler->closure->data == data) &&
((mask & G_SIGNAL_MATCH_UNBLOCKED) || handler->block_count == 0) &&
((mask & G_SIGNAL_MATCH_FUNC) || (handler->closure->marshal == node->c_marshaller &&
handler->closure->meta_marshal == 0 &&
((GCClosure*) handler->closure)->callback == func)))
{
mlist = handler_match_prepend (mlist, handler, hlist->signal_id);
if (one_and_only)
return mlist;
}
{
GClosure bits;
CLOSURE_READ_BITS (handler->closure, &bits);
if (handler->sequential_number &&
((mask & G_SIGNAL_MATCH_DETAIL) || handler->detail == detail) &&
((mask & G_SIGNAL_MATCH_CLOSURE) || handler->closure == closure) &&
((mask & G_SIGNAL_MATCH_DATA) || handler->closure->data == data) &&
((mask & G_SIGNAL_MATCH_UNBLOCKED) || handler->block_count == 0) &&
((mask & G_SIGNAL_MATCH_FUNC) || (handler->closure->marshal == node->c_marshaller &&
bits.meta_marshal == 0 &&
((GCClosure*) handler->closure)->callback == func)))
{
mlist = handler_match_prepend (mlist, handler, hlist->signal_id);
if (one_and_only)
return mlist;
}
}
}
}
}
@@ -567,12 +589,7 @@ handler_ref (Handler *handler)
{
g_return_if_fail (handler->ref_count > 0);
#ifndef G_DISABLE_CHECKS
if (handler->ref_count >= HANDLER_MAX_REF_COUNT - 1)
g_error (G_STRLOC ": handler ref_count overflow, %s", REPORT_BUG);
#endif
handler->ref_count += 1;
g_atomic_int_inc (&handler->ref_count);
}
static inline void
@@ -580,10 +597,13 @@ handler_unref_R (guint signal_id,
gpointer instance,
Handler *handler)
{
gboolean is_zero;
g_return_if_fail (handler->ref_count > 0);
handler->ref_count -= 1;
if (!handler->ref_count)
is_zero = g_atomic_int_dec_and_test (&handler->ref_count);
if (G_UNLIKELY (is_zero))
{
HandlerList *hlist = NULL;