The function returns TRUE if the type was previously initialized and can
be easily reused. It returns FALSE and does not take a reference if the
type is not referenced yet.
g_type_class_ref() uses this to avoid taking locks in the common path,
which speeds up object creation a lot - in particular in multithreaded
applications.
https://bugzilla.gnome.org/show_bug.cgi?id=585375
This does not change any locking behavior at all, it just replaces
simple getters/setters of the variable with atomic versions.
The ref_count variable was kept as unsigned, even though that requires
casting for all operations, to mirror GObject->refcount.
https://bugzilla.gnome.org/show_bug.cgi?id=585375
Currently interface lookups are do a binary search over all the interfaces
an object implements. Its possible to do this lookup in constant time using for
instance the gcj algorighm described at:
http://gcc.gnu.org/ml/java/1999-q3/msg00377.html
This is an implementation of that based on GAtomicArray.
We implement lock free interface lookup by moving the n_ifaces
counter into memory pointed to by TypeNode->iface_entries, and
then updating this in RCU-style by always copying it, modifying
the copy and then when the modification is done replace the old
pointer with g_atomic_pointer_set.
There is one additional complexity when freeing the old memory,
since the old memory region can be in use. To handle this we
don't free such memory, but put it on a free list and reuse it
later. This means that lock-free lookups must be able to
handle the memory being modified in random ways without crashing,
and at the end we verify that the memory didn't change and the
transaction is ok.
With this infrastructure the patch then implements a lock-free
version of type_lookup_iface_entry_L called type_lookup_iface_vtable_I
and use it in: g_type_interface_peek, g_type_interface_peek_parent
and type_node_check_conformities_UorL.
Using the performance tests from bug 557100 shows that the general
performance difference is negligible, but the lack of a lock for each
type check and interface vfunc call should greatly enhance threaded
scalability.
The n_children variable can be written when locked, while the n_supers
variable is read at any time. As they both share the same bytes,
accessing them is not threadsafe.
This patch puts them into different bytes.
Thanks to Xan Lopez and valgrind for noticing this.
2008-07-27 Tor Lillqvist <tml@novell.com>
* gtype.h
* gtype.c: Revert my change from 2008-07-24. No G_TYPE_FORMAT is
needed. Just use G_GSIZE_FORMAT always when printing GType values.
svn path=/trunk/; revision=7256
2008-07-24 Tor Lillqvist <tml@novell.com>
* gtype.h: Define G_TYPE_FORMAT as the printf format for a GType
value. Either G_GSIZE_FORMAT or "lu".
* gtype.c: Use it instead of the C99 zu.
svn path=/trunk/; revision=7250
2008-06-22 Michael Natterer <mitch@imendio.com>
* *.c: remove trailing whitespace from newly added gtk-doc
comments and reformatted some where they contained overly long or
ill-formatted lines.
svn path=/trunk/; revision=7090
2008-06-22 Michael Natterer <mitch@imendio.com>
* *.c: moved includes back to the top of the files (before gtk-doc
SECTION comments). Add "config.h" in all files and move system
included before glib includes. Remove trailing whitespace from
SECTION comments and did some reformatting where lines were overly
long, no documentation content was changed.
svn path=/trunk/; revision=7089
* docs/reference/gobject/tmpl/gobject-unused.sgml:
* gobject/gobject.h:
* gobject/gtype.c:
* gobject/gtype.h:
Move some content for gobject-unused.sgml and cleared empty entries.
The remaining 4 ones should be checked by some else. If they are not
needed. The file can be removed.
svn path=/trunk/; revision=7087
2008-06-10 13:15:29 Tim Janik <timj@imendio.com>
* gtype.c (g_type_class_ref): fixed race condition where references to
partially initialized classes could be handed out.
svn path=/trunk/; revision=6982
2008-02-05 18:52:07 Tim Janik <timj@imendio.com>
* gtype.c: added recursive mutex to protect class initialization,
default interface initialization and per-class interface construction.
a lock to this recursive mutex is held during user callback invocations
such as initializers or finalizers, effectively allowing only one thread
to run class/interface initializers/finalizers at a time.
also made misc fixups. this fixes:
Bug 64764 - Class initialization isn't thread safe.
svn path=/trunk/; revision=6454
2006-06-14 Matthias Clasen <mclasen@redhat.com>
* glib/gkeyfile.c (g_key_file_to_data): Separate groups by
an empty line (#344868, Christian Persch)
2006-06-14 Tor Lillqvist <tml@novell.com>
Tue Nov 1 16:24:20 2005 Tim Janik <timj@imendio.com>
* glib/gmem.[hc]: prepared deprecation of GMemChunk and GAllocator.
added g_slice_*() API to allocate and cache small bits of memory.
an actuall allocator implementation for g_slice_*() is still pending.
* glib/gthread.[hc]: changes from a patch by Matthias Clasen.
changed GRealThread list to use in-structure *next; fields instead
of GSList, in order for thread iteration to not depenend on g_slice_*()
indirectly.
_g_thread_mem_private_get():
_g_thread_mem_private_set(): added accessors for private memory,
needed because the ordinary GPrivate implementation relies on GArray
and GSList and therefore indirectly on working g_slice_*() allocations.
* glib/gthread.[hc]:
g_thread_foreach(): new public API function to loop over all existing threads.
* glib/gdataset.c:
* glib/gstring.c:
* glib/gcache.c:
* glib/garray.c:
* glib/gqueue.c:
* glib/gslist.c:
* glib/glist.c:
* glib/ghash.c:
* glib/gtree.c:
* glib/ghook.c:
* glib/gmain.c:
* glib/gnode.c:
removed GAllocator and free list usages and accompanying locks.
use g_slice_*() API to allocate and cache small bits of memory.
* glib/ghook.h: removed GMemChunk field from public API.
* glib/gslist.h:
* glib/glist.h: deprecate allocator API, provide _free1() for consistency.
* glib/gnode.h: deprecate allocator API.
* glib/gmain.c: reordered GPollRec fields so g_slice_free_chain() can
be used for poll rec lists.
* glib/grel.c: removed mem chunk usage, and allocated tuples via g_slice_*().
g_relation_destroy(): free all tuples from the all_tuples hash table,
this effectively maintains the life time track keeping of tuples.
g_relation_delete_tuple(): free tuples which are removed from the
all_tuples hash table. this fixes a temporary leak that was present
in the memchunk code until the destruction of the relation.
2005-09-08 Kjartan Maraas <kmaraas@gnome.org>
* gclosure.c: (g_closure_set_meta_marshal): Remove some unused
code.
* gsignal.c: (g_signal_emitv): Same here
* gtype.c: (g_type_register_fundamental): And here
* testgobject.c: Mark some functions static.
2005-03-14 Matthias Clasen <mclasen@redhat.com>
* abicheck.sh: Make work again.
* gsourceclosure.c: Fix a typo.
Make PLT-reduction work with gcc4, and don't include
everything in gobjectalias.h:
* gobject.symbols: Group symbols by header and source
file.
* makegobjectalias.pl: Protect definitions by the same
preprocessor symbols used to guard the headers. Move
the alias declarations to a separate file which is
produced when calling makegalias.pl -def
* Makefile.am (gobjectaliasdef.c): Add a rule to
build this file.
* *.c: Include gobjectalias.h after the other i
GLib headers, include gobjectaliasdef.c at the bottom.
Wed Oct 6 02:12:44 2004 <timj@birnet.org>
* gtype.c (g_type_instance_get_private): applied patch from Jean-Yves
Lefort <jylefort@brutele.be> to not access the instance_real_class_bsa
pointer without holding the instance_real_class lock.
2004-09-16 Matthias Clasen <mclasen@redhat.com>
Implement the same PLT reduction technique used in GTK+:
* Makefile.am: Generate gobjectalias.h from gobject.symbols.
(BUILT_SOURCES): Add gobjectalias.h.
* makegobjectalias.pl: Script to generate gobjectalias.h.
* *.c: Include gobjectalias.h
2004-09-16 Matthias Clasen <mclasen@redhat.com>
Add ABI control using the same technique that is used in GTK+.
* gobject.symbols: Master list of symbols.
* gobject.def: Removed. It is now generated from gobject.symbols.
* Makefile.am (gobject.def): Generate from gobject.symbols.
(TESTS): Add abicheck.sh
(EXTRA_DIST): Add abicheck.sh
(export_symbols): Don't export _-prefixed symbols.
* gtype.h:
* gtype.c: Move the declarations of the various _init() functions
to the header, and mark them as G_GNUC_INTERNAL.
Tue Feb 3 21:24:01 2004 Tim Janik <timj@gtk.org>
* gtype.h (_G_TYPE_CVH): provide a short-cut version for
this macro in case value->g_type==checked_type for gcc, similar
to instance and class check short-cuts. this speeds up code that
makes frequent use of G_VALUE_HOLDS_*() (e.g. setters/getters).
* gtype.c (type_data_last_unref_Wm): don't call class-cache functions
for the uncached case, this rendered g_type_class_unref_uncached()
useless. pointed out by Stefan Westerfeld.
Thu Nov 27 17:53:52 2003 Tim Janik <timj@gtk.org>
* gtype.[hc]:
(g_type_class_peek_static): variant of class_peek() which works for
static types only.
* gobject.c:
(g_object_do_class_init): make ::notify a run-action signal.
(g_object_newv): use g_type_class_peek_static() by default to
speed up common code path (trades two write-locks for one read-lock).
(g_object_disconnect):
(g_object_connect): allow signal specification words to be
seperated by '-'.
(g_object_set_valist):
(g_object_new_valist): don't leak values.
(g_object_get_property): check property for readability.
(g_object_set_property): check property for writability and to
not be construct-only.
(g_object_set_valist): check property to not be construct-only.
Thu Oct 2 01:16:50 2003 Owen Taylor <otaylor@redhat.com>
* gtype.[ch]: Add g_type_add/remove_interface_check(),
which allows inserting a post-interface-initialization
check.
* testgobject.c: Fix a deprecated usage.
Mon Sep 29 10:51:01 2003 Owen Taylor <otaylor@redhat.com>
* gtype.[ch]: Add g_type_default_interface_ref/peek/unref
for accessing the default vtable of an interface.
