blob: 53b96932ecd5ec8aa0bf6f95290934c90fc193a7 [file] [log] [blame]
/* grefcount.h: Reference counting
*
* Copyright 2018 Emmanuele Bassi
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*
* 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 2.1 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, see <http://www.gnu.org/licenses/>.
*/
#ifndef __GREFCOUNT_H__
#define __GREFCOUNT_H__
#if !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
#error "Only <glib.h> can be included directly."
#endif
#include <glib/gatomic.h>
#include <glib/gtypes.h>
G_BEGIN_DECLS
GLIB_AVAILABLE_IN_2_58
void g_ref_count_init (grefcount *rc);
GLIB_AVAILABLE_IN_2_58
void g_ref_count_inc (grefcount *rc);
GLIB_AVAILABLE_IN_2_58
gboolean g_ref_count_dec (grefcount *rc);
GLIB_AVAILABLE_IN_2_58
gboolean g_ref_count_compare (grefcount *rc,
gint val);
GLIB_AVAILABLE_IN_2_58
void g_atomic_ref_count_init (gatomicrefcount *arc);
GLIB_AVAILABLE_IN_2_58
void g_atomic_ref_count_inc (gatomicrefcount *arc);
GLIB_AVAILABLE_IN_2_58
gboolean g_atomic_ref_count_dec (gatomicrefcount *arc);
GLIB_AVAILABLE_IN_2_58
gboolean g_atomic_ref_count_compare (gatomicrefcount *arc,
gint val);
/**
* G_REF_COUNT_INIT:
*
* Evaluates to the initial reference count for `grefcount`.
*
* This macro is useful for initializing `grefcount` fields inside
* structures, for instance:
*
* |[<!-- language="C" -->
* typedef struct {
* grefcount ref_count;
* char *name;
* char *address;
* } Person;
*
* static const Person default_person = {
* .ref_count = G_REF_COUNT_INIT,
* .name = "Default name",
* .address = "Default address",
* };
* ]|
*
* Since: 2.78
*/
#define G_REF_COUNT_INIT -1 \
GLIB_AVAILABLE_MACRO_IN_2_78
/**
* G_ATOMIC_REF_COUNT_INIT:
*
* Evaluates to the initial reference count for `gatomicrefcount`.
*
* This macro is useful for initializing `gatomicrefcount` fields inside
* structures, for instance:
*
* |[<!-- language="C" -->
* typedef struct {
* gatomicrefcount ref_count;
* char *name;
* char *address;
* } Person;
*
* static const Person default_person = {
* .ref_count = G_ATOMIC_REF_COUNT_INIT,
* .name = "Default name",
* .address = "Default address",
* };
* ]|
*
* Since: 2.78
*/
#define G_ATOMIC_REF_COUNT_INIT 1 \
GLIB_AVAILABLE_MACRO_IN_2_78
/* On GCC we can use __extension__ to inline the API without using
* ancillary functions; we only do this when disabling checks, as
* it disables warnings when saturating the reference counters
*/
#if defined(__GNUC__) && defined(G_DISABLE_CHECKS)
# define g_ref_count_init(rc) \
(G_GNUC_EXTENSION ({ \
G_STATIC_ASSERT (sizeof *(rc) == sizeof (grefcount)); \
(void) (0 ? *(rc) ^ *(rc) : 1); \
*(rc) = -1; \
}))
# define g_ref_count_inc(rc) \
(G_GNUC_EXTENSION ({ \
G_STATIC_ASSERT (sizeof *(rc) == sizeof (grefcount)); \
(void) (0 ? *(rc) ^ *(rc) : 1); \
if (*(rc) == G_MININT) ; else { \
*(rc) -= 1; \
} \
}))
# define g_ref_count_dec(rc) \
(G_GNUC_EXTENSION ({ \
G_STATIC_ASSERT (sizeof *(rc) == sizeof (grefcount)); \
grefcount __rc = *(rc); \
__rc += 1; \
if (__rc == 0) ; else { \
*(rc) = __rc; \
} \
(gboolean) (__rc == 0); \
}))
# define g_ref_count_compare(rc,val) \
(G_GNUC_EXTENSION ({ \
G_STATIC_ASSERT (sizeof *(rc) == sizeof (grefcount)); \
(void) (0 ? *(rc) ^ (val) : 1); \
(gboolean) (*(rc) == -(val)); \
}))
# define g_atomic_ref_count_init(rc) \
(G_GNUC_EXTENSION ({ \
G_STATIC_ASSERT (sizeof *(rc) == sizeof (gatomicrefcount)); \
(void) (0 ? *(rc) ^ *(rc) : 1); \
*(rc) = 1; \
}))
# define g_atomic_ref_count_inc(rc) \
(G_GNUC_EXTENSION ({ \
G_STATIC_ASSERT (sizeof *(rc) == sizeof (gatomicrefcount)); \
(void) (0 ? *(rc) ^ *(rc) : 1); \
(void) (g_atomic_int_get (rc) == G_MAXINT ? 0 : g_atomic_int_inc ((rc))); \
}))
# define g_atomic_ref_count_dec(rc) \
(G_GNUC_EXTENSION ({ \
G_STATIC_ASSERT (sizeof *(rc) == sizeof (gatomicrefcount)); \
(void) (0 ? *(rc) ^ *(rc) : 1); \
g_atomic_int_dec_and_test ((rc)); \
}))
# define g_atomic_ref_count_compare(rc,val) \
(G_GNUC_EXTENSION ({ \
G_STATIC_ASSERT (sizeof *(rc) == sizeof (gatomicrefcount)); \
(void) (0 ? *(rc) ^ (val) : 1); \
(gboolean) (g_atomic_int_get (rc) == (val)); \
}))
#endif /* __GNUC__ && G_DISABLE_CHECKS */
G_END_DECLS
#endif /* __GREFCOUNT_H__ */