1 /* grefcount.h: Reference counting 2 * 3 * Copyright 2018 Emmanuele Bassi 4 * 5 * This library is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU Lesser General Public 7 * License as published by the Free Software Foundation; either 8 * version 2.1 of the License, or (at your option) any later version. 9 * 10 * This library is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 * Lesser General Public License for more details. 14 * 15 * You should have received a copy of the GNU Lesser General Public 16 * License along with this library; if not, see <http://www.gnu.org/licenses/>. 17 */ 18 19 #ifndef __GREFCOUNT_H__ 20 #define __GREFCOUNT_H__ 21 22 #if !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION) 23 #error "Only <glib.h> can be included directly." 24 #endif 25 26 #include <glib/gatomic.h> 27 #include <glib/gtypes.h> 28 29 G_BEGIN_DECLS 30 31 GLIB_AVAILABLE_IN_2_58 32 void g_ref_count_init (grefcount *rc); 33 GLIB_AVAILABLE_IN_2_58 34 void g_ref_count_inc (grefcount *rc); 35 GLIB_AVAILABLE_IN_2_58 36 gboolean g_ref_count_dec (grefcount *rc); 37 GLIB_AVAILABLE_IN_2_58 38 gboolean g_ref_count_compare (grefcount *rc, 39 gint val); 40 41 GLIB_AVAILABLE_IN_2_58 42 void g_atomic_ref_count_init (gatomicrefcount *arc); 43 GLIB_AVAILABLE_IN_2_58 44 void g_atomic_ref_count_inc (gatomicrefcount *arc); 45 GLIB_AVAILABLE_IN_2_58 46 gboolean g_atomic_ref_count_dec (gatomicrefcount *arc); 47 GLIB_AVAILABLE_IN_2_58 48 gboolean g_atomic_ref_count_compare (gatomicrefcount *arc, 49 gint val); 50 51 /* On GCC we can use __extension__ to inline the API without using 52 * ancillary functions; we only do this when disabling checks, as 53 * it disables warnings when saturating the reference counters 54 */ 55 #if defined(__GNUC__) && defined(G_DISABLE_CHECKS) 56 57 # define g_ref_count_init(rc) \ 58 (G_GNUC_EXTENSION ({ \ 59 G_STATIC_ASSERT (sizeof *(rc) == sizeof (grefcount)); \ 60 (void) (0 ? *(rc) ^ *(rc) : 1); \ 61 *(rc) = -1; \ 62 })) 63 64 # define g_ref_count_inc(rc) \ 65 (G_GNUC_EXTENSION ({ \ 66 G_STATIC_ASSERT (sizeof *(rc) == sizeof (grefcount)); \ 67 (void) (0 ? *(rc) ^ *(rc) : 1); \ 68 if (*(rc) == G_MININT) ; else { \ 69 *(rc) -= 1; \ 70 } \ 71 })) 72 73 # define g_ref_count_dec(rc) \ 74 (G_GNUC_EXTENSION ({ \ 75 G_STATIC_ASSERT (sizeof *(rc) == sizeof (grefcount)); \ 76 grefcount __rc = *(rc); \ 77 __rc += 1; \ 78 if (__rc == 0) ; else { \ 79 *(rc) = __rc; \ 80 } \ 81 (gboolean) (__rc == 0); \ 82 })) 83 84 # define g_ref_count_compare(rc,val) \ 85 (G_GNUC_EXTENSION ({ \ 86 G_STATIC_ASSERT (sizeof *(rc) == sizeof (grefcount)); \ 87 (void) (0 ? *(rc) ^ (val) : 1); \ 88 (gboolean) (*(rc) == -(val)); \ 89 })) 90 91 # define g_atomic_ref_count_init(rc) \ 92 (G_GNUC_EXTENSION ({ \ 93 G_STATIC_ASSERT (sizeof *(rc) == sizeof (gatomicrefcount)); \ 94 (void) (0 ? *(rc) ^ *(rc) : 1); \ 95 *(rc) = 1; \ 96 })) 97 98 # define g_atomic_ref_count_inc(rc) \ 99 (G_GNUC_EXTENSION ({ \ 100 G_STATIC_ASSERT (sizeof *(rc) == sizeof (gatomicrefcount)); \ 101 (void) (0 ? *(rc) ^ *(rc) : 1); \ 102 (void) (g_atomic_int_get (rc) == G_MAXINT ? 0 : g_atomic_int_inc ((rc))); \ 103 })) 104 105 # define g_atomic_ref_count_dec(rc) \ 106 (G_GNUC_EXTENSION ({ \ 107 G_STATIC_ASSERT (sizeof *(rc) == sizeof (gatomicrefcount)); \ 108 (void) (0 ? *(rc) ^ *(rc) : 1); \ 109 g_atomic_int_dec_and_test ((rc)); \ 110 })) 111 112 # define g_atomic_ref_count_compare(rc,val) \ 113 (G_GNUC_EXTENSION ({ \ 114 G_STATIC_ASSERT (sizeof *(rc) == sizeof (gatomicrefcount)); \ 115 (void) (0 ? *(rc) ^ (val) : 1); \ 116 (gboolean) (g_atomic_int_get (rc) == (val)); \ 117 })) 118 119 #endif /* __GNUC__ && G_DISABLE_CHECKS */ 120 121 G_END_DECLS 122 123 #endif /* __GREFCOUNT_H__ */ 124