| 1 | /* classes: h_files */ |
| 2 | |
| 3 | #ifndef SCM_GC_H |
| 4 | #define SCM_GC_H |
| 5 | |
| 6 | /* Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2006, |
| 7 | * 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014 Free Software Foundation, Inc. |
| 8 | * |
| 9 | * This library is free software; you can redistribute it and/or |
| 10 | * modify it under the terms of the GNU Lesser General Public License |
| 11 | * as published by the Free Software Foundation; either version 3 of |
| 12 | * the License, or (at your option) any later version. |
| 13 | * |
| 14 | * This library is distributed in the hope that it will be useful, but |
| 15 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 17 | * Lesser General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU Lesser General Public |
| 20 | * License along with this library; if not, write to the Free Software |
| 21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 22 | * 02110-1301 USA |
| 23 | */ |
| 24 | |
| 25 | \f |
| 26 | |
| 27 | #include "libguile/__scm.h" |
| 28 | |
| 29 | #include "libguile/hooks.h" |
| 30 | #include "libguile/threads.h" |
| 31 | |
| 32 | \f |
| 33 | typedef struct scm_t_cell |
| 34 | { |
| 35 | SCM word_0; |
| 36 | SCM word_1; |
| 37 | } scm_t_cell; |
| 38 | |
| 39 | /* FIXME: deprecate. */ |
| 40 | #define PTR2SCM(x) (SCM_PACK_POINTER (x)) |
| 41 | #define SCM2PTR(x) ((scm_t_cell *) (SCM_UNPACK_POINTER (x))) |
| 42 | |
| 43 | /* Low level cell data accessing macros. These macros should only be used |
| 44 | * from within code related to garbage collection issues, since they will |
| 45 | * never check the cells they are applied to - not even if guile is compiled |
| 46 | * in debug mode. In particular these macros will even work for free cells, |
| 47 | * which should never be encountered by user code. */ |
| 48 | |
| 49 | #define SCM_GC_CELL_OBJECT(x, n) (((SCM *)SCM2PTR (x)) [n]) |
| 50 | #define SCM_GC_CELL_WORD(x, n) (SCM_UNPACK (SCM_GC_CELL_OBJECT ((x), (n)))) |
| 51 | |
| 52 | #define SCM_GC_SET_CELL_OBJECT(x, n, v) ((((SCM *)SCM2PTR (x)) [n]) = (v)) |
| 53 | #define SCM_GC_SET_CELL_WORD(x, n, v) \ |
| 54 | (SCM_GC_SET_CELL_OBJECT ((x), (n), SCM_PACK (v))) |
| 55 | |
| 56 | #define SCM_GC_CELL_TYPE(x) (SCM_GC_CELL_OBJECT ((x), 0)) |
| 57 | |
| 58 | |
| 59 | /* Except for the garbage collector, no part of guile should ever run over a |
| 60 | * free cell. Thus, if guile is compiled in debug mode the SCM_CELL_* and |
| 61 | * SCM_SET_CELL_* macros below report an error if they are applied to a free |
| 62 | * cell. Some other plausibility checks are also performed. However, if |
| 63 | * guile is not compiled in debug mode, there won't be any time penalty at all |
| 64 | * when using these macros. */ |
| 65 | |
| 66 | #if (SCM_DEBUG_CELL_ACCESSES == 1) |
| 67 | # define SCM_VALIDATE_CELL(cell, expr) (scm_assert_cell_valid (cell), (expr)) |
| 68 | #else |
| 69 | # define SCM_VALIDATE_CELL(cell, expr) (expr) |
| 70 | #endif |
| 71 | |
| 72 | #define SCM_CELL_WORD(x, n) \ |
| 73 | SCM_VALIDATE_CELL ((x), SCM_GC_CELL_WORD ((x), (n))) |
| 74 | #define SCM_CELL_WORD_0(x) SCM_CELL_WORD ((x), 0) |
| 75 | #define SCM_CELL_WORD_1(x) SCM_CELL_WORD ((x), 1) |
| 76 | #define SCM_CELL_WORD_2(x) SCM_CELL_WORD ((x), 2) |
| 77 | #define SCM_CELL_WORD_3(x) SCM_CELL_WORD ((x), 3) |
| 78 | |
| 79 | #define SCM_CELL_OBJECT(x, n) \ |
| 80 | SCM_VALIDATE_CELL ((x), SCM_GC_CELL_OBJECT ((x), (n))) |
| 81 | #define SCM_CELL_OBJECT_0(x) SCM_CELL_OBJECT ((x), 0) |
| 82 | #define SCM_CELL_OBJECT_1(x) SCM_CELL_OBJECT ((x), 1) |
| 83 | #define SCM_CELL_OBJECT_2(x) SCM_CELL_OBJECT ((x), 2) |
| 84 | #define SCM_CELL_OBJECT_3(x) SCM_CELL_OBJECT ((x), 3) |
| 85 | |
| 86 | #define SCM_SET_CELL_WORD(x, n, v) \ |
| 87 | SCM_VALIDATE_CELL ((x), SCM_GC_SET_CELL_WORD ((x), (n), (v))) |
| 88 | #define SCM_SET_CELL_WORD_0(x, v) SCM_SET_CELL_WORD ((x), 0, (v)) |
| 89 | #define SCM_SET_CELL_WORD_1(x, v) SCM_SET_CELL_WORD ((x), 1, (v)) |
| 90 | #define SCM_SET_CELL_WORD_2(x, v) SCM_SET_CELL_WORD ((x), 2, (v)) |
| 91 | #define SCM_SET_CELL_WORD_3(x, v) SCM_SET_CELL_WORD ((x), 3, (v)) |
| 92 | |
| 93 | #define SCM_SET_CELL_OBJECT(x, n, v) \ |
| 94 | SCM_VALIDATE_CELL ((x), SCM_GC_SET_CELL_OBJECT ((x), (n), (v))) |
| 95 | #define SCM_SET_CELL_OBJECT_0(x, v) SCM_SET_CELL_OBJECT ((x), 0, (v)) |
| 96 | #define SCM_SET_CELL_OBJECT_1(x, v) SCM_SET_CELL_OBJECT ((x), 1, (v)) |
| 97 | #define SCM_SET_CELL_OBJECT_2(x, v) SCM_SET_CELL_OBJECT ((x), 2, (v)) |
| 98 | #define SCM_SET_CELL_OBJECT_3(x, v) SCM_SET_CELL_OBJECT ((x), 3, (v)) |
| 99 | |
| 100 | #define SCM_CELL_OBJECT_LOC(x, n) (SCM_VALIDATE_CELL((x), &SCM_GC_CELL_OBJECT ((x), (n)))) |
| 101 | #define SCM_CARLOC(x) (SCM_CELL_OBJECT_LOC ((x), 0)) |
| 102 | #define SCM_CDRLOC(x) (SCM_CELL_OBJECT_LOC ((x), 1)) |
| 103 | |
| 104 | #define SCM_CELL_TYPE(x) SCM_CELL_WORD_0 (x) |
| 105 | #define SCM_SET_CELL_TYPE(x, t) SCM_SET_CELL_WORD_0 ((x), (t)) |
| 106 | |
| 107 | |
| 108 | #if (SCM_DEBUG_CELL_ACCESSES == 1) |
| 109 | /* Set this to != 0 if every cell that is accessed shall be checked: |
| 110 | */ |
| 111 | SCM_API int scm_debug_cell_accesses_p; |
| 112 | SCM_API int scm_expensive_debug_cell_accesses_p; |
| 113 | SCM_API int scm_debug_cells_gc_interval ; |
| 114 | SCM_API void scm_i_expensive_validation_check (SCM cell); |
| 115 | #endif |
| 116 | |
| 117 | SCM_INTERNAL scm_i_pthread_mutex_t scm_i_gc_admin_mutex; |
| 118 | |
| 119 | #define scm_gc_running_p 0 |
| 120 | SCM_INTERNAL scm_i_pthread_mutex_t scm_i_sweep_mutex; |
| 121 | |
| 122 | #ifdef __ia64__ |
| 123 | void *scm_ia64_register_backing_store_base (void); |
| 124 | void *scm_ia64_ar_bsp (const void *); |
| 125 | #endif |
| 126 | |
| 127 | \f |
| 128 | |
| 129 | SCM_API unsigned long scm_gc_ports_collected; |
| 130 | |
| 131 | SCM_API SCM scm_after_gc_hook; |
| 132 | |
| 133 | SCM_API scm_t_c_hook scm_before_gc_c_hook; |
| 134 | SCM_API scm_t_c_hook scm_before_mark_c_hook; |
| 135 | SCM_API scm_t_c_hook scm_before_sweep_c_hook; |
| 136 | SCM_API scm_t_c_hook scm_after_sweep_c_hook; |
| 137 | SCM_API scm_t_c_hook scm_after_gc_c_hook; |
| 138 | |
| 139 | \f |
| 140 | |
| 141 | #if (SCM_DEBUG_CELL_ACCESSES == 1) |
| 142 | SCM_API void scm_assert_cell_valid (SCM); |
| 143 | #endif |
| 144 | |
| 145 | SCM_API SCM scm_set_debug_cell_accesses_x (SCM flag); |
| 146 | |
| 147 | |
| 148 | SCM_API SCM scm_object_address (SCM obj); |
| 149 | SCM_API SCM scm_gc_enable (void); |
| 150 | SCM_API SCM scm_gc_disable (void); |
| 151 | SCM_API SCM scm_gc_dump (void); |
| 152 | SCM_API SCM scm_gc_stats (void); |
| 153 | SCM_API SCM scm_gc (void); |
| 154 | SCM_INTERNAL void scm_i_gc (const char *what); |
| 155 | SCM_API void scm_gc_mark (SCM p); |
| 156 | SCM_API void scm_gc_sweep (void); |
| 157 | |
| 158 | SCM_API void scm_gc_register_allocation (size_t size); |
| 159 | |
| 160 | SCM_API void *scm_malloc (size_t size) SCM_MALLOC; |
| 161 | SCM_API void *scm_calloc (size_t size) SCM_MALLOC; |
| 162 | SCM_API void *scm_realloc (void *mem, size_t size); |
| 163 | SCM_API char *scm_strdup (const char *str) SCM_MALLOC; |
| 164 | SCM_API char *scm_strndup (const char *str, size_t n) SCM_MALLOC; |
| 165 | SCM_API void scm_gc_register_collectable_memory (void *mem, size_t size, |
| 166 | const char *what); |
| 167 | SCM_API void scm_gc_unregister_collectable_memory (void *mem, size_t size, |
| 168 | const char *what); |
| 169 | SCM_API void *scm_gc_malloc_pointerless (size_t size, const char *what) |
| 170 | SCM_MALLOC; |
| 171 | SCM_API void *scm_gc_calloc (size_t size, const char *what) |
| 172 | SCM_MALLOC; |
| 173 | SCM_API void *scm_gc_malloc (size_t size, const char *what) |
| 174 | SCM_MALLOC; |
| 175 | SCM_API void *scm_gc_realloc (void *mem, size_t old_size, |
| 176 | size_t new_size, const char *what); |
| 177 | SCM_API void scm_gc_free (void *mem, size_t size, const char *what); |
| 178 | SCM_API char *scm_gc_strdup (const char *str, const char *what) |
| 179 | SCM_MALLOC; |
| 180 | SCM_API char *scm_gc_strndup (const char *str, size_t n, const char *what) |
| 181 | SCM_MALLOC; |
| 182 | |
| 183 | #define scm_gc_typed_calloc(t) ((t *) scm_gc_calloc (sizeof (t), #t)) |
| 184 | |
| 185 | #ifdef BUILDING_LIBGUILE |
| 186 | #include "libguile/bdw-gc.h" |
| 187 | #define SCM_GC_MALLOC(size) GC_MALLOC (size) |
| 188 | #define SCM_GC_MALLOC_POINTERLESS(size) GC_MALLOC_ATOMIC (size) |
| 189 | #else |
| 190 | #define SCM_GC_MALLOC(size) scm_gc_malloc (size, NULL) |
| 191 | #define SCM_GC_MALLOC_POINTERLESS(size) scm_gc_malloc_pointerless (size, NULL) |
| 192 | #endif |
| 193 | |
| 194 | |
| 195 | SCM_INLINE SCM scm_cell (scm_t_bits car, scm_t_bits cdr); |
| 196 | SCM_INLINE SCM scm_double_cell (scm_t_bits car, scm_t_bits cbr, |
| 197 | scm_t_bits ccr, scm_t_bits cdr); |
| 198 | SCM_INLINE SCM scm_words (scm_t_bits car, scm_t_uint32 n_words); |
| 199 | |
| 200 | #if SCM_CAN_INLINE || defined SCM_INLINE_C_IMPLEMENTING_INLINES |
| 201 | |
| 202 | SCM_INLINE_IMPLEMENTATION SCM |
| 203 | scm_cell (scm_t_bits car, scm_t_bits cdr) |
| 204 | { |
| 205 | SCM cell = SCM_PACK_POINTER (SCM_GC_MALLOC (sizeof (scm_t_cell))); |
| 206 | |
| 207 | /* Initialize the type slot last so that the cell is ignored by the GC |
| 208 | until it is completely initialized. This is only relevant when the GC |
| 209 | can actually run during this code, which it can't since the GC only runs |
| 210 | when all other threads are stopped. */ |
| 211 | SCM_GC_SET_CELL_WORD (cell, 1, cdr); |
| 212 | SCM_GC_SET_CELL_WORD (cell, 0, car); |
| 213 | |
| 214 | return cell; |
| 215 | } |
| 216 | |
| 217 | SCM_INLINE_IMPLEMENTATION SCM |
| 218 | scm_double_cell (scm_t_bits car, scm_t_bits cbr, |
| 219 | scm_t_bits ccr, scm_t_bits cdr) |
| 220 | { |
| 221 | SCM z; |
| 222 | |
| 223 | z = SCM_PACK_POINTER (SCM_GC_MALLOC (2 * sizeof (scm_t_cell))); |
| 224 | /* Initialize the type slot last so that the cell is ignored by the |
| 225 | GC until it is completely initialized. This is only relevant |
| 226 | when the GC can actually run during this code, which it can't |
| 227 | since the GC only runs when all other threads are stopped. |
| 228 | */ |
| 229 | SCM_GC_SET_CELL_WORD (z, 1, cbr); |
| 230 | SCM_GC_SET_CELL_WORD (z, 2, ccr); |
| 231 | SCM_GC_SET_CELL_WORD (z, 3, cdr); |
| 232 | SCM_GC_SET_CELL_WORD (z, 0, car); |
| 233 | |
| 234 | /* When this function is inlined, it's possible that the last |
| 235 | SCM_GC_SET_CELL_WORD above will be adjacent to a following |
| 236 | initialization of z. E.g., it occurred in scm_make_real. GCC |
| 237 | from around version 3 (e.g., certainly 3.2) began taking |
| 238 | advantage of strict C aliasing rules which say that it's OK to |
| 239 | interchange the initialization above and the one below when the |
| 240 | pointer types appear to differ sufficiently. We don't want that, |
| 241 | of course. GCC allows this behaviour to be disabled with the |
| 242 | -fno-strict-aliasing option, but would also need to be supplied |
| 243 | by Guile users. Instead, the following statements prevent the |
| 244 | reordering. |
| 245 | */ |
| 246 | #ifdef __GNUC__ |
| 247 | __asm__ volatile ("" : : : "memory"); |
| 248 | #else |
| 249 | /* portable version, just in case any other compiler does the same |
| 250 | thing. */ |
| 251 | scm_remember_upto_here_1 (z); |
| 252 | #endif |
| 253 | |
| 254 | return z; |
| 255 | } |
| 256 | |
| 257 | SCM_INLINE_IMPLEMENTATION SCM |
| 258 | scm_words (scm_t_bits car, scm_t_uint32 n_words) |
| 259 | { |
| 260 | SCM z; |
| 261 | |
| 262 | z = SCM_PACK_POINTER (SCM_GC_MALLOC (sizeof (scm_t_bits) * n_words)); |
| 263 | SCM_GC_SET_CELL_WORD (z, 0, car); |
| 264 | |
| 265 | /* FIXME: is the following concern even relevant with BDW-GC? */ |
| 266 | |
| 267 | /* When this function is inlined, it's possible that the last |
| 268 | SCM_GC_SET_CELL_WORD above will be adjacent to a following |
| 269 | initialization of z. E.g., it occurred in scm_make_real. GCC |
| 270 | from around version 3 (e.g., certainly 3.2) began taking |
| 271 | advantage of strict C aliasing rules which say that it's OK to |
| 272 | interchange the initialization above and the one below when the |
| 273 | pointer types appear to differ sufficiently. We don't want that, |
| 274 | of course. GCC allows this behaviour to be disabled with the |
| 275 | -fno-strict-aliasing option, but would also need to be supplied |
| 276 | by Guile users. Instead, the following statements prevent the |
| 277 | reordering. |
| 278 | */ |
| 279 | #ifdef __GNUC__ |
| 280 | __asm__ volatile ("" : : : "memory"); |
| 281 | #else |
| 282 | /* portable version, just in case any other compiler does the same |
| 283 | thing. */ |
| 284 | scm_remember_upto_here_1 (z); |
| 285 | #endif |
| 286 | |
| 287 | return z; |
| 288 | } |
| 289 | |
| 290 | #endif /* SCM_CAN_INLINE || defined SCM_INLINE_C_IMPLEMENTING_INLINES */ |
| 291 | |
| 292 | SCM_API void scm_remember_upto_here_1 (SCM obj); |
| 293 | SCM_API void scm_remember_upto_here_2 (SCM obj1, SCM obj2); |
| 294 | SCM_API void scm_remember_upto_here (SCM obj1, ...); |
| 295 | |
| 296 | /* In GCC we can force a reference to an SCM by making it an input to an |
| 297 | empty asm. This avoids the code size and slowdown of an actual function |
| 298 | call. Unfortunately there doesn't seem to be any way to do the varargs |
| 299 | scm_remember_upto_here like this. |
| 300 | |
| 301 | __volatile__ ensures nothing will be moved across the asm, and it won't |
| 302 | be optimized away (or only if proved unreachable). Constraint "g" can be |
| 303 | used on all processors and allows any memory or general register (or |
| 304 | immediate) operand. The actual asm syntax doesn't matter, we don't want |
| 305 | to use it, just ensure the operand is still alive. See "Extended Asm" in |
| 306 | the GCC manual for more. */ |
| 307 | |
| 308 | #ifdef __GNUC__ |
| 309 | #define scm_remember_upto_here_1(x) \ |
| 310 | do { \ |
| 311 | __asm__ __volatile__ ("" : : "g" (x)); \ |
| 312 | } while (0) |
| 313 | #define scm_remember_upto_here_2(x, y) \ |
| 314 | do { \ |
| 315 | scm_remember_upto_here_1 (x); \ |
| 316 | scm_remember_upto_here_1 (y); \ |
| 317 | } while (0) |
| 318 | #endif |
| 319 | |
| 320 | SCM_API SCM scm_return_first (SCM elt, ...); |
| 321 | SCM_API int scm_return_first_int (int x, ...); |
| 322 | SCM_API SCM scm_permanent_object (SCM obj); |
| 323 | SCM_API SCM scm_gc_protect_object (SCM obj); |
| 324 | SCM_API SCM scm_gc_unprotect_object (SCM obj); |
| 325 | SCM_API void scm_gc_register_root (SCM *p); |
| 326 | SCM_API void scm_gc_unregister_root (SCM *p); |
| 327 | SCM_API void scm_gc_register_roots (SCM *b, unsigned long n); |
| 328 | SCM_API void scm_gc_unregister_roots (SCM *b, unsigned long n); |
| 329 | SCM_INTERNAL void scm_gc_after_nonlocal_exit (void); |
| 330 | SCM_INTERNAL void scm_storage_prehistory (void); |
| 331 | SCM_INTERNAL void scm_init_gc_protect_object (void); |
| 332 | SCM_INTERNAL void scm_init_gc (void); |
| 333 | |
| 334 | #endif /* SCM_GC_H */ |
| 335 | |
| 336 | /* |
| 337 | Local Variables: |
| 338 | c-file-style: "gnu" |
| 339 | End: |
| 340 | */ |