libguile/gc.h

   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, 2007, 2008 Free Software Foundation, Inc.
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 \f
  24
  25 #include "libguile/__scm.h"
  26
  27 #include "libguile/hooks.h"
  28 #include "libguile/threads.h"
  29
  30 \f
  31 typedef struct scm_t_cell
  32 {
  33   SCM word_0;
  34   SCM word_1;
  35 } scm_t_cell;
  36
  37 /* Cray machines have pointers that are incremented once for each
  38  * word, rather than each byte, the 3 most significant bits encode the
  39  * byte within the word.  The following macros deal with this by
  40  * storing the native Cray pointers like the ones that looks like scm
  41  * expects.  This is done for any pointers that point to a cell,
  42  * pointers to scm_vector elts, functions, &c are not munged.
  43  */
  44 #ifdef _UNICOS
  45 #  define SCM2PTR(x) ((scm_t_cell *) (SCM_UNPACK (x) >> 3))
  46 #  define PTR2SCM(x) (SCM_PACK (((scm_t_bits) (x)) << 3))
  47 #else
  48 #  define SCM2PTR(x) ((scm_t_cell *) (SCM_UNPACK (x)))
  49 #  define PTR2SCM(x) (SCM_PACK ((scm_t_bits) (x)))
  50 #endif /* def _UNICOS */
  51
  52
  53
  54 /* Low level cell data accessing macros.  These macros should only be used
  55  * from within code related to garbage collection issues, since they will
  56  * never check the cells they are applied to - not even if guile is compiled
  57  * in debug mode.  In particular these macros will even work for free cells,
  58  * which should never be encountered by user code.  */
  59
  60 #define SCM_GC_CELL_OBJECT(x, n) (((SCM *)SCM2PTR (x)) [n])
  61 #define SCM_GC_CELL_WORD(x, n)   (SCM_UNPACK (SCM_GC_CELL_OBJECT ((x), (n))))
  62
  63 #define SCM_GC_SET_CELL_OBJECT(x, n, v) ((((SCM *)SCM2PTR (x)) [n]) = (v))
  64 #define SCM_GC_SET_CELL_WORD(x, n, v)  \
  65   (SCM_GC_SET_CELL_OBJECT ((x), (n), SCM_PACK (v)))
  66
  67 #define SCM_GC_CELL_TYPE(x) (SCM_GC_CELL_OBJECT ((x), 0))
  68
  69
  70 /* Except for the garbage collector, no part of guile should ever run over a
  71  * free cell.  Thus, if guile is compiled in debug mode the SCM_CELL_* and
  72  * SCM_SET_CELL_* macros below report an error if they are applied to a free
  73  * cell.  Some other plausibility checks are also performed.  However, if
  74  * guile is not compiled in debug mode, there won't be any time penalty at all
  75  * when using these macros.  */
  76
  77 #if (SCM_DEBUG_CELL_ACCESSES == 1)
  78 #  define SCM_VALIDATE_CELL(cell, expr) (scm_assert_cell_valid (cell), (expr))
  79 #else
  80 #  define SCM_VALIDATE_CELL(cell, expr) (expr)
  81 #endif
  82
  83 #define SCM_CELL_WORD(x, n) \
  84   SCM_VALIDATE_CELL ((x), SCM_GC_CELL_WORD ((x), (n)))
  85 #define SCM_CELL_WORD_0(x) SCM_CELL_WORD ((x), 0)
  86 #define SCM_CELL_WORD_1(x) SCM_CELL_WORD ((x), 1)
  87 #define SCM_CELL_WORD_2(x) SCM_CELL_WORD ((x), 2)
  88 #define SCM_CELL_WORD_3(x) SCM_CELL_WORD ((x), 3)
  89
  90 #define SCM_CELL_OBJECT(x, n) \
  91   SCM_VALIDATE_CELL ((x), SCM_GC_CELL_OBJECT ((x), (n)))
  92 #define SCM_CELL_OBJECT_0(x) SCM_CELL_OBJECT ((x), 0)
  93 #define SCM_CELL_OBJECT_1(x) SCM_CELL_OBJECT ((x), 1)
  94 #define SCM_CELL_OBJECT_2(x) SCM_CELL_OBJECT ((x), 2)
  95 #define SCM_CELL_OBJECT_3(x) SCM_CELL_OBJECT ((x), 3)
  96
  97 #define SCM_SET_CELL_WORD(x, n, v) \
  98   SCM_VALIDATE_CELL ((x), SCM_GC_SET_CELL_WORD ((x), (n), (v)))
  99 #define SCM_SET_CELL_WORD_0(x, v) SCM_SET_CELL_WORD ((x), 0, (v))
 100 #define SCM_SET_CELL_WORD_1(x, v) SCM_SET_CELL_WORD ((x), 1, (v))
 101 #define SCM_SET_CELL_WORD_2(x, v) SCM_SET_CELL_WORD ((x), 2, (v))
 102 #define SCM_SET_CELL_WORD_3(x, v) SCM_SET_CELL_WORD ((x), 3, (v))
 103
 104 #define SCM_SET_CELL_OBJECT(x, n, v) \
 105   SCM_VALIDATE_CELL ((x), SCM_GC_SET_CELL_OBJECT ((x), (n), (v)))
 106 #define SCM_SET_CELL_OBJECT_0(x, v) SCM_SET_CELL_OBJECT ((x), 0, (v))
 107 #define SCM_SET_CELL_OBJECT_1(x, v) SCM_SET_CELL_OBJECT ((x), 1, (v))
 108 #define SCM_SET_CELL_OBJECT_2(x, v) SCM_SET_CELL_OBJECT ((x), 2, (v))
 109 #define SCM_SET_CELL_OBJECT_3(x, v) SCM_SET_CELL_OBJECT ((x), 3, (v))
 110
 111 #define SCM_CELL_OBJECT_LOC(x, n) (SCM_VALIDATE_CELL((x), &SCM_GC_CELL_OBJECT ((x), (n))))
 112 #define SCM_CARLOC(x)             (SCM_CELL_OBJECT_LOC ((x), 0))
 113 #define SCM_CDRLOC(x)             (SCM_CELL_OBJECT_LOC ((x), 1))
 114
 115 #define SCM_CELL_TYPE(x) SCM_CELL_WORD_0 (x)
 116 #define SCM_SET_CELL_TYPE(x, t) SCM_SET_CELL_WORD_0 ((x), (t))
 117
 118 /* Freelists consist of linked cells where the type entry holds the value
 119  * scm_tc_free_cell and the second entry holds a pointer to the next cell of
 120  * the freelist.  Due to this structure, freelist cells are not cons cells
 121  * and thus may not be accessed using SCM_CAR and SCM_CDR.  */
 122
 123 #define SCM_FREE_CELL_CDR(x) \
 124   (SCM_GC_CELL_OBJECT ((x), 1))
 125 #define SCM_SET_FREE_CELL_CDR(x, v) \
 126   (SCM_GC_SET_CELL_OBJECT ((x), 1, (v)))
 127
 128 #if (SCM_DEBUG_CELL_ACCESSES == 1)
 129 /* Set this to != 0 if every cell that is accessed shall be checked:
 130  */
 131 SCM_API int scm_debug_cell_accesses_p;
 132 SCM_API int scm_expensive_debug_cell_accesses_p;
 133 SCM_API int scm_debug_cells_gc_interval ;
 134 void scm_i_expensive_validation_check (SCM cell);
 135 #endif
 136
 137 SCM_INTERNAL scm_i_pthread_mutex_t scm_i_gc_admin_mutex;
 138
 139 #define scm_gc_running_p  0
 140 SCM_INTERNAL scm_i_pthread_mutex_t scm_i_sweep_mutex;
 141
 142 #ifdef __ia64__
 143 void *scm_ia64_register_backing_store_base (void);
 144 void *scm_ia64_ar_bsp (const void *);
 145 #endif
 146
 147 \f
 148
 149 #if (SCM_ENABLE_DEPRECATED == 1)
 150 SCM_API size_t scm_default_init_heap_size_1;
 151 SCM_API int scm_default_min_yield_1;
 152 SCM_API size_t scm_default_init_heap_size_2;
 153 SCM_API int scm_default_min_yield_2;
 154 SCM_API size_t scm_default_max_segment_size;
 155 #else
 156 #define  scm_default_init_heap_size_1 deprecated
 157 #define  scm_default_min_yield_1 deprecated
 158 #define  scm_default_init_heap_size_2 deprecated
 159 #define  scm_default_min_yield_2 deprecated
 160 #define  scm_default_max_segment_size deprecated
 161 #endif
 162
 163
 164 SCM_API size_t scm_max_segment_size;
 165
 166 #define SCM_SET_FREELIST_LOC(key,ptr) scm_i_pthread_setspecific ((key), (ptr))
 167 #define SCM_FREELIST_LOC(key) ((SCM *) scm_i_pthread_getspecific (key))
 168 SCM_API struct scm_t_cell_type_statistics scm_i_master_freelist;
 169 SCM_API struct scm_t_cell_type_statistics scm_i_master_freelist2;
 170
 171 SCM_API unsigned long scm_mallocated;
 172 SCM_API unsigned long scm_gc_ports_collected;
 173 SCM_API unsigned long scm_mtrigger;
 174
 175 SCM_API SCM scm_after_gc_hook;
 176
 177 SCM_API scm_t_c_hook scm_before_gc_c_hook;
 178 SCM_API scm_t_c_hook scm_before_mark_c_hook;
 179 SCM_API scm_t_c_hook scm_before_sweep_c_hook;
 180 SCM_API scm_t_c_hook scm_after_sweep_c_hook;
 181 SCM_API scm_t_c_hook scm_after_gc_c_hook;
 182
 183 #if defined (GUILE_DEBUG) || defined (GUILE_DEBUG_FREELIST)
 184 #if (SCM_ENABLE_DEPRECATED == 1)
 185 SCM scm_map_free_list (void);
 186 #else
 187 #define scm_map_free_list deprecated
 188 #define scm_free_list_length deprecated
 189 #endif
 190 #endif
 191
 192 #if (SCM_ENABLE_DEPRECATED == 1) && defined (GUILE_DEBUG_FREELIST)
 193 SCM_API SCM scm_gc_set_debug_check_freelist_x (SCM flag);
 194 #endif
 195 \f
 196
 197 #if (SCM_DEBUG_CELL_ACCESSES == 1)
 198 SCM_API void scm_assert_cell_valid (SCM);
 199 #endif
 200
 201 SCM_API SCM scm_set_debug_cell_accesses_x (SCM flag);
 202
 203
 204 SCM_API SCM scm_object_address (SCM obj);
 205 SCM_API SCM scm_gc_enable (void);
 206 SCM_API SCM scm_gc_disable (void);
 207 SCM_API SCM scm_gc_dump (void);
 208 SCM_API SCM scm_gc_stats (void);
 209 SCM_API SCM scm_gc_live_object_stats (void);
 210 SCM_API SCM scm_gc (void);
 211 SCM_API void scm_i_gc (const char *what);
 212 SCM_API void scm_gc_mark (SCM p);
 213 SCM_API int scm_in_heap_p (SCM value);
 214 SCM_API void scm_gc_sweep (void);
 215
 216 SCM_API void *scm_malloc (size_t size);
 217 SCM_API void *scm_calloc (size_t size);
 218 SCM_API void *scm_realloc (void *mem, size_t size);
 219 SCM_API char *scm_strdup (const char *str);
 220 SCM_API char *scm_strndup (const char *str, size_t n);
 221 SCM_API void scm_gc_register_collectable_memory (void *mem, size_t size,
 222                                                  const char *what);
 223 SCM_API void scm_gc_unregister_collectable_memory (void *mem, size_t size,
 224                                                    const char *what);
 225 SCM_API void *scm_gc_malloc_pointerless (size_t size, const char *what);
 226 SCM_API void *scm_gc_calloc (size_t size, const char *what);
 227 SCM_API void *scm_gc_malloc (size_t size, const char *what);
 228 SCM_API void *scm_gc_realloc (void *mem, size_t old_size,
 229                               size_t new_size, const char *what);
 230 SCM_API void scm_gc_free (void *mem, size_t size, const char *what);
 231 SCM_API char *scm_gc_strdup (const char *str, const char *what);
 232 SCM_API char *scm_gc_strndup (const char *str, size_t n, const char *what);
 233
 234 SCM_API void scm_remember_upto_here_1 (SCM obj);
 235 SCM_API void scm_remember_upto_here_2 (SCM obj1, SCM obj2);
 236 SCM_API void scm_remember_upto_here (SCM obj1, ...);
 237
 238 /* In GCC we can force a reference to an SCM by making it an input to an
 239    empty asm.  This avoids the code size and slowdown of an actual function
 240    call.  Unfortunately there doesn't seem to be any way to do the varargs
 241    scm_remember_upto_here like this.
 242
 243    __volatile__ ensures nothing will be moved across the asm, and it won't
 244    be optimized away (or only if proved unreachable).  Constraint "g" can be
 245    used on all processors and allows any memory or general register (or
 246    immediate) operand.  The actual asm syntax doesn't matter, we don't want
 247    to use it, just ensure the operand is still alive.  See "Extended Asm" in
 248    the GCC manual for more.  */
 249
 250 #ifdef __GNUC__
 251 #define scm_remember_upto_here_1(x)             \
 252   do {                                          \
 253     __asm__ __volatile__ ("" : : "g" (x));      \
 254   } while (0)
 255 #define scm_remember_upto_here_2(x, y)          \
 256   do {                                          \
 257     scm_remember_upto_here_1 (x);               \
 258     scm_remember_upto_here_1 (y);               \
 259   } while (0)
 260 #endif
 261
 262 SCM_API SCM scm_return_first (SCM elt, ...);
 263 SCM_API int scm_return_first_int (int x, ...);
 264 SCM_API SCM scm_permanent_object (SCM obj);
 265 SCM_API SCM scm_gc_protect_object (SCM obj);
 266 SCM_API SCM scm_gc_unprotect_object (SCM obj);
 267 SCM_API void scm_gc_register_root (SCM *p);
 268 SCM_API void scm_gc_unregister_root (SCM *p);
 269 SCM_API void scm_gc_register_roots (SCM *b, unsigned long n);
 270 SCM_API void scm_gc_unregister_roots (SCM *b, unsigned long n);
 271 SCM_API void scm_storage_prehistory (void);
 272 SCM_API int scm_init_storage (void);
 273 SCM_API void scm_init_gc (void);
 274
 275 #if SCM_ENABLE_DEPRECATED == 1
 276
 277 SCM_API SCM scm_deprecated_newcell (void);
 278 SCM_API SCM scm_deprecated_newcell2 (void);
 279
 280 #define SCM_NEWCELL(_into) \
 281   do { _into = scm_deprecated_newcell (); } while (0)
 282 #define SCM_NEWCELL2(_into) \
 283   do { _into = scm_deprecated_newcell2 (); } while (0)
 284
 285 SCM_API void * scm_must_malloc (size_t len, const char *what);
 286 SCM_API void * scm_must_realloc (void *where,
 287                                  size_t olen, size_t len,
 288                                  const char *what);
 289 SCM_API char *scm_must_strdup (const char *str);
 290 SCM_API char *scm_must_strndup (const char *str, size_t n);
 291 SCM_API void scm_done_malloc (long size);
 292 SCM_API void scm_done_free (long size);
 293 SCM_API void scm_must_free (void *obj);
 294
 295 #endif
 296
 297 #endif  /* SCM_GC_H */
 298
 299 /*
 300   Local Variables:
 301   c-file-style: "gnu"
 302   End:
 303 */