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, 2009, 2010, 2011 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 License
  10  * as published by the Free Software Foundation; either version 3 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful, but
  14  * 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
  21  * 02110-1301 USA
  22  */
  23
  24 \f
  25
  26 #include "libguile/__scm.h"
  27
  28 #include "libguile/hooks.h"
  29 #include "libguile/threads.h"
  30
  31 \f
  32 typedef struct scm_t_cell
  33 {
  34   SCM word_0;
  35   SCM word_1;
  36 } scm_t_cell;
  37
  38 /* Cray machines have pointers that are incremented once for each
  39  * word, rather than each byte, the 3 most significant bits encode the
  40  * byte within the word.  The following macros deal with this by
  41  * storing the native Cray pointers like the ones that looks like scm
  42  * expects.  This is done for any pointers that point to a cell,
  43  * pointers to scm_vector elts, functions, &c are not munged.
  44  */
  45 #ifdef _UNICOS
  46 #  define SCM2PTR(x) ((scm_t_cell *) (SCM_UNPACK (x) >> 3))
  47 #  define PTR2SCM(x) (SCM_PACK (((scm_t_bits) (x)) << 3))
  48 #else
  49 #  define SCM2PTR(x) ((scm_t_cell *) (SCM_UNPACK (x)))
  50 #  define PTR2SCM(x) (SCM_PACK ((scm_t_bits) (x)))
  51 #endif /* def _UNICOS */
  52
  53
  54
  55 /* Low level cell data accessing macros.  These macros should only be used
  56  * from within code related to garbage collection issues, since they will
  57  * never check the cells they are applied to - not even if guile is compiled
  58  * in debug mode.  In particular these macros will even work for free cells,
  59  * which should never be encountered by user code.  */
  60
  61 #define SCM_GC_CELL_OBJECT(x, n) (((SCM *)SCM2PTR (x)) [n])
  62 #define SCM_GC_CELL_WORD(x, n)   (SCM_UNPACK (SCM_GC_CELL_OBJECT ((x), (n))))
  63
  64 #define SCM_GC_SET_CELL_OBJECT(x, n, v) ((((SCM *)SCM2PTR (x)) [n]) = (v))
  65 #define SCM_GC_SET_CELL_WORD(x, n, v)  \
  66   (SCM_GC_SET_CELL_OBJECT ((x), (n), SCM_PACK (v)))
  67
  68 #define SCM_GC_CELL_TYPE(x) (SCM_GC_CELL_OBJECT ((x), 0))
  69
  70
  71 /* Except for the garbage collector, no part of guile should ever run over a
  72  * free cell.  Thus, if guile is compiled in debug mode the SCM_CELL_* and
  73  * SCM_SET_CELL_* macros below report an error if they are applied to a free
  74  * cell.  Some other plausibility checks are also performed.  However, if
  75  * guile is not compiled in debug mode, there won't be any time penalty at all
  76  * when using these macros.  */
  77
  78 #if (SCM_DEBUG_CELL_ACCESSES == 1)
  79 #  define SCM_VALIDATE_CELL(cell, expr) (scm_assert_cell_valid (cell), (expr))
  80 #else
  81 #  define SCM_VALIDATE_CELL(cell, expr) (expr)
  82 #endif
  83
  84 #define SCM_CELL_WORD(x, n) \
  85   SCM_VALIDATE_CELL ((x), SCM_GC_CELL_WORD ((x), (n)))
  86 #define SCM_CELL_WORD_0(x) SCM_CELL_WORD ((x), 0)
  87 #define SCM_CELL_WORD_1(x) SCM_CELL_WORD ((x), 1)
  88 #define SCM_CELL_WORD_2(x) SCM_CELL_WORD ((x), 2)
  89 #define SCM_CELL_WORD_3(x) SCM_CELL_WORD ((x), 3)
  90
  91 #define SCM_CELL_OBJECT(x, n) \
  92   SCM_VALIDATE_CELL ((x), SCM_GC_CELL_OBJECT ((x), (n)))
  93 #define SCM_CELL_OBJECT_0(x) SCM_CELL_OBJECT ((x), 0)
  94 #define SCM_CELL_OBJECT_1(x) SCM_CELL_OBJECT ((x), 1)
  95 #define SCM_CELL_OBJECT_2(x) SCM_CELL_OBJECT ((x), 2)
  96 #define SCM_CELL_OBJECT_3(x) SCM_CELL_OBJECT ((x), 3)
  97
  98 #define SCM_SET_CELL_WORD(x, n, v) \
  99   SCM_VALIDATE_CELL ((x), SCM_GC_SET_CELL_WORD ((x), (n), (v)))
 100 #define SCM_SET_CELL_WORD_0(x, v) SCM_SET_CELL_WORD ((x), 0, (v))
 101 #define SCM_SET_CELL_WORD_1(x, v) SCM_SET_CELL_WORD ((x), 1, (v))
 102 #define SCM_SET_CELL_WORD_2(x, v) SCM_SET_CELL_WORD ((x), 2, (v))
 103 #define SCM_SET_CELL_WORD_3(x, v) SCM_SET_CELL_WORD ((x), 3, (v))
 104
 105 #define SCM_SET_CELL_OBJECT(x, n, v) \
 106   SCM_VALIDATE_CELL ((x), SCM_GC_SET_CELL_OBJECT ((x), (n), (v)))
 107 #define SCM_SET_CELL_OBJECT_0(x, v) SCM_SET_CELL_OBJECT ((x), 0, (v))
 108 #define SCM_SET_CELL_OBJECT_1(x, v) SCM_SET_CELL_OBJECT ((x), 1, (v))
 109 #define SCM_SET_CELL_OBJECT_2(x, v) SCM_SET_CELL_OBJECT ((x), 2, (v))
 110 #define SCM_SET_CELL_OBJECT_3(x, v) SCM_SET_CELL_OBJECT ((x), 3, (v))
 111
 112 #define SCM_CELL_OBJECT_LOC(x, n) (SCM_VALIDATE_CELL((x), &SCM_GC_CELL_OBJECT ((x), (n))))
 113 #define SCM_CARLOC(x)             (SCM_CELL_OBJECT_LOC ((x), 0))
 114 #define SCM_CDRLOC(x)             (SCM_CELL_OBJECT_LOC ((x), 1))
 115
 116 #define SCM_CELL_TYPE(x) SCM_CELL_WORD_0 (x)
 117 #define SCM_SET_CELL_TYPE(x, t) SCM_SET_CELL_WORD_0 ((x), (t))
 118
 119
 120 #if (SCM_DEBUG_CELL_ACCESSES == 1)
 121 /* Set this to != 0 if every cell that is accessed shall be checked:
 122  */
 123 SCM_API int scm_debug_cell_accesses_p;
 124 SCM_API int scm_expensive_debug_cell_accesses_p;
 125 SCM_API int scm_debug_cells_gc_interval ;
 126 SCM_API void scm_i_expensive_validation_check (SCM cell);
 127 #endif
 128
 129 SCM_INTERNAL scm_i_pthread_mutex_t scm_i_gc_admin_mutex;
 130
 131 #define scm_gc_running_p  0
 132 SCM_INTERNAL scm_i_pthread_mutex_t scm_i_sweep_mutex;
 133
 134 #ifdef __ia64__
 135 void *scm_ia64_register_backing_store_base (void);
 136 void *scm_ia64_ar_bsp (const void *);
 137 #endif
 138
 139 \f
 140
 141 #if (SCM_ENABLE_DEPRECATED == 1)
 142 SCM_DEPRECATED size_t scm_default_init_heap_size_1;
 143 SCM_DEPRECATED int scm_default_min_yield_1;
 144 SCM_DEPRECATED size_t scm_default_init_heap_size_2;
 145 SCM_DEPRECATED int scm_default_min_yield_2;
 146 SCM_DEPRECATED size_t scm_default_max_segment_size;
 147 #else
 148 #define  scm_default_init_heap_size_1 deprecated
 149 #define  scm_default_min_yield_1 deprecated
 150 #define  scm_default_init_heap_size_2 deprecated
 151 #define  scm_default_min_yield_2 deprecated
 152 #define  scm_default_max_segment_size deprecated
 153 #endif
 154
 155 SCM_API unsigned long scm_gc_ports_collected;
 156
 157 SCM_API SCM scm_after_gc_hook;
 158
 159 SCM_API scm_t_c_hook scm_before_gc_c_hook;
 160 SCM_API scm_t_c_hook scm_before_mark_c_hook;
 161 SCM_API scm_t_c_hook scm_before_sweep_c_hook;
 162 SCM_API scm_t_c_hook scm_after_sweep_c_hook;
 163 SCM_API scm_t_c_hook scm_after_gc_c_hook;
 164
 165 \f
 166
 167 #if (SCM_DEBUG_CELL_ACCESSES == 1)
 168 SCM_API void scm_assert_cell_valid (SCM);
 169 #endif
 170
 171 SCM_API SCM scm_set_debug_cell_accesses_x (SCM flag);
 172
 173
 174 SCM_API SCM scm_object_address (SCM obj);
 175 SCM_API SCM scm_gc_enable (void);
 176 SCM_API SCM scm_gc_disable (void);
 177 SCM_API SCM scm_gc_dump (void);
 178 SCM_API SCM scm_gc_stats (void);
 179 SCM_API SCM scm_gc_live_object_stats (void);
 180 SCM_API SCM scm_gc (void);
 181 SCM_INTERNAL void scm_i_gc (const char *what);
 182 SCM_API void scm_gc_mark (SCM p);
 183 SCM_API void scm_gc_sweep (void);
 184
 185 SCM_API void scm_gc_register_allocation (size_t size);
 186
 187 SCM_API void *scm_malloc (size_t size) SCM_MALLOC;
 188 SCM_API void *scm_calloc (size_t size) SCM_MALLOC;
 189 SCM_API void *scm_realloc (void *mem, size_t size);
 190 SCM_API char *scm_strdup (const char *str) SCM_MALLOC;
 191 SCM_API char *scm_strndup (const char *str, size_t n) SCM_MALLOC;
 192 SCM_API void scm_gc_register_collectable_memory (void *mem, size_t size,
 193                                                  const char *what);
 194 SCM_API void scm_gc_unregister_collectable_memory (void *mem, size_t size,
 195                                                    const char *what);
 196 SCM_API void *scm_gc_malloc_pointerless (size_t size, const char *what)
 197   SCM_MALLOC;
 198 SCM_API void *scm_gc_calloc (size_t size, const char *what)
 199   SCM_MALLOC;
 200 SCM_API void *scm_gc_malloc (size_t size, const char *what)
 201   SCM_MALLOC;
 202 SCM_API void *scm_gc_realloc (void *mem, size_t old_size,
 203                               size_t new_size, const char *what);
 204 SCM_API void scm_gc_free (void *mem, size_t size, const char *what);
 205 SCM_API char *scm_gc_strdup (const char *str, const char *what)
 206   SCM_MALLOC;
 207 SCM_API char *scm_gc_strndup (const char *str, size_t n, const char *what)
 208   SCM_MALLOC;
 209
 210
 211 #ifdef BUILDING_LIBGUILE
 212 #include "libguile/bdw-gc.h"
 213 #define SCM_GC_MALLOC(size) GC_MALLOC (size)
 214 #define SCM_GC_MALLOC_POINTERLESS(size) GC_MALLOC_ATOMIC (size)
 215 #else
 216 #define SCM_GC_MALLOC(size) scm_gc_malloc (size, NULL)
 217 #define SCM_GC_MALLOC_POINTERLESS(size) scm_gc_malloc_pointerless (size, NULL)
 218 #endif
 219
 220
 221 SCM_API void scm_remember_upto_here_1 (SCM obj);
 222 SCM_API void scm_remember_upto_here_2 (SCM obj1, SCM obj2);
 223 SCM_API void scm_remember_upto_here (SCM obj1, ...);
 224
 225 /* In GCC we can force a reference to an SCM by making it an input to an
 226    empty asm.  This avoids the code size and slowdown of an actual function
 227    call.  Unfortunately there doesn't seem to be any way to do the varargs
 228    scm_remember_upto_here like this.
 229
 230    __volatile__ ensures nothing will be moved across the asm, and it won't
 231    be optimized away (or only if proved unreachable).  Constraint "g" can be
 232    used on all processors and allows any memory or general register (or
 233    immediate) operand.  The actual asm syntax doesn't matter, we don't want
 234    to use it, just ensure the operand is still alive.  See "Extended Asm" in
 235    the GCC manual for more.  */
 236
 237 #ifdef __GNUC__
 238 #define scm_remember_upto_here_1(x)             \
 239   do {                                          \
 240     __asm__ __volatile__ ("" : : "g" (x));      \
 241   } while (0)
 242 #define scm_remember_upto_here_2(x, y)          \
 243   do {                                          \
 244     scm_remember_upto_here_1 (x);               \
 245     scm_remember_upto_here_1 (y);               \
 246   } while (0)
 247 #endif
 248
 249 SCM_API SCM scm_return_first (SCM elt, ...);
 250 SCM_API int scm_return_first_int (int x, ...);
 251 SCM_API SCM scm_permanent_object (SCM obj);
 252 SCM_API SCM scm_gc_protect_object (SCM obj);
 253 SCM_API SCM scm_gc_unprotect_object (SCM obj);
 254 SCM_API void scm_gc_register_root (SCM *p);
 255 SCM_API void scm_gc_unregister_root (SCM *p);
 256 SCM_API void scm_gc_register_roots (SCM *b, unsigned long n);
 257 SCM_API void scm_gc_unregister_roots (SCM *b, unsigned long n);
 258 #if SCM_ENABLE_DEPRECATED == 1
 259 SCM_DEPRECATED SCM scm_protects;
 260 #endif
 261 SCM_INTERNAL void scm_storage_prehistory (void);
 262 SCM_INTERNAL void scm_init_gc_protect_object (void);
 263 SCM_INTERNAL void scm_init_gc (void);
 264
 265 #if SCM_ENABLE_DEPRECATED == 1
 266
 267 SCM_DEPRECATED SCM scm_deprecated_newcell (void);
 268 SCM_DEPRECATED SCM scm_deprecated_newcell2 (void);
 269
 270 #define SCM_NEWCELL(_into) \
 271   do { _into = scm_deprecated_newcell (); } while (0)
 272 #define SCM_NEWCELL2(_into) \
 273   do { _into = scm_deprecated_newcell2 (); } while (0)
 274
 275 SCM_DEPRECATED void * scm_must_malloc (size_t len, const char *what);
 276 SCM_DEPRECATED void * scm_must_realloc (void *where,
 277                                         size_t olen, size_t len,
 278                                         const char *what);
 279 SCM_DEPRECATED char *scm_must_strdup (const char *str);
 280 SCM_DEPRECATED char *scm_must_strndup (const char *str, size_t n);
 281 SCM_DEPRECATED void scm_done_malloc (long size);
 282 SCM_DEPRECATED void scm_done_free (long size);
 283 SCM_DEPRECATED void scm_must_free (void *obj);
 284
 285 #endif
 286
 287 #endif  /* SCM_GC_H */
 288
 289 /*
 290   Local Variables:
 291   c-file-style: "gnu"
 292   End:
 293 */