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 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_API size_t scm_default_init_heap_size_1;
 143 SCM_API int scm_default_min_yield_1;
 144 SCM_API size_t scm_default_init_heap_size_2;
 145 SCM_API int scm_default_min_yield_2;
 146 SCM_API 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_API 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_malloc (size_t size);
 186 SCM_API void *scm_calloc (size_t size);
 187 SCM_API void *scm_realloc (void *mem, size_t size);
 188 SCM_API char *scm_strdup (const char *str);
 189 SCM_API char *scm_strndup (const char *str, size_t n);
 190 SCM_API void scm_gc_register_collectable_memory (void *mem, size_t size,
 191                                                  const char *what);
 192 SCM_API void scm_gc_unregister_collectable_memory (void *mem, size_t size,
 193                                                    const char *what);
 194 SCM_API void *scm_gc_malloc_pointerless (size_t size, const char *what);
 195 SCM_API void *scm_gc_calloc (size_t size, const char *what);
 196 SCM_API void *scm_gc_malloc (size_t size, const char *what);
 197 SCM_API void *scm_gc_realloc (void *mem, size_t old_size,
 198                               size_t new_size, const char *what);
 199 SCM_API void scm_gc_free (void *mem, size_t size, const char *what);
 200 SCM_API char *scm_gc_strdup (const char *str, const char *what);
 201 SCM_API char *scm_gc_strndup (const char *str, size_t n, const char *what);
 202
 203 SCM_API void scm_remember_upto_here_1 (SCM obj);
 204 SCM_API void scm_remember_upto_here_2 (SCM obj1, SCM obj2);
 205 SCM_API void scm_remember_upto_here (SCM obj1, ...);
 206
 207 /* In GCC we can force a reference to an SCM by making it an input to an
 208    empty asm.  This avoids the code size and slowdown of an actual function
 209    call.  Unfortunately there doesn't seem to be any way to do the varargs
 210    scm_remember_upto_here like this.
 211
 212    __volatile__ ensures nothing will be moved across the asm, and it won't
 213    be optimized away (or only if proved unreachable).  Constraint "g" can be
 214    used on all processors and allows any memory or general register (or
 215    immediate) operand.  The actual asm syntax doesn't matter, we don't want
 216    to use it, just ensure the operand is still alive.  See "Extended Asm" in
 217    the GCC manual for more.  */
 218
 219 #ifdef __GNUC__
 220 #define scm_remember_upto_here_1(x)             \
 221   do {                                          \
 222     __asm__ __volatile__ ("" : : "g" (x));      \
 223   } while (0)
 224 #define scm_remember_upto_here_2(x, y)          \
 225   do {                                          \
 226     scm_remember_upto_here_1 (x);               \
 227     scm_remember_upto_here_1 (y);               \
 228   } while (0)
 229 #endif
 230
 231 SCM_API SCM scm_return_first (SCM elt, ...);
 232 SCM_API int scm_return_first_int (int x, ...);
 233 SCM_API SCM scm_permanent_object (SCM obj);
 234 SCM_API SCM scm_gc_protect_object (SCM obj);
 235 SCM_API SCM scm_gc_unprotect_object (SCM obj);
 236 SCM_API void scm_gc_register_root (SCM *p);
 237 SCM_API void scm_gc_unregister_root (SCM *p);
 238 SCM_API void scm_gc_register_roots (SCM *b, unsigned long n);
 239 SCM_API void scm_gc_unregister_roots (SCM *b, unsigned long n);
 240 SCM_API void scm_storage_prehistory (void);
 241 SCM_API int scm_init_storage (void);
 242 SCM_API void scm_init_gc (void);
 243
 244 #if SCM_ENABLE_DEPRECATED == 1
 245
 246 SCM_API SCM scm_deprecated_newcell (void);
 247 SCM_API SCM scm_deprecated_newcell2 (void);
 248
 249 #define SCM_NEWCELL(_into) \
 250   do { _into = scm_deprecated_newcell (); } while (0)
 251 #define SCM_NEWCELL2(_into) \
 252   do { _into = scm_deprecated_newcell2 (); } while (0)
 253
 254 SCM_API void * scm_must_malloc (size_t len, const char *what);
 255 SCM_API void * scm_must_realloc (void *where,
 256                                  size_t olen, size_t len,
 257                                  const char *what);
 258 SCM_API char *scm_must_strdup (const char *str);
 259 SCM_API char *scm_must_strndup (const char *str, size_t n);
 260 SCM_API void scm_done_malloc (long size);
 261 SCM_API void scm_done_free (long size);
 262 SCM_API void scm_must_free (void *obj);
 263
 264 #endif
 265
 266 #endif  /* SCM_GC_H */
 267
 268 /*
 269   Local Variables:
 270   c-file-style: "gnu"
 271   End:
 272 */