6 /* Copyright (C) 1995,1996,1998,1999,2000,2001, 2002, 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
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.
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.
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
26 #include "libguile/__scm.h"
28 #include "libguile/hooks.h"
29 #include "libguile/threads.h"
32 typedef struct scm_t_cell
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.
46 # define SCM2PTR(x) ((scm_t_cell *) (SCM_UNPACK (x) >> 3))
47 # define PTR2SCM(x) (SCM_PACK (((scm_t_bits) (x)) << 3))
49 # define SCM2PTR(x) ((scm_t_cell *) (SCM_UNPACK (x)))
50 # define PTR2SCM(x) (SCM_PACK ((scm_t_bits) (x)))
51 #endif /* def _UNICOS */
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. */
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))))
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)))
68 #define SCM_GC_CELL_TYPE(x) (SCM_GC_CELL_OBJECT ((x), 0))
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. */
78 #if (SCM_DEBUG_CELL_ACCESSES == 1)
79 # define SCM_VALIDATE_CELL(cell, expr) (scm_assert_cell_valid (cell), (expr))
81 # define SCM_VALIDATE_CELL(cell, expr) (expr)
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)
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)
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))
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))
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))
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))
120 #if (SCM_DEBUG_CELL_ACCESSES == 1)
121 /* Set this to != 0 if every cell that is accessed shall be checked:
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
);
129 SCM_INTERNAL scm_i_pthread_mutex_t scm_i_gc_admin_mutex
;
131 #define scm_gc_running_p 0
132 SCM_INTERNAL scm_i_pthread_mutex_t scm_i_sweep_mutex
;
135 void *scm_ia64_register_backing_store_base (void);
136 void *scm_ia64_ar_bsp (const void *);
141 SCM_API
unsigned long scm_gc_ports_collected
;
143 SCM_API SCM scm_after_gc_hook
;
145 SCM_API scm_t_c_hook scm_before_gc_c_hook
;
146 SCM_API scm_t_c_hook scm_before_mark_c_hook
;
147 SCM_API scm_t_c_hook scm_before_sweep_c_hook
;
148 SCM_API scm_t_c_hook scm_after_sweep_c_hook
;
149 SCM_API scm_t_c_hook scm_after_gc_c_hook
;
153 #if (SCM_DEBUG_CELL_ACCESSES == 1)
154 SCM_API
void scm_assert_cell_valid (SCM
);
157 SCM_API SCM
scm_set_debug_cell_accesses_x (SCM flag
);
160 SCM_API SCM
scm_object_address (SCM obj
);
161 SCM_API SCM
scm_gc_enable (void);
162 SCM_API SCM
scm_gc_disable (void);
163 SCM_API SCM
scm_gc_dump (void);
164 SCM_API SCM
scm_gc_stats (void);
165 SCM_API SCM
scm_gc_live_object_stats (void);
166 SCM_API SCM
scm_gc (void);
167 SCM_INTERNAL
void scm_i_gc (const char *what
);
168 SCM_API
void scm_gc_mark (SCM p
);
169 SCM_API
void scm_gc_sweep (void);
171 SCM_API
void *scm_malloc (size_t size
) SCM_MALLOC
;
172 SCM_API
void *scm_calloc (size_t size
) SCM_MALLOC
;
173 SCM_API
void *scm_realloc (void *mem
, size_t size
);
174 SCM_API
char *scm_strdup (const char *str
) SCM_MALLOC
;
175 SCM_API
char *scm_strndup (const char *str
, size_t n
) SCM_MALLOC
;
176 SCM_API
void scm_gc_register_collectable_memory (void *mem
, size_t size
,
178 SCM_API
void scm_gc_unregister_collectable_memory (void *mem
, size_t size
,
180 SCM_API
void *scm_gc_malloc_pointerless (size_t size
, const char *what
)
182 SCM_API
void *scm_gc_calloc (size_t size
, const char *what
)
184 SCM_API
void *scm_gc_malloc (size_t size
, const char *what
)
186 SCM_API
void *scm_gc_realloc (void *mem
, size_t old_size
,
187 size_t new_size
, const char *what
);
188 SCM_API
void scm_gc_free (void *mem
, size_t size
, const char *what
);
189 SCM_API
char *scm_gc_strdup (const char *str
, const char *what
)
191 SCM_API
char *scm_gc_strndup (const char *str
, size_t n
, const char *what
)
195 #ifdef BUILDING_LIBGUILE
196 #include "libguile/bdw-gc.h"
197 #define SCM_GC_MALLOC(size) GC_MALLOC (size)
198 #define SCM_GC_MALLOC_POINTERLESS(size) GC_MALLOC_ATOMIC (size)
200 #define SCM_GC_MALLOC(size) scm_gc_malloc (size, NULL)
201 #define SCM_GC_MALLOC_POINTERLESS(size) scm_gc_malloc_pointerless (size, NULL)
205 SCM_INLINE SCM
scm_cell (scm_t_bits car
, scm_t_bits cdr
);
206 SCM_INLINE SCM
scm_double_cell (scm_t_bits car
, scm_t_bits cbr
,
207 scm_t_bits ccr
, scm_t_bits cdr
);
208 SCM_INLINE SCM
scm_words (scm_t_bits car
, scm_t_uint16 n_words
);
210 #if SCM_CAN_INLINE || defined SCM_INLINE_C_IMPLEMENTING_INLINES
212 SCM_INLINE_IMPLEMENTATION SCM
213 scm_cell (scm_t_bits car
, scm_t_bits cdr
)
215 SCM cell
= PTR2SCM (SCM_GC_MALLOC (sizeof (scm_t_cell
)));
217 /* Initialize the type slot last so that the cell is ignored by the GC
218 until it is completely initialized. This is only relevant when the GC
219 can actually run during this code, which it can't since the GC only runs
220 when all other threads are stopped. */
221 SCM_GC_SET_CELL_WORD (cell
, 1, cdr
);
222 SCM_GC_SET_CELL_WORD (cell
, 0, car
);
227 SCM_INLINE_IMPLEMENTATION SCM
228 scm_double_cell (scm_t_bits car
, scm_t_bits cbr
,
229 scm_t_bits ccr
, scm_t_bits cdr
)
233 z
= PTR2SCM (SCM_GC_MALLOC (2 * sizeof (scm_t_cell
)));
234 /* Initialize the type slot last so that the cell is ignored by the
235 GC until it is completely initialized. This is only relevant
236 when the GC can actually run during this code, which it can't
237 since the GC only runs when all other threads are stopped.
239 SCM_GC_SET_CELL_WORD (z
, 1, cbr
);
240 SCM_GC_SET_CELL_WORD (z
, 2, ccr
);
241 SCM_GC_SET_CELL_WORD (z
, 3, cdr
);
242 SCM_GC_SET_CELL_WORD (z
, 0, car
);
244 /* When this function is inlined, it's possible that the last
245 SCM_GC_SET_CELL_WORD above will be adjacent to a following
246 initialization of z. E.g., it occurred in scm_make_real. GCC
247 from around version 3 (e.g., certainly 3.2) began taking
248 advantage of strict C aliasing rules which say that it's OK to
249 interchange the initialization above and the one below when the
250 pointer types appear to differ sufficiently. We don't want that,
251 of course. GCC allows this behaviour to be disabled with the
252 -fno-strict-aliasing option, but would also need to be supplied
253 by Guile users. Instead, the following statements prevent the
257 __asm__
volatile ("" : : : "memory");
259 /* portable version, just in case any other compiler does the same
261 scm_remember_upto_here_1 (z
);
267 SCM_INLINE_IMPLEMENTATION SCM
268 scm_words (scm_t_bits car
, scm_t_uint16 n_words
)
272 z
= PTR2SCM (SCM_GC_MALLOC (sizeof (scm_t_bits
) * n_words
));
273 SCM_GC_SET_CELL_WORD (z
, 0, car
);
275 /* FIXME: is the following concern even relevant with BDW-GC? */
277 /* When this function is inlined, it's possible that the last
278 SCM_GC_SET_CELL_WORD above will be adjacent to a following
279 initialization of z. E.g., it occurred in scm_make_real. GCC
280 from around version 3 (e.g., certainly 3.2) began taking
281 advantage of strict C aliasing rules which say that it's OK to
282 interchange the initialization above and the one below when the
283 pointer types appear to differ sufficiently. We don't want that,
284 of course. GCC allows this behaviour to be disabled with the
285 -fno-strict-aliasing option, but would also need to be supplied
286 by Guile users. Instead, the following statements prevent the
290 __asm__
volatile ("" : : : "memory");
292 /* portable version, just in case any other compiler does the same
294 scm_remember_upto_here_1 (z
);
300 #endif /* SCM_CAN_INLINE || defined SCM_INLINE_C_IMPLEMENTING_INLINES */
302 SCM_API
void scm_remember_upto_here_1 (SCM obj
);
303 SCM_API
void scm_remember_upto_here_2 (SCM obj1
, SCM obj2
);
304 SCM_API
void scm_remember_upto_here (SCM obj1
, ...);
306 /* In GCC we can force a reference to an SCM by making it an input to an
307 empty asm. This avoids the code size and slowdown of an actual function
308 call. Unfortunately there doesn't seem to be any way to do the varargs
309 scm_remember_upto_here like this.
311 __volatile__ ensures nothing will be moved across the asm, and it won't
312 be optimized away (or only if proved unreachable). Constraint "g" can be
313 used on all processors and allows any memory or general register (or
314 immediate) operand. The actual asm syntax doesn't matter, we don't want
315 to use it, just ensure the operand is still alive. See "Extended Asm" in
316 the GCC manual for more. */
319 #define scm_remember_upto_here_1(x) \
321 __asm__ __volatile__ ("" : : "g" (x)); \
323 #define scm_remember_upto_here_2(x, y) \
325 scm_remember_upto_here_1 (x); \
326 scm_remember_upto_here_1 (y); \
330 SCM_API SCM
scm_return_first (SCM elt
, ...);
331 SCM_API
int scm_return_first_int (int x
, ...);
332 SCM_API SCM
scm_permanent_object (SCM obj
);
333 SCM_API SCM
scm_gc_protect_object (SCM obj
);
334 SCM_API SCM
scm_gc_unprotect_object (SCM obj
);
335 SCM_API
void scm_gc_register_root (SCM
*p
);
336 SCM_API
void scm_gc_unregister_root (SCM
*p
);
337 SCM_API
void scm_gc_register_roots (SCM
*b
, unsigned long n
);
338 SCM_API
void scm_gc_unregister_roots (SCM
*b
, unsigned long n
);
339 SCM_API SCM scm_protects
;
340 SCM_INTERNAL
void scm_storage_prehistory (void);
341 SCM_INTERNAL
void scm_init_gc_protect_object (void);
342 SCM_INTERNAL
void scm_init_gc (void);
344 #endif /* SCM_GC_H */