libguile/inline.h

   1 /* classes: h_files */
   2
   3 #ifndef SCM_INLINE_H
   4 #define SCM_INLINE_H
   5
   6 /* Copyright (C) 2001, 2002, 2003, 2004, 2006 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 /* This file is for inline functions.  On platforms that don't support
  24    inlining functions, they are turned into ordinary functions.  See
  25    "inline.c".
  26 */
  27
  28 #include "libguile/__scm.h"
  29
  30 #if (SCM_DEBUG_CELL_ACCESSES == 1)
  31 #include <stdio.h>
  32 #endif
  33
  34 #include "libguile/pairs.h"
  35 #include "libguile/gc.h"
  36 #include "libguile/threads.h"
  37 #include "libguile/unif.h"
  38 #include "libguile/pairs.h"
  39
  40
  41 SCM_API SCM scm_cell (scm_t_bits car, scm_t_bits cdr);
  42 SCM_API SCM scm_double_cell (scm_t_bits car, scm_t_bits cbr,
  43                              scm_t_bits ccr, scm_t_bits cdr);
  44
  45 SCM_API SCM scm_array_handle_ref (scm_t_array_handle *h, ssize_t pos);
  46 SCM_API void scm_array_handle_set (scm_t_array_handle *h, ssize_t pos, SCM val);
  47
  48
  49 #if defined SCM_C_INLINE || defined SCM_INLINE_C_INCLUDING_INLINE_H
  50 /* either inlining, or being included from inline.c.  We use (and
  51    repeat) this long #if test here and below so that we don't have to
  52    introduce any extraneous symbols into the public namespace.  We
  53    only need SCM_C_INLINE to be seen publically . */
  54
  55 extern unsigned scm_newcell2_count;
  56 extern unsigned scm_newcell_count;
  57
  58 #if defined SCM_C_INLINE && ! defined SCM_INLINE_C_INCLUDING_INLINE_H
  59 /* definitely inlining */
  60 #ifdef __GNUC__
  61 extern
  62 #else
  63 static
  64 #endif
  65 SCM_C_INLINE
  66 #endif
  67 SCM
  68 scm_cell (scm_t_bits car, scm_t_bits cdr)
  69 {
  70   SCM z;
  71   SCM *freelist = SCM_FREELIST_LOC (scm_i_freelist);
  72
  73   if (scm_is_null (*freelist))
  74     z = scm_gc_for_newcell (&scm_i_master_freelist, freelist);
  75   else
  76     {
  77       z = *freelist;
  78       *freelist = SCM_FREE_CELL_CDR (*freelist);
  79     }
  80
  81   /*
  82     We update scm_cells_allocated from this function. If we don't
  83     update this explicitly, we will have to walk a freelist somewhere
  84     later on, which seems a lot more expensive.
  85    */
  86   scm_cells_allocated += 1;
  87
  88 #if (SCM_DEBUG_CELL_ACCESSES == 1)
  89     if (scm_debug_cell_accesses_p)
  90       {
  91         if (SCM_GC_MARK_P (z))
  92           {
  93             fprintf(stderr, "scm_cell tried to allocate a marked cell.\n");
  94             abort();
  95           }
  96         else if (SCM_GC_CELL_WORD(z, 0) != scm_tc_free_cell)
  97           {
  98             fprintf(stderr, "cell from freelist is not a free cell.\n");
  99             abort();
 100           }
 101       }
 102
 103     /*
 104       Always set mark. Otherwise cells that are alloced before
 105       scm_debug_cell_accesses_p is toggled seem invalid.
 106     */
 107     SCM_SET_GC_MARK (z);
 108
 109     /*
 110       TODO: figure out if this use of mark bits is valid with
 111       threading. What if another thread is doing GC at this point
 112       ... ?
 113      */
 114
 115 #endif
 116
 117
 118   /* Initialize the type slot last so that the cell is ignored by the
 119      GC until it is completely initialized.  This is only relevant
 120      when the GC can actually run during this code, which it can't
 121      since the GC only runs when all other threads are stopped.
 122   */
 123   SCM_GC_SET_CELL_WORD (z, 1, cdr);
 124   SCM_GC_SET_CELL_WORD (z, 0, car);
 125
 126 #if (SCM_DEBUG_CELL_ACCESSES == 1)
 127   if (scm_expensive_debug_cell_accesses_p )
 128     scm_i_expensive_validation_check (z);
 129 #endif
 130
 131   return z;
 132 }
 133
 134 #if defined SCM_C_INLINE && ! defined SCM_INLINE_C_INCLUDING_INLINE_H
 135 /* definitely inlining */
 136 #ifdef __GNUC__
 137 extern
 138 #else
 139 static
 140 #endif
 141 SCM_C_INLINE
 142 #endif
 143 SCM
 144 scm_double_cell (scm_t_bits car, scm_t_bits cbr,
 145                  scm_t_bits ccr, scm_t_bits cdr)
 146 {
 147   SCM z;
 148   SCM *freelist = SCM_FREELIST_LOC (scm_i_freelist2);
 149
 150   if (scm_is_null (*freelist))
 151     z = scm_gc_for_newcell (&scm_i_master_freelist2, freelist);
 152   else
 153     {
 154       z = *freelist;
 155       *freelist = SCM_FREE_CELL_CDR (*freelist);
 156     }
 157
 158   scm_cells_allocated += 2;
 159
 160   /* Initialize the type slot last so that the cell is ignored by the
 161      GC until it is completely initialized.  This is only relevant
 162      when the GC can actually run during this code, which it can't
 163      since the GC only runs when all other threads are stopped.
 164   */
 165   SCM_GC_SET_CELL_WORD (z, 1, cbr);
 166   SCM_GC_SET_CELL_WORD (z, 2, ccr);
 167   SCM_GC_SET_CELL_WORD (z, 3, cdr);
 168   SCM_GC_SET_CELL_WORD (z, 0, car);
 169
 170 #if (SCM_DEBUG_CELL_ACCESSES == 1)
 171   if (scm_debug_cell_accesses_p)
 172     {
 173       if (SCM_GC_MARK_P (z))
 174         {
 175           fprintf(stderr,
 176                   "scm_double_cell tried to allocate a marked cell.\n");
 177           abort();
 178         }
 179     }
 180
 181   /* see above. */
 182   SCM_SET_GC_MARK (z);
 183
 184 #endif
 185
 186   /* When this function is inlined, it's possible that the last
 187      SCM_GC_SET_CELL_WORD above will be adjacent to a following
 188      initialization of z.  E.g., it occurred in scm_make_real.  GCC
 189      from around version 3 (e.g., certainly 3.2) began taking
 190      advantage of strict C aliasing rules which say that it's OK to
 191      interchange the initialization above and the one below when the
 192      pointer types appear to differ sufficiently.  We don't want that,
 193      of course.  GCC allows this behaviour to be disabled with the
 194      -fno-strict-aliasing option, but would also need to be supplied
 195      by Guile users.  Instead, the following statements prevent the
 196      reordering.
 197    */
 198 #ifdef __GNUC__
 199   __asm__ volatile ("" : : : "memory");
 200 #else
 201   /* portable version, just in case any other compiler does the same
 202      thing.  */
 203   scm_remember_upto_here_1 (z);
 204 #endif
 205
 206   return z;
 207 }
 208
 209 #if defined SCM_C_INLINE && ! defined SCM_INLINE_C_INCLUDING_INLINE_H
 210 /* definitely inlining */
 211 #ifdef __GNUC__
 212 extern
 213 #else
 214 static
 215 #endif
 216 SCM_C_INLINE
 217 #endif
 218 SCM
 219 scm_array_handle_ref (scm_t_array_handle *h, ssize_t p)
 220 {
 221   return h->ref (h, p);
 222 }
 223
 224 #if defined SCM_C_INLINE && ! defined SCM_INLINE_C_INCLUDING_INLINE_H
 225 /* definitely inlining */
 226 #ifdef __GNUC__
 227 extern
 228 #else
 229 static
 230 #endif
 231 SCM_C_INLINE
 232 #endif
 233 void
 234 scm_array_handle_set (scm_t_array_handle *h, ssize_t p, SCM v)
 235 {
 236   h->set (h, p, v);
 237 }
 238
 239 #if defined SCM_C_INLINE && ! defined SCM_INLINE_C_INCLUDING_INLINE_H
 240 /* definitely inlining */
 241 #ifdef __GNUC__
 242 extern
 243 #else
 244 static
 245 #endif
 246 SCM_C_INLINE
 247 #endif
 248 int
 249 scm_is_pair (SCM x)
 250 {
 251   return SCM_I_CONSP (x);
 252 }
 253
 254 #endif
 255 #endif