libguile/private-gc.h

   1 /*
   2  * private-gc.h - private declarations for garbage collection.
   3  *
   4  * Copyright (C) 2002, 03, 04, 05, 06, 07, 08 Free Software Foundation, Inc.
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #ifndef PRIVATE_GC
  22 #define PRIVATE_GC
  23
  24 #include  "_scm.h"
  25
  26 /* {heap tuning parameters}
  27  *
  28  * These are parameters for controlling memory allocation.  The heap
  29  * is the area out of which scm_cons, and object headers are allocated.
  30  *
  31  * Each heap cell is 8 bytes on a 32 bit machine and 16 bytes on a
  32  * 64 bit machine.  The units of the _SIZE parameters are bytes.
  33  * Cons pairs and object headers occupy one heap cell.
  34  *
  35  * SCM_MIN_HEAP_SEG_SIZE is minimum size of heap to accept when more heap
  36  * is needed.
  37  */
  38
  39
  40 /*
  41  * Heap size 45000 and 40% min yield gives quick startup and no extra
  42  * heap allocation.  Having higher values on min yield may lead to
  43  * large heaps, especially if code behaviour is varying its
  44  * maximum consumption between different freelists.
  45  */
  46
  47 /*
  48   These values used to be global C variables. However, they're also
  49   available through the environment, and having a double interface is
  50   confusing. Now they're #defines --hwn.
  51  */
  52
  53 #define SCM_DEFAULT_INIT_HEAP_SIZE_1  256*1024
  54 #define SCM_DEFAULT_MIN_YIELD_1 40
  55 #define SCM_DEFAULT_INIT_HEAP_SIZE_2 32*1024
  56
  57 /*
  58   How many cells to collect during one sweep call. This is the pool
  59   size of each thread.
  60  */
  61 #define DEFAULT_SWEEP_AMOUNT 512
  62
  63 /* The following value may seem large, but note that if we get to GC at
  64  * all, this means that we have a numerically intensive application
  65  */
  66 #define SCM_DEFAULT_MIN_YIELD_2 40
  67
  68 #define SCM_DEFAULT_MAX_SEGMENT_SIZE  (20*1024*1024L)
  69
  70 #define SCM_MIN_HEAP_SEG_SIZE (8 * SCM_GC_SIZEOF_CARD)
  71 #define SCM_HEAP_SEG_SIZE (16384L * sizeof (scm_t_cell))
  72
  73 #define SCM_DOUBLECELL_ALIGNED_P(x)  (((2 * sizeof (scm_t_cell) - 1) & SCM_UNPACK (x)) == 0)
  74
  75
  76 #define SCM_GC_CARD_BVEC_SIZE_IN_LONGS \
  77     ((SCM_GC_CARD_N_CELLS + SCM_C_BVEC_LONG_BITS - 1) / SCM_C_BVEC_LONG_BITS)
  78 #define SCM_GC_IN_CARD_HEADERP(x) \
  79   (scm_t_cell *) (x) <  SCM_GC_CELL_CARD (x) + SCM_GC_CARD_N_HEADER_CELLS
  80
  81 int scm_getenv_int (const char *var, int def);
  82
  83
  84 typedef enum { return_on_error, abort_on_error } policy_on_error;
  85
  86
  87 #define SCM_MAX(A, B) ((A) > (B) ? (A) : (B))
  88 #define SCM_MIN(A, B) ((A) < (B) ? (A) : (B))
  89
  90 /* CELL_P checks a random word whether it has the right form for a
  91    pointer to a cell.  Use scm_i_find_heap_segment_containing_object
  92    to find out whether it actually points to a real cell.
  93
  94    The right form for a cell pointer is this: the low three bits must
  95    be scm_tc3_cons, and when the scm_tc3_cons tag is stripped, the
  96    resulting pointer must be correctly aligned.
  97    scm_i_initialize_heap_segment_data guarantees that the test below
  98    works.
  99 */
 100 #define CELL_P(x)  ((SCM_UNPACK(x) & (sizeof(scm_t_cell)-1)) == scm_tc3_cons)
 101
 102 /*
 103   gc-mark
 104  */
 105
 106 /* this can be used to ensure that set/clear gc marks only happen when
 107    allowed. */
 108 int scm_i_marking;
 109
 110 void scm_mark_all (void);
 111
 112 extern long int scm_i_deprecated_memory_return;
 113 extern long int scm_i_find_heap_calls;
 114
 115 SCM_INTERNAL char const *scm_i_tag_name (scm_t_bits tag); /* MOVEME */
 116
 117
 118 /*
 119   global init funcs.
 120  */
 121 void scm_gc_init_malloc (void);
 122 void scm_gc_init_freelist (void);
 123 void scm_gc_init_segments (void);
 124 void scm_gc_init_mark (void);
 125
 126
 127 #endif