libguile/private-gc.h

   1 /*
   2  * private-gc.h - private declarations for garbage collection.
   3  *
   4  * Copyright (C) 2002, 03, 04, 05, 06, 07 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_INIT_HEAP_SIZE is the initial size of heap.  If this much heap is
  36  * allocated initially the heap will grow by half its current size
  37  * each subsequent time more heap is needed.
  38  *
  39  * If SCM_INIT_HEAP_SIZE heap cannot be allocated initially, SCM_HEAP_SEG_SIZE
  40  * will be used, and the heap will grow by SCM_HEAP_SEG_SIZE when more
  41  * heap is needed.  SCM_HEAP_SEG_SIZE must fit into type size_t.  This code
  42  * is in scm_init_storage() and alloc_some_heap() in sys.c
  43  *
  44  * If SCM_INIT_HEAP_SIZE can be allocated initially, the heap will grow by
  45  * SCM_EXPHEAP(scm_heap_size) when more heap is needed.
  46  *
  47  * SCM_MIN_HEAP_SEG_SIZE is minimum size of heap to accept when more heap
  48  * is needed.
  49  */
  50
  51
  52 /*
  53  * Heap size 45000 and 40% min yield gives quick startup and no extra
  54  * heap allocation.  Having higher values on min yield may lead to
  55  * large heaps, especially if code behaviour is varying its
  56  * maximum consumption between different freelists.
  57  */
  58
  59 /*
  60   These values used to be global C variables. However, they're also
  61   available through the environment, and having a double interface is
  62   confusing. Now they're #defines --hwn.
  63  */
  64
  65 #define SCM_DEFAULT_INIT_HEAP_SIZE_1  256*1024
  66 #define SCM_DEFAULT_MIN_YIELD_1 40
  67 #define SCM_DEFAULT_INIT_HEAP_SIZE_2 32*1024
  68
  69 /* The following value may seem large, but note that if we get to GC at
  70  * all, this means that we have a numerically intensive application
  71  */
  72 #define SCM_DEFAULT_MIN_YIELD_2 40
  73
  74 #define SCM_DEFAULT_MAX_SEGMENT_SIZE  (20*1024*1024L)
  75
  76
  77
  78 #define SCM_MIN_HEAP_SEG_SIZE (8 * SCM_GC_SIZEOF_CARD)
  79 #define SCM_HEAP_SEG_SIZE (16384L * sizeof (scm_t_cell))
  80
  81
  82 #define SCM_DOUBLECELL_ALIGNED_P(x)  (((2 * sizeof (scm_t_cell) - 1) & SCM_UNPACK (x)) == 0)
  83
  84
  85 #define SCM_GC_CARD_BVEC_SIZE_IN_LONGS \
  86     ((SCM_GC_CARD_N_CELLS + SCM_C_BVEC_LONG_BITS - 1) / SCM_C_BVEC_LONG_BITS)
  87 #define SCM_GC_IN_CARD_HEADERP(x) \
  88   (scm_t_cell *) (x) <  SCM_GC_CELL_CARD (x) + SCM_GC_CARD_N_HEADER_CELLS
  89
  90
  91 int scm_getenv_int (const char *var, int def);
  92
  93
  94 typedef enum { return_on_error, abort_on_error } policy_on_error;
  95
  96
  97 #define SCM_MAX(A, B) ((A) > (B) ? (A) : (B))
  98 #define SCM_MIN(A, B) ((A) < (B) ? (A) : (B))
  99
 100 /* CELL_P checks a random word whether it has the right form for a
 101    pointer to a cell.  Use scm_i_find_heap_segment_containing_object
 102    to find out whether it actually points to a real cell.
 103
 104    The right form for a cell pointer is this: the low three bits must
 105    be scm_tc3_cons, and when the scm_tc3_cons tag is stripped, the
 106    resulting pointer must be correctly aligned.
 107    scm_i_initialize_heap_segment_data guarantees that the test below
 108    works.
 109 */
 110 #define CELL_P(x)  ((SCM_UNPACK(x) & (sizeof(scm_t_cell)-1)) == scm_tc3_cons)
 111
 112 /*
 113   gc-mark
 114  */
 115
 116
 117 void scm_mark_all (void);
 118
 119
 120 char const *scm_i_tag_name (scm_t_bits tag); /* MOVEME */
 121
 122
 123 extern long int scm_i_deprecated_memory_return;
 124
 125
 126 /*
 127   global init funcs.
 128  */
 129 void scm_gc_init_malloc (void);
 130 void scm_gc_init_freelist (void);
 131 void scm_gc_init_segments (void);
 132 void scm_gc_init_mark (void);
 133
 134
 135 #endif