include/AD/gc/gcconfig.h

   1 //////////////////////////////////////////////////////////////////////////////
   2 // NOTICE:
   3 //
   4 // ADLib, Prop and their related set of tools and documentation are in the
   5 // public domain.   The author(s) of this software reserve no copyrights on
   6 // the source code and any code generated using the tools.  You are encouraged
   7 // to use ADLib and Prop to develop software, in both academic and commercial
   8 // settings, and are welcomed to incorporate any part of ADLib and Prop into
   9 // your programs.
  10 //
  11 // Although you are under no obligation to do so, we strongly recommend that
  12 // you give away all software developed using our tools.
  13 //
  14 // We also ask that credit be given to us when ADLib and/or Prop are used in
  15 // your programs, and that this notice be preserved intact in all the source
  16 // code.
  17 //
  18 // This software is still under development and we welcome(read crave for)
  19 // any suggestions and help from the users.
  20 //
  21 // Allen Leung (leunga@cs.nyu.edu)
  22 // 1994-1995
  23 //////////////////////////////////////////////////////////////////////////////
  24
  25 #ifndef gc_configuration_h
  26 #define gc_configuration_h
  27
  28 #include <AD/config/config.h>
  29
  30 //////////////////////////////////////////////////////////////////////////////
  31 //  This file is used to customize the garbage collectors.  Please
  32 //  read this through carefully and customize it to suit your platform's
  33 //  needs.
  34 //////////////////////////////////////////////////////////////////////////////
  35
  36 //////////////////////////////////////////////////////////////////////////////
  37 //  Maximum number of garbage collectors instance.
  38 //  Notice that more than one type of heaps are allowed.
  39 //////////////////////////////////////////////////////////////////////////////
  40 #define GC_MAX_NUMBER_OF_COLLECTORS 256
  41
  42 //////////////////////////////////////////////////////////////////////////////
  43 //  Size of a *logical* page in bytes.  Memory managed by the managers
  44 //  are partitioned into logical pages.  Increasing the page size will
  45 //  decrease the sizes bookkeeping data structures, but may increase retention.
  46 //  Page size *MUST* be a power of two but it doesn't have to match the
  47 //  underlying page size of the VM.
  48 //
  49 //  I think 256 bytes is probably too small while something like 4K
  50 //  is probably too large.
  51 //////////////////////////////////////////////////////////////////////////////
  52 #define GC_PAGE_SIZE 512
  53
  54 //////////////////////////////////////////////////////////////////////////////
  55 //  Should we use blacklisting to decrease the likehood of
  56 //  false root identification?
  57 //
  58 //     The default is yes.
  59 //     We'll allow up to ten percentage of all memory to be blacklisted,
  60 //     or 64K of memory at one time, or 512K total, whichever is lower.
  61 //
  62 //////////////////////////////////////////////////////////////////////////////
  63 #define GC_USE_BLACKLISTING
  64 #define GC_MIN_BLACKLISTED_PAGES       4
  65 #define GC_MAX_BLACKLISTED_PERCENTAGE  10
  66 #define GC_MAX_BLACKLISTED_PAGES       (65536/GC_PAGE_SIZE)
  67 #define GC_MAX_TOTAL_BLACKLISTED_PAGES (512*1024/GC_PAGE_SIZE)
  68
  69 //////////////////////////////////////////////////////////////////////////////
  70 //  Should cross heap pointers be allowed?
  71 //  The default is yes.   If you want to allocate connecting structures
  72 //  in multiple collectable heaps then this is a must.  If you'll only use
  73 //  one collector at a time then you can safely comment this option
  74 //  out.  The code will be a bit faster.
  75 //////////////////////////////////////////////////////////////////////////////
  76 #define GC_HAS_CROSS_HEAP_POINTERS
  77
  78 //////////////////////////////////////////////////////////////////////////////
  79 //  Should we try to keep track of garbage collection time?
  80 //  The default is yes.  This is generally a good idea since you may want
  81 //  to profile the programs during fine-tuning.   The timer code should
  82 //  work on both BSD and System V systems.
  83 //////////////////////////////////////////////////////////////////////////////
  84 #if defined(PROP_HAS_GETRUSAGE) || defined(PROP_HAS_TIMES)
  85 #define GC_USE_TIMER
  86 #endif
  87
  88 //////////////////////////////////////////////////////////////////////////////
  89 //  Debugging flag.  Off for production use.
  90 //////////////////////////////////////////////////////////////////////////////
  91 // #define DEBUG_GC
  92
  93 //////////////////////////////////////////////////////////////////////////////
  94 //  Architecture dependent information follows:
  95 //
  96 //  GC_ALIGNMENT          -- a suitable data alignment in bytes.  This is
  97 //                           8 on most platforms.  All data allocated
  98 //                           are guaranteed to satisfy this constraint.
  99 //                           Notice that while decrease this alignment may
 100 //                           decrease the sizes of objects allocated, it
 101 //                           will also increase the sizes of the internal
 102 //                           bitmaps and the times for roots identification,
 103 //                           as more addresses will become candidates.
 104 //  GC_DATA_START         -- a macro to find the start of static data
 105 //  GC_DATA_END           -- a macro to find the end of the static data
 106 //
 107 //  GC_GET_HEAP_BOTTOM    -- a macro to locate the bottom of the heap
 108 //  GC_GET_HEAP_TOP       -- a macro to locate the top of the heap
 109 //
 110 //  Some assumptions that I've made:
 111 //
 112 //     8 bits in a bytes.
 113 //     32 bit processor.
 114 //     4 byte alignment for pointers.
 115 //     linear address space.
 116 //     the static area is contiguous and not expandable during execution.
 117 //     the heap area is contiguous.
 118 //     the stack area is contiguous(no spaghetti stack please).
 119 //     _setjmp() will properly flush the registers onto the stack.
 120 //////////////////////////////////////////////////////////////////////////////
 121
 122 //////////////////////////////////////////////////////////////////////////////
 123 //  Configuration for Linux on x86 architectures.
 124 //  Configuration for Sparc on SUN/OS
 125 //////////////////////////////////////////////////////////////////////////////
 126 #if defined(linux) || (defined(sparc) && ! defined(__SVR4))
 127 #  define GC_ALIGNMENT           8   // use 8-byte alignment for our heap
 128 extern int etext;
 129 extern int end;
 130 #  define GC_DATA_START  (void*)(((unsigned long)(&etext) + 0xfff) & ~0xfff)
 131 #  define GC_DATA_END    (void*)(&end)
 132 #include <stdlib.h>
 133 #include <unistd.h>
 134 //extern "C" void * sbrk(int);
 135 #  define GC_GET_HEAP_BOTTOM sbrk(0)
 136 #  define GC_GET_HEAP_TOP    sbrk(0)
 137 #  define GC_CONFIGURED
 138 #endif
 139
 140 //////////////////////////////////////////////////////////////////////////////
 141 // Configuration for Sparc on Solaris 5.*
 142 //   Paul F. Dietz, 2/26/97
 143 //////////////////////////////////////////////////////////////////////////////
 144 #if defined(sparc) && defined(__SVR4)
 145 #  define GC_ALIGNMENT           8   // use 8-byte alignment for our heap
 146 extern int etext;
 147 extern int end;
 148
 149 //
 150 // The data segment in Solaris Sparc binaries does not start
 151 // on the next page after the text segment.  The first symbol
 152 // in the data segment is apparently _GLOBAL_OFFSET_TABLE.
 153 // So, make the first page be the page containing this symbol.
 154 //  PFD 2/26/97
 155 //
 156 extern int _GLOBAL_OFFSET_TABLE_;
 157 #  define GC_DATA_START  (void*)((unsigned long)(&_GLOBAL_OFFSET_TABLE_)\
 158                                   & ~0xfff)
 159 #  define GC_DATA_END    (void*)(&end)
 160 #include <stdlib.h>
 161 #include <unistd.h>
 162 extern "C" void * sbrk(int);
 163 #  define GC_GET_HEAP_BOTTOM sbrk(0)
 164 #  define GC_GET_HEAP_TOP    sbrk(0)
 165 #  define GC_CONFIGURED
 166 #endif
 167
 168 //////////////////////////////////////////////////////////////////////////////
 169 //  Default configuration: assume vanilla Unixes.
 170 //  Caution: I don't know if it'll work!!!!
 171 //
 172 //  Please add your own and email any new configurations to
 173 //
 174 //     leunga@cs.nyu.edu
 175 //
 176 //  It'll be much appreciated.
 177 //////////////////////////////////////////////////////////////////////////////
 178 #ifndef GC_CONFIGURED
 179 struct GC_ALIGNMENT_TYPE { int a; void * b; double c; };
 180 #define GC_ALIGNMENT sizeof(GC_ALIGNMENT_TYPE)
 181 extern int etext;
 182 extern int end;
 183 #  define GC_DATA_START  (void*)(((unsigned long)(&etext) + 0xfff) & ~0xfff)
 184 #  define GC_DATA_END    (void*)(&end)
 185 #include <stdlib.h>
 186 #include <unistd.h>
 187 extern "C" void * sbrk(int);
 188 #  define GC_GET_HEAP_BOTTOM sbrk(0)
 189 #  define GC_GET_HEAP_TOP    sbrk(0)
 190 #endif
 191
 192 #endif
 193