vm/data_gc.h

   1 void gc(void);
   2 DLLEXPORT void minor_gc(void);
   3
   4 /* used during garbage collection only */
   5
   6 F_ZONE *newspace;
   7 bool performing_gc;
   8 CELL collecting_gen;
   9
  10 /* if true, we collecting AGING space for the second time, so if it is still
  11 full, we go on to collect TENURED */
  12 bool collecting_aging_again;
  13
  14 /* in case a generation fills up in the middle of a gc, we jump back
  15 up to try collecting the next generation. */
  16 jmp_buf gc_jmp;
  17
  18 /* statistics */
  19 typedef struct {
  20         CELL collections;
  21         u64 gc_time;
  22         u64 max_gc_time;
  23         CELL object_count;
  24         u64 bytes_copied;
  25 } F_GC_STATS;
  26
  27 F_GC_STATS gc_stats[MAX_GEN_COUNT];
  28 u64 cards_scanned;
  29 u64 decks_scanned;
  30 CELL code_heap_scans;
  31
  32 /* What generation was being collected when copy_code_heap_roots() was last
  33 called? Until the next call to add_compiled_block(), future
  34 collections of younger generations don't have to touch the code
  35 heap. */
  36 CELL last_code_heap_scan;
  37
  38 /* sometimes we grow the heap */
  39 bool growing_data_heap;
  40 F_DATA_HEAP *old_data_heap;
  41
  42 INLINE bool collecting_accumulation_gen_p(void)
  43 {
  44         return ((HAVE_AGING_P
  45                 && collecting_gen == AGING
  46                 && !collecting_aging_again)
  47                 || collecting_gen == TENURED);
  48 }
  49
  50 /* test if the pointer is in generation being collected, or a younger one. */
  51 INLINE bool should_copy(CELL untagged)
  52 {
  53         if(in_zone(newspace,untagged))
  54                 return false;
  55         if(collecting_gen == TENURED)
  56                 return true;
  57         else if(HAVE_AGING_P && collecting_gen == AGING)
  58                 return !in_zone(&data_heap->generations[TENURED],untagged);
  59         else if(HAVE_NURSERY_P && collecting_gen == NURSERY)
  60                 return in_zone(&nursery,untagged);
  61         else
  62         {
  63                 critical_error("Bug in should_copy",untagged);
  64                 return false;
  65         }
  66 }
  67
  68 void copy_handle(CELL *handle);
  69
  70 void garbage_collection(volatile CELL gen,
  71         bool growing_data_heap_,
  72         CELL requested_bytes);
  73
  74 /* We leave this many bytes free at the top of the nursery so that inline
  75 allocation (which does not call GC because of possible roots in volatile
  76 registers) does not run out of memory */
  77 #define ALLOT_BUFFER_ZONE 1024
  78
  79 /*
  80  * It is up to the caller to fill in the object's fields in a meaningful
  81  * fashion!
  82  */
  83 INLINE void *allot_object(CELL type, CELL a)
  84 {
  85         CELL *object;
  86
  87         if(HAVE_NURSERY_P && nursery.size - ALLOT_BUFFER_ZONE > a)
  88         {
  89                 /* If there is insufficient room, collect the nursery */
  90                 if(nursery.here + ALLOT_BUFFER_ZONE + a > nursery.end)
  91                         garbage_collection(NURSERY,false,0);
  92
  93                 CELL h = nursery.here;
  94                 nursery.here = h + align8(a);
  95                 object = (void*)h;
  96         }
  97         /* If the object is bigger than the nursery, allocate it in
  98         tenured space */
  99         else
 100         {
 101                 F_ZONE *tenured = &data_heap->generations[TENURED];
 102
 103                 /* If tenured space does not have enough room, collect */
 104                 if(tenured->here + a > tenured->end)
 105                 {
 106                         gc();
 107                         tenured = &data_heap->generations[TENURED];
 108                 }
 109
 110                 /* If it still won't fit, grow the heap */
 111                 if(tenured->here + a > tenured->end)
 112                 {
 113                         garbage_collection(TENURED,true,a);
 114                         tenured = &data_heap->generations[TENURED];
 115                 }
 116
 117                 object = allot_zone(tenured,a);
 118
 119                 /* We have to do this */
 120                 allot_barrier((CELL)object);
 121
 122                 /* Allows initialization code to store old->new pointers
 123                 without hitting the write barrier in the common case of
 124                 a nursery allocation */
 125                 write_barrier((CELL)object);
 126         }
 127
 128         *object = tag_header(type);
 129         return object;
 130 }
 131
 132 void copy_reachable_objects(CELL scan, CELL *end);
 133
 134 void primitive_gc(void);
 135 void primitive_gc_stats(void);
 136 void clear_gc_stats(void);
 137 void primitive_clear_gc_stats(void);
 138 void primitive_become(void);