mono/metadata/sgen-gray.c

   1 #define GRAY_QUEUE_SECTION_SIZE 125
   2 #define GRAY_QUEUE_LENGTH_LIMIT 64
   3
   4 typedef struct _GrayQueueSection GrayQueueSection;
   5 struct _GrayQueueSection {
   6         int start;
   7         int end;
   8         GrayQueueSection *next;
   9         char *objects [GRAY_QUEUE_SECTION_SIZE];
  10 };
  11
  12 static GrayQueueSection *gray_queue_start = NULL;
  13 static GrayQueueSection *gray_queue_end = NULL;
  14
  15 static GrayQueueSection *gray_queue_section_free_list = NULL;
  16 static int gray_queue_free_list_length = 0;
  17
  18 static int gray_queue_balance = 0;
  19 static int num_gray_queue_sections = 0;
  20
  21 static void
  22 gray_object_alloc_queue_section (void)
  23 {
  24         GrayQueueSection *section;
  25
  26         if (gray_queue_section_free_list) {
  27                 section = gray_queue_section_free_list;
  28                 gray_queue_section_free_list = gray_queue_section_free_list->next;
  29                 --gray_queue_free_list_length;
  30         } else {
  31                 section = get_internal_mem (sizeof (GrayQueueSection), INTERNAL_MEM_GRAY_QUEUE);
  32                 ++num_gray_queue_sections;
  33         }
  34
  35         section->start = section->end = 0;
  36         section->next = NULL;
  37
  38         if (gray_queue_end) {
  39                 g_assert (gray_queue_start);
  40                 gray_queue_end = gray_queue_end->next = section;
  41         } else {
  42                 g_assert (!gray_queue_start);
  43                 gray_queue_start = gray_queue_end = section;
  44         }
  45 }
  46
  47 static void
  48 gray_object_enqueue (char *obj)
  49 {
  50         g_assert (obj);
  51         if (!gray_queue_end || gray_queue_end->end == GRAY_QUEUE_SECTION_SIZE)
  52                 gray_object_alloc_queue_section ();
  53         g_assert (gray_queue_end && gray_queue_end->end < GRAY_QUEUE_SECTION_SIZE);
  54         gray_queue_end->objects [gray_queue_end->end++] = obj;
  55
  56         ++gray_queue_balance;
  57 }
  58
  59 static gboolean
  60 gray_object_queue_is_empty (void)
  61 {
  62         if (!gray_queue_start) {
  63                 g_assert (!gray_queue_end);
  64                 return TRUE;
  65         } else {
  66                 g_assert (gray_queue_end);
  67                 return FALSE;
  68         }
  69 }
  70
  71 static char*
  72 gray_object_dequeue (void)
  73 {
  74         char *obj;
  75
  76         if (gray_object_queue_is_empty ())
  77                 return NULL;
  78
  79         g_assert (gray_queue_start->start < gray_queue_start->end);
  80
  81         obj = gray_queue_start->objects [gray_queue_start->start++];
  82
  83         if (gray_queue_start->start == gray_queue_start->end) {
  84                 GrayQueueSection *section = gray_queue_start->next;
  85                 if (gray_queue_free_list_length >= GRAY_QUEUE_LENGTH_LIMIT) {
  86                         free_internal_mem (gray_queue_start, INTERNAL_MEM_GRAY_QUEUE);
  87                 } else {
  88                         gray_queue_start->next = gray_queue_section_free_list;
  89                         gray_queue_section_free_list = gray_queue_start;
  90                         ++gray_queue_free_list_length;
  91                 }
  92                 if (section)
  93                         gray_queue_start = section;
  94                 else
  95                         gray_queue_start = gray_queue_end = NULL;
  96         }
  97
  98         --gray_queue_balance;
  99
 100         return obj;
 101 }
 102
 103 static void
 104 gray_object_queue_init (void)
 105 {
 106         g_assert (gray_object_queue_is_empty ());
 107         g_assert (sizeof (GrayQueueSection) < MAX_FREELIST_SIZE);
 108         g_assert (gray_queue_balance == 0);
 109 }