mono/metadata/sgen-pinning.c

   1 /*
   2  * Copyright 2001-2003 Ximian, Inc
   3  * Copyright 2003-2010 Novell, Inc.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining
   6  * a copy of this software and associated documentation files (the
   7  * "Software"), to deal in the Software without restriction, including
   8  * without limitation the rights to use, copy, modify, merge, publish,
   9  * distribute, sublicense, and/or sell copies of the Software, and to
  10  * permit persons to whom the Software is furnished to do so, subject to
  11  * the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be
  14  * included in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  17  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  19  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  20  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  21  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  22  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24 #define PIN_STAGING_AREA_SIZE   1024
  25
  26 static void* pin_staging_area [PIN_STAGING_AREA_SIZE];
  27 static int pin_staging_area_index;
  28
  29 static void** pin_queue;
  30 static int pin_queue_size = 0;
  31 static int next_pin_slot = 0;
  32
  33 static void
  34 init_pinning (void)
  35 {
  36         pin_staging_area_index = 0;
  37 }
  38
  39 static void
  40 realloc_pin_queue (void)
  41 {
  42         int new_size = pin_queue_size? pin_queue_size + pin_queue_size/2: 1024;
  43         void **new_pin = get_internal_mem (sizeof (void*) * new_size, INTERNAL_MEM_PIN_QUEUE);
  44         memcpy (new_pin, pin_queue, sizeof (void*) * next_pin_slot);
  45         free_internal_mem (pin_queue, INTERNAL_MEM_PIN_QUEUE);
  46         pin_queue = new_pin;
  47         pin_queue_size = new_size;
  48         DEBUG (4, fprintf (gc_debug_file, "Reallocated pin queue to size: %d\n", new_size));
  49 }
  50
  51 static void
  52 evacuate_pin_staging_area (void)
  53 {
  54         int i;
  55
  56         g_assert (pin_staging_area_index >= 0 && pin_staging_area_index <= PIN_STAGING_AREA_SIZE);
  57
  58         if (pin_staging_area_index == 0)
  59                 return;
  60
  61         /*
  62          * The pinning addresses might come from undefined memory, this is normal. Since they
  63          * are used in lots of functions, we make the memory defined here instead of having
  64          * to add a supression for those functions.
  65          */
  66         VALGRIND_MAKE_MEM_DEFINED (pin_staging_area, pin_staging_area_index * sizeof (void*));
  67
  68         sort_addresses (pin_staging_area, pin_staging_area_index);
  69
  70         while (next_pin_slot + pin_staging_area_index > pin_queue_size)
  71                 realloc_pin_queue ();
  72
  73         pin_queue [next_pin_slot++] = pin_staging_area [0];
  74         for (i = 1; i < pin_staging_area_index; ++i) {
  75                 void *p = pin_staging_area [i];
  76                 if (p != pin_queue [next_pin_slot - 1])
  77                         pin_queue [next_pin_slot++] = p;
  78         }
  79
  80         g_assert (next_pin_slot <= pin_queue_size);
  81
  82         pin_staging_area_index = 0;
  83 }
  84
  85 static void
  86 pin_stage_ptr (void *ptr)
  87 {
  88         if (pin_staging_area_index >= PIN_STAGING_AREA_SIZE)
  89                 evacuate_pin_staging_area ();
  90
  91         pin_staging_area [pin_staging_area_index++] = ptr;
  92 }
  93
  94 static int
  95 optimized_pin_queue_search (void *addr)
  96 {
  97         int first = 0, last = next_pin_slot;
  98         while (first < last) {
  99                 int middle = first + ((last - first) >> 1);
 100                 if (addr <= pin_queue [middle])
 101                         last = middle;
 102                 else
 103                         first = middle + 1;
 104         }
 105         g_assert (first == last);
 106         return first;
 107 }
 108
 109 static void
 110 find_optimized_pin_queue_area (void *start, void *end, int *first, int *last)
 111 {
 112         *first = optimized_pin_queue_search (start);
 113         *last = optimized_pin_queue_search (end);
 114 }
 115
 116 static void
 117 find_section_pin_queue_start_end (GCMemSection *section)
 118 {
 119         int start, end;
 120         DEBUG (6, fprintf (gc_debug_file, "Pinning from section %p (%p-%p)\n", section, section->data, section->end_data));
 121         find_optimized_pin_queue_area (section->data, section->end_data, &start, &end);
 122         DEBUG (6, fprintf (gc_debug_file, "Found %d pinning addresses in section %p (%d-%d)\n",
 123                                         end - start, section, start, end));
 124         section->pin_queue_start = start;
 125         section->pin_queue_end = end;
 126 }