vm/full_collector.cpp

   1 #include "master.hpp"
   2
   3 namespace factor
   4 {
   5
   6 inline static code_block_visitor<code_workhorse> make_code_visitor(factor_vm *parent)
   7 {
   8         return code_block_visitor<code_workhorse>(parent,code_workhorse(parent));
   9 }
  10
  11 full_collector::full_collector(factor_vm *parent_) :
  12         collector<tenured_space,full_policy>(
  13                 parent_,
  14                 parent_->data->tenured,
  15                 full_policy(parent_)),
  16         code_visitor(make_code_visitor(parent_)) {}
  17
  18 void full_collector::trace_code_block(code_block *compiled)
  19 {
  20         data_visitor.visit_referenced_literals(compiled);
  21         code_visitor.visit_referenced_code_blocks(compiled);
  22 }
  23
  24 void full_collector::trace_context_code_blocks()
  25 {
  26         code_visitor.visit_context_code_blocks();
  27 }
  28
  29 void full_collector::trace_callback_code_blocks()
  30 {
  31         code_visitor.visit_callback_code_blocks();
  32 }
  33
  34 void full_collector::trace_object_code_block(object *obj)
  35 {
  36         code_visitor.visit_object_code_block(obj);
  37 }
  38
  39 /* After a sweep, invalidate any code heap roots which are not marked,
  40 so that if a block makes a tail call to a generic word, and the PIC
  41 compiler triggers a GC, and the caller block gets gets GCd as a result,
  42 the PIC code won't try to overwrite the call site */
  43 void factor_vm::update_code_roots_for_sweep()
  44 {
  45         std::vector<code_root *>::const_iterator iter = code_roots.begin();
  46         std::vector<code_root *>::const_iterator end = code_roots.end();
  47
  48         mark_bits<code_block> *state = &code->allocator->state;
  49
  50         for(; iter < end; iter++)
  51         {
  52                 code_root *root = *iter;
  53                 code_block *block = (code_block *)(root->value & -block_granularity);
  54                 if(root->valid && !state->marked_p(block))
  55                         root->valid = false;
  56         }
  57 }
  58
  59 /* After a compaction, invalidate any code heap roots which are not
  60 marked as above, and also slide the valid roots up so that call sites
  61 can be updated correctly. */
  62 void factor_vm::update_code_roots_for_compaction()
  63 {
  64         std::vector<code_root *>::const_iterator iter = code_roots.begin();
  65         std::vector<code_root *>::const_iterator end = code_roots.end();
  66
  67         mark_bits<code_block> *state = &code->allocator->state;
  68
  69         for(; iter < end; iter++)
  70         {
  71                 code_root *root = *iter;
  72                 code_block *block = (code_block *)(root->value & -block_granularity);
  73
  74                 /* Offset of return address within 16-byte allocation line */
  75                 cell offset = root->value - (cell)block;
  76
  77                 if(root->valid && state->marked_p((code_block *)root->value))
  78                 {
  79                         block = state->forward_block(block);
  80                         root->value = (cell)block + offset;
  81                 }
  82                 else
  83                         root->valid = false;
  84         }
  85 }
  86
  87 void factor_vm::collect_mark_impl(bool trace_contexts_p)
  88 {
  89         full_collector collector(this);
  90
  91         mark_stack.clear();
  92
  93         code->clear_mark_bits();
  94         data->tenured->clear_mark_bits();
  95
  96         collector.trace_roots();
  97         if(trace_contexts_p)
  98         {
  99                 collector.trace_contexts();
 100                 collector.trace_context_code_blocks();
 101                 collector.trace_callback_code_blocks();
 102         }
 103
 104         while(!mark_stack.empty())
 105         {
 106                 cell ptr = mark_stack.back();
 107                 mark_stack.pop_back();
 108
 109                 if(ptr & 1)
 110                 {
 111                         code_block *compiled = (code_block *)(ptr - 1);
 112                         collector.trace_code_block(compiled);
 113                 }
 114                 else
 115                 {
 116                         object *obj = (object *)ptr;
 117                         collector.trace_object(obj);
 118                         collector.trace_object_code_block(obj);
 119                 }
 120         }
 121
 122         data->reset_generation(data->tenured);
 123         data->reset_generation(data->aging);
 124         data->reset_generation(&nursery);
 125         code->clear_remembered_set();
 126 }
 127
 128 void factor_vm::collect_sweep_impl()
 129 {
 130         current_gc->event->started_data_sweep();
 131         data->tenured->sweep();
 132         current_gc->event->ended_data_sweep();
 133
 134         update_code_roots_for_sweep();
 135
 136         current_gc->event->started_code_sweep();
 137         code->allocator->sweep();
 138         current_gc->event->ended_code_sweep();
 139 }
 140
 141 void factor_vm::collect_full(bool trace_contexts_p)
 142 {
 143         collect_mark_impl(trace_contexts_p);
 144         collect_sweep_impl();
 145         if(data->low_memory_p())
 146         {
 147                 current_gc->op = collect_compact_op;
 148                 current_gc->event->op = collect_compact_op;
 149                 collect_compact_impl(trace_contexts_p);
 150         }
 151 }
 152
 153 void factor_vm::collect_compact(bool trace_contexts_p)
 154 {
 155         collect_mark_impl(trace_contexts_p);
 156         collect_compact_impl(trace_contexts_p);
 157 }
 158
 159 void factor_vm::collect_growing_heap(cell requested_bytes, bool trace_contexts_p)
 160 {
 161         /* Grow the data heap and copy all live objects to the new heap. */
 162         data_heap *old = data;
 163         set_data_heap(data->grow(requested_bytes));
 164         collect_mark_impl(trace_contexts_p);
 165         collect_compact_code_impl(trace_contexts_p);
 166         delete old;
 167 }
 168
 169 }