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_code_block_objects(compiled);
  21         data_visitor.visit_embedded_literals(compiled);
  22         code_visitor.visit_embedded_code_pointers(compiled);
  23 }
  24
  25 void full_collector::trace_context_code_blocks()
  26 {
  27         code_visitor.visit_context_code_blocks();
  28 }
  29
  30 void full_collector::trace_object_code_block(object *obj)
  31 {
  32         code_visitor.visit_object_code_block(obj);
  33 }
  34
  35 /* After a sweep, invalidate any code heap roots which are not marked,
  36 so that if a block makes a tail call to a generic word, and the PIC
  37 compiler triggers a GC, and the caller block gets gets GCd as a result,
  38 the PIC code won't try to overwrite the call site */
  39 void factor_vm::update_code_roots_for_sweep()
  40 {
  41         std::vector<code_root *>::const_iterator iter = code_roots.begin();
  42         std::vector<code_root *>::const_iterator end = code_roots.end();
  43
  44         mark_bits<code_block> *state = &code->allocator->state;
  45
  46         for(; iter < end; iter++)
  47         {
  48                 code_root *root = *iter;
  49                 code_block *block = (code_block *)(root->value & -data_alignment);
  50                 if(root->valid && !state->marked_p(block))
  51                         root->valid = false;
  52         }
  53 }
  54
  55 /* After a compaction, invalidate any code heap roots which are not
  56 marked as above, and also slide the valid roots up so that call sites
  57 can be updated correctly. */
  58 void factor_vm::update_code_roots_for_compaction()
  59 {
  60         std::vector<code_root *>::const_iterator iter = code_roots.begin();
  61         std::vector<code_root *>::const_iterator end = code_roots.end();
  62
  63         mark_bits<code_block> *state = &code->allocator->state;
  64
  65         for(; iter < end; iter++)
  66         {
  67                 code_root *root = *iter;
  68                 code_block *block = (code_block *)(root->value & -data_alignment);
  69
  70                 /* Offset of return address within 16-byte allocation line */
  71                 cell offset = root->value - (cell)block;
  72
  73                 if(root->valid && state->marked_p((code_block *)root->value))
  74                 {
  75                         block = state->forward_block(block);
  76                         root->value = (cell)block + offset;
  77                 }
  78                 else
  79                         root->valid = false;
  80         }
  81 }
  82
  83 void factor_vm::collect_mark_impl(bool trace_contexts_p)
  84 {
  85         full_collector collector(this);
  86
  87         mark_stack.clear();
  88
  89         code->clear_mark_bits();
  90         data->tenured->clear_mark_bits();
  91
  92         collector.trace_roots();
  93         if(trace_contexts_p)
  94         {
  95                 collector.trace_contexts();
  96                 collector.trace_context_code_blocks();
  97         }
  98
  99         while(!mark_stack.empty())
 100         {
 101                 cell ptr = mark_stack.back();
 102                 mark_stack.pop_back();
 103
 104                 if(ptr & 1)
 105                 {
 106                         code_block *compiled = (code_block *)(ptr - 1);
 107                         collector.trace_code_block(compiled);
 108                 }
 109                 else
 110                 {
 111                         object *obj = (object *)ptr;
 112                         collector.trace_object(obj);
 113                         collector.trace_object_code_block(obj);
 114                 }
 115         }
 116
 117         data->reset_generation(data->tenured);
 118         data->reset_generation(data->aging);
 119         data->reset_generation(&nursery);
 120         code->clear_remembered_set();
 121 }
 122
 123 void factor_vm::collect_sweep_impl()
 124 {
 125         current_gc->event->started_data_sweep();
 126         data->tenured->sweep();
 127         current_gc->event->ended_data_sweep();
 128
 129         update_code_roots_for_sweep();
 130
 131         current_gc->event->started_code_sweep();
 132         code->allocator->sweep();
 133         current_gc->event->ended_code_sweep();
 134 }
 135
 136 void factor_vm::collect_full(bool trace_contexts_p)
 137 {
 138         collect_mark_impl(trace_contexts_p);
 139         collect_sweep_impl();
 140         if(data->low_memory_p())
 141         {
 142                 current_gc->op = collect_compact_op;
 143                 current_gc->event->op = collect_compact_op;
 144                 collect_compact_impl(trace_contexts_p);
 145         }
 146         code->flush_icache();
 147 }
 148
 149 }