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vm: if an aging GC is triggered while uninitialized code blocks are in the code heap, the code heap remembered set becomes out of date, resulting in code blocks pointing at invalid data

db4
Slava Pestov 2009-12-22 15:49:21 +13:00
parent dbbcf74cda
commit febccd5f62
1 changed files with 15 additions and 3 deletions
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18
vm/code_blocks.cpp
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@ -293,10 +293,17 @@ struct initial_code_block_visitor {
void factor_vm::initialize_code_block(code_block *compiled)
{
std::map<code_block *,cell>::iterator iter = code->uninitialized_blocks.find(compiled);
initial_code_block_visitor visitor(this,iter->second);
compiled->each_instruction_operand(visitor);
compiled->flush_icache();
code->uninitialized_blocks.erase(iter);
/* next time we do a minor GC, we have to trace this code block, since
the newly-installed instruction operands might point to literals in
nursery or aging */
code->write_barrier(compiled);
}
/* Fixup labels. This is done at compile time, not image load time */
@ -378,11 +385,16 @@ code_block *factor_vm::add_code_block(code_block_type type, cell code_, cell lab
if(to_boolean(labels.value()))
fixup_labels(labels.as<array>().untagged(),compiled);
/* next time we do a minor GC, we have to scan the code heap for
literals */
this->code->write_barrier(compiled);
/* Once we are ready, fill in literal and word references in this code
block's instruction operands. In most cases this is done right after this
method returns, except when compiling words with the non-optimizing
compiler at the beginning of bootstrap */
this->code->uninitialized_blocks.insert(std::make_pair(compiled,literals.value()));
/* next time we do a minor GC, we have to trace this code block, since
the fields of the code_block struct might point into nursery or aging */
this->code->write_barrier(compiled);
return compiled;
}