code_block *callback_heap::add(cell owner, cell return_rewind) { tagged<array> code_template(parent->special_objects[CALLBACK_STUB]); tagged<byte_array> insns(array_nth(code_template.untagged(),1)); cell size = array_capacity(insns.untagged()); cell bump = align(size + sizeof(code_block),data_alignment); if(here + bump > seg->end) fatal_error("Out of callback space",0); free_heap_block *free_block = (free_heap_block *)here; free_block->make_free(bump); here += bump; code_block *stub = (code_block *)free_block; stub->owner = owner; stub->parameters = false_object; stub->relocation = false_object; memcpy(stub->entry_point(),insns->data<void>(),size); /* Store VM pointer */ store_callback_operand(stub,0,(cell)parent); cell index; if(setup_seh_p()) { store_callback_operand(stub,1); index = 1; } else index = 0; /* Store VM pointer */ store_callback_operand(stub,index + 2,(cell)parent); /* On x86, the RET instruction takes an argument which depends on the callback's calling convention */ if(return_takes_param_p()) store_callback_operand(stub,index + 3,return_rewind); update(stub); return stub; }
code_block* callback_heap::add(cell owner, cell return_rewind) { tagged<array> code_template(parent->special_objects[CALLBACK_STUB]); tagged<byte_array> insns(array_nth(code_template.untagged(), 1)); cell size = array_capacity(insns.untagged()); cell bump = align(size + sizeof(code_block), data_alignment); code_block* stub = allocator->allot(bump); if (!stub) { parent->general_error(ERROR_CALLBACK_SPACE_OVERFLOW, false_object, false_object); } stub->header = bump & ~7; stub->owner = owner; stub->parameters = false_object; stub->relocation = false_object; memcpy((void*)stub->entry_point(), insns->data<void>(), size); /* Store VM pointer */ store_callback_operand(stub, 0, (cell)parent); cell index; if (setup_seh_p()) { store_callback_operand(stub, 1); index = 1; } else index = 0; /* Store VM pointer */ store_callback_operand(stub, index + 2, (cell) parent); /* On x86, the RET instruction takes an argument which depends on the callback's calling convention */ if (return_takes_param_p()) store_callback_operand(stub, index + 3, return_rewind); update(stub); return stub; }
void callback_heap::update(code_block* stub) { store_callback_operand(stub, setup_seh_p() ? 2 : 1, (cell)callback_entry_point(stub)); stub->flush_icache(); }