602 
 603     switch (iter.type()) {
 604 
 605     case relocInfo::virtual_call_type:
 606       clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), this, true);
 607       break;
 608 
 609     case relocInfo::opt_virtual_call_type:
 610       clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), this, true);
 611       break;
 612 
 613     case relocInfo::static_call_type:
 614       clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), this, true);
 615       break;
 616 
 617     default:
 618       break;
 619     }
 620   }
 621 }

 602 
 603     switch (iter.type()) {
 604 
 605     case relocInfo::virtual_call_type:
 606       clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), this, true);
 607       break;
 608 
 609     case relocInfo::opt_virtual_call_type:
 610       clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), this, true);
 611       break;
 612 
 613     case relocInfo::static_call_type:
 614       clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), this, true);
 615       break;
 616 
 617     default:
 618       break;
 619     }
 620   }
 621 }
 622 
 623 // Iterating over all nmethods, e.g. with the help of CodeCache::nmethods_do(fun) was found
 624 // to not be inherently safe. There is a chance that fields are seen which are not properly
 625 // initialized. This happens despite the fact that nmethods_do() asserts the CodeCache_lock
 626 // to be held.
 627 // To bundle knowledge about necessary checks in one place, this function was introduced.
 628 // It is not claimed that these checks are sufficient, but they were found to be necessary.
 629 bool CompiledMethod::nmethod_access_is_safe(nmethod* nm) {
 630   Method* method = (nm == NULL) ? NULL : nm->method();  // nm->method() may be uninitialized, i.e. != NULL, but invalid
 631   return (nm != NULL) && (method != NULL) && (method->signature() != NULL) &&
 632          !nm->is_zombie() && !nm->is_not_installed() &&
 633          os::is_readable_pointer(method) &&
 634          os::is_readable_pointer(method->constants()) &&
 635          os::is_readable_pointer(method->signature());
 636 }