archive/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2025-08-28 15:24:43 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

8199852: Print more information about class loaders in LinkageErrors

Browse source 
Reviewed-by: dholmes, lfoltan, gtriantafill
This commit is contained in:
Goetz Lindenmaier 2018-05-07 11:38:21 +02:00
parent 5f40eda733
commit 72a2ac8b8b
28 changed files with 660 additions and 97 deletions
Download patch file Download diff file Expand all files Collapse all files

55
src/hotspot/share/classfile/systemDictionary.cpp
View file

@ -2124,10 +2124,19 @@ BasicType SystemDictionary::box_klass_type(Klass* k) {
void SystemDictionary::check_constraints(unsigned int d_hash,
InstanceKlass* k,
Handle class_loader, bool defining,
Handle class_loader,
bool defining,
TRAPS) {
ResourceMark rm(THREAD);
stringStream ss;
bool throwException = false;
const char *linkage_error1 = NULL;
const char *linkage_error2 = NULL;
const char *linkage_error3 = "";
// Remember the loader of the similar class that is already loaded.
const char *existing_klass_loader_name = "";
{
Symbol* name = k->name();
ClassLoaderData *loader_data = class_loader_data(class_loader);
@ -2136,16 +2145,18 @@ void SystemDictionary::check_constraints(unsigned int d_hash,
InstanceKlass* check = find_class(d_hash, name, loader_data->dictionary());
if (check != NULL) {
// if different InstanceKlass - duplicate class definition,
// else - ok, class loaded by a different thread in parallel,
// we should only have found it if it was done loading and ok to use
// dictionary only holds instance classes, placeholders
// also holds array classes
// If different InstanceKlass - duplicate class definition,
// else - ok, class loaded by a different thread in parallel.
// We should only have found it if it was done loading and ok to use.
// The dictionary only holds instance classes, placeholders
// also hold array classes.
assert(check->is_instance_klass(), "noninstance in systemdictionary");
if ((defining == true) || (k != check)) {
linkage_error1 = "loader (instance of ";
linkage_error2 = "): attempted duplicate class definition for name: \"";
throwException = true;
ss.print("loader %s", java_lang_ClassLoader::describe_external(class_loader()));
ss.print(" attempted duplicate %s definition for %s.",
k->external_kind(), k->external_name());
} else {
return;
}
@ -2156,30 +2167,30 @@ void SystemDictionary::check_constraints(unsigned int d_hash,
assert(ph_check == NULL || ph_check == name, "invalid symbol");
#endif
if (linkage_error1 == NULL) {
if (throwException == false) {
if (constraints()->check_or_update(k, class_loader, name) == false) {
linkage_error1 = "loader constraint violation: loader (instance of ";
linkage_error2 = ") previously initiated loading for a different type with name \"";
throwException = true;
ss.print("loader constraint violation: loader %s",
java_lang_ClassLoader::describe_external(class_loader()));
ss.print(" wants to load %s %s.",
k->external_kind(), k->external_name());
Klass *existing_klass = constraints()->find_constrained_klass(name, class_loader);
if (existing_klass->class_loader() != class_loader()) {
ss.print(" A different %s with the same name was previously loaded by %s.",
existing_klass->external_kind(),
java_lang_ClassLoader::describe_external(existing_klass->class_loader()));
}
}
}
}
// Throw error now if needed (cannot throw while holding
// SystemDictionary_lock because of rank ordering)
if (linkage_error1) {
ResourceMark rm(THREAD);
const char* class_loader_name = loader_name(class_loader());
char* type_name = k->name()->as_C_string();
size_t buflen = strlen(linkage_error1) + strlen(class_loader_name) +
strlen(linkage_error2) + strlen(type_name) + 2; // +2 for '"' and null byte.
char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
jio_snprintf(buf, buflen, "%s%s%s%s\"", linkage_error1, class_loader_name, linkage_error2, type_name);
THROW_MSG(vmSymbols::java_lang_LinkageError(), buf);
if (throwException == true) {
THROW_MSG(vmSymbols::java_lang_LinkageError(), ss.as_string());
}
}
// Update class loader data dictionary - done after check_constraint and add_to_hierachy
// have been called.
void SystemDictionary::update_dictionary(unsigned int d_hash,