8081323: ConstantPool::_resolved_references is missing in heap dump
Summary: Add resolved_references and init_lock as hidden static field in class so root is found.
Reviewed-by: hseigel, jiangli, sspitsyn
--- a/src/hotspot/share/classfile/vmSymbols.hpp Tue Sep 26 06:53:35 2017 -0400
+++ b/src/hotspot/share/classfile/vmSymbols.hpp Tue Sep 26 10:03:17 2017 -0400
@@ -461,6 +461,8 @@
template(getProtectionDomain_signature, "(Ljava/security/CodeSource;)Ljava/security/ProtectionDomain;") \
template(url_code_signer_array_void_signature, "(Ljava/net/URL;[Ljava/security/CodeSigner;)V") \
template(module_entry_name, "module_entry") \
+ template(resolved_references_name, "<resolved_references>") \
+ template(init_lock_name, "<init_lock>") \
\
/* name symbols needed by intrinsics */ \
VM_INTRINSICS_DO(VM_INTRINSIC_IGNORE, VM_SYMBOL_IGNORE, template, VM_SYMBOL_IGNORE, VM_ALIAS_IGNORE) \
--- a/src/hotspot/share/oops/constantPool.cpp Tue Sep 26 06:53:35 2017 -0400
+++ b/src/hotspot/share/oops/constantPool.cpp Tue Sep 26 10:03:17 2017 -0400
@@ -135,6 +135,16 @@
return (objArrayOop)_cache->resolved_references();
}
+// Called from outside constant pool resolution where a resolved_reference array
+// may not be present.
+objArrayOop ConstantPool::resolved_references_or_null() const {
+ if (_cache == NULL) {
+ return NULL;
+ } else {
+ return (objArrayOop)_cache->resolved_references();
+ }
+}
+
// Create resolved_references array and mapping array for original cp indexes
// The ldc bytecode was rewritten to have the resolved reference array index so need a way
// to map it back for resolving and some unlikely miscellaneous uses.
--- a/src/hotspot/share/oops/constantPool.hpp Tue Sep 26 06:53:35 2017 -0400
+++ b/src/hotspot/share/oops/constantPool.hpp Tue Sep 26 10:03:17 2017 -0400
@@ -226,6 +226,7 @@
// resolved strings, methodHandles and callsite objects from the constant pool
objArrayOop resolved_references() const;
+ objArrayOop resolved_references_or_null() const;
// mapping resolved object array indexes to cp indexes and back.
int object_to_cp_index(int index) { return reference_map()->at(index); }
int cp_to_object_index(int index);
--- a/src/hotspot/share/services/heapDumper.cpp Tue Sep 26 06:53:35 2017 -0400
+++ b/src/hotspot/share/services/heapDumper.cpp Tue Sep 26 10:03:17 2017 -0400
@@ -856,6 +856,29 @@
if (fldc.access_flags().is_static()) field_count++;
}
+ // Add in resolved_references which is referenced by the cpCache
+ // The resolved_references is an array per InstanceKlass holding the
+ // strings and other oops resolved from the constant pool.
+ oop resolved_references = ik->constants()->resolved_references_or_null();
+ if (resolved_references != NULL) {
+ field_count++;
+
+ // Add in the resolved_references of the used previous versions of the class
+ // in the case of RedefineClasses
+ InstanceKlass* prev = ik->previous_versions();
+ while (prev != NULL && prev->constants()->resolved_references_or_null() != NULL) {
+ field_count++;
+ prev = prev->previous_versions();
+ }
+ }
+
+ // Also provide a pointer to the init_lock if present, so there aren't unreferenced int[0]
+ // arrays.
+ oop init_lock = ik->init_lock();
+ if (init_lock != NULL) {
+ field_count++;
+ }
+
writer->write_u2(field_count);
// pass 2 - dump the field descriptors and raw values
@@ -873,6 +896,29 @@
dump_field_value(writer, sig->byte_at(0), addr);
}
}
+
+ // Add resolved_references for each class that has them
+ if (resolved_references != NULL) {
+ writer->write_symbolID(vmSymbols::resolved_references_name()); // name
+ writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type
+ writer->write_objectID(resolved_references);
+
+ // Also write any previous versions
+ InstanceKlass* prev = ik->previous_versions();
+ while (prev != NULL && prev->constants()->resolved_references_or_null() != NULL) {
+ writer->write_symbolID(vmSymbols::resolved_references_name()); // name
+ writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type
+ writer->write_objectID(prev->constants()->resolved_references());
+ prev = prev->previous_versions();
+ }
+ }
+
+ // Add init lock to the end if the class is not yet initialized
+ if (init_lock != NULL) {
+ writer->write_symbolID(vmSymbols::init_lock_name()); // name
+ writer->write_u1(sig2tag(vmSymbols::int_array_signature())); // type
+ writer->write_objectID(init_lock);
+ }
}
// dump the raw values of the instance fields of the given object
@@ -908,7 +954,7 @@
if (!fld.access_flags().is_static()) {
Symbol* sig = fld.signature();
- writer->write_symbolID(fld.name()); // name
+ writer->write_symbolID(fld.name()); // name
writer->write_u1(sig2tag(sig)); // type
}
}
@@ -1822,6 +1868,8 @@
// HPROF_GC_ROOT_JNI_GLOBAL
JNIGlobalsDumper jni_dumper(writer());
JNIHandles::oops_do(&jni_dumper);
+ Universe::oops_do(&jni_dumper); // technically not jni roots, but global roots
+ // for things like preallocated throwable backtraces
check_segment_length();
// HPROF_GC_ROOT_STICKY_CLASS