--- a/src/hotspot/share/memory/heapShared.cpp Tue Sep 11 13:34:13 2018 -0400
+++ b/src/hotspot/share/memory/heapShared.cpp Wed Sep 05 18:14:45 2018 -0700
@@ -45,8 +45,6 @@
int HeapShared::_num_archived_subgraph_info_records = 0;
Array<ArchivedKlassSubGraphInfoRecord>* HeapShared::_archived_subgraph_info_records = NULL;
-// Currently there is only one class mirror (ArchivedModuleGraph) with archived
-// sub-graphs.
KlassSubGraphInfo* HeapShared::find_subgraph_info(Klass* k) {
KlassSubGraphInfo* info = _subgraph_info_list;
while (info != NULL) {
@@ -145,6 +143,13 @@
return;
}
+ if (log_is_enabled(Debug, cds, heap)) {
+ if (!_subgraph_object_klasses->contains(relocated_k)) {
+ ResourceMark rm;
+ log_debug(cds, heap)("Adding klass %s", orig_k->external_name());
+ }
+ }
+
_subgraph_object_klasses->append_if_missing(relocated_k);
}
@@ -153,7 +158,7 @@
_k = info->klass();
_next = NULL;
_entry_field_records = NULL;
- _subgraph_klasses = NULL;
+ _subgraph_object_klasses = NULL;
// populate the entry fields
GrowableArray<juint>* entry_fields = info->subgraph_entry_fields();
@@ -168,20 +173,20 @@
}
// the Klasses of the objects in the sub-graphs
- GrowableArray<Klass*>* subgraph_klasses = info->subgraph_object_klasses();
- if (subgraph_klasses != NULL) {
- int num_subgraphs_klasses = subgraph_klasses->length();
- _subgraph_klasses =
+ GrowableArray<Klass*>* subgraph_object_klasses = info->subgraph_object_klasses();
+ if (subgraph_object_klasses != NULL) {
+ int num_subgraphs_klasses = subgraph_object_klasses->length();
+ _subgraph_object_klasses =
MetaspaceShared::new_ro_array<Klass*>(num_subgraphs_klasses);
for (int i = 0; i < num_subgraphs_klasses; i++) {
- Klass* subgraph_k = subgraph_klasses->at(i);
+ Klass* subgraph_k = subgraph_object_klasses->at(i);
if (log_is_enabled(Info, cds, heap)) {
ResourceMark rm;
log_info(cds, heap)(
- "Archived object klass (%d): %s in %s sub-graphs",
- i, subgraph_k->external_name(), _k->external_name());
+ "Archived object klass %s (%2d) => %s",
+ _k->external_name(), i, subgraph_k->external_name());
}
- _subgraph_klasses->at_put(i, subgraph_k);
+ _subgraph_object_klasses->at_put(i, subgraph_k);
}
}
}
@@ -194,8 +199,7 @@
// - A list of klasses that need to be loaded/initialized before archived
// java object sub-graph can be accessed at runtime.
//
-// The records are saved in the archive file and reloaded at runtime. Currently
-// there is only one class mirror (ArchivedModuleGraph) with archived sub-graphs.
+// The records are saved in the archive file and reloaded at runtime.
//
// Layout of the archived subgraph info records:
//
@@ -273,9 +277,8 @@
return; // no subgraph info records
}
- // Initialize from archived data. Currently only ArchivedModuleGraph
- // has archived object subgraphs, which is used during VM initialization
- // time when bootstraping the system modules. No lock is needed.
+ // Initialize from archived data. Currently this is done only
+ // during VM initialization time. No lock is needed.
Thread* THREAD = Thread::current();
for (int i = 0; i < _archived_subgraph_info_records->length(); i++) {
ArchivedKlassSubGraphInfoRecord* record = _archived_subgraph_info_records->adr_at(i);
@@ -284,7 +287,7 @@
// Found the archived subgraph info record for the requesting klass.
// Load/link/initialize the klasses of the objects in the subgraph.
// NULL class loader is used.
- Array<Klass*>* klasses = record->subgraph_klasses();
+ Array<Klass*>* klasses = record->subgraph_object_klasses();
if (klasses != NULL) {
for (i = 0; i < klasses->length(); i++) {
Klass* obj_k = klasses->at(i);
@@ -339,15 +342,19 @@
class WalkOopAndArchiveClosure: public BasicOopIterateClosure {
int _level;
+ bool _record_klasses_only;
KlassSubGraphInfo* _subgraph_info;
oop _orig_referencing_obj;
oop _archived_referencing_obj;
+ Thread* _thread;
public:
- WalkOopAndArchiveClosure(int level, KlassSubGraphInfo* subgraph_info,
- oop orig, oop archived) : _level(level),
- _subgraph_info(subgraph_info),
- _orig_referencing_obj(orig),
- _archived_referencing_obj(archived) {}
+ WalkOopAndArchiveClosure(int level, bool record_klasses_only,
+ KlassSubGraphInfo* subgraph_info,
+ oop orig, oop archived, TRAPS) :
+ _level(level), _record_klasses_only(record_klasses_only),
+ _subgraph_info(subgraph_info),
+ _orig_referencing_obj(orig), _archived_referencing_obj(archived),
+ _thread(THREAD) {}
void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
@@ -355,89 +362,105 @@
template <class T> void do_oop_work(T *p) {
oop obj = RawAccess<>::oop_load(p);
if (!CompressedOops::is_null(obj)) {
- // A java.lang.Class instance can not be included in an archived
- // object sub-graph.
- if (java_lang_Class::is_instance(obj)) {
- log_error(cds, heap)("Unknown java.lang.Class object is in the archived sub-graph\n");
- vm_exit(1);
- }
+ assert(!MetaspaceShared::is_archive_object(obj),
+ "original objects must not point to archived objects");
- LogTarget(Debug, cds, heap) log;
- LogStream ls(log);
- outputStream* out = &ls;
- {
+ size_t field_delta = pointer_delta(p, _orig_referencing_obj, sizeof(char));
+ T* new_p = (T*)(address(_archived_referencing_obj) + field_delta);
+ Thread* THREAD = _thread;
+
+ if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) {
ResourceMark rm;
- log.print("(%d) %s <--- referenced from: %s",
- _level, obj->klass()->external_name(),
- CompressedOops::is_null(_orig_referencing_obj) ?
- "" : _orig_referencing_obj->klass()->external_name());
- obj->print_on(out);
- }
-
- if (MetaspaceShared::is_archive_object(obj)) {
- // The current oop is an archived oop, nothing needs to be done
- log.print("--- object is already archived ---");
- return;
+ log_debug(cds, heap)("(%d) %s[" SIZE_FORMAT "] ==> " PTR_FORMAT " size %d %s", _level,
+ _orig_referencing_obj->klass()->external_name(), field_delta,
+ p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
+ LogTarget(Trace, cds, heap) log;
+ LogStream out(log);
+ obj->print_on(&out);
}
- size_t field_delta = pointer_delta(
- p, _orig_referencing_obj, sizeof(char));
- T* new_p = (T*)(address(_archived_referencing_obj) + field_delta);
- oop archived = MetaspaceShared::find_archived_heap_object(obj);
- if (archived != NULL) {
- // There is an archived copy existing, update reference to point
- // to the archived copy
- RawAccess<IS_NOT_NULL>::oop_store(new_p, archived);
- log.print(
- "--- found existing archived copy, store archived " PTR_FORMAT " in " PTR_FORMAT,
- p2i(archived), p2i(new_p));
- return;
- }
+ oop archived = HeapShared::archive_reachable_objects_from(_level + 1, _subgraph_info, obj, THREAD);
+ assert(archived != NULL, "VM should have exited with unarchivable objects for _level > 1");
+ assert(MetaspaceShared::is_archive_object(archived), "must be");
- int l = _level + 1;
- Thread* THREAD = Thread::current();
- // Archive the current oop before iterating through its references
- archived = MetaspaceShared::archive_heap_object(obj, THREAD);
- if (archived == NULL) {
- ResourceMark rm;
- LogTarget(Error, cds, heap) log_err;
- LogStream ls_err(log_err);
- outputStream* out_err = &ls_err;
- log_err.print("Failed to archive %s object ("
- PTR_FORMAT "), size[" SIZE_FORMAT "] in sub-graph",
- obj->klass()->external_name(), p2i(obj), (size_t)obj->size());
- obj->print_on(out_err);
- vm_exit(1);
+ if (!_record_klasses_only) {
+ // Update the reference in the archived copy of the referencing object.
+ log_debug(cds, heap)("(%d) updating oop @[" PTR_FORMAT "] " PTR_FORMAT " ==> " PTR_FORMAT,
+ _level, p2i(new_p), p2i(obj), p2i(archived));
+ RawAccess<IS_NOT_NULL>::oop_store(new_p, archived);
}
- assert(MetaspaceShared::is_archive_object(archived), "must be archived");
- log.print("=== archiving oop " PTR_FORMAT " ==> " PTR_FORMAT,
- p2i(obj), p2i(archived));
-
- // Following the references in the current oop and archive any
- // encountered objects during the process
- WalkOopAndArchiveClosure walker(l, _subgraph_info, obj, archived);
- obj->oop_iterate(&walker);
-
- // Update the reference in the archived copy of the referencing object
- RawAccess<IS_NOT_NULL>::oop_store(new_p, archived);
- log.print("=== store archived " PTR_FORMAT " in " PTR_FORMAT,
- p2i(archived), p2i(new_p));
-
- // Add the klass to the list of classes that need to be loaded before
- // module system initialization
- Klass *orig_k = obj->klass();
- Klass *relocated_k = archived->klass();
- _subgraph_info->add_subgraph_object_klass(orig_k, relocated_k);
}
}
};
+// (1) If orig_obj has not been archived yet, archive it.
+// (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
+// trace all objects that are reachable from it, and make sure these objects are archived.
+// (3) Record the klasses of all orig_obj and all reachable objects.
+oop HeapShared::archive_reachable_objects_from(int level, KlassSubGraphInfo* subgraph_info, oop orig_obj, TRAPS) {
+ assert(orig_obj != NULL, "must be");
+ assert(!MetaspaceShared::is_archive_object(orig_obj), "sanity");
+
+ // java.lang.Class instances cannot be included in an archived
+ // object sub-graph.
+ if (java_lang_Class::is_instance(orig_obj)) {
+ log_error(cds, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
+ vm_exit(1);
+ }
+
+ oop archived_obj = MetaspaceShared::find_archived_heap_object(orig_obj);
+ if (java_lang_String::is_instance(orig_obj) && archived_obj != NULL) {
+ // To save time, don't walk strings that are already archived. They just contain
+ // pointers to a type array, whose klass doesn't need to be recorded.
+ return archived_obj;
+ }
+
+ if (has_been_seen_during_subgraph_recording(orig_obj)) {
+ // orig_obj has already been archived and traced. Nothing more to do.
+ return archived_obj;
+ } else {
+ set_has_been_seen_during_subgraph_recording(orig_obj);
+ }
+
+ bool record_klasses_only = (archived_obj != NULL);
+ if (archived_obj == NULL) {
+ ++_num_new_archived_objs;
+ archived_obj = MetaspaceShared::archive_heap_object(orig_obj, THREAD);
+ if (archived_obj == NULL) {
+ // Skip archiving the sub-graph referenced from the current entry field.
+ ResourceMark rm;
+ log_error(cds, heap)(
+ "Cannot archive the sub-graph referenced from %s object ("
+ PTR_FORMAT ") size %d, skipped.",
+ orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
+ if (level == 1) {
+ // Don't archive a subgraph root that's too big. For archives static fields, that's OK
+ // as the Java code will take care of initializing this field dynamically.
+ return NULL;
+ } else {
+ // We don't know how to handle an object that has been archived, but some of its reachable
+ // objects cannot be archived. Bail out for now. We might need to fix this in the future if
+ // we have a real use case.
+ vm_exit(1);
+ }
+ }
+ }
+
+ assert(archived_obj != NULL, "must be");
+ Klass *orig_k = orig_obj->klass();
+ Klass *relocated_k = archived_obj->klass();
+ subgraph_info->add_subgraph_object_klass(orig_k, relocated_k);
+
+ WalkOopAndArchiveClosure walker(level, record_klasses_only, subgraph_info, orig_obj, archived_obj, THREAD);
+ orig_obj->oop_iterate(&walker);
+ return archived_obj;
+}
+
//
// Start from the given static field in a java mirror and archive the
// complete sub-graph of java heap objects that are reached directly
// or indirectly from the starting object by following references.
-// Currently, only ArchivedModuleGraph class instance (mirror) has archived
-// object subgraphs. Sub-graph archiving restrictions (current):
+// Sub-graph archiving restrictions (current):
//
// - All classes of objects in the archived sub-graph (including the
// entry class) must be boot class only.
@@ -461,20 +484,19 @@
// archive the sub-graph of objects starting from each reference.
//
// 4) Updates the pointer in the archived copy of referencing object to
-// point to the current archived object.
+// point to the current archived object.
//
// 5) The Klass of the current java object is added to the list of Klasses
// for loading and initialzing before any object in the archived graph can
// be accessed at runtime.
//
-void HeapShared::archive_reachable_objects_from_static_field(Klass *k,
+void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
+ const char* klass_name,
int field_offset,
- BasicType field_type,
+ const char* field_name,
TRAPS) {
assert(DumpSharedSpaces, "dump time only");
- assert(k->is_instance_klass(), "sanity");
- assert(InstanceKlass::cast(k)->is_shared_boot_class(),
- "must be boot class");
+ assert(k->is_shared_boot_class(), "must be boot class");
oop m = k->java_mirror();
oop archived_m = MetaspaceShared::find_archived_heap_object(m);
@@ -482,58 +504,160 @@
return;
}
- if (field_type == T_OBJECT || field_type == T_ARRAY) {
- // obtain k's subGraph Info
- KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
+ KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
+ oop f = m->obj_field(field_offset);
- // get the object referenced by the field
- oop f = m->obj_field(field_offset);
- if (!CompressedOops::is_null(f)) {
- LogTarget(Debug, cds, heap) log;
- LogStream ls(log);
- outputStream* out = &ls;
- log.print("Start from: ");
- f->print_on(out);
+ log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
- // get the archived copy of the field referenced object
- oop af = MetaspaceShared::archive_heap_object(f, THREAD);
- if (af == NULL) {
- // Skip archiving the sub-graph referenced from the current entry field.
- ResourceMark rm;
- log_info(cds, heap)(
- "Cannot archive the sub-graph referenced from %s object ("
- PTR_FORMAT ") size[" SIZE_FORMAT "], skipped.",
- f->klass()->external_name(), p2i(f), (size_t)f->size());
- return;
- }
- if (!MetaspaceShared::is_archive_object(f)) {
- WalkOopAndArchiveClosure walker(1, subgraph_info, f, af);
- f->oop_iterate(&walker);
- }
+ if (!CompressedOops::is_null(f)) {
+ if (log_is_enabled(Trace, cds, heap)) {
+ LogTarget(Trace, cds, heap) log;
+ LogStream out(log);
+ f->print_on(&out);
+ }
- // The field value is not preserved in the archived mirror.
+ oop af = archive_reachable_objects_from(1, subgraph_info, f, CHECK);
+
+ if (af == NULL) {
+ log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
+ klass_name, field_name);
+ } else {
+ // Note: the field value is not preserved in the archived mirror.
// Record the field as a new subGraph entry point. The recorded
// information is restored from the archive at runtime.
subgraph_info->add_subgraph_entry_field(field_offset, af);
- Klass *relocated_k = af->klass();
- Klass *orig_k = f->klass();
- subgraph_info->add_subgraph_object_klass(orig_k, relocated_k);
- ResourceMark rm;
- log_info(cds, heap)(
- "Archived the sub-graph referenced from %s object " PTR_FORMAT,
- f->klass()->external_name(), p2i(f));
- } else {
- // The field contains null, we still need to record the entry point,
- // so it can be restored at runtime.
- subgraph_info->add_subgraph_entry_field(field_offset, NULL);
+ log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(af));
}
} else {
- ShouldNotReachHere();
+ // The field contains null, we still need to record the entry point,
+ // so it can be restored at runtime.
+ subgraph_info->add_subgraph_entry_field(field_offset, NULL);
+ }
+}
+
+#ifndef PRODUCT
+class VerifySharedOopClosure: public BasicOopIterateClosure {
+ private:
+ bool _is_archived;
+
+ public:
+ VerifySharedOopClosure(bool is_archived) : _is_archived(is_archived) {}
+
+ void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
+ void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
+
+ protected:
+ template <class T> void do_oop_work(T *p) {
+ oop obj = RawAccess<>::oop_load(p);
+ if (!CompressedOops::is_null(obj)) {
+ HeapShared::verify_reachable_objects_from(obj, _is_archived);
+ }
+ }
+};
+
+void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
+ assert(DumpSharedSpaces, "dump time only");
+ assert(k->is_shared_boot_class(), "must be boot class");
+
+ oop m = k->java_mirror();
+ oop archived_m = MetaspaceShared::find_archived_heap_object(m);
+ if (CompressedOops::is_null(archived_m)) {
+ return;
+ }
+ oop f = m->obj_field(field_offset);
+ if (!CompressedOops::is_null(f)) {
+ verify_subgraph_from(f);
}
}
+void HeapShared::verify_subgraph_from(oop orig_obj) {
+ oop archived_obj = MetaspaceShared::find_archived_heap_object(orig_obj);
+ if (archived_obj == NULL) {
+ // It's OK for the root of a subgraph to be not archived. See comments in
+ // archive_reachable_objects_from().
+ return;
+ }
+
+ // Verify that all objects reachable from orig_obj are archived.
+ init_seen_objects_table();
+ verify_reachable_objects_from(orig_obj, false);
+ delete_seen_objects_table();
+
+ // Note: we could also verify that all objects reachable from the archived
+ // copy of orig_obj can only point to archived objects, with:
+ // init_seen_objects_table();
+ // verify_reachable_objects_from(archived_obj, true);
+ // init_seen_objects_table();
+ // but that's already done in G1HeapVerifier::verify_archive_regions so we
+ // won't do it here.
+}
+
+void HeapShared::verify_reachable_objects_from(oop obj, bool is_archived) {
+ _num_total_verifications ++;
+ if (!has_been_seen_during_subgraph_recording(obj)) {
+ set_has_been_seen_during_subgraph_recording(obj);
+
+ if (is_archived) {
+ assert(MetaspaceShared::is_archive_object(obj), "must be");
+ assert(MetaspaceShared::find_archived_heap_object(obj) == NULL, "must be");
+ } else {
+ assert(!MetaspaceShared::is_archive_object(obj), "must be");
+ assert(MetaspaceShared::find_archived_heap_object(obj) != NULL, "must be");
+ }
+
+ VerifySharedOopClosure walker(is_archived);
+ obj->oop_iterate(&walker);
+ }
+}
+#endif
+
+HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = NULL;
+int HeapShared::_num_new_walked_objs;
+int HeapShared::_num_new_archived_objs;
+int HeapShared::_num_old_recorded_klasses;
+
+int HeapShared::_num_total_subgraph_recordings = 0;
+int HeapShared::_num_total_walked_objs = 0;
+int HeapShared::_num_total_archived_objs = 0;
+int HeapShared::_num_total_recorded_klasses = 0;
+int HeapShared::_num_total_verifications = 0;
+
+bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
+ return _seen_objects_table->get(obj) != NULL;
+}
+
+void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
+ assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
+ _seen_objects_table->put(obj, true);
+ ++ _num_new_walked_objs;
+}
+
+void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name) {
+ log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
+ init_seen_objects_table();
+ _num_new_walked_objs = 0;
+ _num_new_archived_objs = 0;
+ _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
+}
+
+void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
+ int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
+ _num_old_recorded_klasses;
+ log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: "
+ "walked %d objs, archived %d new objs, recorded %d classes",
+ class_name, _num_new_walked_objs, _num_new_archived_objs,
+ num_new_recorded_klasses);
+
+ delete_seen_objects_table();
+
+ _num_total_subgraph_recordings ++;
+ _num_total_walked_objs += _num_new_walked_objs;
+ _num_total_archived_objs += _num_new_archived_objs;
+ _num_total_recorded_klasses += num_new_recorded_klasses;
+}
+
struct ArchivableStaticFieldInfo {
- const char* class_name;
+ const char* klass_name;
const char* field_name;
InstanceKlass* klass;
int offset;
@@ -553,39 +677,37 @@
{"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
};
-const static int num_archivable_static_fields = sizeof(archivable_static_fields) / sizeof(ArchivableStaticFieldInfo);
+const static int num_archivable_static_fields =
+ sizeof(archivable_static_fields) / sizeof(ArchivableStaticFieldInfo);
class ArchivableStaticFieldFinder: public FieldClosure {
InstanceKlass* _ik;
Symbol* _field_name;
bool _found;
int _offset;
- BasicType _type;
public:
ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
- _ik(ik), _field_name(field_name), _found(false), _offset(-1), _type(T_ILLEGAL) {}
+ _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
virtual void do_field(fieldDescriptor* fd) {
if (fd->name() == _field_name) {
assert(!_found, "fields cannot be overloaded");
+ assert(fd->field_type() == T_OBJECT || fd->field_type() == T_ARRAY, "can archive only obj or array fields");
_found = true;
_offset = fd->offset();
- _type = fd->field_type();
- assert(_type == T_OBJECT || _type == T_ARRAY, "can archive only obj or array fields");
}
}
bool found() { return _found; }
int offset() { return _offset; }
- BasicType type() { return _type; }
};
void HeapShared::init_archivable_static_fields(Thread* THREAD) {
for (int i = 0; i < num_archivable_static_fields; i++) {
ArchivableStaticFieldInfo* info = &archivable_static_fields[i];
- TempNewSymbol class_name = SymbolTable::new_symbol(info->class_name, THREAD);
+ TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name, THREAD);
TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name, THREAD);
- Klass* k = SystemDictionary::resolve_or_null(class_name, THREAD);
+ Klass* k = SystemDictionary::resolve_or_null(klass_name, THREAD);
assert(k != NULL && !HAS_PENDING_EXCEPTION, "class must exist");
InstanceKlass* ik = InstanceKlass::cast(k);
@@ -595,15 +717,50 @@
info->klass = ik;
info->offset = finder.offset();
- info->type = finder.type();
}
}
-void HeapShared::archive_module_graph_objects(Thread* THREAD) {
- for (int i = 0; i < num_archivable_static_fields; i++) {
+void HeapShared::archive_static_fields(Thread* THREAD) {
+ // For each class X that has one or more archived fields:
+ // [1] Dump the subgraph of each archived field
+ // [2] Create a list of all the class of the objects that can be reached
+ // by any of these static fields.
+ // At runtime, these classes are initialized before X's archived fields
+ // are restored by HeapShared::initialize_from_archived_subgraph().
+ int i;
+ for (i = 0; i < num_archivable_static_fields; ) {
ArchivableStaticFieldInfo* info = &archivable_static_fields[i];
- archive_reachable_objects_from_static_field(info->klass, info->offset, info->type, CHECK);
+ const char* klass_name = info->klass_name;
+ start_recording_subgraph(info->klass, klass_name);
+
+ // If you have specified consecutive fields of the same klass in
+ // archivable_static_fields[], these will be archived in the same
+ // {start_recording_subgraph ... done_recording_subgraph} pass to
+ // save time.
+ for (; i < num_archivable_static_fields; i++) {
+ ArchivableStaticFieldInfo* f = &archivable_static_fields[i];
+ if (f->klass_name != klass_name) {
+ break;
+ }
+ archive_reachable_objects_from_static_field(f->klass, f->klass_name,
+ f->offset, f->field_name, CHECK);
+ }
+ done_recording_subgraph(info->klass, klass_name);
}
+
+ log_info(cds, heap)("Performed subgraph records = %d times", _num_total_subgraph_recordings);
+ log_info(cds, heap)("Walked %d objects", _num_total_walked_objs);
+ log_info(cds, heap)("Archived %d objects", _num_total_archived_objs);
+ log_info(cds, heap)("Recorded %d klasses", _num_total_recorded_klasses);
+
+
+#ifndef PRODUCT
+ for (int i = 0; i < num_archivable_static_fields; i++) {
+ ArchivableStaticFieldInfo* f = &archivable_static_fields[i];
+ verify_subgraph_from_static_field(f->klass, f->offset);
+ }
+ log_info(cds, heap)("Verified %d references", _num_total_verifications);
+#endif
}
// At dump-time, find the location of all the non-null oop pointers in an archived heap
--- a/src/hotspot/share/memory/heapShared.hpp Tue Sep 11 13:34:13 2018 -0400
+++ b/src/hotspot/share/memory/heapShared.hpp Wed Sep 05 18:14:45 2018 -0700
@@ -26,12 +26,14 @@
#define SHARE_VM_MEMORY_HEAPSHARED_HPP
#include "classfile/systemDictionary.hpp"
+#include "memory/allocation.hpp"
#include "memory/universe.hpp"
#include "oops/objArrayKlass.hpp"
#include "oops/oop.hpp"
#include "oops/typeArrayKlass.hpp"
#include "utilities/bitMap.hpp"
#include "utilities/growableArray.hpp"
+#include "utilities/resourceHash.hpp"
#if INCLUDE_CDS_JAVA_HEAP
// A dump time sub-graph info for Klass _k. It includes the entry points
@@ -74,6 +76,10 @@
}
void add_subgraph_entry_field(int static_field_offset, oop v);
void add_subgraph_object_klass(Klass *orig_k, Klass *relocated_k);
+ int num_subgraph_object_klasses() {
+ return _subgraph_object_klasses == NULL ? 0 :
+ _subgraph_object_klasses->length();
+ }
};
// An archived record of object sub-graphs reachable from static
@@ -89,20 +95,21 @@
// klasses of objects in archived sub-graphs referenced from the entry points
// (static fields) in the containing class
- Array<Klass*>* _subgraph_klasses;
+ Array<Klass*>* _subgraph_object_klasses;
public:
ArchivedKlassSubGraphInfoRecord() :
- _next(NULL), _k(NULL), _entry_field_records(NULL), _subgraph_klasses(NULL) {}
+ _next(NULL), _k(NULL), _entry_field_records(NULL), _subgraph_object_klasses(NULL) {}
void init(KlassSubGraphInfo* info);
Klass* klass() { return _k; }
ArchivedKlassSubGraphInfoRecord* next() { return _next; }
void set_next(ArchivedKlassSubGraphInfoRecord* next) { _next = next; }
Array<juint>* entry_field_records() { return _entry_field_records; }
- Array<Klass*>* subgraph_klasses() { return _subgraph_klasses; }
+ Array<Klass*>* subgraph_object_klasses() { return _subgraph_object_klasses; }
};
#endif // INCLUDE_CDS_JAVA_HEAP
class HeapShared: AllStatic {
+ friend class VerifySharedOopClosure;
private:
#if INCLUDE_CDS_JAVA_HEAP
// This is a list of subgraph infos built at dump time while
@@ -117,7 +124,12 @@
// Archive object sub-graph starting from the given static field
// in Klass k's mirror.
static void archive_reachable_objects_from_static_field(
- Klass* k, int field_ofset, BasicType field_type, TRAPS);
+ InstanceKlass* k, const char* klass_name,
+ int field_offset, const char* field_name, TRAPS);
+ static void verify_subgraph_from_static_field(
+ InstanceKlass* k, int field_offset) PRODUCT_RETURN;
+
+ static void verify_reachable_objects_from(oop obj, bool is_archived) PRODUCT_RETURN;
static KlassSubGraphInfo* find_subgraph_info(Klass *k);
static KlassSubGraphInfo* get_subgraph_info(Klass *k);
@@ -129,6 +141,49 @@
static address _narrow_oop_base;
static int _narrow_oop_shift;
+ static bool oop_equals(oop const& p1, oop const& p2) {
+ return primitive_equals<oop>(p1, p2);
+ }
+
+ static unsigned oop_hash(oop const& p) {
+ return primitive_hash<address>((address)p);
+ }
+
+ typedef ResourceHashtable<oop, bool,
+ HeapShared::oop_hash,
+ HeapShared::oop_equals,
+ 15889, // prime number
+ ResourceObj::C_HEAP> SeenObjectsTable;
+
+ static SeenObjectsTable *_seen_objects_table;
+
+ static void init_seen_objects_table() {
+ assert(_seen_objects_table == NULL, "must be");
+ _seen_objects_table = new (ResourceObj::C_HEAP, mtClass)SeenObjectsTable();
+ }
+ static void delete_seen_objects_table() {
+ assert(_seen_objects_table != NULL, "must be");
+ delete _seen_objects_table;
+ _seen_objects_table = NULL;
+ }
+
+ // Statistics (for one round of start_recording_subgraph ... done_recording_subgraph)
+ static int _num_new_walked_objs;
+ static int _num_new_archived_objs;
+ static int _num_old_recorded_klasses;
+
+ // Statistics (for all archived subgraphs)
+ static int _num_total_subgraph_recordings;
+ static int _num_total_walked_objs;
+ static int _num_total_archived_objs;
+ static int _num_total_recorded_klasses;
+ static int _num_total_verifications;
+
+ static void start_recording_subgraph(InstanceKlass *k, const char* klass_name);
+ static void done_recording_subgraph(InstanceKlass *k, const char* klass_name);
+
+ static bool has_been_seen_during_subgraph_recording(oop obj);
+ static void set_has_been_seen_during_subgraph_recording(oop obj);
#endif // INCLUDE_CDS_JAVA_HEAP
public:
static char* read_archived_subgraph_infos(char* buffer) NOT_CDS_JAVA_HEAP_RETURN_(buffer);
@@ -147,10 +202,12 @@
size_t oopmap_in_bits) NOT_CDS_JAVA_HEAP_RETURN;
static void init_archivable_static_fields(Thread* THREAD) NOT_CDS_JAVA_HEAP_RETURN;
- static void archive_module_graph_objects(Thread* THREAD) NOT_CDS_JAVA_HEAP_RETURN;
+ static void archive_static_fields(Thread* THREAD) NOT_CDS_JAVA_HEAP_RETURN;
#if INCLUDE_CDS_JAVA_HEAP
static ResourceBitMap calculate_oopmap(MemRegion region);
+ static oop archive_reachable_objects_from(int level, KlassSubGraphInfo* subgraph_info, oop orig_obj, TRAPS);
+ static void verify_subgraph_from(oop orig_obj) PRODUCT_RETURN;
#endif
};
#endif // SHARE_VM_MEMORY_HEAPSHARED_HPP