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coleenpcoleenp
committedJul 22, 2020
8249768: Move static oops and NullPointerException oops from Universe into OopStorage
Make NPE oops an objArrayOop. Reviewed-by: dholmes, eosterlund
·
JEP-429-branchpoint
1 parent 4d43cf9 commit 2d8e74d

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14 files changed

+241
-219
lines changed

14 files changed

+241
-219
lines changed
 

‎src/hotspot/cpu/aarch64/templateTable_aarch64.cpp

+1
Original file line numberDiff line numberDiff line change
@@ -413,6 +413,7 @@ void TemplateTable::fast_aldc(bool wide)
413413
// Stash null_sentinel address to get its value later
414414
__ movptr(rarg, (uintptr_t)Universe::the_null_sentinel_addr());
415415
__ ldr(tmp, Address(rarg));
416+
__ resolve_oop_handle(tmp);
416417
__ cmpoop(result, tmp);
417418
__ br(Assembler::NE, notNull);
418419
__ mov(result, 0); // NULL object reference

‎src/hotspot/cpu/arm/templateTable_arm.cpp

+1
Original file line numberDiff line numberDiff line change
@@ -462,6 +462,7 @@ void TemplateTable::fast_aldc(bool wide) {
462462
// Stash null_sentinel address to get its value later
463463
__ mov_slow(rarg, (uintptr_t)Universe::the_null_sentinel_addr());
464464
__ ldr(tmp, Address(rarg));
465+
__ resolve_oop_handle(tmp);
465466
__ cmp(result, tmp);
466467
__ b(notNull, ne);
467468
__ mov(result, 0); // NULL object reference

‎src/hotspot/cpu/ppc/templateTable_ppc_64.cpp

+2-1
Original file line numberDiff line numberDiff line change
@@ -317,9 +317,10 @@ void TemplateTable::fast_aldc(bool wide) {
317317
__ get_cache_index_at_bcp(Rscratch, 1, index_size); // Load index.
318318
__ load_resolved_reference_at_index(R17_tos, Rscratch, &is_null);
319319

320-
// Convert null sentinel to NULL.
320+
// Convert null sentinel to NULL
321321
int simm16_rest = __ load_const_optimized(Rscratch, Universe::the_null_sentinel_addr(), R0, true);
322322
__ ld(Rscratch, simm16_rest, Rscratch);
323+
__ resolve_oop_handle(Rscratch);
323324
__ cmpld(CCR0, R17_tos, Rscratch);
324325
if (VM_Version::has_isel()) {
325326
__ isel_0(R17_tos, CCR0, Assembler::equal);

‎src/hotspot/cpu/s390/templateTable_s390.cpp

+1
Original file line numberDiff line numberDiff line change
@@ -466,6 +466,7 @@ void TemplateTable::fast_aldc(bool wide) {
466466

467467
// Convert null sentinel to NULL.
468468
__ load_const_optimized(Z_R1_scratch, (intptr_t)Universe::the_null_sentinel_addr());
469+
__ resolve_oop_handle(Z_R1_scratch);
469470
__ z_cg(Z_tos, Address(Z_R1_scratch));
470471
__ z_brne(L_resolved);
471472
__ clear_reg(Z_tos);

‎src/hotspot/cpu/x86/templateTable_x86.cpp

+1
Original file line numberDiff line numberDiff line change
@@ -448,6 +448,7 @@ void TemplateTable::fast_aldc(bool wide) {
448448
Label notNull;
449449
ExternalAddress null_sentinel((address)Universe::the_null_sentinel_addr());
450450
__ movptr(tmp, null_sentinel);
451+
__ resolve_oop_handle(tmp);
451452
__ cmpoop(tmp, result);
452453
__ jccb(Assembler::notEqual, notNull);
453454
__ xorptr(result, result); // NULL object reference

‎src/hotspot/share/memory/universe.cpp

+180-126
Large diffs are not rendered by default.

‎src/hotspot/share/memory/universe.hpp

+48-50
Original file line numberDiff line numberDiff line change
@@ -27,6 +27,7 @@
2727

2828
#include "gc/shared/verifyOption.hpp"
2929
#include "oops/array.hpp"
30+
#include "oops/oopHandle.hpp"
3031
#include "runtime/handles.hpp"
3132
#include "utilities/growableArray.hpp"
3233

@@ -106,31 +107,27 @@ class Universe: AllStatic {
106107
static oop _short_mirror;
107108
static oop _void_mirror;
108109

109-
static oop _main_thread_group; // Reference to the main thread group object
110-
static oop _system_thread_group; // Reference to the system thread group object
110+
static OopHandle _main_thread_group; // Reference to the main thread group object
111+
static OopHandle _system_thread_group; // Reference to the system thread group object
112+
113+
static OopHandle _the_empty_class_array; // Canonicalized obj array of type java.lang.Class
114+
static OopHandle _the_null_string; // A cache of "null" as a Java string
115+
static OopHandle _the_min_jint_string; // A cache of "-2147483648" as a Java string
116+
117+
static OopHandle _the_null_sentinel; // A unique object pointer unused except as a sentinel for null.
118+
119+
// preallocated error objects (no backtrace)
120+
static OopHandle _out_of_memory_errors;
121+
122+
// preallocated cause message for delayed StackOverflowError
123+
static OopHandle _delayed_stack_overflow_error_message;
111124

112-
static objArrayOop _the_empty_class_klass_array; // Canonicalized obj array of type java.lang.Class
113-
static oop _the_null_sentinel; // A unique object pointer unused except as a sentinel for null.
114-
static oop _the_null_string; // A cache of "null" as a Java string
115-
static oop _the_min_jint_string; // A cache of "-2147483648" as a Java string
116125
static LatestMethodCache* _finalizer_register_cache; // static method for registering finalizable objects
117126
static LatestMethodCache* _loader_addClass_cache; // method for registering loaded classes in class loader vector
118127
static LatestMethodCache* _throw_illegal_access_error_cache; // Unsafe.throwIllegalAccessError() method
119128
static LatestMethodCache* _throw_no_such_method_error_cache; // Unsafe.throwNoSuchMethodError() method
120129
static LatestMethodCache* _do_stack_walk_cache; // method for stack walker callback
121130

122-
// preallocated error objects (no backtrace)
123-
static oop _out_of_memory_error_java_heap;
124-
static oop _out_of_memory_error_metaspace;
125-
static oop _out_of_memory_error_class_metaspace;
126-
static oop _out_of_memory_error_array_size;
127-
static oop _out_of_memory_error_gc_overhead_limit;
128-
static oop _out_of_memory_error_realloc_objects;
129-
static oop _out_of_memory_error_retry;
130-
131-
// preallocated cause message for delayed StackOverflowError
132-
static oop _delayed_stack_overflow_error_message;
133-
134131
static Array<int>* _the_empty_int_array; // Canonicalized int array
135132
static Array<u2>* _the_empty_short_array; // Canonicalized short array
136133
static Array<Klass*>* _the_empty_klass_array; // Canonicalized klass array
@@ -140,17 +137,14 @@ class Universe: AllStatic {
140137
static Array<Klass*>* _the_array_interfaces_array;
141138

142139
// array of preallocated error objects with backtrace
143-
static objArrayOop _preallocated_out_of_memory_error_array;
140+
static OopHandle _preallocated_out_of_memory_error_array;
144141

145142
// number of preallocated error objects available for use
146143
static volatile jint _preallocated_out_of_memory_error_avail_count;
147144

148-
static oop _null_ptr_exception_instance; // preallocated exception object
149-
static oop _arithmetic_exception_instance; // preallocated exception object
150-
static oop _virtual_machine_error_instance; // preallocated exception object
151-
// The object used as an exception dummy when exceptions are thrown for
152-
// the vm thread.
153-
static oop _vm_exception;
145+
static OopHandle _null_ptr_exception_instance; // preallocated exception object
146+
static OopHandle _arithmetic_exception_instance; // preallocated exception object
147+
static OopHandle _virtual_machine_error_instance; // preallocated exception object
154148

155149
// References waiting to be transferred to the ReferenceHandler
156150
static oop _reference_pending_list;
@@ -161,8 +155,7 @@ class Universe: AllStatic {
161155
static intptr_t _non_oop_bits;
162156

163157
// array of dummy objects used with +FullGCAlot
164-
debug_only(static objArrayOop _fullgc_alot_dummy_array;)
165-
// index of next entry to clear
158+
debug_only(static OopHandle _fullgc_alot_dummy_array;)
166159
debug_only(static int _fullgc_alot_dummy_next;)
167160

168161
// Compiler/dispatch support
@@ -174,8 +167,9 @@ class Universe: AllStatic {
174167
static bool _fully_initialized; // true after universe_init and initialize_vtables called
175168

176169
// the array of preallocated errors with backtraces
177-
static objArrayOop preallocated_out_of_memory_errors() { return _preallocated_out_of_memory_error_array; }
170+
static objArrayOop preallocated_out_of_memory_errors();
178171

172+
static objArrayOop out_of_memory_errors();
179173
// generate an out of memory error; if possible using an error with preallocated backtrace;
180174
// otherwise return the given default error.
181175
static oop gen_out_of_memory_error(oop default_err);
@@ -265,17 +259,23 @@ class Universe: AllStatic {
265259
assert((uint)t < T_VOID+1, "range check");
266260
return check_mirror(_mirrors[t]);
267261
}
268-
static oop main_thread_group() { return _main_thread_group; }
269-
static void set_main_thread_group(oop group) { _main_thread_group = group;}
262+
static oop main_thread_group();
263+
static void set_main_thread_group(oop group);
270264

271-
static oop system_thread_group() { return _system_thread_group; }
272-
static void set_system_thread_group(oop group) { _system_thread_group = group;}
265+
static oop system_thread_group();
266+
static void set_system_thread_group(oop group);
273267

274-
static objArrayOop the_empty_class_klass_array () { return _the_empty_class_klass_array; }
275-
static Array<Klass*>* the_array_interfaces_array() { return _the_array_interfaces_array; }
276-
static oop the_null_string() { return _the_null_string; }
277-
static oop the_min_jint_string() { return _the_min_jint_string; }
268+
static objArrayOop the_empty_class_array ();
278269

270+
static oop the_null_string();
271+
static oop the_min_jint_string();
272+
273+
static oop null_ptr_exception_instance();
274+
static oop arithmetic_exception_instance();
275+
static oop virtual_machine_error_instance();
276+
static oop vm_exception() { return virtual_machine_error_instance(); }
277+
278+
static Array<Klass*>* the_array_interfaces_array() { return _the_array_interfaces_array; }
279279
static Method* finalizer_register_method() { return _finalizer_register_cache->get_method(); }
280280
static Method* loader_addClass_method() { return _loader_addClass_cache->get_method(); }
281281

@@ -284,16 +284,13 @@ class Universe: AllStatic {
284284

285285
static Method* do_stack_walk_method() { return _do_stack_walk_cache->get_method(); }
286286

287-
static oop the_null_sentinel() { return _the_null_sentinel; }
287+
static oop the_null_sentinel();
288288
static address the_null_sentinel_addr() { return (address) &_the_null_sentinel; }
289289

290290
// Function to initialize these
291291
static void initialize_known_methods(TRAPS);
292292

293-
static oop null_ptr_exception_instance() { return _null_ptr_exception_instance; }
294-
static oop arithmetic_exception_instance() { return _arithmetic_exception_instance; }
295-
static oop virtual_machine_error_instance() { return _virtual_machine_error_instance; }
296-
static oop vm_exception() { return _vm_exception; }
293+
static void create_preallocated_out_of_memory_errors(TRAPS);
297294

298295
// Reference pending list manipulation. Access is protected by
299296
// Heap_lock. The getter, setter and predicate require the caller
@@ -302,7 +299,7 @@ class Universe: AllStatic {
302299
// Heap_lock, so requires the lock is locked, but not necessarily by
303300
// the current thread.
304301
static oop reference_pending_list();
305-
static void set_reference_pending_list(oop list);
302+
static void clear_reference_pending_list();
306303
static bool has_reference_pending_list();
307304
static oop swap_reference_pending_list(oop list);
308305

@@ -315,15 +312,16 @@ class Universe: AllStatic {
315312
// OutOfMemoryError support. Returns an error with the required message. The returned error
316313
// may or may not have a backtrace. If error has a backtrace then the stack trace is already
317314
// filled in.
318-
static oop out_of_memory_error_java_heap() { return gen_out_of_memory_error(_out_of_memory_error_java_heap); }
319-
static oop out_of_memory_error_metaspace() { return gen_out_of_memory_error(_out_of_memory_error_metaspace); }
320-
static oop out_of_memory_error_class_metaspace() { return gen_out_of_memory_error(_out_of_memory_error_class_metaspace); }
321-
static oop out_of_memory_error_array_size() { return gen_out_of_memory_error(_out_of_memory_error_array_size); }
322-
static oop out_of_memory_error_gc_overhead_limit() { return gen_out_of_memory_error(_out_of_memory_error_gc_overhead_limit); }
323-
static oop out_of_memory_error_realloc_objects() { return gen_out_of_memory_error(_out_of_memory_error_realloc_objects); }
315+
static oop out_of_memory_error_java_heap();
316+
static oop out_of_memory_error_metaspace();
317+
static oop out_of_memory_error_class_metaspace();
318+
static oop out_of_memory_error_array_size();
319+
static oop out_of_memory_error_gc_overhead_limit();
320+
static oop out_of_memory_error_realloc_objects();
321+
324322
// Throw default _out_of_memory_error_retry object as it will never propagate out of the VM
325-
static oop out_of_memory_error_retry() { return _out_of_memory_error_retry; }
326-
static oop delayed_stack_overflow_error_message() { return _delayed_stack_overflow_error_message; }
323+
static oop out_of_memory_error_retry();
324+
static oop delayed_stack_overflow_error_message();
327325

328326
// The particular choice of collected heap.
329327
static CollectedHeap* heap() { return _collectedHeap; }

‎src/hotspot/share/oops/method.cpp

+1-1
Original file line numberDiff line numberDiff line change
@@ -805,7 +805,7 @@ bool Method::needs_clinit_barrier() const {
805805
objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
806806
int length = method->checked_exceptions_length();
807807
if (length == 0) { // common case
808-
return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());
808+
return objArrayHandle(THREAD, Universe::the_empty_class_array());
809809
} else {
810810
methodHandle h_this(THREAD, method);
811811
objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));

‎src/hotspot/share/oops/oopHandle.hpp

+2
Original file line numberDiff line numberDiff line change
@@ -48,6 +48,8 @@ class OopHandle {
4848
inline oop resolve() const;
4949
inline oop peek() const;
5050

51+
bool is_empty() const { return _obj == NULL; }
52+
5153
inline void release(OopStorage* storage);
5254

5355
// Used only for removing handle.

‎src/hotspot/share/prims/jvm.cpp

+1-1
Original file line numberDiff line numberDiff line change
@@ -3409,7 +3409,7 @@ JVM_ENTRY(jobject, JVM_GetAndClearReferencePendingList(JNIEnv* env))
34093409
MonitorLocker ml(Heap_lock);
34103410
oop ref = Universe::reference_pending_list();
34113411
if (ref != NULL) {
3412-
Universe::set_reference_pending_list(NULL);
3412+
Universe::clear_reference_pending_list();
34133413
}
34143414
return JNIHandles::make_local(THREAD, ref);
34153415
JVM_END

‎src/hotspot/share/runtime/reflection.cpp

+2-3
Original file line numberDiff line numberDiff line change
@@ -812,8 +812,7 @@ oop Reflection::new_method(const methodHandle& method, bool for_constant_pool_ac
812812
Handle return_type(THREAD, return_type_oop);
813813

814814
objArrayHandle exception_types = get_exception_types(method, CHECK_NULL);
815-
816-
if (exception_types.is_null()) return NULL;
815+
assert(!exception_types.is_null(), "cannot return null");
817816

818817
Symbol* method_name = method->name();
819818
oop name_oop = StringTable::intern(method_name, CHECK_NULL);
@@ -859,7 +858,7 @@ oop Reflection::new_constructor(const methodHandle& method, TRAPS) {
859858
if (parameter_types.is_null()) return NULL;
860859

861860
objArrayHandle exception_types = get_exception_types(method, CHECK_NULL);
862-
if (exception_types.is_null()) return NULL;
861+
assert(!exception_types.is_null(), "cannot return null");
863862

864863
const int modifiers = method->access_flags().as_int() & JVM_RECOGNIZED_METHOD_MODIFIERS;
865864

‎src/hotspot/share/runtime/vmStructs.cpp

-16
Original file line numberDiff line numberDiff line change
@@ -369,23 +369,7 @@ typedef HashtableEntry<InstanceKlass*, mtClass> KlassHashtableEntry;
369369
/************/ \
370370
/* Universe */ \
371371
/************/ \
372-
\
373-
static_field(Universe, _mirrors[0], oop) \
374-
static_field(Universe, _main_thread_group, oop) \
375-
static_field(Universe, _system_thread_group, oop) \
376-
static_field(Universe, _the_empty_class_klass_array, objArrayOop) \
377-
static_field(Universe, _null_ptr_exception_instance, oop) \
378-
static_field(Universe, _arithmetic_exception_instance, oop) \
379-
static_field(Universe, _vm_exception, oop) \
380372
static_field(Universe, _collectedHeap, CollectedHeap*) \
381-
static_field(Universe, _base_vtable_size, int) \
382-
static_field(Universe, _bootstrapping, bool) \
383-
static_field(Universe, _fully_initialized, bool) \
384-
static_field(Universe, _verify_count, int) \
385-
static_field(Universe, _verify_oop_mask, uintptr_t) \
386-
static_field(Universe, _verify_oop_bits, uintptr_t) \
387-
static_field(Universe, _non_oop_bits, intptr_t) \
388-
\
389373
/******************/ \
390374
/* CompressedOops */ \
391375
/******************/ \

‎src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/memory/Universe.java

-18
Original file line numberDiff line numberDiff line change
@@ -51,8 +51,6 @@
5151
public class Universe {
5252
private static AddressField collectedHeapField;
5353
private static VirtualConstructor heapConstructor;
54-
private static sun.jvm.hotspot.types.OopField mainThreadGroupField;
55-
private static sun.jvm.hotspot.types.OopField systemThreadGroupField;
5654

5755
static {
5856
VM.registerVMInitializedObserver(new Observer() {
@@ -91,9 +89,6 @@ private static synchronized void initialize(TypeDataBase db) {
9189
addHeapTypeIfInDB(db, ZCollectedHeap.class);
9290
addHeapTypeIfInDB(db, ShenandoahHeap.class);
9391

94-
mainThreadGroupField = type.getOopField("_main_thread_group");
95-
systemThreadGroupField = type.getOopField("_system_thread_group");
96-
9792
UniverseExt.initialize(heapConstructor);
9893
}
9994

@@ -114,19 +109,6 @@ public boolean isInReserved(Address p) {
114109
return heap().isInReserved(p);
115110
}
116111

117-
private Oop newOop(OopHandle handle) {
118-
return VM.getVM().getObjectHeap().newOop(handle);
119-
}
120-
121-
public Oop mainThreadGroup() {
122-
return newOop(mainThreadGroupField.getValue());
123-
}
124-
125-
public Oop systemThreadGroup() {
126-
return newOop(systemThreadGroupField.getValue());
127-
}
128-
129-
130112
public void print() { printOn(System.out); }
131113
public void printOn(PrintStream tty) {
132114
heap().printOn(tty);

‎test/hotspot/jtreg/serviceability/sa/ClhsdbPrintStatics.java

+1-3
Original file line numberDiff line numberDiff line change
@@ -71,9 +71,7 @@ public static void main(String[] args) throws Exception {
7171
"_number_of_threads", "_number_of_non_daemon_threads"));
7272
expStrMap.put("printstatics Universe", List.of(
7373
"Static fields of Universe",
74-
"uintptr_t Universe::_verify_oop_mask",
75-
"intptr_t Universe::_non_oop_bits",
76-
"bool Universe::_fully_initialized"));
74+
"Universe::_collectedHeap"));
7775
expStrMap.put("printstatics JvmtiExport", List.of(
7876
"Static fields of JvmtiExport",
7977
"bool JvmtiExport::_can_access_local_variables",

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