1 /*
2 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc/shared/gcLocker.inline.hpp"
27 #include "interpreter/interpreter.hpp"
28 #include "logging/log.hpp"
29 #include "oops/oop.inline.hpp"
30 #include "oops/fieldStreams.hpp"
31 #include "oops/method.hpp"
32 #include "oops/objArrayKlass.hpp"
33 #include "oops/valueKlass.hpp"
34 #include "oops/valueArrayKlass.hpp"
35 #include "runtime/signature.hpp"
36 #include "utilities/copy.hpp"
37
38 int ValueKlass::first_field_offset() const {
39 #ifdef ASSERT
40 int first_offset = INT_MAX;
41 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
42 if (fs.offset() < first_offset) first_offset= fs.offset();
43 }
44 #endif
45 int base_offset = instanceOopDesc::base_offset_in_bytes();
46 // The first field of value types is aligned on a long boundary
47 base_offset = align_size_up(base_offset, BytesPerLong);
48 assert(base_offset == first_offset, "inconsistent offsets");
49 return base_offset;
50 }
51
52 int ValueKlass::raw_value_byte_size() const {
53 assert(this != SystemDictionary::___Value_klass(),
54 "This is not the value type klass you are looking for");
55 int heapOopAlignedSize = nonstatic_field_size() << LogBytesPerHeapOop;
56 // If bigger than 64 bits or needs oop alignment, then use jlong aligned
57 // which for values should be jlong aligned, asserts in raw_field_copy otherwise
58 if (heapOopAlignedSize >= longSize || contains_oops()) {
59 return heapOopAlignedSize;
60 }
61 // Small primitives...
62 // If a few small basic type fields, return the actual size, i.e.
63 // 1 byte = 1
64 // 2 byte = 2
65 // 3 byte = 4, because pow2 needed for element stores
66 int first_offset = first_field_offset();
67 int last_offset = 0; // find the last offset, add basic type size
68 int last_tsz = 0;
69 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
70 if (fs.offset() > last_offset) {
71 BasicType type = fs.field_descriptor().field_type();
72 if (is_java_primitive(type)) {
73 last_tsz = type2aelembytes(type);
74 } else if (type == T_VALUETYPE) {
75 // Not just primitives. Layout aligns embedded value, so use jlong aligned it is
76 return heapOopAlignedSize;
77 } else {
78 guarantee(0, "Unknown type %d", type);
79 }
80 assert(last_tsz != 0, "Invariant");
81 last_offset = fs.offset();
82 }
83 }
84 // Assumes VT with no fields are meaningless and illegal
85 last_offset += last_tsz;
86 assert(last_offset > first_offset && last_tsz, "Invariant");
87 return 1 << upper_log2(last_offset - first_offset);
88 }
89
90 instanceOop ValueKlass::allocate_instance(TRAPS) {
91 int size = size_helper(); // Query before forming handle.
92
93 return (instanceOop)CollectedHeap::obj_allocate(this, size, CHECK_NULL);
94 }
95
96 instanceOop ValueKlass::allocate_buffered_or_heap_instance(bool* in_heap, TRAPS) {
97 assert(THREAD->is_Java_thread(), "Only Java threads can call this method");
98
99 instanceOop value = NULL;
100 if (is_bufferable()) {
101 value = (instanceOop)VTBuffer::allocate_value(this, CHECK_NULL);
102 *in_heap = false;
103 }
104 if (value == NULL) {
105 log_info(valuetypes)("Value buffering failed, allocating in the Java heap");
106 value = allocate_instance(CHECK_NULL);
107 *in_heap = true;
108 }
109 return value;
110 }
111
112 bool ValueKlass::is_atomic() {
113 return (nonstatic_field_size() * heapOopSize) <= longSize;
114 }
115
116 int ValueKlass::nonstatic_oop_count() {
117 int oops = 0;
118 int map_count = nonstatic_oop_map_count();
119 OopMapBlock* block = start_of_nonstatic_oop_maps();
120 OopMapBlock* end = block + map_count;
121 while (block != end) {
122 oops += block->count();
123 block++;
124 }
125 return oops;
126 }
127
128 // Arrays of...
129
130 bool ValueKlass::flatten_array() {
131 if (!ValueArrayFlatten) {
132 return false;
133 }
134
135 int elem_bytes = raw_value_byte_size();
136 // Too big
137 if ((ValueArrayElemMaxFlatSize >= 0) && (elem_bytes > ValueArrayElemMaxFlatSize)) {
138 return false;
139 }
140 // Too many embedded oops
141 if ((ValueArrayElemMaxFlatOops >= 0) && (nonstatic_oop_count() > ValueArrayElemMaxFlatOops)) {
142 return false;
143 }
144
145 return true;
146 }
147
148
149 Klass* ValueKlass::array_klass_impl(bool or_null, int n, TRAPS) {
150 if (!flatten_array()) {
151 return InstanceKlass::array_klass_impl(or_null, n, THREAD);
152 }
153
154 // Basically the same as instanceKlass, but using "ValueArrayKlass::allocate_klass"
155 if (array_klasses() == NULL) {
156 if (or_null) return NULL;
157
158 ResourceMark rm;
159 JavaThread *jt = (JavaThread *)THREAD;
160 {
161 // Atomic creation of array_klasses
162 MutexLocker mc(Compile_lock, THREAD); // for vtables
163 MutexLocker ma(MultiArray_lock, THREAD);
164
165 // Check if update has already taken place
166 if (array_klasses() == NULL) {
167 Klass* ak;
168 if (is_atomic() || (!ValueArrayAtomicAccess)) {
169 ak = ValueArrayKlass::allocate_klass(this, CHECK_NULL);
170 } else {
171 ak = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
172 }
173 set_array_klasses(ak);
174 }
175 }
176 }
177 // _this will always be set at this point
178 ArrayKlass* ak = ArrayKlass::cast(array_klasses());
179 if (or_null) {
180 return ak->array_klass_or_null(n);
181 }
182 return ak->array_klass(n, THREAD);
183 }
184
185 Klass* ValueKlass::array_klass_impl(bool or_null, TRAPS) {
186 return array_klass_impl(or_null, 1, THREAD);
187 }
188
189 void ValueKlass::raw_field_copy(void* src, void* dst, size_t raw_byte_size) {
190 /*
191 * Try not to shear fields even if not an atomic store...
192 *
193 * First 3 cases handle value array store, otherwise works on the same basis
194 * as JVM_Clone, at this size data is aligned. The order of primitive types
195 * is largest to smallest, and it not possible for fields to stradle long
196 * copy boundaries.
197 *
198 * If MT without exclusive access, possible to observe partial value store,
199 * but not partial primitive and reference field values
200 */
201 switch (raw_byte_size) {
202 case 1:
203 *((jbyte*) dst) = *(jbyte*)src;
204 break;
205 case 2:
206 *((jshort*) dst) = *(jshort*)src;
207 break;
208 case 4:
209 *((jint*) dst) = *(jint*) src;
210 break;
211 default:
212 assert(raw_byte_size % sizeof(jlong) == 0, "Unaligned raw_byte_size");
213 Copy::conjoint_jlongs_atomic((jlong*)src, (jlong*)dst, raw_byte_size >> LogBytesPerLong);
214 }
215 }
216
217 /*
218 * Store the value of this klass contained with src into dst.
219 *
220 * This operation is appropriate for use from vastore, vaload and putfield (for values)
221 *
222 * GC barriers currently can lock with no safepoint check and allocate c-heap,
223 * so raw point is "safe" for now.
224 *
225 * Going forward, look to use machine generated (stub gen or bc) version for most used klass layouts
226 *
227 */
228 void ValueKlass::value_store(void* src, void* dst, size_t raw_byte_size, bool dst_heap, bool dst_uninitialized) {
229 if (contains_oops() && dst_heap) {
230 // src/dst aren't oops, need offset to adjust oop map offset
231 const address dst_oop_addr = ((address) dst) - first_field_offset();
232
233 // Pre-barriers...
234 OopMapBlock* map = start_of_nonstatic_oop_maps();
235 OopMapBlock* const end = map + nonstatic_oop_map_count();
236 while (map != end) {
237 // Shame we can't just use the existing oop iterator...src/dst aren't oop
238 address doop_address = dst_oop_addr + map->offset();
239 if (UseCompressedOops) {
240 oopDesc::bs()->write_ref_array_pre((narrowOop*) doop_address, map->count(), dst_uninitialized);
241 } else {
242 oopDesc::bs()->write_ref_array_pre((oop*) doop_address, map->count(), dst_uninitialized);
243 }
244 map++;
245 }
246
247 raw_field_copy(src, dst, raw_byte_size);
248
249 // Post-barriers...
250 map = start_of_nonstatic_oop_maps();
251 while (map != end) {
252 address doop_address = dst_oop_addr + map->offset();
253 oopDesc::bs()->write_ref_array((HeapWord*) doop_address, map->count());
254 map++;
255 }
256 } else { // Primitive-only case...
257 raw_field_copy(src, dst, raw_byte_size);
258 }
259 }
260
261 oop ValueKlass::box(Handle src, InstanceKlass* target_klass, TRAPS) {
262 assert(src()->klass()->is_value(), "src must be a value type");
263 assert(!target_klass->is_value(), "target_klass must not be a value type");
264
265 target_klass->initialize(CHECK_0);
266 instanceOop box = target_klass->allocate_instance(CHECK_0);
267 value_store(data_for_oop(src()), data_for_oop(box), true, false);
268
269 assert(!box->klass()->is_value(), "Sanity check");
270 return box;
271 }
272
273 oop ValueKlass::unbox(Handle src, InstanceKlass* target_klass, TRAPS) {
274 assert(!src()->klass()->is_value(), "src must not be a value type");
275 assert(target_klass->is_value(), "target_klass must be a value type");
276 ValueKlass* vtklass = ValueKlass::cast(target_klass);
277
278 vtklass->initialize(CHECK_0);
279 bool in_heap;
280 instanceOop value = vtklass->allocate_buffered_or_heap_instance(&in_heap, CHECK_0);
281 value_store(data_for_oop(src()), data_for_oop(value), in_heap, false);
282
283 assert(value->klass()->is_value(), "Sanity check");
284 return value;
285 }
286
287 // Value type arguments are not passed by reference, instead each
288 // field of the value type is passed as an argument. This helper
289 // function collects the fields of the value types (including embedded
290 // value type's fields) in a list. Included with the field's type is
291 // the offset of each field in the value type: i2c and c2i adapters
292 // need that to load or store fields. Finally, the list of fields is
293 // sorted in order of increasing offsets: the adapters and the
294 // compiled code need and agreed upon order of fields.
295 //
296 // The list of basic types that is returned starts with a T_VALUETYPE
297 // and ends with an extra T_VOID. T_VALUETYPE/T_VOID are used as
298 // delimiters. Every entry between the two is a field of the value
299 // type. If there's an embedded value type in the list, it also starts
300 // with a T_VALUETYPE and ends with a T_VOID. This is so we can
301 // generate a unique fingerprint for the method's adapters and we can
302 // generate the list of basic types from the interpreter point of view
303 // (value types passed as reference: iterate on the list until a
304 // T_VALUETYPE, drop everything until and including the closing
305 // T_VOID) or the compiler point of view (each field of the value
306 // types is an argument: drop all T_VALUETYPE/T_VOID from the list).
307 GrowableArray<SigEntry> ValueKlass::collect_fields(int base_off) const {
308 GrowableArray<SigEntry> sig_extended;
309 sig_extended.push(SigEntry(T_VALUETYPE, base_off));
310 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
311 if (fs.access_flags().is_static()) continue;
312 fieldDescriptor& fd = fs.field_descriptor();
313 BasicType bt = fd.field_type();
314 int offset = base_off + fd.offset() - (base_off > 0 ? first_field_offset() : 0);
315 if (bt == T_VALUETYPE) {
316 Symbol* signature = fd.signature();
317 JavaThread* THREAD = JavaThread::current();
318 oop loader = class_loader();
319 oop domain = protection_domain();
320 ResetNoHandleMark rnhm;
321 HandleMark hm;
322 NoSafepointVerifier nsv;
323 Klass* klass = SystemDictionary::resolve_or_null(signature,
324 Handle(THREAD, loader), Handle(THREAD, domain),
325 THREAD);
326 assert(klass != NULL && !HAS_PENDING_EXCEPTION, "lookup shouldn't fail");
327 const GrowableArray<SigEntry>& embedded = ValueKlass::cast(klass)->collect_fields(offset);
328 sig_extended.appendAll(&embedded);
329 } else {
330 sig_extended.push(SigEntry(bt, offset));
331 if (bt == T_LONG || bt == T_DOUBLE) {
332 sig_extended.push(SigEntry(T_VOID, offset));
333 }
334 }
335 }
336 int offset = base_off + size_helper()*HeapWordSize - (base_off > 0 ? first_field_offset() : 0);
337 sig_extended.push(SigEntry(T_VOID, offset)); // hack: use T_VOID to mark end of value type fields
338 if (base_off == 0) {
339 sig_extended.sort(SigEntry::compare);
340 }
341 assert(sig_extended.at(0)._bt == T_VALUETYPE && sig_extended.at(sig_extended.length()-1)._bt == T_VOID, "broken structure");
342 return sig_extended;
343 }
344
345 // Returns the basic types and registers for fields to return an
346 // instance of this value type in registers if possible.
347 GrowableArray<SigEntry> ValueKlass::return_convention(VMRegPair*& regs, int& nb_fields) const {
348 assert(ValueTypeReturnedAsFields, "inconsistent");
349 const GrowableArray<SigEntry>& sig_vk = collect_fields();
350 nb_fields = SigEntry::count_fields(sig_vk)+1;
351 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, nb_fields);
352 sig_bt[0] = T_METADATA;
353 SigEntry::fill_sig_bt(sig_vk, sig_bt+1, nb_fields-1, true);
354 regs = NEW_RESOURCE_ARRAY(VMRegPair, nb_fields);
355 int total = SharedRuntime::java_return_convention(sig_bt, regs, nb_fields);
356
357 if (total <= 0) {
358 regs = NULL;
359 }
360
361 return sig_vk;
362 }
363
364 // Create handles for all oop fields returned in registers that are
365 // going to be live across a safepoint.
366 bool ValueKlass::save_oop_results(RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
367 if (ValueTypeReturnedAsFields) {
368 int nb_fields;
369 VMRegPair* regs;
370 const GrowableArray<SigEntry>& sig_vk = return_convention(regs, nb_fields);
371
372 if (regs != NULL) {
373 regs++;
374 nb_fields--;
375 save_oop_fields(sig_vk, reg_map, regs, handles, nb_fields);
376 return true;
377 }
378 }
379 return false;
380 }
381
382 // Same as above but with pre-computed return convention
383 void ValueKlass::save_oop_fields(const GrowableArray<SigEntry>& sig_vk, RegisterMap& reg_map, const VMRegPair* regs, GrowableArray<Handle>& handles, int nb_fields) const {
384 int j = 0;
385 Thread* thread = Thread::current();
386 for (int i = 0; i < sig_vk.length(); i++) {
387 BasicType bt = sig_vk.at(i)._bt;
388 if (bt == T_OBJECT || bt == T_ARRAY) {
389 int off = sig_vk.at(i)._offset;
390 VMRegPair pair = regs[j];
391 address loc = reg_map.location(pair.first());
392 oop v = *(oop*)loc;
393 assert(v == NULL || v->is_oop(), "not an oop?");
394 assert(Universe::heap()->is_in_or_null(v), "must be heap pointer");
395 handles.push(Handle(thread, v));
396 }
397 if (bt == T_VALUETYPE) {
398 continue;
399 }
400 if (bt == T_VOID &&
401 sig_vk.at(i-1)._bt != T_LONG &&
402 sig_vk.at(i-1)._bt != T_DOUBLE) {
403 continue;
404 }
405 j++;
406 }
407 assert(j == nb_fields, "missed a field?");
408 }
409
410 // Update oop fields in registers from handles after a safepoint
411 void ValueKlass::restore_oop_results(RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
412 assert(ValueTypeReturnedAsFields, "inconsistent");
413 int nb_fields;
414 VMRegPair* regs;
415 const GrowableArray<SigEntry>& sig_vk = return_convention(regs, nb_fields);
416 assert(regs != NULL, "inconsistent");
417
418 regs++;
419 nb_fields--;
420
421 int j = 0;
422 for (int i = 0, k = 0; i < sig_vk.length(); i++) {
423 BasicType bt = sig_vk.at(i)._bt;
424 if (bt == T_OBJECT || bt == T_ARRAY) {
425 int off = sig_vk.at(i)._offset;
426 VMRegPair pair = regs[j];
427 address loc = reg_map.location(pair.first());
428 *(oop*)loc = handles.at(k++)();
429 }
430 if (bt == T_VALUETYPE) {
431 continue;
432 }
433 if (bt == T_VOID &&
434 sig_vk.at(i-1)._bt != T_LONG &&
435 sig_vk.at(i-1)._bt != T_DOUBLE) {
436 continue;
437 }
438 j++;
439 }
440 assert(j == nb_fields, "missed a field?");
441 }
442
443 // Fields are in registers. Create an instance of the value type and
444 // initialize it with the values of the fields.
445 oop ValueKlass::realloc_result(const GrowableArray<SigEntry>& sig_vk, const RegisterMap& reg_map, const VMRegPair* regs,
446 const GrowableArray<Handle>& handles, int nb_fields, TRAPS) {
447 oop new_vt = allocate_instance(CHECK_NULL);
448
449 int j = 0;
450 int k = 0;
451 for (int i = 0; i < sig_vk.length(); i++) {
452 BasicType bt = sig_vk.at(i)._bt;
453 if (bt == T_VALUETYPE) {
454 continue;
455 }
456 if (bt == T_VOID) {
457 if (sig_vk.at(i-1)._bt == T_LONG ||
458 sig_vk.at(i-1)._bt == T_DOUBLE) {
459 j++;
460 }
461 continue;
462 }
463 int off = sig_vk.at(i)._offset;
464 VMRegPair pair = regs[j];
465 address loc = reg_map.location(pair.first());
466 switch(bt) {
467 case T_BOOLEAN: {
468 jboolean v = *(intptr_t*)loc;
469 *(jboolean*)((address)new_vt + off) = v;
470 break;
471 }
472 case T_CHAR: {
473 jchar v = *(intptr_t*)loc;
474 *(jchar*)((address)new_vt + off) = v;
475 break;
476 }
477 case T_BYTE: {
478 jbyte v = *(intptr_t*)loc;
479 *(jbyte*)((address)new_vt + off) = v;
480 break;
481 }
482 case T_SHORT: {
483 jshort v = *(intptr_t*)loc;
484 *(jshort*)((address)new_vt + off) = v;
485 break;
486 }
487 case T_INT: {
488 jint v = *(intptr_t*)loc;
489 *(jint*)((address)new_vt + off) = v;
490 break;
491 }
492 case T_LONG: {
493 #ifdef _LP64
494 jlong v = *(intptr_t*)loc;
495 *(jlong*)((address)new_vt + off) = v;
496 #else
497 Unimplemented();
498 #endif
499 break;
500 }
501 case T_OBJECT:
502 case T_ARRAY: {
503 Handle handle = handles.at(k++);
504 oop v = handle();
505 if (!UseCompressedOops) {
506 oop* p = (oop*)((address)new_vt + off);
507 oopDesc::store_heap_oop(p, v);
508 } else {
509 narrowOop* p = (narrowOop*)((address)new_vt + off);
510 oopDesc::encode_store_heap_oop(p, v);
511 }
512 break;
513 }
514 case T_FLOAT: {
515 jfloat v = *(jfloat*)loc;
516 *(jfloat*)((address)new_vt + off) = v;
517 break;
518 }
519 case T_DOUBLE: {
520 jdouble v = *(jdouble*)loc;
521 *(jdouble*)((address)new_vt + off) = v;
522 break;
523 }
524 default:
525 ShouldNotReachHere();
526 }
527 j++;
528 }
529 assert(j == nb_fields, "missed a field?");
530 assert(k == handles.length(), "missed an oop?");
531 return new_vt;
532 }
533
534 ValueKlass* ValueKlass::returned_value_type(const RegisterMap& map) {
535 BasicType bt = T_METADATA;
536 VMRegPair pair;
537 int nb = SharedRuntime::java_return_convention(&bt, &pair, 1);
538 assert(nb == 1, "broken");
539
540 address loc = map.location(pair.first());
541 intptr_t ptr = *(intptr_t*)loc;
542 if (Metaspace::contains((void*)ptr)) {
543 return (ValueKlass*)ptr;
544 }
545 return NULL;
546 // if (Universe::heap()->is_in_reserved((void*)ptr)) {
547 // return NULL;
548 // }
549 // return (ValueKlass*)ptr;
550 }
551