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