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