1 /*
  2  * Copyright (c) 2017, 2025, 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 #ifndef SHARE_GC_Z_ZBARRIERSET_INLINE_HPP
 25 #define SHARE_GC_Z_ZBARRIERSET_INLINE_HPP
 26 
 27 #include "gc/z/zBarrierSet.hpp"
 28 
 29 #include "gc/shared/accessBarrierSupport.inline.hpp"
 30 #include "gc/z/zAddress.inline.hpp"
 31 #include "gc/z/zHeap.hpp"
 32 #include "gc/z/zNMethod.hpp"
 33 #include "oops/objArrayOop.hpp"
 34 #include "utilities/debug.hpp"
 35 
 36 template <DecoratorSet decorators, typename BarrierSetT>
 37 template <DecoratorSet expected>
 38 inline void ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::verify_decorators_present() {
 39   if ((decorators & expected) == 0) {
 40     fatal("Using unsupported access decorators");
 41   }
 42 }
 43 
 44 template <DecoratorSet decorators, typename BarrierSetT>
 45 template <DecoratorSet expected>
 46 inline void ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::verify_decorators_absent() {
 47   if ((decorators & expected) != 0) {
 48     fatal("Using unsupported access decorators");
 49   }
 50 }
 51 
 52 template <DecoratorSet decorators, typename BarrierSetT>
 53 inline void ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::unsupported() {
 54   ShouldNotReachHere();
 55 }
 56 
 57 template <DecoratorSet decorators, typename BarrierSetT>
 58 inline zpointer* ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::field_addr(oop base, ptrdiff_t offset) {
 59   assert(base != nullptr, "Invalid base");
 60   return reinterpret_cast<zpointer*>(reinterpret_cast<intptr_t>((void*)base) + offset);
 61 }
 62 
 63 template <DecoratorSet decorators, typename BarrierSetT>
 64 inline zaddress ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::load_barrier(zpointer* p, zpointer o) {
 65   verify_decorators_absent<ON_UNKNOWN_OOP_REF>();
 66 
 67   if (HasDecorator<decorators, AS_NO_KEEPALIVE>::value) {
 68     if (HasDecorator<decorators, ON_STRONG_OOP_REF>::value) {
 69       // Load barriers on strong oop refs don't keep objects alive
 70       return ZBarrierSet::load_barrier_on_oop_field_preloaded(p, o);
 71     } else if (HasDecorator<decorators, ON_WEAK_OOP_REF>::value) {
 72       return ZBarrierSet::no_keep_alive_load_barrier_on_weak_oop_field_preloaded(p, o);
 73     } else {
 74       assert((HasDecorator<decorators, ON_PHANTOM_OOP_REF>::value), "Must be");
 75       return ZBarrierSet::no_keep_alive_load_barrier_on_phantom_oop_field_preloaded(p, o);
 76     }
 77   } else {
 78     if (HasDecorator<decorators, ON_STRONG_OOP_REF>::value) {
 79       return ZBarrierSet::load_barrier_on_oop_field_preloaded(p, o);
 80     } else if (HasDecorator<decorators, ON_WEAK_OOP_REF>::value) {
 81       return ZBarrierSet::load_barrier_on_weak_oop_field_preloaded(p, o);
 82     } else {
 83       assert((HasDecorator<decorators, ON_PHANTOM_OOP_REF>::value), "Must be");
 84       return ZBarrierSet::load_barrier_on_phantom_oop_field_preloaded(p, o);
 85     }
 86   }
 87 }
 88 
 89 template <DecoratorSet decorators, typename BarrierSetT>
 90 inline zaddress ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::load_barrier_on_unknown_oop_ref(oop base, ptrdiff_t offset, zpointer* p, zpointer o) {
 91   verify_decorators_present<ON_UNKNOWN_OOP_REF>();
 92 
 93   const DecoratorSet decorators_known_strength =
 94     AccessBarrierSupport::resolve_possibly_unknown_oop_ref_strength<decorators>(base, offset);
 95 
 96   if (HasDecorator<decorators, AS_NO_KEEPALIVE>::value) {
 97     if (decorators_known_strength & ON_STRONG_OOP_REF) {
 98       // Load barriers on strong oop refs don't keep objects alive
 99       return ZBarrierSet::load_barrier_on_oop_field_preloaded(p, o);
100     } else if (decorators_known_strength & ON_WEAK_OOP_REF) {
101       return ZBarrierSet::no_keep_alive_load_barrier_on_weak_oop_field_preloaded(p, o);
102     } else {
103       assert(decorators_known_strength & ON_PHANTOM_OOP_REF, "Must be");
104       return ZBarrierSet::no_keep_alive_load_barrier_on_phantom_oop_field_preloaded(p, o);
105     }
106   } else {
107     if (decorators_known_strength & ON_STRONG_OOP_REF) {
108       return ZBarrierSet::load_barrier_on_oop_field_preloaded(p, o);
109     } else if (decorators_known_strength & ON_WEAK_OOP_REF) {
110       return ZBarrierSet::load_barrier_on_weak_oop_field_preloaded(p, o);
111     } else {
112       assert(decorators_known_strength & ON_PHANTOM_OOP_REF, "Must be");
113       return ZBarrierSet::load_barrier_on_phantom_oop_field_preloaded(p, o);
114     }
115   }
116 }
117 
118 inline zpointer ZBarrierSet::store_good(oop obj) {
119   assert(ZPointerStoreGoodMask != 0, "sanity");
120 
121   const zaddress addr = to_zaddress(obj);
122   return ZAddress::store_good(addr);
123 }
124 
125 template <DecoratorSet decorators, typename BarrierSetT>
126 inline void ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::store_barrier_heap_with_healing(zpointer* p) {
127   if (!HasDecorator<decorators, IS_DEST_UNINITIALIZED>::value) {
128     ZBarrierSet::store_barrier_on_heap_oop_field(p, true /* heal */);
129   } else {
130     assert(false, "Should not be used on uninitialized memory");
131   }
132 }
133 
134 template <DecoratorSet decorators, typename BarrierSetT>
135 inline void ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::store_barrier_heap_without_healing(zpointer* p) {
136   if (!HasDecorator<decorators, IS_DEST_UNINITIALIZED>::value) {
137     ZBarrierSet::store_barrier_on_heap_oop_field(p, false /* heal */);
138   }
139 }
140 
141 template <DecoratorSet decorators, typename BarrierSetT>
142 inline void ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::no_keep_alive_store_barrier_heap(zpointer* p) {
143   if (!HasDecorator<decorators, IS_DEST_UNINITIALIZED>::value) {
144     ZBarrierSet::no_keep_alive_store_barrier_on_heap_oop_field(p);
145   }
146 }
147 
148 template <DecoratorSet decorators, typename BarrierSetT>
149 inline void ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::store_barrier_native_with_healing(zpointer* p) {
150   if (!HasDecorator<decorators, IS_DEST_UNINITIALIZED>::value) {
151     ZBarrierSet::store_barrier_on_native_oop_field(p, true /* heal */);
152   } else {
153     assert(false, "Should not be used on uninitialized memory");
154   }
155 }
156 
157 template <DecoratorSet decorators, typename BarrierSetT>
158 inline void ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::store_barrier_native_without_healing(zpointer* p) {
159   if (!HasDecorator<decorators, IS_DEST_UNINITIALIZED>::value) {
160     ZBarrierSet::store_barrier_on_native_oop_field(p, false /* heal */);
161   }
162 }
163 
164 //
165 // In heap
166 //
167 template <DecoratorSet decorators, typename BarrierSetT>
168 inline oop ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_in_heap(zpointer* p) {
169   verify_decorators_absent<ON_UNKNOWN_OOP_REF>();
170 
171   const zpointer o = Raw::load_in_heap(p);
172   assert_is_valid(o);
173 
174   return to_oop(load_barrier(p, o));
175 }
176 
177 template <DecoratorSet decorators, typename BarrierSetT>
178 inline oop ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_in_heap_at(oop base, ptrdiff_t offset) {
179   zpointer* const p = field_addr(base, offset);
180 
181   const zpointer o = Raw::load_in_heap(p);
182   assert_is_valid(o);
183 
184   if (HasDecorator<decorators, ON_UNKNOWN_OOP_REF>::value) {
185     return to_oop(load_barrier_on_unknown_oop_ref(base, offset, p, o));
186   }
187 
188   return to_oop(load_barrier(p, o));
189 }
190 
191 template <DecoratorSet decorators>
192 bool is_store_barrier_no_keep_alive() {
193   if (HasDecorator<decorators, ON_STRONG_OOP_REF>::value) {
194     return HasDecorator<decorators, AS_NO_KEEPALIVE>::value;
195   }
196 
197   if (HasDecorator<decorators, ON_WEAK_OOP_REF>::value) {
198     return true;
199   }
200 
201   assert((decorators & ON_PHANTOM_OOP_REF) != 0, "Must be");
202   return true;
203 }
204 
205 template <DecoratorSet decorators>
206 inline bool is_store_barrier_no_keep_alive(oop base, ptrdiff_t offset) {
207   if (!HasDecorator<decorators, ON_UNKNOWN_OOP_REF>::value) {
208     return is_store_barrier_no_keep_alive<decorators>();
209   }
210 
211   const DecoratorSet decorators_known_strength =
212       AccessBarrierSupport::resolve_possibly_unknown_oop_ref_strength<decorators>(base, offset);
213 
214   if ((decorators_known_strength & ON_STRONG_OOP_REF) != 0) {
215     return (decorators & AS_NO_KEEPALIVE) != 0;
216   }
217 
218   if ((decorators_known_strength & ON_WEAK_OOP_REF) != 0) {
219     return true;
220   }
221 
222   assert((decorators_known_strength & ON_PHANTOM_OOP_REF) != 0, "Must be");
223   return true;
224 }
225 
226 template <DecoratorSet decorators, typename BarrierSetT>
227 inline void ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_in_heap(zpointer* p, oop value) {
228   verify_decorators_absent<ON_UNKNOWN_OOP_REF>();
229 
230   if (is_store_barrier_no_keep_alive<decorators>()) {
231     no_keep_alive_store_barrier_heap(p);
232   } else {
233     store_barrier_heap_without_healing(p);
234   }
235 
236   Raw::store_in_heap(p, store_good(value));
237 }
238 
239 template <DecoratorSet decorators, typename BarrierSetT>
240 inline void ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
241   zpointer* const p = field_addr(base, offset);
242 
243   if (is_store_barrier_no_keep_alive<decorators>(base, offset)) {
244     no_keep_alive_store_barrier_heap(p);
245   } else {
246     store_barrier_heap_without_healing(p);
247   }
248 
249   Raw::store_in_heap(p, store_good(value));
250 }
251 
252 template <DecoratorSet decorators, typename BarrierSetT>
253 inline void ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_not_in_heap(zpointer* p, oop value) {
254   verify_decorators_absent<ON_UNKNOWN_OOP_REF>();
255 
256   if (!is_store_barrier_no_keep_alive<decorators>()) {
257     store_barrier_native_without_healing(p);
258   }
259 
260   Raw::store(p, store_good(value));
261 }
262 
263 template <DecoratorSet decorators, typename BarrierSetT>
264 inline oop ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_in_heap(zpointer* p, oop compare_value, oop new_value) {
265   verify_decorators_present<ON_STRONG_OOP_REF>();
266   verify_decorators_absent<AS_NO_KEEPALIVE>();
267 
268   store_barrier_heap_with_healing(p);
269 
270   const zpointer o = Raw::atomic_cmpxchg_in_heap(p, store_good(compare_value), store_good(new_value));
271   assert_is_valid(o);
272 
273   return to_oop(ZPointer::uncolor_store_good(o));
274 }
275 
276 template <DecoratorSet decorators, typename BarrierSetT>
277 inline oop ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_in_heap_at(oop base, ptrdiff_t offset, oop compare_value, oop new_value) {
278   verify_decorators_present<ON_STRONG_OOP_REF | ON_UNKNOWN_OOP_REF>();
279   verify_decorators_absent<AS_NO_KEEPALIVE>();
280 
281   // Through Unsafe.CompareAndExchangeObject()/CompareAndSetObject() we can receive
282   // calls with ON_UNKNOWN_OOP_REF set. However, we treat these as ON_STRONG_OOP_REF,
283   // with the motivation that if you're doing Unsafe operations on a Reference.referent
284   // field, then you're on your own anyway.
285   zpointer* const p = field_addr(base, offset);
286 
287   store_barrier_heap_with_healing(p);
288 
289   const zpointer o = Raw::atomic_cmpxchg_in_heap(p, store_good(compare_value), store_good(new_value));
290   assert_is_valid(o);
291 
292   return to_oop(ZPointer::uncolor_store_good(o));
293 }
294 
295 template <DecoratorSet decorators, typename BarrierSetT>
296 inline oop ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_in_heap(zpointer* p, oop new_value) {
297   verify_decorators_present<ON_STRONG_OOP_REF>();
298   verify_decorators_absent<AS_NO_KEEPALIVE>();
299 
300   store_barrier_heap_with_healing(p);
301 
302   const zpointer o = Raw::atomic_xchg_in_heap(p, store_good(new_value));
303   assert_is_valid(o);
304 
305   return to_oop(ZPointer::uncolor_store_good(o));
306 }
307 
308 template <DecoratorSet decorators, typename BarrierSetT>
309 inline oop ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_in_heap_at(oop base, ptrdiff_t offset, oop new_value) {
310   verify_decorators_present<ON_STRONG_OOP_REF>();
311   verify_decorators_absent<AS_NO_KEEPALIVE>();
312 
313   zpointer* const p = field_addr(base, offset);
314 
315   store_barrier_heap_with_healing(p);
316 
317   const zpointer o = Raw::atomic_xchg_in_heap(p, store_good(new_value));
318   assert_is_valid(o);
319 
320   return to_oop(ZPointer::uncolor_store_good(o));
321 }
322 
323 template <DecoratorSet decorators, typename BarrierSetT>
324 inline zaddress ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_copy_one_barriers(zpointer* dst, zpointer* src) {
325   store_barrier_heap_without_healing(dst);
326 
327   return ZBarrierSet::load_barrier_on_oop_field(src);
328 }
329 
330 template <DecoratorSet decorators, typename BarrierSetT>
331 inline void ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_copy_one(zpointer* dst, zpointer* src) {
332   const zaddress obj = oop_copy_one_barriers(dst, src);
333 
334   AtomicAccess::store(dst, ZAddress::store_good(obj));
335 }
336 
337 template <DecoratorSet decorators, typename BarrierSetT>
338 inline bool ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_copy_one_check_cast(zpointer* dst, zpointer* src, Klass* dst_klass) {
339   const zaddress obj = oop_copy_one_barriers(dst, src);
340 
341   if (!oopDesc::is_instanceof_or_null(to_oop(obj), dst_klass)) {
342     // Check cast failed
343     return false;
344   }
345 
346   AtomicAccess::store(dst, ZAddress::store_good(obj));
347 
348   return true;
349 }
350 
351 template <DecoratorSet decorators, typename BarrierSetT>
352 inline bool ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_arraycopy_in_heap_check_cast(zpointer* dst, zpointer* src, size_t length, Klass* dst_klass) {
353   // Check cast and copy each elements
354   for (const zpointer* const end = src + length; src < end; src++, dst++) {
355     if (!oop_copy_one_check_cast(dst, src, dst_klass)) {
356       // Check cast failed
357       return false;
358     }
359   }
360 
361   return true;
362 }
363 
364 template <DecoratorSet decorators, typename BarrierSetT>
365 inline bool ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_arraycopy_in_heap_no_check_cast(zpointer* dst, zpointer* src, size_t length) {
366   const bool is_disjoint = HasDecorator<decorators, ARRAYCOPY_DISJOINT>::value;
367 
368   if (is_disjoint || src > dst) {
369     for (const zpointer* const end = src + length; src < end; src++, dst++) {
370       oop_copy_one(dst, src);
371     }
372     return true;
373   }
374 
375   if (src < dst) {
376     const zpointer* const end = src;
377     src += length - 1;
378     dst += length - 1;
379     for ( ; src >= end; src--, dst--) {
380       oop_copy_one(dst, src);
381     }
382     return true;
383   }
384 
385   // src and dst are the same; nothing to do
386   return true;
387 }
388 
389 template <DecoratorSet decorators, typename BarrierSetT>
390 inline bool ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, zpointer* src_raw,
391                                                                                        arrayOop dst_obj, size_t dst_offset_in_bytes, zpointer* dst_raw,
392                                                                                        size_t length) {
393   zpointer* const src = arrayOopDesc::obj_offset_to_raw(src_obj, src_offset_in_bytes, src_raw);
394   zpointer* const dst = arrayOopDesc::obj_offset_to_raw(dst_obj, dst_offset_in_bytes, dst_raw);
395 
396   if (HasDecorator<decorators, ARRAYCOPY_CHECKCAST>::value) {
397     Klass* const dst_klass = objArrayOop(dst_obj)->element_klass();
398     return oop_arraycopy_in_heap_check_cast(dst, src, length, dst_klass);
399   }
400 
401   return oop_arraycopy_in_heap_no_check_cast(dst, src, length);
402 }
403 
404 template <DecoratorSet decorators, typename BarrierSetT>
405 inline void ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::clone_in_heap(oop src, oop dst, size_t size) {
406   check_is_valid_zaddress(src);
407 
408   if (dst->is_objArray()) {
409     // Cloning an object array is similar to performing array copy.
410     // If an array is large enough to have its allocation segmented,
411     // this operation might require GC barriers. However, the intrinsics
412     // for cloning arrays transform the clone to an optimized allocation
413     // and arraycopy sequence, so the performance of this runtime call
414     // does not matter for object arrays.
415     clone_obj_array(objArrayOop(src), objArrayOop(dst));
416     return;
417   }
418 
419   // Fix the oops
420   ZBarrierSet::load_barrier_all(src, size);
421 
422   // Clone the object
423   Raw::clone_in_heap(src, dst, size);
424 
425   // Color store good before handing out
426   ZBarrierSet::color_store_good_all(dst, size);
427 }
428 
429 //
430 // Not in heap
431 //
432 template <DecoratorSet decorators, typename BarrierSetT>
433 inline oop ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_not_in_heap(zpointer* p) {
434   verify_decorators_absent<ON_UNKNOWN_OOP_REF>();
435 
436   const zpointer o = Raw::template load<zpointer>(p);
437   assert_is_valid(o);
438   return to_oop(load_barrier(p, o));
439 }
440 
441 template <DecoratorSet decorators, typename BarrierSetT>
442 inline oop ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_not_in_heap(oop* p) {
443   verify_decorators_absent<ON_UNKNOWN_OOP_REF>();
444 
445   return oop_load_not_in_heap((zpointer*)p);
446 }
447 
448 template <DecoratorSet decorators, typename BarrierSetT>
449 inline oop ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_not_in_heap(zpointer* p, oop compare_value, oop new_value) {
450   verify_decorators_present<ON_STRONG_OOP_REF>();
451   verify_decorators_absent<AS_NO_KEEPALIVE>();
452 
453   store_barrier_native_with_healing(p);
454 
455   const zpointer o = Raw::atomic_cmpxchg(p, store_good(compare_value), store_good(new_value));
456   assert_is_valid(o);
457 
458   return to_oop(ZPointer::uncolor_store_good(o));
459 }
460 
461 template <DecoratorSet decorators, typename BarrierSetT>
462 inline oop ZBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_not_in_heap(zpointer* p, oop new_value) {
463   verify_decorators_present<ON_STRONG_OOP_REF>();
464   verify_decorators_absent<AS_NO_KEEPALIVE>();
465 
466   store_barrier_native_with_healing(p);
467 
468   const zpointer o = Raw::atomic_xchg(p, store_good(new_value));
469   assert_is_valid(o);
470 
471   return to_oop(ZPointer::uncolor_store_good(o));
472 }
473 
474 #endif // SHARE_GC_Z_ZBARRIERSET_INLINE_HPP