277 }
278
279 // Retry
280 addr = prev_top;
281 }
282 }
283
284 inline bool ZPage::undo_alloc_object(uintptr_t addr, size_t size) {
285 assert(is_allocating(), "Invalid state");
286
287 const uintptr_t offset = ZAddress::offset(addr);
288 const size_t aligned_size = align_up(size, object_alignment());
289 const uintptr_t old_top = top();
290 const uintptr_t new_top = old_top - aligned_size;
291
292 if (new_top != offset) {
293 // Failed to undo allocation, not the last allocated object
294 return false;
295 }
296
297 _top = new_top;
298
299 // Success
300 return true;
301 }
302
303 inline bool ZPage::undo_alloc_object_atomic(uintptr_t addr, size_t size) {
304 assert(is_allocating(), "Invalid state");
305
306 const uintptr_t offset = ZAddress::offset(addr);
307 const size_t aligned_size = align_up(size, object_alignment());
308 uintptr_t old_top = top();
309
310 for (;;) {
311 const uintptr_t new_top = old_top - aligned_size;
312 if (new_top != offset) {
313 // Failed to undo allocation, not the last allocated object
314 return false;
315 }
316
317 const uintptr_t prev_top = Atomic::cmpxchg(new_top, &_top, old_top);
318 if (prev_top == old_top) {
319 // Success
320 return true;
321 }
322
323 // Retry
324 old_top = prev_top;
325 }
326 }
327
328 #endif // SHARE_GC_Z_ZPAGE_INLINE_HPP
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277 }
278
279 // Retry
280 addr = prev_top;
281 }
282 }
283
284 inline bool ZPage::undo_alloc_object(uintptr_t addr, size_t size) {
285 assert(is_allocating(), "Invalid state");
286
287 const uintptr_t offset = ZAddress::offset(addr);
288 const size_t aligned_size = align_up(size, object_alignment());
289 const uintptr_t old_top = top();
290 const uintptr_t new_top = old_top - aligned_size;
291
292 if (new_top != offset) {
293 // Failed to undo allocation, not the last allocated object
294 return false;
295 }
296
297 // Clear memory
298 ZUtils::zero(addr, size);
299
300 _top = new_top;
301
302 // Success
303 return true;
304 }
305
306 inline bool ZPage::undo_alloc_object_atomic(uintptr_t addr, size_t size) {
307 assert(is_allocating(), "Invalid state");
308
309 const uintptr_t offset = ZAddress::offset(addr);
310 const size_t aligned_size = align_up(size, object_alignment());
311 uintptr_t old_top = top();
312
313 for (;;) {
314 const uintptr_t new_top = old_top - aligned_size;
315 if (new_top != offset) {
316 // Failed to undo allocation, not the last allocated object
317 return false;
318 }
319
320 // Clear memory
321 ZUtils::zero(addr, size);
322
323 const uintptr_t prev_top = Atomic::cmpxchg(new_top, &_top, old_top);
324 if (prev_top == old_top) {
325 // Success
326 return true;
327 }
328
329 // Retry
330 old_top = prev_top;
331 }
332 }
333
334 #endif // SHARE_GC_Z_ZPAGE_INLINE_HPP
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