99 _page_size, heap_rs.base(), heap_rs.size());
100 if (!heap_rs.is_reserved()) {
101 vm_exit_during_initialization("Could not reserve enough space for the "
102 "card marking array");
103 }
104
105 // The assember store_check code will do an unsigned shift of the oop,
106 // then add it to byte_map_base, i.e.
107 //
108 // _byte_map = byte_map_base + (uintptr_t(low_bound) >> card_shift)
109 _byte_map = (jbyte*) heap_rs.base();
110 byte_map_base = _byte_map - (uintptr_t(low_bound) >> card_shift);
111 assert(byte_for(low_bound) == &_byte_map[0], "Checking start of map");
112 assert(byte_for(high_bound-1) <= &_byte_map[_last_valid_index], "Checking end of map");
113
114 jbyte* guard_card = &_byte_map[_guard_index];
115 uintptr_t guard_page = align_size_down((uintptr_t)guard_card, _page_size);
116 _guard_region = MemRegion((HeapWord*)guard_page, _page_size);
117 if (!os::commit_memory((char*)guard_page, _page_size, _page_size)) {
118 // Do better than this for Merlin
119 vm_exit_out_of_memory(_page_size, "card table last card");
120 }
121
122 *guard_card = last_card;
123
124 _lowest_non_clean =
125 NEW_C_HEAP_ARRAY(CardArr, max_covered_regions, mtGC);
126 _lowest_non_clean_chunk_size =
127 NEW_C_HEAP_ARRAY(size_t, max_covered_regions, mtGC);
128 _lowest_non_clean_base_chunk_index =
129 NEW_C_HEAP_ARRAY(uintptr_t, max_covered_regions, mtGC);
130 _last_LNC_resizing_collection =
131 NEW_C_HEAP_ARRAY(int, max_covered_regions, mtGC);
132 if (_lowest_non_clean == NULL
133 || _lowest_non_clean_chunk_size == NULL
134 || _lowest_non_clean_base_chunk_index == NULL
135 || _last_LNC_resizing_collection == NULL)
136 vm_exit_during_initialization("couldn't allocate an LNC array.");
137 for (i = 0; i < max_covered_regions; i++) {
138 _lowest_non_clean[i] = NULL;
139 _lowest_non_clean_chunk_size[i] = 0;
275 // "guarded" is used for assertion checking below and recalls the fact
276 // that the would-be end of the new committed region would have
277 // penetrated the guard page.
278 HeapWord* new_end_for_commit = new_end_aligned;
279
280 DEBUG_ONLY(bool guarded = false;)
281 if (new_end_for_commit > _guard_region.start()) {
282 new_end_for_commit = _guard_region.start();
283 DEBUG_ONLY(guarded = true;)
284 }
285
286 if (new_end_for_commit > cur_committed.end()) {
287 // Must commit new pages.
288 MemRegion const new_committed =
289 MemRegion(cur_committed.end(), new_end_for_commit);
290
291 assert(!new_committed.is_empty(), "Region should not be empty here");
292 if (!os::commit_memory((char*)new_committed.start(),
293 new_committed.byte_size(), _page_size)) {
294 // Do better than this for Merlin
295 vm_exit_out_of_memory(new_committed.byte_size(),
296 "card table expansion");
297 }
298 // Use new_end_aligned (as opposed to new_end_for_commit) because
299 // the cur_committed region may include the guard region.
300 } else if (new_end_aligned < cur_committed.end()) {
301 // Must uncommit pages.
302 MemRegion const uncommit_region =
303 committed_unique_to_self(ind, MemRegion(new_end_aligned,
304 cur_committed.end()));
305 if (!uncommit_region.is_empty()) {
306 // It is not safe to uncommit cards if the boundary between
307 // the generations is moving. A shrink can uncommit cards
308 // owned by generation A but being used by generation B.
309 if (!UseAdaptiveGCBoundary) {
310 if (!os::uncommit_memory((char*)uncommit_region.start(),
311 uncommit_region.byte_size())) {
312 assert(false, "Card table contraction failed");
313 // The call failed so don't change the end of the
314 // committed region. This is better than taking the
315 // VM down.
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99 _page_size, heap_rs.base(), heap_rs.size());
100 if (!heap_rs.is_reserved()) {
101 vm_exit_during_initialization("Could not reserve enough space for the "
102 "card marking array");
103 }
104
105 // The assember store_check code will do an unsigned shift of the oop,
106 // then add it to byte_map_base, i.e.
107 //
108 // _byte_map = byte_map_base + (uintptr_t(low_bound) >> card_shift)
109 _byte_map = (jbyte*) heap_rs.base();
110 byte_map_base = _byte_map - (uintptr_t(low_bound) >> card_shift);
111 assert(byte_for(low_bound) == &_byte_map[0], "Checking start of map");
112 assert(byte_for(high_bound-1) <= &_byte_map[_last_valid_index], "Checking end of map");
113
114 jbyte* guard_card = &_byte_map[_guard_index];
115 uintptr_t guard_page = align_size_down((uintptr_t)guard_card, _page_size);
116 _guard_region = MemRegion((HeapWord*)guard_page, _page_size);
117 if (!os::commit_memory((char*)guard_page, _page_size, _page_size)) {
118 // Do better than this for Merlin
119 vm_exit_out_of_memory(_page_size, OOM_MMAP_ERROR, "card table last card");
120 }
121
122 *guard_card = last_card;
123
124 _lowest_non_clean =
125 NEW_C_HEAP_ARRAY(CardArr, max_covered_regions, mtGC);
126 _lowest_non_clean_chunk_size =
127 NEW_C_HEAP_ARRAY(size_t, max_covered_regions, mtGC);
128 _lowest_non_clean_base_chunk_index =
129 NEW_C_HEAP_ARRAY(uintptr_t, max_covered_regions, mtGC);
130 _last_LNC_resizing_collection =
131 NEW_C_HEAP_ARRAY(int, max_covered_regions, mtGC);
132 if (_lowest_non_clean == NULL
133 || _lowest_non_clean_chunk_size == NULL
134 || _lowest_non_clean_base_chunk_index == NULL
135 || _last_LNC_resizing_collection == NULL)
136 vm_exit_during_initialization("couldn't allocate an LNC array.");
137 for (i = 0; i < max_covered_regions; i++) {
138 _lowest_non_clean[i] = NULL;
139 _lowest_non_clean_chunk_size[i] = 0;
275 // "guarded" is used for assertion checking below and recalls the fact
276 // that the would-be end of the new committed region would have
277 // penetrated the guard page.
278 HeapWord* new_end_for_commit = new_end_aligned;
279
280 DEBUG_ONLY(bool guarded = false;)
281 if (new_end_for_commit > _guard_region.start()) {
282 new_end_for_commit = _guard_region.start();
283 DEBUG_ONLY(guarded = true;)
284 }
285
286 if (new_end_for_commit > cur_committed.end()) {
287 // Must commit new pages.
288 MemRegion const new_committed =
289 MemRegion(cur_committed.end(), new_end_for_commit);
290
291 assert(!new_committed.is_empty(), "Region should not be empty here");
292 if (!os::commit_memory((char*)new_committed.start(),
293 new_committed.byte_size(), _page_size)) {
294 // Do better than this for Merlin
295 vm_exit_out_of_memory(new_committed.byte_size(), OOM_MMAP_ERROR,
296 "card table expansion");
297 }
298 // Use new_end_aligned (as opposed to new_end_for_commit) because
299 // the cur_committed region may include the guard region.
300 } else if (new_end_aligned < cur_committed.end()) {
301 // Must uncommit pages.
302 MemRegion const uncommit_region =
303 committed_unique_to_self(ind, MemRegion(new_end_aligned,
304 cur_committed.end()));
305 if (!uncommit_region.is_empty()) {
306 // It is not safe to uncommit cards if the boundary between
307 // the generations is moving. A shrink can uncommit cards
308 // owned by generation A but being used by generation B.
309 if (!UseAdaptiveGCBoundary) {
310 if (!os::uncommit_memory((char*)uncommit_region.start(),
311 uncommit_region.byte_size())) {
312 assert(false, "Card table contraction failed");
313 // The call failed so don't change the end of the
314 // committed region. This is better than taking the
315 // VM down.
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