86 // Allocate the mark sweep views of spaces
87 _eden_mark_sweep =
88 new PSMarkSweepDecorator(_eden_space, NULL, MarkSweepDeadRatio);
89 _from_mark_sweep =
90 new PSMarkSweepDecorator(_from_space, NULL, MarkSweepDeadRatio);
91 _to_mark_sweep =
92 new PSMarkSweepDecorator(_to_space, NULL, MarkSweepDeadRatio);
93
94 if (_eden_mark_sweep == NULL ||
95 _from_mark_sweep == NULL ||
96 _to_mark_sweep == NULL) {
97 vm_exit_during_initialization("Could not complete allocation"
98 " of the young generation");
99 }
100
101 // Generation Counters - generation 0, 3 subspaces
102 _gen_counters = new PSGenerationCounters("new", 0, 3, _virtual_space);
103
104 // Compute maximum space sizes for performance counters
105 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
106 size_t alignment = heap->intra_heap_alignment();
107 size_t size = virtual_space()->reserved_size();
108
109 size_t max_survivor_size;
110 size_t max_eden_size;
111
112 if (UseAdaptiveSizePolicy) {
113 max_survivor_size = size / MinSurvivorRatio;
114
115 // round the survivor space size down to the nearest alignment
116 // and make sure its size is greater than 0.
117 max_survivor_size = align_size_down(max_survivor_size, alignment);
118 max_survivor_size = MAX2(max_survivor_size, alignment);
119
120 // set the maximum size of eden to be the size of the young gen
121 // less two times the minimum survivor size. The minimum survivor
122 // size for UseAdaptiveSizePolicy is one alignment.
123 max_eden_size = size - 2 * alignment;
124 } else {
125 max_survivor_size = size / InitialSurvivorRatio;
126
139 // is the point where eden reachs its maximum size. At this point,
140 // the size of a survivor space is max_survivor_size.
141 max_eden_size = size - 2 * max_survivor_size;
142 }
143
144 _eden_counters = new SpaceCounters("eden", 0, max_eden_size, _eden_space,
145 _gen_counters);
146 _from_counters = new SpaceCounters("s0", 1, max_survivor_size, _from_space,
147 _gen_counters);
148 _to_counters = new SpaceCounters("s1", 2, max_survivor_size, _to_space,
149 _gen_counters);
150
151 compute_initial_space_boundaries();
152 }
153
154 void PSYoungGen::compute_initial_space_boundaries() {
155 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
156 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
157
158 // Compute sizes
159 size_t alignment = heap->intra_heap_alignment();
160 size_t size = virtual_space()->committed_size();
161
162 size_t survivor_size = size / InitialSurvivorRatio;
163 survivor_size = align_size_down(survivor_size, alignment);
164 // ... but never less than an alignment
165 survivor_size = MAX2(survivor_size, alignment);
166
167 // Young generation is eden + 2 survivor spaces
168 size_t eden_size = size - (2 * survivor_size);
169
170 // Now go ahead and set 'em.
171 set_space_boundaries(eden_size, survivor_size);
172 space_invariants();
173
174 if (UsePerfData) {
175 _eden_counters->update_capacity();
176 _from_counters->update_capacity();
177 _to_counters->update_capacity();
178 }
179 }
180
190 char *from_start = to_start + survivor_size;
191 char *from_end = from_start + survivor_size;
192
193 assert(from_end == virtual_space()->high(), "just checking");
194 assert(is_object_aligned((intptr_t)eden_start), "checking alignment");
195 assert(is_object_aligned((intptr_t)to_start), "checking alignment");
196 assert(is_object_aligned((intptr_t)from_start), "checking alignment");
197
198 MemRegion eden_mr((HeapWord*)eden_start, (HeapWord*)to_start);
199 MemRegion to_mr ((HeapWord*)to_start, (HeapWord*)from_start);
200 MemRegion from_mr((HeapWord*)from_start, (HeapWord*)from_end);
201
202 eden_space()->initialize(eden_mr, true, ZapUnusedHeapArea);
203 to_space()->initialize(to_mr , true, ZapUnusedHeapArea);
204 from_space()->initialize(from_mr, true, ZapUnusedHeapArea);
205 }
206
207 #ifndef PRODUCT
208 void PSYoungGen::space_invariants() {
209 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
210 const size_t alignment = heap->intra_heap_alignment();
211
212 // Currently, our eden size cannot shrink to zero
213 guarantee(eden_space()->capacity_in_bytes() >= alignment, "eden too small");
214 guarantee(from_space()->capacity_in_bytes() >= alignment, "from too small");
215 guarantee(to_space()->capacity_in_bytes() >= alignment, "to too small");
216
217 // Relationship of spaces to each other
218 char* eden_start = (char*)eden_space()->bottom();
219 char* eden_end = (char*)eden_space()->end();
220 char* from_start = (char*)from_space()->bottom();
221 char* from_end = (char*)from_space()->end();
222 char* to_start = (char*)to_space()->bottom();
223 char* to_end = (char*)to_space()->end();
224
225 guarantee(eden_start >= virtual_space()->low(), "eden bottom");
226 guarantee(eden_start < eden_end, "eden space consistency");
227 guarantee(from_start < from_end, "from space consistency");
228 guarantee(to_start < to_end, "to space consistency");
229
230 // Check whether from space is below to space
474 }
475
476 // There's nothing to do if the new sizes are the same as the current
477 if (requested_survivor_size == to_space()->capacity_in_bytes() &&
478 requested_survivor_size == from_space()->capacity_in_bytes() &&
479 requested_eden_size == eden_space()->capacity_in_bytes()) {
480 if (PrintAdaptiveSizePolicy && Verbose) {
481 gclog_or_tty->print_cr(" capacities are the right sizes, returning");
482 }
483 return;
484 }
485
486 char* eden_start = (char*)eden_space()->bottom();
487 char* eden_end = (char*)eden_space()->end();
488 char* from_start = (char*)from_space()->bottom();
489 char* from_end = (char*)from_space()->end();
490 char* to_start = (char*)to_space()->bottom();
491 char* to_end = (char*)to_space()->end();
492
493 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
494 const size_t alignment = heap->intra_heap_alignment();
495 const bool maintain_minimum =
496 (requested_eden_size + 2 * requested_survivor_size) <= min_gen_size();
497
498 bool eden_from_to_order = from_start < to_start;
499 // Check whether from space is below to space
500 if (eden_from_to_order) {
501 // Eden, from, to
502 eden_from_to_order = true;
503 if (PrintAdaptiveSizePolicy && Verbose) {
504 gclog_or_tty->print_cr(" Eden, from, to:");
505 }
506
507 // Set eden
508 // "requested_eden_size" is a goal for the size of eden
509 // and may not be attainable. "eden_size" below is
510 // calculated based on the location of from-space and
511 // the goal for the size of eden. from-space is
512 // fixed in place because it contains live data.
513 // The calculation is done this way to avoid 32bit
514 // overflow (i.e., eden_start + requested_eden_size
823 ShouldNotReachHere();
824 return 0;
825 }
826
827 size_t PSYoungGen::available_for_contraction() {
828 ShouldNotReachHere();
829 return 0;
830 }
831
832 size_t PSYoungGen::available_to_min_gen() {
833 assert(virtual_space()->committed_size() >= min_gen_size(), "Invariant");
834 return virtual_space()->committed_size() - min_gen_size();
835 }
836
837 // This method assumes that from-space has live data and that
838 // any shrinkage of the young gen is limited by location of
839 // from-space.
840 size_t PSYoungGen::available_to_live() {
841 size_t delta_in_survivor = 0;
842 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
843 const size_t space_alignment = heap->intra_heap_alignment();
844 const size_t gen_alignment = heap->young_gen_alignment();
845
846 MutableSpace* space_shrinking = NULL;
847 if (from_space()->end() > to_space()->end()) {
848 space_shrinking = from_space();
849 } else {
850 space_shrinking = to_space();
851 }
852
853 // Include any space that is committed but not included in
854 // the survivor spaces.
855 assert(((HeapWord*)virtual_space()->high()) >= space_shrinking->end(),
856 "Survivor space beyond high end");
857 size_t unused_committed = pointer_delta(virtual_space()->high(),
858 space_shrinking->end(), sizeof(char));
859
860 if (space_shrinking->is_empty()) {
861 // Don't let the space shrink to 0
862 assert(space_shrinking->capacity_in_bytes() >= space_alignment,
863 "Space is too small");
864 delta_in_survivor = space_shrinking->capacity_in_bytes() - space_alignment;
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86 // Allocate the mark sweep views of spaces
87 _eden_mark_sweep =
88 new PSMarkSweepDecorator(_eden_space, NULL, MarkSweepDeadRatio);
89 _from_mark_sweep =
90 new PSMarkSweepDecorator(_from_space, NULL, MarkSweepDeadRatio);
91 _to_mark_sweep =
92 new PSMarkSweepDecorator(_to_space, NULL, MarkSweepDeadRatio);
93
94 if (_eden_mark_sweep == NULL ||
95 _from_mark_sweep == NULL ||
96 _to_mark_sweep == NULL) {
97 vm_exit_during_initialization("Could not complete allocation"
98 " of the young generation");
99 }
100
101 // Generation Counters - generation 0, 3 subspaces
102 _gen_counters = new PSGenerationCounters("new", 0, 3, _virtual_space);
103
104 // Compute maximum space sizes for performance counters
105 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
106 size_t alignment = heap->space_alignment();
107 size_t size = virtual_space()->reserved_size();
108
109 size_t max_survivor_size;
110 size_t max_eden_size;
111
112 if (UseAdaptiveSizePolicy) {
113 max_survivor_size = size / MinSurvivorRatio;
114
115 // round the survivor space size down to the nearest alignment
116 // and make sure its size is greater than 0.
117 max_survivor_size = align_size_down(max_survivor_size, alignment);
118 max_survivor_size = MAX2(max_survivor_size, alignment);
119
120 // set the maximum size of eden to be the size of the young gen
121 // less two times the minimum survivor size. The minimum survivor
122 // size for UseAdaptiveSizePolicy is one alignment.
123 max_eden_size = size - 2 * alignment;
124 } else {
125 max_survivor_size = size / InitialSurvivorRatio;
126
139 // is the point where eden reachs its maximum size. At this point,
140 // the size of a survivor space is max_survivor_size.
141 max_eden_size = size - 2 * max_survivor_size;
142 }
143
144 _eden_counters = new SpaceCounters("eden", 0, max_eden_size, _eden_space,
145 _gen_counters);
146 _from_counters = new SpaceCounters("s0", 1, max_survivor_size, _from_space,
147 _gen_counters);
148 _to_counters = new SpaceCounters("s1", 2, max_survivor_size, _to_space,
149 _gen_counters);
150
151 compute_initial_space_boundaries();
152 }
153
154 void PSYoungGen::compute_initial_space_boundaries() {
155 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
156 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
157
158 // Compute sizes
159 size_t alignment = heap->space_alignment();
160 size_t size = virtual_space()->committed_size();
161 assert(size >= 3 * alignment, "Young space is not large enough for eden + 2 survivors");
162
163 size_t survivor_size = size / InitialSurvivorRatio;
164 survivor_size = align_size_down(survivor_size, alignment);
165 // ... but never less than an alignment
166 survivor_size = MAX2(survivor_size, alignment);
167
168 // Young generation is eden + 2 survivor spaces
169 size_t eden_size = size - (2 * survivor_size);
170
171 // Now go ahead and set 'em.
172 set_space_boundaries(eden_size, survivor_size);
173 space_invariants();
174
175 if (UsePerfData) {
176 _eden_counters->update_capacity();
177 _from_counters->update_capacity();
178 _to_counters->update_capacity();
179 }
180 }
181
191 char *from_start = to_start + survivor_size;
192 char *from_end = from_start + survivor_size;
193
194 assert(from_end == virtual_space()->high(), "just checking");
195 assert(is_object_aligned((intptr_t)eden_start), "checking alignment");
196 assert(is_object_aligned((intptr_t)to_start), "checking alignment");
197 assert(is_object_aligned((intptr_t)from_start), "checking alignment");
198
199 MemRegion eden_mr((HeapWord*)eden_start, (HeapWord*)to_start);
200 MemRegion to_mr ((HeapWord*)to_start, (HeapWord*)from_start);
201 MemRegion from_mr((HeapWord*)from_start, (HeapWord*)from_end);
202
203 eden_space()->initialize(eden_mr, true, ZapUnusedHeapArea);
204 to_space()->initialize(to_mr , true, ZapUnusedHeapArea);
205 from_space()->initialize(from_mr, true, ZapUnusedHeapArea);
206 }
207
208 #ifndef PRODUCT
209 void PSYoungGen::space_invariants() {
210 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
211 const size_t alignment = heap->space_alignment();
212
213 // Currently, our eden size cannot shrink to zero
214 guarantee(eden_space()->capacity_in_bytes() >= alignment, "eden too small");
215 guarantee(from_space()->capacity_in_bytes() >= alignment, "from too small");
216 guarantee(to_space()->capacity_in_bytes() >= alignment, "to too small");
217
218 // Relationship of spaces to each other
219 char* eden_start = (char*)eden_space()->bottom();
220 char* eden_end = (char*)eden_space()->end();
221 char* from_start = (char*)from_space()->bottom();
222 char* from_end = (char*)from_space()->end();
223 char* to_start = (char*)to_space()->bottom();
224 char* to_end = (char*)to_space()->end();
225
226 guarantee(eden_start >= virtual_space()->low(), "eden bottom");
227 guarantee(eden_start < eden_end, "eden space consistency");
228 guarantee(from_start < from_end, "from space consistency");
229 guarantee(to_start < to_end, "to space consistency");
230
231 // Check whether from space is below to space
475 }
476
477 // There's nothing to do if the new sizes are the same as the current
478 if (requested_survivor_size == to_space()->capacity_in_bytes() &&
479 requested_survivor_size == from_space()->capacity_in_bytes() &&
480 requested_eden_size == eden_space()->capacity_in_bytes()) {
481 if (PrintAdaptiveSizePolicy && Verbose) {
482 gclog_or_tty->print_cr(" capacities are the right sizes, returning");
483 }
484 return;
485 }
486
487 char* eden_start = (char*)eden_space()->bottom();
488 char* eden_end = (char*)eden_space()->end();
489 char* from_start = (char*)from_space()->bottom();
490 char* from_end = (char*)from_space()->end();
491 char* to_start = (char*)to_space()->bottom();
492 char* to_end = (char*)to_space()->end();
493
494 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
495 const size_t alignment = heap->space_alignment();
496 const bool maintain_minimum =
497 (requested_eden_size + 2 * requested_survivor_size) <= min_gen_size();
498
499 bool eden_from_to_order = from_start < to_start;
500 // Check whether from space is below to space
501 if (eden_from_to_order) {
502 // Eden, from, to
503 eden_from_to_order = true;
504 if (PrintAdaptiveSizePolicy && Verbose) {
505 gclog_or_tty->print_cr(" Eden, from, to:");
506 }
507
508 // Set eden
509 // "requested_eden_size" is a goal for the size of eden
510 // and may not be attainable. "eden_size" below is
511 // calculated based on the location of from-space and
512 // the goal for the size of eden. from-space is
513 // fixed in place because it contains live data.
514 // The calculation is done this way to avoid 32bit
515 // overflow (i.e., eden_start + requested_eden_size
824 ShouldNotReachHere();
825 return 0;
826 }
827
828 size_t PSYoungGen::available_for_contraction() {
829 ShouldNotReachHere();
830 return 0;
831 }
832
833 size_t PSYoungGen::available_to_min_gen() {
834 assert(virtual_space()->committed_size() >= min_gen_size(), "Invariant");
835 return virtual_space()->committed_size() - min_gen_size();
836 }
837
838 // This method assumes that from-space has live data and that
839 // any shrinkage of the young gen is limited by location of
840 // from-space.
841 size_t PSYoungGen::available_to_live() {
842 size_t delta_in_survivor = 0;
843 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
844 const size_t space_alignment = heap->space_alignment();
845 const size_t gen_alignment = heap->generation_alignment();
846
847 MutableSpace* space_shrinking = NULL;
848 if (from_space()->end() > to_space()->end()) {
849 space_shrinking = from_space();
850 } else {
851 space_shrinking = to_space();
852 }
853
854 // Include any space that is committed but not included in
855 // the survivor spaces.
856 assert(((HeapWord*)virtual_space()->high()) >= space_shrinking->end(),
857 "Survivor space beyond high end");
858 size_t unused_committed = pointer_delta(virtual_space()->high(),
859 space_shrinking->end(), sizeof(char));
860
861 if (space_shrinking->is_empty()) {
862 // Don't let the space shrink to 0
863 assert(space_shrinking->capacity_in_bytes() >= space_alignment,
864 "Space is too small");
865 delta_in_survivor = space_shrinking->capacity_in_bytes() - space_alignment;
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