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 #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONLAB_HPP
  26 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONLAB_HPP
  27 
  28 #include "gc_implementation/parallelScavenge/objectStartArray.hpp"
  29 #include "gc_interface/collectedHeap.hpp"
  30 #include "memory/allocation.hpp"
  31 
  32 //
  33 // PSPromotionLAB is a parallel scavenge promotion lab. This class acts very
  34 // much like a MutableSpace. We couldn't embed a MutableSpace, though, as
  35 // it has a considerable number of asserts and invariants that are violated.
  36 //
  37 
  38 class ObjectStartArray;
  39 
  40 class PSPromotionLAB : public CHeapObj<mtGC> {
  41  protected:
  42   static size_t filler_header_size;
  43 
  44   enum LabState {
  45     needs_flush,
  46     flushed,
  47     zero_size
  48   };
  49 

 117     // Cannot test for this now that we're doing promotion failures
 118     // assert(_state != flushed, "Sanity");
 119     assert(_start_array != NULL, "Sanity");
 120     HeapWord* obj = top();
 121     HeapWord* new_top = obj + size;
 122     // The 'new_top>obj' check is needed to detect overflow of obj+size.
 123     if (new_top > obj && new_top <= end()) {
 124       set_top(new_top);
 125       assert(is_object_aligned((intptr_t)obj) && is_object_aligned((intptr_t)new_top),
 126              "checking alignment");
 127       _start_array->allocate_block(obj);
 128       return obj;
 129     }
 130 
 131     return NULL;
 132   }
 133 
 134   debug_only(virtual bool lab_is_valid(MemRegion lab));
 135 };
 136 
 137 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONLAB_HPP

   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 #ifndef SHARE_VM_GC_PARALLEL_PSPROMOTIONLAB_HPP
  26 #define SHARE_VM_GC_PARALLEL_PSPROMOTIONLAB_HPP
  27 
  28 #include "gc/parallel/objectStartArray.hpp"
  29 #include "gc/shared/collectedHeap.hpp"
  30 #include "memory/allocation.hpp"
  31 
  32 //
  33 // PSPromotionLAB is a parallel scavenge promotion lab. This class acts very
  34 // much like a MutableSpace. We couldn't embed a MutableSpace, though, as
  35 // it has a considerable number of asserts and invariants that are violated.
  36 //
  37 
  38 class ObjectStartArray;
  39 
  40 class PSPromotionLAB : public CHeapObj<mtGC> {
  41  protected:
  42   static size_t filler_header_size;
  43 
  44   enum LabState {
  45     needs_flush,
  46     flushed,
  47     zero_size
  48   };
  49 

 117     // Cannot test for this now that we're doing promotion failures
 118     // assert(_state != flushed, "Sanity");
 119     assert(_start_array != NULL, "Sanity");
 120     HeapWord* obj = top();
 121     HeapWord* new_top = obj + size;
 122     // The 'new_top>obj' check is needed to detect overflow of obj+size.
 123     if (new_top > obj && new_top <= end()) {
 124       set_top(new_top);
 125       assert(is_object_aligned((intptr_t)obj) && is_object_aligned((intptr_t)new_top),
 126              "checking alignment");
 127       _start_array->allocate_block(obj);
 128       return obj;
 129     }
 130 
 131     return NULL;
 132   }
 133 
 134   debug_only(virtual bool lab_is_valid(MemRegion lab));
 135 };
 136 
 137 #endif // SHARE_VM_GC_PARALLEL_PSPROMOTIONLAB_HPP