98     _old_gen = new PSOldGen(init_low_byte_size,
  99                             min_low_byte_size,
 100                             max_low_byte_size,
 101                             "old", 1);
 102 
 103     // The virtual spaces are created by the initialization of the gens.
 104     _young_gen->initialize(young_rs, alignment);
 105     assert(young_gen()->gen_size_limit() == young_rs.size(),
 106       "Consistency check");
 107     _old_gen->initialize(old_rs, alignment, "old", 1);
 108     assert(old_gen()->gen_size_limit() == old_rs.size(), "Consistency check");
 109   }
 110 }
 111 
 112 size_t AdjoiningGenerations::reserved_byte_size() {
 113   return virtual_spaces()->reserved_space().size();
 114 }
 115 
 116 
 117 // Make checks on the current sizes of the generations and
 118 // the contraints on the sizes of the generations.  Push
 119 // up the boundary within the contraints.  A partial
 120 // push can occur.
 121 void AdjoiningGenerations::request_old_gen_expansion(size_t expand_in_bytes) {
 122   assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check");
 123 
 124   assert_lock_strong(ExpandHeap_lock);
 125   assert_locked_or_safepoint(Heap_lock);
 126 
 127   // These sizes limit the amount the boundaries can move.  Effectively,
 128   // the generation says how much it is willing to yield to the other
 129   // generation.
 130   const size_t young_gen_available = young_gen()->available_for_contraction();
 131   const size_t old_gen_available = old_gen()->available_for_expansion();
 132   const size_t alignment = virtual_spaces()->alignment();
 133   size_t change_in_bytes = MIN3(young_gen_available,
 134                                 old_gen_available,
 135                                 align_size_up_(expand_in_bytes, alignment));
 136 
 137   if (change_in_bytes == 0) {
 138     return;
 139   }

  98     _old_gen = new PSOldGen(init_low_byte_size,
  99                             min_low_byte_size,
 100                             max_low_byte_size,
 101                             "old", 1);
 102 
 103     // The virtual spaces are created by the initialization of the gens.
 104     _young_gen->initialize(young_rs, alignment);
 105     assert(young_gen()->gen_size_limit() == young_rs.size(),
 106       "Consistency check");
 107     _old_gen->initialize(old_rs, alignment, "old", 1);
 108     assert(old_gen()->gen_size_limit() == old_rs.size(), "Consistency check");
 109   }
 110 }
 111 
 112 size_t AdjoiningGenerations::reserved_byte_size() {
 113   return virtual_spaces()->reserved_space().size();
 114 }
 115 
 116 
 117 // Make checks on the current sizes of the generations and
 118 // the constraints on the sizes of the generations.  Push
 119 // up the boundary within the constraints.  A partial
 120 // push can occur.
 121 void AdjoiningGenerations::request_old_gen_expansion(size_t expand_in_bytes) {
 122   assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check");
 123 
 124   assert_lock_strong(ExpandHeap_lock);
 125   assert_locked_or_safepoint(Heap_lock);
 126 
 127   // These sizes limit the amount the boundaries can move.  Effectively,
 128   // the generation says how much it is willing to yield to the other
 129   // generation.
 130   const size_t young_gen_available = young_gen()->available_for_contraction();
 131   const size_t old_gen_available = old_gen()->available_for_expansion();
 132   const size_t alignment = virtual_spaces()->alignment();
 133   size_t change_in_bytes = MIN3(young_gen_available,
 134                                 old_gen_available,
 135                                 align_size_up_(expand_in_bytes, alignment));
 136 
 137   if (change_in_bytes == 0) {
 138     return;
 139   }