2174   HeapRegion* dummy_region = new_heap_region(0 /* index of bottom region */,
2175                                              _g1_reserved.start());
2176   // We'll re-use the same region whether the alloc region will
2177   // require BOT updates or not and, if it doesn't, then a non-young
2178   // region will complain that it cannot support allocations without
2179   // BOT updates. So we'll tag the dummy region as young to avoid that.
2180   dummy_region->set_young();
2181   // Make sure it's full.
2182   dummy_region->set_top(dummy_region->end());
2183   G1AllocRegion::setup(this, dummy_region);
2184 
2185   init_mutator_alloc_region();
2186 
2187   // Do create of the monitoring and management support so that
2188   // values in the heap have been properly initialized.
2189   _g1mm = new G1MonitoringSupport(this);
2190 
2191   return JNI_OK;
2192 }
2193 
2194 size_t G1CollectedHeap::conservative_max_heap_alignment() {
2195   return HeapRegion::max_region_size();
2196 }
2197 
2198 void G1CollectedHeap::ref_processing_init() {
2199   // Reference processing in G1 currently works as follows:
2200   //
2201   // * There are two reference processor instances. One is
2202   //   used to record and process discovered references
2203   //   during concurrent marking; the other is used to
2204   //   record and process references during STW pauses
2205   //   (both full and incremental).
2206   // * Both ref processors need to 'span' the entire heap as
2207   //   the regions in the collection set may be dotted around.
2208   //
2209   // * For the concurrent marking ref processor:
2210   //   * Reference discovery is enabled at initial marking.
2211   //   * Reference discovery is disabled and the discovered
2212   //     references processed etc during remarking.
2213   //   * Reference discovery is MT (see below).
2214   //   * Reference discovery requires a barrier (see below).
2215   //   * Reference processing may or may not be MT
2216   //     (depending on the value of ParallelRefProcEnabled
2217   //     and ParallelGCThreads).

2174   HeapRegion* dummy_region = new_heap_region(0 /* index of bottom region */,
2175                                              _g1_reserved.start());
2176   // We'll re-use the same region whether the alloc region will
2177   // require BOT updates or not and, if it doesn't, then a non-young
2178   // region will complain that it cannot support allocations without
2179   // BOT updates. So we'll tag the dummy region as young to avoid that.
2180   dummy_region->set_young();
2181   // Make sure it's full.
2182   dummy_region->set_top(dummy_region->end());
2183   G1AllocRegion::setup(this, dummy_region);
2184 
2185   init_mutator_alloc_region();
2186 
2187   // Do create of the monitoring and management support so that
2188   // values in the heap have been properly initialized.
2189   _g1mm = new G1MonitoringSupport(this);
2190 
2191   return JNI_OK;
2192 }
2193 




2194 void G1CollectedHeap::ref_processing_init() {
2195   // Reference processing in G1 currently works as follows:
2196   //
2197   // * There are two reference processor instances. One is
2198   //   used to record and process discovered references
2199   //   during concurrent marking; the other is used to
2200   //   record and process references during STW pauses
2201   //   (both full and incremental).
2202   // * Both ref processors need to 'span' the entire heap as
2203   //   the regions in the collection set may be dotted around.
2204   //
2205   // * For the concurrent marking ref processor:
2206   //   * Reference discovery is enabled at initial marking.
2207   //   * Reference discovery is disabled and the discovered
2208   //     references processed etc during remarking.
2209   //   * Reference discovery is MT (see below).
2210   //   * Reference discovery requires a barrier (see below).
2211   //   * Reference processing may or may not be MT
2212   //     (depending on the value of ParallelRefProcEnabled
2213   //     and ParallelGCThreads).