2164   HeapRegion* dummy_region = new_heap_region(0 /* index of bottom region */,
2165                                              _g1_reserved.start());
2166   // We'll re-use the same region whether the alloc region will
2167   // require BOT updates or not and, if it doesn't, then a non-young
2168   // region will complain that it cannot support allocations without
2169   // BOT updates. So we'll tag the dummy region as young to avoid that.
2170   dummy_region->set_young();
2171   // Make sure it's full.
2172   dummy_region->set_top(dummy_region->end());
2173   G1AllocRegion::setup(this, dummy_region);
2174 
2175   init_mutator_alloc_region();
2176 
2177   // Do create of the monitoring and management support so that
2178   // values in the heap have been properly initialized.
2179   _g1mm = new G1MonitoringSupport(this);
2180 
2181   return JNI_OK;
2182 }
2183 
2184 size_t G1CollectedHeap::conservative_max_heap_alignment() {
2185   return HeapRegion::max_region_size();
2186 }
2187 
2188 void G1CollectedHeap::ref_processing_init() {
2189   // Reference processing in G1 currently works as follows:
2190   //
2191   // * There are two reference processor instances. One is
2192   //   used to record and process discovered references
2193   //   during concurrent marking; the other is used to
2194   //   record and process references during STW pauses
2195   //   (both full and incremental).
2196   // * Both ref processors need to 'span' the entire heap as
2197   //   the regions in the collection set may be dotted around.
2198   //
2199   // * For the concurrent marking ref processor:
2200   //   * Reference discovery is enabled at initial marking.
2201   //   * Reference discovery is disabled and the discovered
2202   //     references processed etc during remarking.
2203   //   * Reference discovery is MT (see below).
2204   //   * Reference discovery requires a barrier (see below).
2205   //   * Reference processing may or may not be MT
2206   //     (depending on the value of ParallelRefProcEnabled
2207   //     and ParallelGCThreads).

2164   HeapRegion* dummy_region = new_heap_region(0 /* index of bottom region */,
2165                                              _g1_reserved.start());
2166   // We'll re-use the same region whether the alloc region will
2167   // require BOT updates or not and, if it doesn't, then a non-young
2168   // region will complain that it cannot support allocations without
2169   // BOT updates. So we'll tag the dummy region as young to avoid that.
2170   dummy_region->set_young();
2171   // Make sure it's full.
2172   dummy_region->set_top(dummy_region->end());
2173   G1AllocRegion::setup(this, dummy_region);
2174 
2175   init_mutator_alloc_region();
2176 
2177   // Do create of the monitoring and management support so that
2178   // values in the heap have been properly initialized.
2179   _g1mm = new G1MonitoringSupport(this);
2180 
2181   return JNI_OK;
2182 }
2183 




2184 void G1CollectedHeap::ref_processing_init() {
2185   // Reference processing in G1 currently works as follows:
2186   //
2187   // * There are two reference processor instances. One is
2188   //   used to record and process discovered references
2189   //   during concurrent marking; the other is used to
2190   //   record and process references during STW pauses
2191   //   (both full and incremental).
2192   // * Both ref processors need to 'span' the entire heap as
2193   //   the regions in the collection set may be dotted around.
2194   //
2195   // * For the concurrent marking ref processor:
2196   //   * Reference discovery is enabled at initial marking.
2197   //   * Reference discovery is disabled and the discovered
2198   //     references processed etc during remarking.
2199   //   * Reference discovery is MT (see below).
2200   //   * Reference discovery requires a barrier (see below).
2201   //   * Reference processing may or may not be MT
2202   //     (depending on the value of ParallelRefProcEnabled
2203   //     and ParallelGCThreads).