--- a/src/share/vm/gc_implementation/g1/g1MonitoringSupport.cpp	Thu Sep 22 10:57:37 2011 -0700
+++ b/src/share/vm/gc_implementation/g1/g1MonitoringSupport.cpp	Fri Sep 23 16:07:49 2011 -0400
@@ -27,19 +27,69 @@
 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
 
-G1MonitoringSupport::G1MonitoringSupport(G1CollectedHeap* g1h,
-                                         VirtualSpace* g1_storage_addr) :
+G1GenerationCounters::G1GenerationCounters(G1MonitoringSupport* g1mm,
+                                           const char* name,
+                                           int ordinal, int spaces,
+                                           size_t min_capacity,
+                                           size_t max_capacity,
+                                           size_t curr_capacity)
+  : GenerationCounters(name, ordinal, spaces, min_capacity,
+                       max_capacity, curr_capacity), _g1mm(g1mm) { }
+
+// We pad the capacity three times given that the young generation
+// contains three spaces (eden and two survivors).
+G1YoungGenerationCounters::G1YoungGenerationCounters(G1MonitoringSupport* g1mm,
+                                                     const char* name)
+  : G1GenerationCounters(g1mm, name, 0 /* ordinal */, 3 /* spaces */,
+               G1MonitoringSupport::pad_capacity(0, 3) /* min_capacity */,
+               G1MonitoringSupport::pad_capacity(g1mm->young_gen_max(), 3),
+               G1MonitoringSupport::pad_capacity(0, 3) /* curr_capacity */) {
+  update_all();
+}
+
+G1OldGenerationCounters::G1OldGenerationCounters(G1MonitoringSupport* g1mm,
+                                                 const char* name)
+  : G1GenerationCounters(g1mm, name, 1 /* ordinal */, 1 /* spaces */,
+               G1MonitoringSupport::pad_capacity(0) /* min_capacity */,
+               G1MonitoringSupport::pad_capacity(g1mm->old_gen_max()),
+               G1MonitoringSupport::pad_capacity(0) /* curr_capacity */) {
+  update_all();
+}
+
+void G1YoungGenerationCounters::update_all() {
+  size_t committed =
+            G1MonitoringSupport::pad_capacity(_g1mm->young_gen_committed(), 3);
+  _current_size->set_value(committed);
+}
+
+void G1OldGenerationCounters::update_all() {
+  size_t committed =
+            G1MonitoringSupport::pad_capacity(_g1mm->old_gen_committed());
+  _current_size->set_value(committed);
+}
+
+G1MonitoringSupport::G1MonitoringSupport(G1CollectedHeap* g1h) :
   _g1h(g1h),
   _incremental_collection_counters(NULL),
   _full_collection_counters(NULL),
-  _non_young_collection_counters(NULL),
+  _old_collection_counters(NULL),
   _old_space_counters(NULL),
   _young_collection_counters(NULL),
   _eden_counters(NULL),
   _from_counters(NULL),
   _to_counters(NULL),
-  _g1_storage_addr(g1_storage_addr)
-{
+
+  _overall_reserved(0),
+  _overall_committed(0),    _overall_used(0),
+  _young_region_num(0),
+  _young_gen_committed(0),
+  _eden_committed(0),       _eden_used(0),
+  _survivor_committed(0),   _survivor_used(0),
+  _old_committed(0),        _old_used(0) {
+
+  _overall_reserved = g1h->max_capacity();
+  recalculate_sizes();
+
   // Counters for GC collections
   //
   //  name "collector.0".  In a generational collector this would be the
@@ -69,110 +119,147 @@
   // generational GC terms.  The "1, 1" parameters are for
   // the n-th generation (=1) with 1 space.
   // Counters are created from minCapacity, maxCapacity, and capacity
-  _non_young_collection_counters =
-    new GenerationCounters("whole heap", 1, 1, _g1_storage_addr);
+  _old_collection_counters = new G1OldGenerationCounters(this, "old");
 
   //  name  "generation.1.space.0"
   // Counters are created from maxCapacity, capacity, initCapacity,
   // and used.
-  _old_space_counters = new HSpaceCounters("space", 0,
-    _g1h->max_capacity(), _g1h->capacity(), _non_young_collection_counters);
+  _old_space_counters = new HSpaceCounters("space", 0 /* ordinal */,
+    pad_capacity(overall_reserved()) /* max_capacity */,
+    pad_capacity(old_space_committed()) /* init_capacity */,
+   _old_collection_counters);
 
   //   Young collection set
   //  name "generation.0".  This is logically the young generation.
   //  The "0, 3" are paremeters for the n-th genertaion (=0) with 3 spaces.
-  // See  _non_young_collection_counters for additional counters
-  _young_collection_counters = new GenerationCounters("young", 0, 3, NULL);
+  // See  _old_collection_counters for additional counters
+  _young_collection_counters = new G1YoungGenerationCounters(this, "young");
 
-  // Replace "max_heap_byte_size() with maximum young gen size for
-  // g1Collectedheap
   //  name "generation.0.space.0"
   // See _old_space_counters for additional counters
-  _eden_counters = new HSpaceCounters("eden", 0,
-    _g1h->max_capacity(), eden_space_committed(),
+  _eden_counters = new HSpaceCounters("eden", 0 /* ordinal */,
+    pad_capacity(overall_reserved()) /* max_capacity */,
+    pad_capacity(eden_space_committed()) /* init_capacity */,
     _young_collection_counters);
 
   //  name "generation.0.space.1"
   // See _old_space_counters for additional counters
   // Set the arguments to indicate that this survivor space is not used.
-  _from_counters = new HSpaceCounters("s0", 1, (long) 0, (long) 0,
+  _from_counters = new HSpaceCounters("s0", 1 /* ordinal */,
+    pad_capacity(0) /* max_capacity */,
+    pad_capacity(0) /* init_capacity */,
     _young_collection_counters);
+  // Given that this survivor space is not used, we update it here
+  // once to reflect that its used space is 0 so that we don't have to
+  // worry about updating it again later.
+  _from_counters->update_used(0);
 
   //  name "generation.0.space.2"
   // See _old_space_counters for additional counters
-  _to_counters = new HSpaceCounters("s1", 2,
-    _g1h->max_capacity(),
-    survivor_space_committed(),
+  _to_counters = new HSpaceCounters("s1", 2 /* ordinal */,
+    pad_capacity(overall_reserved()) /* max_capacity */,
+    pad_capacity(survivor_space_committed()) /* init_capacity */,
     _young_collection_counters);
 }
 
-size_t G1MonitoringSupport::overall_committed() {
-  return g1h()->capacity();
-}
+void G1MonitoringSupport::recalculate_sizes() {
+  G1CollectedHeap* g1 = g1h();
+
+  // Recalculate all the sizes from scratch. We assume that this is
+  // called at a point where no concurrent updates to the various
+  // values we read here are possible (i.e., at a STW phase at the end
+  // of a GC).
 
-size_t G1MonitoringSupport::overall_used() {
-  return g1h()->used_unlocked();
-}
+  size_t young_list_length = g1->young_list()->length();
+  size_t survivor_list_length = g1->g1_policy()->recorded_survivor_regions();
+  assert(young_list_length >= survivor_list_length, "invariant");
+  size_t eden_list_length = young_list_length - survivor_list_length;
+  // Max length includes any potential extensions to the young gen
+  // we'll do when the GC locker is active.
+  size_t young_list_max_length = g1->g1_policy()->young_list_max_length();
+  assert(young_list_max_length >= survivor_list_length, "invariant");
+  size_t eden_list_max_length = young_list_max_length - survivor_list_length;
 
-size_t G1MonitoringSupport::eden_space_committed() {
-  return MAX2(eden_space_used(), (size_t) HeapRegion::GrainBytes);
-}
+  _overall_used = g1->used_unlocked();
+  _eden_used = eden_list_length * HeapRegion::GrainBytes;
+  _survivor_used = survivor_list_length * HeapRegion::GrainBytes;
+  _young_region_num = young_list_length;
+  _old_used = subtract_up_to_zero(_overall_used, _eden_used + _survivor_used);
+
+  // First calculate the committed sizes that can be calculated independently.
+  _survivor_committed = _survivor_used;
+  _old_committed = HeapRegion::align_up_to_region_byte_size(_old_used);
 
-size_t G1MonitoringSupport::eden_space_used() {
-  size_t young_list_length = g1h()->young_list()->length();
-  size_t eden_used = young_list_length * HeapRegion::GrainBytes;
-  size_t survivor_used = survivor_space_used();
-  eden_used = subtract_up_to_zero(eden_used, survivor_used);
-  return eden_used;
-}
+  // Next, start with the overall committed size.
+  _overall_committed = g1->capacity();
+  size_t committed = _overall_committed;
+
+  // Remove the committed size we have calculated so far (for the
+  // survivor and old space).
+  assert(committed >= (_survivor_committed + _old_committed), "sanity");
+  committed -= _survivor_committed + _old_committed;
+
+  // Next, calculate and remove the committed size for the eden.
+  _eden_committed = eden_list_max_length * HeapRegion::GrainBytes;
+  // Somewhat defensive: be robust in case there are inaccuracies in
+  // the calculations
+  _eden_committed = MIN2(_eden_committed, committed);
+  committed -= _eden_committed;
 
-size_t G1MonitoringSupport::survivor_space_committed() {
-  return MAX2(survivor_space_used(),
-              (size_t) HeapRegion::GrainBytes);
-}
+  // Finally, give the rest to the old space...
+  _old_committed += committed;
+  // ..and calculate the young gen committed.
+  _young_gen_committed = _eden_committed + _survivor_committed;
 
-size_t G1MonitoringSupport::survivor_space_used() {
-  size_t survivor_num = g1h()->g1_policy()->recorded_survivor_regions();
-  size_t survivor_used = survivor_num * HeapRegion::GrainBytes;
-  return survivor_used;
+  assert(_overall_committed ==
+         (_eden_committed + _survivor_committed + _old_committed),
+         "the committed sizes should add up");
+  // Somewhat defensive: cap the eden used size to make sure it
+  // never exceeds the committed size.
+  _eden_used = MIN2(_eden_used, _eden_committed);
+  // _survivor_committed and _old_committed are calculated in terms of
+  // the corresponding _*_used value, so the next two conditions
+  // should hold.
+  assert(_survivor_used <= _survivor_committed, "post-condition");
+  assert(_old_used <= _old_committed, "post-condition");
 }
 
-size_t G1MonitoringSupport::old_space_committed() {
-  size_t committed = overall_committed();
-  size_t eden_committed = eden_space_committed();
-  size_t survivor_committed = survivor_space_committed();
-  committed = subtract_up_to_zero(committed, eden_committed);
-  committed = subtract_up_to_zero(committed, survivor_committed);
-  committed = MAX2(committed, (size_t) HeapRegion::GrainBytes);
-  return committed;
-}
+void G1MonitoringSupport::recalculate_eden_size() {
+  G1CollectedHeap* g1 = g1h();
+
+  // When a new eden region is allocated, only the eden_used size is
+  // affected (since we have recalculated everything else at the last GC).
 
-// See the comment near the top of g1MonitoringSupport.hpp for
-// an explanation of these calculations for "used" and "capacity".
-size_t G1MonitoringSupport::old_space_used() {
-  size_t used = overall_used();
-  size_t eden_used = eden_space_used();
-  size_t survivor_used = survivor_space_used();
-  used = subtract_up_to_zero(used, eden_used);
-  used = subtract_up_to_zero(used, survivor_used);
-  return used;
-}
-
-void G1MonitoringSupport::update_counters() {
-  if (UsePerfData) {
-    eden_counters()->update_capacity(eden_space_committed());
-    eden_counters()->update_used(eden_space_used());
-    to_counters()->update_capacity(survivor_space_committed());
-    to_counters()->update_used(survivor_space_used());
-    old_space_counters()->update_capacity(old_space_committed());
-    old_space_counters()->update_used(old_space_used());
-    non_young_collection_counters()->update_all();
+  size_t young_region_num = g1h()->young_list()->length();
+  if (young_region_num > _young_region_num) {
+    size_t diff = young_region_num - _young_region_num;
+    _eden_used += diff * HeapRegion::GrainBytes;
+    // Somewhat defensive: cap the eden used size to make sure it
+    // never exceeds the committed size.
+    _eden_used = MIN2(_eden_used, _eden_committed);
+    _young_region_num = young_region_num;
   }
 }
 
-void G1MonitoringSupport::update_eden_counters() {
+void G1MonitoringSupport::update_sizes() {
+  recalculate_sizes();
   if (UsePerfData) {
-    eden_counters()->update_capacity(eden_space_committed());
+    eden_counters()->update_capacity(pad_capacity(eden_space_committed()));
+    eden_counters()->update_used(eden_space_used());
+    // only the to survivor space (s1) is active, so we don't need to
+    // update the counteres for the from survivor space (s0)
+    to_counters()->update_capacity(pad_capacity(survivor_space_committed()));
+    to_counters()->update_used(survivor_space_used());
+    old_space_counters()->update_capacity(pad_capacity(old_space_committed()));
+    old_space_counters()->update_used(old_space_used());
+    old_collection_counters()->update_all();
+    young_collection_counters()->update_all();
+  }
+}
+
+void G1MonitoringSupport::update_eden_size() {
+  recalculate_eden_size();
+  if (UsePerfData) {
     eden_counters()->update_used(eden_space_used());
   }
 }