6916968: CMS: freeList.cpp:304 assert(_allocation_stats.prevSweep() + ...,...

6916968: CMS: freeList.cpp:304 assert(_allocation_stats.prevSweep() + ..., "Conservation Principle")
Summary: Fix assert and adjust demand volume computation by adding missing factor.
Reviewed-by: jmasa, tonyp

src/share/vm/gc_implementation/concurrentMarkSweep/freeList.cpp

@@ -300,8 +300,21 @@ void FreeList::verify_stats() const {
   // dictionary for example, this might be the first block and
   // in that case there would be no place that we could record
   // the stats (which are kept in the block itself).
-  assert(_allocation_stats.prevSweep() + _allocation_stats.splitBirths() + 1   // Total Stock + 1
-          >= _allocation_stats.splitDeaths() + (ssize_t)count(), "Conservation Principle");
+  assert((_allocation_stats.prevSweep() + _allocation_stats.splitBirths()
+          + _allocation_stats.coalBirths() + 1)   // Total Production Stock + 1
+         >= (_allocation_stats.splitDeaths() + _allocation_stats.coalDeaths()
+             + (ssize_t)count()),                // Total Current Stock + depletion
+         err_msg("FreeList " PTR_FORMAT " of size " SIZE_FORMAT
+                 " violates Conservation Principle: "
+                 "prevSweep(" SIZE_FORMAT ")"
+                 " + splitBirths(" SIZE_FORMAT ")"
+                 " + coalBirths(" SIZE_FORMAT ") + 1 >= "
+                 " splitDeaths(" SIZE_FORMAT ")"
+                 " coalDeaths(" SIZE_FORMAT ")"
+                 " + count(" SSIZE_FORMAT ")",
+                 this, _size, _allocation_stats.prevSweep(), _allocation_stats.splitBirths(),
+                 _allocation_stats.splitBirths(), _allocation_stats.splitDeaths(),
+                 _allocation_stats.coalDeaths(), count()));
 }
 
 void FreeList::assert_proper_lock_protection_work() const {

src/share/vm/gc_implementation/shared/allocationStats.hpp

@@ -99,14 +99,16 @@ class AllocationStats VALUE_OBJ_CLASS_SPEC {
     // vulnerable to noisy glitches. In such cases, we
     // ignore the current sample and use currently available
     // historical estimates.
-    // XXX NEEDS TO BE FIXED
-    // assert(prevSweep() + splitBirths() >= splitDeaths() + (ssize_t)count, "Conservation Principle");
-    //     ^^^^^^^^^^^^^^^^^^^^^^^^^^^    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-    //     "Total Stock"                  "Not used at this block size"
+    assert(prevSweep() + splitBirths() + coalBirths()        // "Total Production Stock"
+           >= splitDeaths() + coalDeaths() + (ssize_t)count, // "Current stock + depletion"
+           "Conservation Principle");
     if (inter_sweep_current > _threshold) {
-      ssize_t demand = prevSweep() - (ssize_t)count + splitBirths() - splitDeaths();
-      // XXX NEEDS TO BE FIXED
-      // assert(demand >= 0, "Demand should be non-negative");
+      ssize_t demand = prevSweep() - (ssize_t)count + splitBirths() + coalBirths()
+                       - splitDeaths() - coalDeaths();
+      assert(demand >= 0,
+             err_msg("Demand (" SSIZE_FORMAT ") should be non-negative for "
+                     PTR_FORMAT " (size=" SIZE_FORMAT ")",
+                     demand, this, count));
       // Defensive: adjust for imprecision in event counting
       if (demand < 0) {
         demand = 0;