src/hotspot/share/gc/g1/g1CollectedHeap.cpp

rev 52448 : JDK-8212657: Implementation of JDK-8204089 Promptly Return Unused Committed Memory from G1
Summary: Issue optional, default enabled, concurrent cycles when the VM is idle to reclaim unused internal and Java heap memory.
Reviewed-by:
Contributed-by: Rodrigo Bruno <rbruno@gsd.inesc-id.pt>, Ruslan Synytsky <rs@jelastic.com>, Thomas Schatzl <thomas.schatzl@oracle.com>

@@ -1149,10 +1149,12 @@
   bool dummy = do_full_collection(true,                /* explicit_gc */
                                   clear_all_soft_refs);
 }
 
 void G1CollectedHeap::resize_heap_if_necessary() {
+  assert_at_safepoint_on_vm_thread();
+
   // Capacity, free and used after the GC counted as full regions to
   // include the waste in the following calculations.
   const size_t capacity_after_gc = capacity();
   const size_t used_after_gc = capacity_after_gc - unused_committed_regions_in_bytes();
 

@@ -1971,10 +1973,11 @@
 
 bool G1CollectedHeap::should_do_concurrent_full_gc(GCCause::Cause cause) {
   switch (cause) {
     case GCCause::_gc_locker:               return GCLockerInvokesConcurrent;
     case GCCause::_g1_humongous_allocation: return true;
+    case GCCause::_g1_periodic_collection:  return G1PeriodicGCInvokesConcurrent;
     default:                                return is_user_requested_concurrent_full_gc(cause);
   }
 }
 
 #ifndef PRODUCT