8357218: G1: Remove loop in G1CollectedHeap::try_collect_fullgc

Reviewed-by: kbarrett, tschatzl

Author: albertnetymk

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

@@ -1860,30 +1860,6 @@ bool G1CollectedHeap::try_collect_concurrently(GCCause::Cause cause,
   }
 }
 
-bool G1CollectedHeap::try_collect_fullgc(GCCause::Cause cause,
-                                         const G1GCCounters& counters_before) {
-  assert_heap_not_locked();
-
-  while(true) {
-    VM_G1CollectFull op(counters_before.total_collections(),
-                        counters_before.total_full_collections(),
-                        cause);
-    VMThread::execute(&op);
-
-    // Request is trivially finished.
-    if (!GCCause::is_explicit_full_gc(cause) || op.gc_succeeded()) {
-      return op.gc_succeeded();
-    }
-
-    {
-      MutexLocker ml(Heap_lock);
-      if (counters_before.total_full_collections() != total_full_collections()) {
-        return true;
-      }
-    }
-  }
-}
-
 bool G1CollectedHeap::try_collect(GCCause::Cause cause,
                                   const G1GCCounters& counters_before) {
   if (should_do_concurrent_full_gc(cause)) {
@@ -1902,7 +1878,11 @@ bool G1CollectedHeap::try_collect(GCCause::Cause cause,
     return op.gc_succeeded();
   } else {
     // Schedule a Full GC.
-    return try_collect_fullgc(cause, counters_before);
+    VM_G1CollectFull op(counters_before.total_collections(),
+                        counters_before.total_full_collections(),
+                        cause);
+    VMThread::execute(&op);
+    return op.gc_succeeded();
   }
 }
 

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

@@ -280,9 +280,6 @@ class G1CollectedHeap : public CollectedHeap {
                                 uint gc_counter,
                                 uint old_marking_started_before);
 
-  bool try_collect_fullgc(GCCause::Cause cause,
-                          const G1GCCounters& counters_before);
-
   // indicates whether we are in young or mixed GC mode
   G1CollectorState _collector_state;
 

src/hotspot/share/gc/g1/g1VMOperations.cpp

@@ -50,8 +50,8 @@ bool VM_G1CollectFull::skip_operation() const {
 void VM_G1CollectFull::doit() {
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
   GCCauseSetter x(g1h, _gc_cause);
-  _gc_succeeded = g1h->do_full_collection(false /* clear_all_soft_refs */,
-                                          false /* do_maximal_compaction */);
+  g1h->do_full_collection(false /* clear_all_soft_refs */,
+                          false /* do_maximal_compaction */);
 }
 
 VM_G1TryInitiateConcMark::VM_G1TryInitiateConcMark(uint gc_count_before,

src/hotspot/share/gc/g1/g1VMOperations.hpp

@@ -31,20 +31,17 @@
 // VM_operations for the G1 collector.
 
 class VM_G1CollectFull : public VM_GC_Operation {
-  bool _gc_succeeded;
-
 protected:
   bool skip_operation() const override;
 
 public:
   VM_G1CollectFull(uint gc_count_before,
                    uint full_gc_count_before,
                    GCCause::Cause cause) :
-    VM_GC_Operation(gc_count_before, cause, full_gc_count_before, true),
-    _gc_succeeded(false) { }
+    VM_GC_Operation(gc_count_before, cause, full_gc_count_before, true) { }
   VMOp_Type type() const override { return VMOp_G1CollectFull; }
   void doit() override;
-  bool gc_succeeded() const { return _gc_succeeded; }
+  bool gc_succeeded() const { return prologue_succeeded(); }
 };
 
 class VM_G1TryInitiateConcMark : public VM_GC_Operation {