Playing around with heap region printing

Author: Thomas Schatzl

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

@@ -2057,16 +2057,6 @@ bool G1CollectedHeap::supports_concurrent_gc_breakpoints() const {
   return true;
 }
 
-class PrintRegionClosure: public HeapRegionClosure {
-  outputStream* _st;
-public:
-  PrintRegionClosure(outputStream* st) : _st(st) {}
-  bool do_heap_region(HeapRegion* r) {
-    r->print_on(_st);
-    return false;
-  }
-};
-
 bool G1CollectedHeap::is_obj_dead_cond(const oop obj,
                                        const HeapRegion* hr,
                                        const VerifyOption vo) const {
@@ -2088,11 +2078,11 @@ bool G1CollectedHeap::is_obj_dead_cond(const oop obj,
   return false; // keep some compilers happy
 }
 
-void G1CollectedHeap::print_heap_regions() const {
+void G1CollectedHeap::print_heap_regions(bool print_pin_counts) const {
   LogTarget(Trace, gc, heap, region) lt;
   if (lt.is_enabled()) {
     LogStream ls(lt);
-    print_regions_on(&ls);
+    print_regions_on(&ls, print_pin_counts);
   }
 }
 
@@ -2126,13 +2116,25 @@ void G1CollectedHeap::print_on(outputStream* st) const {
   MetaspaceUtils::print_on(st);
 }
 
-void G1CollectedHeap::print_regions_on(outputStream* st) const {
+
+class PrintRegionClosure: public HeapRegionClosure {
+  outputStream* _st;
+  const bool _print_pin_counts;
+public:
+  PrintRegionClosure(outputStream* st, bool print_pin_counts) : _st(st), _print_pin_counts(print_pin_counts) {}
+  bool do_heap_region(HeapRegion* r) {
+    r->print_on(_st, _print_pin_counts);
+    return false;
+  }
+};
+
+void G1CollectedHeap::print_regions_on(outputStream* st, bool print_pin_counts) const {
   st->print_cr("Heap Regions: E=young(eden), S=young(survivor), O=old, "
                "HS=humongous(starts), HC=humongous(continues), "
                "CS=collection set, F=free, "
                "TAMS=top-at-mark-start, "
                "PB=parsable bottom");
-  PrintRegionClosure blk(st);
+  PrintRegionClosure blk(st, print_pin_counts);
   heap_region_iterate(&blk);
 }
 
@@ -2141,7 +2143,7 @@ void G1CollectedHeap::print_extended_on(outputStream* st) const {
 
   // Print the per-region information.
   st->cr();
-  print_regions_on(st);
+  print_regions_on(st, true /* print_pin_counts */);
 }
 
 void G1CollectedHeap::print_on_error(outputStream* st) const {
@@ -2422,7 +2424,8 @@ G1HeapPrinterMark::G1HeapPrinterMark(G1CollectedHeap* g1h) : _g1h(g1h), _heap_tr
                                                _g1h->total_collections(),
                                                true /* show_thread_times */);
   _g1h->print_heap_before_gc();
-  _g1h->print_heap_regions();
+  // We did not merge in the cached pin counts yet, making the output confusing.
+  _g1h->print_heap_regions(false /* print_pin_counts */);
 }
 
 G1HeapPrinterMark::~G1HeapPrinterMark() {
@@ -2434,7 +2437,7 @@ G1HeapPrinterMark::~G1HeapPrinterMark() {
                                                false /* show_thread_times */);
 
   _heap_transition.print();
-  _g1h->print_heap_regions();
+  _g1h->print_heap_regions(true /* print_pin_counts */);
   _g1h->print_heap_after_gc();
   // Print NUMA statistics.
   _g1h->numa()->print_statistics();

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

@@ -1306,8 +1306,8 @@ class G1CollectedHeap : public CollectedHeap {
 
   // Printing
 private:
-  void print_heap_regions() const;
-  void print_regions_on(outputStream* st) const;
+  void print_heap_regions(bool print_pin_counts) const;
+  void print_regions_on(outputStream* st, bool print_pin_counts) const;
 
 public:
   void print_on(outputStream* st) const override;

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

@@ -399,9 +399,7 @@ bool HeapRegion::verify_code_roots(VerifyOption vo) const {
   return cb_cl.failures();
 }
 
-void HeapRegion::print() const { print_on(tty); }
-
-void HeapRegion::print_on(outputStream* st) const {
+void HeapRegion::print_on(outputStream* st, bool print_pin_counts) const {
   st->print("|%4u", this->_hrm_index);
   st->print("|" PTR_FORMAT ", " PTR_FORMAT ", " PTR_FORMAT,
             p2i(bottom()), p2i(top()), p2i(end()));
@@ -425,7 +423,7 @@ void HeapRegion::print_on(outputStream* st) const {
       st->print("|-");
     }
   }
-  st->print("|%3zu", Atomic::load(&_pinned_object_count));
+  st->print("|%s%3zu", print_pin_counts ? "" : "~", Atomic::load(&_pinned_object_count));
   st->print("|%3zu", Atomic::load(&_total_pinned_atomicops));
   st->print_cr("");
 }

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

@@ -575,8 +575,7 @@ class HeapRegion : public CHeapObj<mtGC> {
   bool verify_code_roots(VerifyOption vo) const;
   bool verify_liveness_and_remset(VerifyOption vo) const;
 
-  void print() const;
-  void print_on(outputStream* st) const;
+  void print_on(outputStream* st, bool print_pin_counts) const;
 
   bool verify(VerifyOption vo) const;
 };