8229278: Improve hs_err location printing to assume less about GC internals

Reviewed-by: stefank, kbarrett

Author: fisk

src/hotspot/share/gc/epsilon/epsilonHeap.cpp

@@ -26,6 +26,7 @@
 #include "gc/epsilon/epsilonMemoryPool.hpp"
 #include "gc/epsilon/epsilonThreadLocalData.hpp"
 #include "gc/shared/gcArguments.hpp"
+#include "gc/shared/locationPrinter.inline.hpp"
 #include "memory/allocation.hpp"
 #include "memory/allocation.inline.hpp"
 #include "memory/resourceArea.hpp"
@@ -305,6 +306,10 @@ void EpsilonHeap::print_on(outputStream *st) const {
   MetaspaceUtils::print_on(st);
 }
 
+bool EpsilonHeap::print_location(outputStream* st, void* addr) const {
+  return BlockLocationPrinter<EpsilonHeap>::print_location(st, addr);
+}
+
 void EpsilonHeap::print_tracing_info() const {
   print_heap_info(used());
   print_metaspace_info();

src/hotspot/share/gc/epsilon/epsilonHeap.hpp

@@ -114,8 +114,8 @@ class EpsilonHeap : public CollectedHeap {
   virtual void unpin_object(JavaThread* thread, oop obj) { }
 
   // No support for block parsing.
-  virtual HeapWord* block_start(const void* addr) const { return NULL;  }
-  virtual bool block_is_obj(const HeapWord* addr) const { return false; }
+  HeapWord* block_start(const void* addr) const { return NULL;  }
+  bool block_is_obj(const HeapWord* addr) const { return false; }
 
   // No GC threads
   virtual void print_gc_threads_on(outputStream* st) const {}
@@ -138,6 +138,7 @@ class EpsilonHeap : public CollectedHeap {
 
   virtual void print_on(outputStream* st) const;
   virtual void print_tracing_info() const;
+  virtual bool print_location(outputStream* st, void* addr) const;
 
 private:
   void print_heap_info(size_t used) const;

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

@@ -74,6 +74,7 @@
 #include "gc/shared/gcTraceTime.inline.hpp"
 #include "gc/shared/generationSpec.hpp"
 #include "gc/shared/isGCActiveMark.hpp"
+#include "gc/shared/locationPrinter.inline.hpp"
 #include "gc/shared/oopStorageParState.hpp"
 #include "gc/shared/preservedMarks.inline.hpp"
 #include "gc/shared/suspendibleThreadSet.hpp"
@@ -2490,6 +2491,10 @@ void G1CollectedHeap::print_all_rsets() {
 }
 #endif // PRODUCT
 
+bool G1CollectedHeap::print_location(outputStream* st, void* addr) const {
+  return BlockLocationPrinter<G1CollectedHeap>::print_location(st, addr);
+}
+
 G1HeapSummary G1CollectedHeap::create_g1_heap_summary() {
 
   size_t eden_used_bytes = _eden.used_bytes();

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

@@ -1211,11 +1211,11 @@ class G1CollectedHeap : public CollectedHeap {
   // address "addr".  We say "blocks" instead of "object" since some heaps
   // may not pack objects densely; a chunk may either be an object or a
   // non-object.
-  virtual HeapWord* block_start(const void* addr) const;
+  HeapWord* block_start(const void* addr) const;
 
   // Requires "addr" to be the start of a block, and returns "TRUE" iff
   // the block is an object.
-  virtual bool block_is_obj(const HeapWord* addr) const;
+  bool block_is_obj(const HeapWord* addr) const;
 
   // Section on thread-local allocation buffers (TLABs)
   // See CollectedHeap for semantics.
@@ -1428,6 +1428,9 @@ class G1CollectedHeap : public CollectedHeap {
   void print_cset_rsets() PRODUCT_RETURN;
   void print_all_rsets() PRODUCT_RETURN;
 
+  // Used to print information about locations in the hs_err file.
+  virtual bool print_location(outputStream* st, void* addr) const;
+
   size_t pending_card_num();
 };
 

src/hotspot/share/gc/parallel/parallelScavengeHeap.cpp

@@ -41,6 +41,7 @@
 #include "gc/shared/gcLocker.hpp"
 #include "gc/shared/gcWhen.hpp"
 #include "gc/shared/genArguments.hpp"
+#include "gc/shared/locationPrinter.inline.hpp"
 #include "gc/shared/scavengableNMethods.hpp"
 #include "logging/log.hpp"
 #include "memory/metaspaceCounters.hpp"
@@ -584,6 +585,10 @@ PSHeapSummary ParallelScavengeHeap::create_ps_heap_summary() {
   return PSHeapSummary(heap_summary, used(), old_summary, old_space, young_summary, eden_space, from_space, to_space);
 }
 
+bool ParallelScavengeHeap::print_location(outputStream* st, void* addr) const {
+  return BlockLocationPrinter<ParallelScavengeHeap>::print_location(st, addr);
+}
+
 void ParallelScavengeHeap::print_on(outputStream* st) const {
   young_gen()->print_on(st);
   old_gen()->print_on(st);

src/hotspot/share/gc/parallel/parallelScavengeHeap.hpp

@@ -228,6 +228,9 @@ class ParallelScavengeHeap : public CollectedHeap {
   PreGenGCValues get_pre_gc_values() const;
   void print_heap_change(const PreGenGCValues& pre_gc_values) const;
 
+  // Used to print information about locations in the hs_err file.
+  virtual bool print_location(outputStream* st, void* addr) const;
+
   void verify(VerifyOption option /* ignored */);
 
   // Resize the young generation.  The reserved space for the

src/hotspot/share/gc/shared/collectedHeap.hpp

@@ -402,28 +402,6 @@ class CollectedHeap : public CHeapObj<mtInternal> {
   // over live objects.
   virtual void safe_object_iterate(ObjectClosure* cl) = 0;
 
-  // NOTE! There is no requirement that a collector implement these
-  // functions.
-  //
-  // A CollectedHeap is divided into a dense sequence of "blocks"; that is,
-  // each address in the (reserved) heap is a member of exactly
-  // one block.  The defining characteristic of a block is that it is
-  // possible to find its size, and thus to progress forward to the next
-  // block.  (Blocks may be of different sizes.)  Thus, blocks may
-  // represent Java objects, or they might be free blocks in a
-  // free-list-based heap (or subheap), as long as the two kinds are
-  // distinguishable and the size of each is determinable.
-
-  // Returns the address of the start of the "block" that contains the
-  // address "addr".  We say "blocks" instead of "object" since some heaps
-  // may not pack objects densely; a chunk may either be an object or a
-  // non-object.
-  virtual HeapWord* block_start(const void* addr) const = 0;
-
-  // Requires "addr" to be the start of a block, and returns "TRUE" iff
-  // the block is an object.
-  virtual bool block_is_obj(const HeapWord* addr) const = 0;
-
   // Returns the longest time (in ms) that has elapsed since the last
   // time that any part of the heap was examined by a garbage collection.
   virtual jlong millis_since_last_gc() = 0;
@@ -461,6 +439,9 @@ class CollectedHeap : public CHeapObj<mtInternal> {
 
   virtual void print_on_error(outputStream* st) const;
 
+  // Used to print information about locations in the hs_err file.
+  virtual bool print_location(outputStream* st, void* addr) const = 0;
+
   // Print all GC threads (other than the VM thread)
   // used by this heap.
   virtual void print_gc_threads_on(outputStream* st) const = 0;

src/hotspot/share/gc/shared/genCollectedHeap.cpp

@@ -47,6 +47,7 @@
 #include "gc/shared/genCollectedHeap.hpp"
 #include "gc/shared/genOopClosures.inline.hpp"
 #include "gc/shared/generationSpec.hpp"
+#include "gc/shared/locationPrinter.inline.hpp"
 #include "gc/shared/oopStorageParState.inline.hpp"
 #include "gc/shared/scavengableNMethods.hpp"
 #include "gc/shared/space.hpp"
@@ -1260,6 +1261,10 @@ void GenCollectedHeap::gc_threads_do(ThreadClosure* tc) const {
 void GenCollectedHeap::print_gc_threads_on(outputStream* st) const {
 }
 
+bool GenCollectedHeap::print_location(outputStream* st, void* addr) const {
+  return BlockLocationPrinter<GenCollectedHeap>::print_location(st, addr);
+}
+
 void GenCollectedHeap::print_tracing_info() const {
   if (log_is_enabled(Debug, gc, heap, exit)) {
     LogStreamHandle(Debug, gc, heap, exit) lsh;

src/hotspot/share/gc/shared/genCollectedHeap.hpp

@@ -260,13 +260,13 @@ class GenCollectedHeap : public CollectedHeap {
   // address "addr".  We say "blocks" instead of "object" since some heaps
   // may not pack objects densely; a chunk may either be an object or a
   // non-object.
-  virtual HeapWord* block_start(const void* addr) const;
+  HeapWord* block_start(const void* addr) const;
 
   // Requires "addr" to be the start of a block, and returns "TRUE" iff
   // the block is an object. Assumes (and verifies in non-product
   // builds) that addr is in the allocated part of the heap and is
   // the start of a chunk.
-  virtual bool block_is_obj(const HeapWord* addr) const;
+  bool block_is_obj(const HeapWord* addr) const;
 
   // Section on TLAB's.
   virtual bool supports_tlab_allocation() const;
@@ -332,6 +332,9 @@ class GenCollectedHeap : public CollectedHeap {
   virtual void gc_threads_do(ThreadClosure* tc) const;
   virtual void print_tracing_info() const;
 
+  // Used to print information about locations in the hs_err file.
+  virtual bool print_location(outputStream* st, void* addr) const;
+
   void print_heap_change(size_t young_prev_used, size_t old_prev_used) const;
 
   // The functions below are helper functions that a subclass of

src/hotspot/share/gc/shared/locationPrinter.cpp

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "gc/shared/collectedHeap.hpp"
+#include "gc/shared/locationPrinter.hpp"
+#include "memory/universe.hpp"
+#include "runtime/os.hpp"
+#include "oops/klass.hpp"
+
+bool LocationPrinter::is_valid_obj(void* obj) {
+  if (!is_object_aligned(obj)) {
+    return false;
+  }
+  if (obj < (void*)os::min_page_size()) {
+    return false;
+  }
+
+  // We need at least the mark and the klass word in the committed region.
+  if (!os::is_readable_range(obj, (HeapWord*)obj + oopDesc::header_size())) {
+    return false;
+  }
+  if (!Universe::heap()->is_in(obj)) {
+    return false;
+  }
+
+  Klass* k = (Klass*)oopDesc::load_klass_raw((oopDesc*)obj);
+  return Klass::is_valid(k);
+}