--- /dev/null	2018-11-26 11:49:18.255023023 +0100
+++ new/src/hotspot/share/gc/shenandoah/shenandoahAsserts.cpp	2018-11-26 21:28:52.710728967 +0100
@@ -0,0 +1,361 @@
+/*
+ * Copyright (c) 2018, Red Hat, Inc. All rights reserved.
+ *
+ * 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/shenandoah/shenandoahAsserts.hpp"
+#include "gc/shenandoah/shenandoahBrooksPointer.hpp"
+#include "gc/shenandoah/shenandoahHeap.hpp"
+#include "gc/shenandoah/shenandoahHeap.inline.hpp"
+#include "gc/shenandoah/shenandoahHeapRegionSet.inline.hpp"
+#include "gc/shenandoah/shenandoahMarkingContext.inline.hpp"
+#include "gc/shenandoah/shenandoahTraversalGC.hpp"
+#include "gc/shenandoah/shenandoahUtils.hpp"
+#include "memory/resourceArea.hpp"
+
+void print_raw_memory(ShenandoahMessageBuffer &msg, void* loc) {
+  // Be extra safe. Only access data that is guaranteed to be safe:
+  // should be in heap, in known committed region, within that region.
+
+  ShenandoahHeap* heap = ShenandoahHeap::heap();
+  if (!heap->is_in(loc)) return;
+
+  ShenandoahHeapRegion* r = heap->heap_region_containing(loc);
+  if (r != NULL && r->is_committed()) {
+    address start = MAX2((address) r->bottom(), (address) loc - 32);
+    address end   = MIN2((address) r->end(),    (address) loc + 128);
+    if (start >= end) return;
+
+    stringStream ss;
+    os::print_hex_dump(&ss, start, end, 4);
+    msg.append("\n");
+    msg.append("Raw heap memory:\n%s", ss.as_string());
+  }
+}
+
+void ShenandoahAsserts::print_obj(ShenandoahMessageBuffer& msg, oop obj) {
+  ShenandoahHeap* heap = ShenandoahHeap::heap();
+  ShenandoahHeapRegion *r = heap->heap_region_containing(obj);
+
+  ResourceMark rm;
+  stringStream ss;
+  r->print_on(&ss);
+
+  ShenandoahMarkingContext* const ctx = heap->marking_context();
+
+  msg.append("  " PTR_FORMAT " - klass " PTR_FORMAT " %s\n", p2i(obj), p2i(obj->klass()), obj->klass()->external_name());
+  msg.append("    %3s allocated after mark start\n", ctx->allocated_after_mark_start((HeapWord *) obj) ? "" : "not");
+  msg.append("    %3s marked \n",                    ctx->is_marked(obj) ? "" : "not");
+  msg.append("    %3s in collection set\n",          heap->in_collection_set(obj) ? "" : "not");
+  if (heap->traversal_gc() != NULL) {
+    msg.append("    %3s in traversal set\n",         heap->traversal_gc()->traversal_set()->is_in((HeapWord*) obj) ? "" : "not");
+  }
+  msg.append("  region: %s", ss.as_string());
+}
+
+void ShenandoahAsserts::print_non_obj(ShenandoahMessageBuffer& msg, void* loc) {
+  ShenandoahHeap* heap = ShenandoahHeap::heap();
+  if (heap->is_in(loc)) {
+    msg.append("  inside Java heap\n");
+    ShenandoahHeapRegion *r = heap->heap_region_containing(loc);
+    stringStream ss;
+    r->print_on(&ss);
+
+    msg.append("    %3s in collection set\n",    heap->in_collection_set(loc) ? "" : "not");
+    msg.append("  region: %s", ss.as_string());
+  } else {
+    msg.append("  outside of Java heap\n");
+    stringStream ss;
+    os::print_location(&ss, (intptr_t) loc, false);
+    msg.append("  %s", ss.as_string());
+  }
+}
+
+void ShenandoahAsserts::print_obj_safe(ShenandoahMessageBuffer& msg, void* loc) {
+  ShenandoahHeap* heap = ShenandoahHeap::heap();
+  msg.append("  " PTR_FORMAT " - safe print, no details\n", p2i(loc));
+  if (heap->is_in(loc)) {
+    ShenandoahHeapRegion* r = heap->heap_region_containing(loc);
+    if (r != NULL) {
+      stringStream ss;
+      r->print_on(&ss);
+      msg.append("  region: %s", ss.as_string());
+      print_raw_memory(msg, loc);
+    }
+  }
+}
+
+void ShenandoahAsserts::print_failure(SafeLevel level, oop obj, void* interior_loc, oop loc,
+                                       const char* phase, const char* label,
+                                       const char* file, int line) {
+  ShenandoahHeap* heap = ShenandoahHeap::heap();
+  ResourceMark rm;
+
+  bool loc_in_heap = (loc != NULL && heap->is_in(loc));
+
+  ShenandoahMessageBuffer msg("%s; %s\n\n", phase, label);
+
+  msg.append("Referenced from:\n");
+  if (interior_loc != NULL) {
+    msg.append("  interior location: " PTR_FORMAT "\n", p2i(interior_loc));
+    if (loc_in_heap) {
+      print_obj(msg, loc);
+    } else {
+      print_non_obj(msg, interior_loc);
+    }
+  } else {
+    msg.append("  no interior location recorded (probably a plain heap scan, or detached oop)\n");
+  }
+  msg.append("\n");
+
+  msg.append("Object:\n");
+  if (level >= _safe_oop) {
+    print_obj(msg, obj);
+  } else {
+    print_obj_safe(msg, obj);
+  }
+  msg.append("\n");
+
+  if (level >= _safe_oop) {
+    oop fwd = (oop) ShenandoahBrooksPointer::get_raw_unchecked(obj);
+    msg.append("Forwardee:\n");
+    if (!oopDesc::equals_raw(obj, fwd)) {
+      if (level >= _safe_oop_fwd) {
+        print_obj(msg, fwd);
+      } else {
+        print_obj_safe(msg, fwd);
+      }
+    } else {
+      msg.append("  (the object itself)");
+    }
+    msg.append("\n");
+  }
+
+  if (level >= _safe_oop_fwd) {
+    oop fwd = (oop) ShenandoahBrooksPointer::get_raw_unchecked(obj);
+    oop fwd2 = (oop) ShenandoahBrooksPointer::get_raw_unchecked(fwd);
+    if (!oopDesc::equals_raw(fwd, fwd2)) {
+      msg.append("Second forwardee:\n");
+      print_obj_safe(msg, fwd2);
+      msg.append("\n");
+    }
+  }
+
+  report_vm_error(file, line, msg.buffer());
+}
+
+void ShenandoahAsserts::assert_in_heap(void* interior_loc, oop obj, const char *file, int line) {
+  ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
+
+  if (!heap->is_in(obj)) {
+    print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_in_heap failed",
+                  "oop must point to a heap address",
+                  file, line);
+  }
+}
+
+void ShenandoahAsserts::assert_correct(void* interior_loc, oop obj, const char* file, int line) {
+  ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
+
+  // Step 1. Check that obj is correct.
+  // After this step, it is safe to call heap_region_containing().
+  if (!heap->is_in(obj)) {
+    print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
+                  "oop must point to a heap address",
+                  file, line);
+  }
+
+  Klass* obj_klass = obj->klass_or_null();
+  if (obj_klass == NULL) {
+    print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
+                  "Object klass pointer should not be NULL",
+                  file,line);
+  }
+
+  if (!Metaspace::contains(obj_klass)) {
+    print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
+                  "Object klass pointer must go to metaspace",
+                  file,line);
+  }
+
+  oop fwd = oop(ShenandoahBrooksPointer::get_raw_unchecked(obj));
+
+  if (!oopDesc::equals_raw(obj, fwd)) {
+    // When Full GC moves the objects, we cannot trust fwdptrs. If we got here, it means something
+    // tries fwdptr manipulation when Full GC is running. The only exception is using the fwdptr
+    // that still points to the object itself.
+    if (heap->is_full_gc_move_in_progress()) {
+      print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
+                    "Non-trivial forwarding pointer during Full GC moves, probable bug.",
+                    file, line);
+    }
+
+    // Step 2. Check that forwardee is correct
+    if (!heap->is_in(fwd)) {
+      print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
+                    "Forwardee must point to a heap address",
+                    file, line);
+    }
+
+    if (obj_klass != fwd->klass()) {
+      print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
+                    "Forwardee klass disagrees with object class",
+                    file, line);
+    }
+
+    // Step 3. Check that forwardee points to correct region
+    if (heap->heap_region_index_containing(fwd) == heap->heap_region_index_containing(obj)) {
+      print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
+                    "Non-trivial forwardee should in another region",
+                    file, line);
+    }
+
+    // Step 4. Check for multiple forwardings
+    oop fwd2 = oop(ShenandoahBrooksPointer::get_raw_unchecked(fwd));
+    if (!oopDesc::equals_raw(fwd, fwd2)) {
+      print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
+                    "Multiple forwardings",
+                    file, line);
+    }
+  }
+}
+
+void ShenandoahAsserts::assert_in_correct_region(void* interior_loc, oop obj, const char* file, int line) {
+  assert_correct(interior_loc, obj, file, line);
+
+  ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
+  ShenandoahHeapRegion* r = heap->heap_region_containing(obj);
+  if (!r->is_active()) {
+    print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_in_correct_region failed",
+                  "Object must reside in active region",
+                  file, line);
+  }
+
+  size_t alloc_size = obj->size() + ShenandoahBrooksPointer::word_size();
+  if (alloc_size > ShenandoahHeapRegion::humongous_threshold_words()) {
+    size_t idx = r->region_number();
+    size_t num_regions = ShenandoahHeapRegion::required_regions(alloc_size * HeapWordSize);
+    for (size_t i = idx; i < idx + num_regions; i++) {
+      ShenandoahHeapRegion* chain_reg = heap->get_region(i);
+      if (i == idx && !chain_reg->is_humongous_start()) {
+        print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_in_correct_region failed",
+                      "Object must reside in humongous start",
+                      file, line);
+      }
+      if (i != idx && !chain_reg->is_humongous_continuation()) {
+        print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_in_correct_region failed",
+                      "Humongous continuation should be of proper size",
+                      file, line);
+      }
+    }
+  }
+}
+
+void ShenandoahAsserts::assert_forwarded(void* interior_loc, oop obj, const char* file, int line) {
+  assert_correct(interior_loc, obj, file, line);
+  oop fwd = oop(ShenandoahBrooksPointer::get_raw_unchecked(obj));
+
+  if (oopDesc::equals_raw(obj, fwd)) {
+    print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_forwarded failed",
+                  "Object should be forwarded",
+                  file, line);
+  }
+}
+
+void ShenandoahAsserts::assert_not_forwarded(void* interior_loc, oop obj, const char* file, int line) {
+  assert_correct(interior_loc, obj, file, line);
+  oop fwd = oop(ShenandoahBrooksPointer::get_raw_unchecked(obj));
+
+  if (!oopDesc::equals_raw(obj, fwd)) {
+    print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_not_forwarded failed",
+                  "Object should not be forwarded",
+                  file, line);
+  }
+}
+
+void ShenandoahAsserts::assert_marked(void *interior_loc, oop obj, const char *file, int line) {
+  assert_correct(interior_loc, obj, file, line);
+
+  ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
+  if (!heap->marking_context()->is_marked(obj)) {
+    print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_marked failed",
+                  "Object should be marked",
+                  file, line);
+  }
+}
+
+void ShenandoahAsserts::assert_in_cset(void* interior_loc, oop obj, const char* file, int line) {
+  assert_correct(interior_loc, obj, file, line);
+
+  ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
+  if (!heap->in_collection_set(obj)) {
+    print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_in_cset failed",
+                  "Object should be in collection set",
+                  file, line);
+  }
+}
+
+void ShenandoahAsserts::assert_not_in_cset(void* interior_loc, oop obj, const char* file, int line) {
+  assert_correct(interior_loc, obj, file, line);
+
+  ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
+  if (heap->in_collection_set(obj)) {
+    print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_not_in_cset failed",
+                  "Object should not be in collection set",
+                  file, line);
+  }
+}
+
+void ShenandoahAsserts::assert_not_in_cset_loc(void* interior_loc, const char* file, int line) {
+  ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
+  if (heap->in_collection_set(interior_loc)) {
+    print_failure(_safe_unknown, NULL, interior_loc, NULL, "Shenandoah assert_not_in_cset_loc failed",
+                  "Interior location should not be in collection set",
+                  file, line);
+  }
+}
+
+void ShenandoahAsserts::print_rp_failure(const char *label, BoolObjectClosure* actual,
+                                         const char *file, int line) {
+  ShenandoahMessageBuffer msg("%s\n", label);
+  msg.append(" Actual:                  " PTR_FORMAT "\n", p2i(actual));
+  report_vm_error(file, line, msg.buffer());
+}
+
+void ShenandoahAsserts::assert_rp_isalive_not_installed(const char *file, int line) {
+  ShenandoahHeap* heap = ShenandoahHeap::heap();
+  ReferenceProcessor* rp = heap->ref_processor();
+  if (rp->is_alive_non_header() != NULL) {
+    print_rp_failure("Shenandoah assert_rp_isalive_not_installed failed", rp->is_alive_non_header(),
+                     file, line);
+  }
+}
+
+void ShenandoahAsserts::assert_rp_isalive_installed(const char *file, int line) {
+  ShenandoahHeap* heap = ShenandoahHeap::heap();
+  ReferenceProcessor* rp = heap->ref_processor();
+  if (rp->is_alive_non_header() == NULL) {
+    print_rp_failure("Shenandoah assert_rp_isalive_installed failed", rp->is_alive_non_header(),
+                     file, line);
+  }
+}