/*

 * Copyright (c) 2018, 2019, 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/shenandoahForwarding.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);

  stringStream mw_ss;

  obj->mark().print_on(&mw_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("  mark:%s\n", mw_ss.as_string());

  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) ShenandoahForwarding::get_forwardee_raw_unchecked(obj);

    msg.append("Forwardee:\n");

    if (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) ShenandoahForwarding::get_forwardee_raw_unchecked(obj);

    oop fwd2 = (oop) ShenandoahForwarding::get_forwardee_raw_unchecked(fwd);

    if (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(ShenandoahForwarding::get_forwardee_raw_unchecked(obj));

  if (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(ShenandoahForwarding::get_forwardee_raw_unchecked(fwd));

    if (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();

  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(ShenandoahForwarding::get_forwardee_raw_unchecked(obj));

  if (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(ShenandoahForwarding::get_forwardee_raw_unchecked(obj));

  if (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);

  }

}

void ShenandoahAsserts::assert_locked_or_shenandoah_safepoint(Mutex* lock, const char* file, int line) {

  if (ShenandoahSafepoint::is_at_shenandoah_safepoint()) {

    return;

  }

  if (lock->owned_by_self()) {

    return;

  }

  ShenandoahMessageBuffer msg("Must ba at a Shenandoah safepoint or held %s lock", lock->name());

  report_vm_error(file, line, msg.buffer());

}