1 /*
   2  * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "runtime/safepointVerifiers.hpp"
  27 #include "gc/shared/collectedHeap.hpp"
  28 #include "memory/universe.hpp"
  29 #include "utilities/debug.hpp"
  30 
  31 // Implementation of NoGCVerifier
  32 
  33 #ifdef ASSERT
  34 
  35 NoGCVerifier::NoGCVerifier(bool verifygc) {
  36   _verifygc = verifygc;
  37   if (_verifygc) {
  38     CollectedHeap* h = Universe::heap();
  39     assert(!h->is_gc_active(), "GC active during NoGCVerifier");
  40     _old_invocations = h->total_collections();
  41   }
  42 }
  43 
  44 
  45 NoGCVerifier::~NoGCVerifier() {
  46   if (_verifygc) {
  47     CollectedHeap* h = Universe::heap();
  48     assert(!h->is_gc_active(), "GC active during NoGCVerifier");
  49     if (_old_invocations != h->total_collections()) {
  50       fatal("collection in a NoGCVerifier secured function");
  51     }
  52   }
  53 }
  54 
  55 PauseNoGCVerifier::PauseNoGCVerifier(NoGCVerifier * ngcv) {
  56   _ngcv = ngcv;
  57   if (_ngcv->_verifygc) {
  58     // if we were verifying, then make sure that nothing is
  59     // wrong before we "pause" verification
  60     CollectedHeap* h = Universe::heap();
  61     assert(!h->is_gc_active(), "GC active during NoGCVerifier");
  62     if (_ngcv->_old_invocations != h->total_collections()) {
  63       fatal("collection in a NoGCVerifier secured function");
  64     }
  65   }
  66 }
  67 
  68 
  69 PauseNoGCVerifier::~PauseNoGCVerifier() {
  70   if (_ngcv->_verifygc) {
  71     // if we were verifying before, then reenable verification
  72     CollectedHeap* h = Universe::heap();
  73     assert(!h->is_gc_active(), "GC active during NoGCVerifier");
  74     _ngcv->_old_invocations = h->total_collections();
  75   }
  76 }
  77 
  78 #endif