1 /*
   2  * Copyright (c) 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 "logging/log.hpp"
  27 #include "runtime/globals.hpp"
  28 #include "runtime/os.hpp"
  29 #include "runtime/safepointMechanism.hpp"
  30 #include "utilities/globalDefinitions.hpp"
  31 
  32 void SafepointMechanism::default_initialize() {
  33   const size_t page_size = os::vm_page_size();
  34   char* polling_page = os::reserve_memory(page_size, NULL, page_size);
  35   os::commit_memory_or_exit(polling_page, page_size, false, "Unable to commit Safepoint polling page");
  36   bool res = os::protect_memory(polling_page, page_size, os::MEM_PROT_READ);
  37 
  38   log_info(os)("SafePoint Polling address: " INTPTR_FORMAT, p2i(polling_page));
  39   os::set_polling_page((address)(polling_page));
  40 }
  41 
  42 void SafepointMechanism::initialize_serialize_page() {
  43   if (!UseMembar) {
  44     const size_t page_size = os::vm_page_size();
  45     char* serialize_page = os::reserve_memory(page_size, NULL, page_size);
  46     os::commit_memory_or_exit(serialize_page, page_size, false, "Unable to commit memory serialization page");
  47     log_info(os)("Memory Serialize Page address: " INTPTR_FORMAT, p2i(serialize_page));
  48     os::set_memory_serialize_page((address)(serialize_page));
  49   }
  50 }
  51 
  52 void SafepointMechanism::initialize() {
  53   pd_initialize();
  54   initialize_serialize_page();
  55 }