1 /*
   2  * Copyright (c) 2015, 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/arguments.hpp"
  27 #include "runtime/commandLineFlagConstraintsRuntime.hpp"
  28 #include "runtime/globals.hpp"
  29 #include "utilities/defaultStream.hpp"
  30 
  31 Flag::Error ObjectAlignmentInBytesConstraintFunc(bool verbose, intx* value) {
  32   if (!is_power_of_2(*value)) {
  33     if (verbose == true) {
  34       jio_fprintf(defaultStream::error_stream(),
  35                 "ObjectAlignmentInBytes=" INTX_FORMAT " must be power of 2\n",
  36                 *value);
  37     }
  38     return Flag::VIOLATES_CONSTRAINT;
  39   }
  40   // In case page size is very small.
  41   if (*value >= (intx)os::vm_page_size()) {
  42     if (verbose == true) {
  43       jio_fprintf(defaultStream::error_stream(),
  44                 "ObjectAlignmentInBytes=" INTX_FORMAT " must be less than page size " INTX_FORMAT "\n",
  45                 *value, (intx)os::vm_page_size());
  46     }
  47     return Flag::VIOLATES_CONSTRAINT;
  48   }
  49   return Flag::SUCCESS;
  50 }
  51 
  52 // Need to enforce the padding not to break the existing field alignments.
  53 // It is sufficient to check against the largest type size.
  54 Flag::Error ContendedPaddingWidthConstraintFunc(bool verbose, intx* value) {
  55   if ((*value != 0) && ((*value % BytesPerLong) != 0)) {
  56     if (verbose == true) {
  57       jio_fprintf(defaultStream::error_stream(),
  58                 "ContendedPaddingWidth=" INTX_FORMAT " must be a multiple of %d\n",
  59                 *value, BytesPerLong);
  60     }
  61     return Flag::VIOLATES_CONSTRAINT;
  62   } else {
  63     return Flag::SUCCESS;
  64   }
  65 }