1 /*
   2  * Copyright 2003-2007 Sun Microsystems, Inc.  All Rights Reserved.
   3  * Copyright 2010 Red Hat, Inc.
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This code is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This code is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * version 2 for more details (a copy is included in the LICENSE file that
  14  * accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License version
  17  * 2 along with this work; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  */
  25 
  26 // This function should match SharkStack::CreateStackOverflowCheck
  27 inline void ZeroStack::overflow_check(int required_words, TRAPS) {
  28   // Check the Zero stack
  29   if (available_words() < required_words) {
  30     handle_overflow(THREAD);
  31     return;
  32   }
  33 
  34   // Check the ABI stack
  35   if (abi_stack_available(THREAD) < 0) {
  36     handle_overflow(THREAD);
  37     return;
  38   }
  39 }
  40 
  41 // This method returns the amount of ABI stack available for us
  42 // to use under normal circumstances.  Note that the returned
  43 // value can be negative.
  44 inline int ZeroStack::abi_stack_available(Thread *thread) const {
  45   int stack_used = thread->stack_base() - (address) &stack_used;
  46   int stack_free = thread->stack_size() - stack_used;
  47   return stack_free - shadow_pages_size();
  48 }