src/os_cpu/windows_x86/vm/assembler_windows_x86.cpp

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   1 /*
   2  * Copyright (c) 1999, 2008, 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 "incls/_precompiled.incl"
  26 #include "incls/_assembler_windows_x86.cpp.incl"



  27 
  28 
  29 void MacroAssembler::int3() {
  30   emit_byte(0xCC);
  31 }
  32 
  33 #ifndef _LP64
  34 //  The current scheme to accelerate access to the thread
  35 //  pointer is to store the current thread in the os_exception_wrapper
  36 //  and reference the current thread from stubs and compiled code
  37 //  via the FS register.  FS[0] contains a pointer to the structured
  38 //  exception block which is actually a stack address.  The first time
  39 //  we call the os exception wrapper, we calculate and store the
  40 //  offset from this exception block and use that offset here.
  41 //
  42 //  The last mechanism we used was problematic in that the
  43 //  the offset we had hard coded in the VM kept changing as Microsoft
  44 //  evolved the OS.
  45 //
  46 // Warning: This mechanism assumes that we only attempt to get the


   1 /*
   2  * Copyright (c) 1999, 2010, 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 "asm/assembler.hpp"
  27 #include "assembler_x86.inline.hpp"
  28 #include "runtime/os.hpp"
  29 #include "runtime/threadLocalStorage.hpp"
  30 
  31 
  32 void MacroAssembler::int3() {
  33   emit_byte(0xCC);
  34 }
  35 
  36 #ifndef _LP64
  37 //  The current scheme to accelerate access to the thread
  38 //  pointer is to store the current thread in the os_exception_wrapper
  39 //  and reference the current thread from stubs and compiled code
  40 //  via the FS register.  FS[0] contains a pointer to the structured
  41 //  exception block which is actually a stack address.  The first time
  42 //  we call the os exception wrapper, we calculate and store the
  43 //  offset from this exception block and use that offset here.
  44 //
  45 //  The last mechanism we used was problematic in that the
  46 //  the offset we had hard coded in the VM kept changing as Microsoft
  47 //  evolved the OS.
  48 //
  49 // Warning: This mechanism assumes that we only attempt to get the