view src/os_cpu/linux_sparc/vm/thread_linux_sparc.hpp @ 453:c96030fff130

6684579: SoftReference processing can be made more efficient Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not. Reviewed-by: jmasa
author ysr
date Thu, 20 Nov 2008 16:56:09 -0800
parents d1605aabd0a1
children c18cbe5936b8
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/*
 * Copyright 1998-2008 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 */

private:

  void pd_initialize() {
    _anchor.clear();
    _base_of_stack_pointer        = NULL;
  }

  frame pd_last_frame() {
    assert(has_last_Java_frame(), "must have last_Java_sp() when suspended");
    assert(_anchor.walkable(), "thread has not dumped its register windows yet");

    assert(_anchor.last_Java_pc() != NULL, "Ack no pc!");
    return frame(last_Java_sp(), frame::unpatchable, _anchor.last_Java_pc());
  }

  // Sometimes the trap handler needs to record both PC and NPC.
  // This is a SPARC-specific companion to Thread::set_saved_exception_pc.
  address _saved_exception_npc;

  // In polling_page_safepoint_handler_blob(s) we have to tail call other
  // blobs without blowing any registers.  A tail call requires some
  // register to jump with and we can't blow any registers, so it must
  // be restored in the delay slot.  'restore' cannot be used as it
  // will chop the heads off of 64-bit %o registers in the 32-bit
  // build.  Instead we reload the registers using G2_thread and this
  // location.  Must be 64bits in the 32-bit LION build.
  jdouble _o_reg_temps[6];

  // a stack pointer older than any java frame stack pointer.  It is
  // used to validate stack pointers in frame::next_younger_sp (it
  // provides the upper bound in the range check).  This is necessary
  // on Solaris/SPARC since the ucontext passed to a signal handler is
  // sometimes corrupt and we need a way to check the extracted sp.
  intptr_t* _base_of_stack_pointer;

public:

  static int o_reg_temps_offset_in_bytes() { return offset_of(JavaThread, _o_reg_temps); }

#ifndef _LP64
  address o_reg_temps(int i) { return (address)&_o_reg_temps[i]; }
#endif

  static int saved_exception_npc_offset_in_bytes() { return offset_of(JavaThread,_saved_exception_npc); }

  address  saved_exception_npc()             { return _saved_exception_npc; }
  void set_saved_exception_npc(address a)    { _saved_exception_npc = a; }


public:

  intptr_t* base_of_stack_pointer() { return _base_of_stack_pointer; }

  void set_base_of_stack_pointer(intptr_t* base_sp) {
    _base_of_stack_pointer = base_sp;
  }

  void record_base_of_stack_pointer() {
    intptr_t *sp = (intptr_t *)(((intptr_t)StubRoutines::Sparc::flush_callers_register_windows_func()()));
    intptr_t *ysp;
    while((ysp = (intptr_t*)sp[FP->sp_offset_in_saved_window()]) != NULL) {
      sp = (intptr_t *)((intptr_t)ysp + STACK_BIAS);
    }
    _base_of_stack_pointer = sp;
  }

  bool pd_get_top_frame_for_signal_handler(frame* fr_addr, void* ucontext,
    bool isInJava);

  // These routines are only used on cpu architectures that
  // have separate register stacks (Itanium).
  static bool register_stack_overflow() { return false; }
  static void enable_register_stack_guard() {}
  static void disable_register_stack_guard() {}