view src/os_cpu/windows_x86/vm/thread_windows_x86.cpp @ 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 a61af66fc99e
children c18cbe5936b8
line wrap: on
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/*
 * Copyright 2003-2005 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.
 *
 */

#include "incls/_precompiled.incl"
#include "incls/_thread_windows_x86.cpp.incl"

// For Forte Analyzer AsyncGetCallTrace profiling support - thread is
// currently interrupted by SIGPROF
bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr,
  void* ucontext, bool isInJava) {

  assert(Thread::current() == this, "caller must be current thread");
  assert(this->is_Java_thread(), "must be JavaThread");

  JavaThread* jt = (JavaThread *)this;

  // If we have a last_Java_frame, then we should use it even if
  // isInJava == true.  It should be more reliable than CONTEXT info.
  if (jt->has_last_Java_frame()) {
    *fr_addr = jt->pd_last_frame();
    return true;
  }

  // At this point, we don't have a last_Java_frame, so
  // we try to glean some information out of the CONTEXT
  // if we were running Java code when SIGPROF came in.
  if (isInJava) {
    CONTEXT* uc = (CONTEXT*)ucontext;

#ifdef AMD64
    intptr_t* ret_fp = (intptr_t*) uc->Rbp;
    intptr_t* ret_sp = (intptr_t*) uc->Rsp;
    ExtendedPC addr = ExtendedPC((address)uc->Rip);
#else
    intptr_t* ret_fp = (intptr_t*) uc->Ebp;
    intptr_t* ret_sp = (intptr_t*) uc->Esp;
    ExtendedPC addr = ExtendedPC((address)uc->Eip);
#endif // AMD64
    if (addr.pc() == NULL || ret_sp == NULL ) {
      // CONTEXT wasn't useful
      return false;
    }

    frame ret_frame(ret_sp, ret_fp, addr.pc());
    if (!ret_frame.safe_for_sender(jt)) {
#ifdef COMPILER2
      // C2 uses ebp as a general register see if NULL fp helps
      frame ret_frame2(ret_sp, NULL, addr.pc());
      if (!ret_frame2.safe_for_sender(jt)) {
        // nothing else to try if the frame isn't good
        return false;
      }
      ret_frame = ret_frame2;
#else
      // nothing else to try if the frame isn't good
      return false;
#endif /* COMPILER2 */
    }
    *fr_addr = ret_frame;
    return true;
  }

  // nothing else to try
  return false;
}