/*

 * 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_linux_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 ucontext 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 ucontext

  // if we were running Java code when SIGPROF came in.

  if (isInJava) {

    ucontext_t* uc = (ucontext_t*) ucontext;

    intptr_t* ret_fp;

    intptr_t* ret_sp;

    ExtendedPC addr = os::Linux::fetch_frame_from_ucontext(this, uc,

      &ret_sp, &ret_fp);

    if (addr.pc() == NULL || ret_sp == NULL ) {

      // ucontext 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;

}