1 /*
   2  * Copyright (c) 2003, 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 "runtime/frame.inline.hpp"
  27 #include "runtime/thread.inline.hpp"
  28 
  29 // For Forte Analyzer AsyncGetCallTrace profiling support - thread is
  30 // currently interrupted by SIGPROF
  31 bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr,
  32   void* ucontext, bool isInJava) {
  33 
  34   assert(Thread::current() == this, "caller must be current thread");
  35   assert(this->is_Java_thread(), "must be JavaThread");
  36 
  37   JavaThread* jt = (JavaThread *)this;
  38 
  39   // If we have a last_Java_frame, then we should use it even if
  40   // isInJava == true.  It should be more reliable than ucontext info.
  41   if (jt->has_last_Java_frame()) {
  42     *fr_addr = jt->pd_last_frame();
  43     return true;
  44   }
  45 
  46   // At this point, we don't have a last_Java_frame, so
  47   // we try to glean some information out of the ucontext
  48   // if we were running Java code when SIGPROF came in.
  49   if (isInJava) {
  50     ucontext_t* uc = (ucontext_t*) ucontext;
  51 
  52     intptr_t* ret_fp;
  53     intptr_t* ret_sp;
  54     ExtendedPC addr = os::Bsd::fetch_frame_from_ucontext(this, uc,
  55       &ret_sp, &ret_fp);
  56     if (addr.pc() == NULL || ret_sp == NULL ) {
  57       // ucontext wasn't useful
  58       return false;
  59     }
  60 
  61     frame ret_frame(ret_sp, ret_fp, addr.pc());
  62     if (!ret_frame.safe_for_sender(jt)) {
  63 #ifdef COMPILER2
  64       // C2 uses ebp as a general register see if NULL fp helps
  65       frame ret_frame2(ret_sp, NULL, addr.pc());
  66       if (!ret_frame2.safe_for_sender(jt)) {
  67         // nothing else to try if the frame isn't good
  68         return false;
  69       }
  70       ret_frame = ret_frame2;
  71 #else
  72       // nothing else to try if the frame isn't good
  73       return false;
  74 #endif /* COMPILER2 */
  75     }
  76     *fr_addr = ret_frame;
  77     return true;
  78   }
  79 
  80   // nothing else to try
  81   return false;
  82 }
  83 
  84 void JavaThread::cache_global_variables() { }