1 /*
   2  * Copyright (c) 2003, 2018, 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 "memory/metaspaceShared.hpp"
  27 #include "runtime/frame.inline.hpp"
  28 #include "runtime/thread.inline.hpp"
  29 
  30 frame JavaThread::pd_last_frame() {
  31   assert(has_last_Java_frame(), "must have last_Java_sp() when suspended");
  32   vmassert(_anchor.last_Java_pc() != NULL, "not walkable");
  33   return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp(), _anchor.last_Java_pc());
  34 }
  35 
  36 // For Forte Analyzer AsyncGetCallTrace profiling support - thread is
  37 // currently interrupted by SIGPROF
  38 bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr,
  39   void* ucontext, bool isInJava) {
  40 
  41   assert(Thread::current() == this, "caller must be current thread");
  42   return pd_get_top_frame(fr_addr, ucontext, isInJava);
  43 }
  44 
  45 bool JavaThread::pd_get_top_frame_for_profiling(frame* fr_addr, void* ucontext, bool isInJava) {
  46   return pd_get_top_frame(fr_addr, ucontext, isInJava);
  47 }
  48 
  49 bool JavaThread::pd_get_top_frame(frame* fr_addr, void* ucontext, bool isInJava) {
  50 
  51   assert(this->is_Java_thread(), "must be JavaThread");
  52 
  53   JavaThread* jt = (JavaThread *)this;
  54 
  55   // If we have a last_Java_frame, then we should use it even if
  56   // isInJava == true.  It should be more reliable than CONTEXT info.
  57   if (jt->has_last_Java_frame() && jt->frame_anchor()->walkable()) {
  58     *fr_addr = jt->pd_last_frame();
  59     return true;
  60   }
  61 
  62   // At this point, we don't have a last_Java_frame, so
  63   // we try to glean some information out of the CONTEXT
  64   // if we were running Java code when SIGPROF came in.
  65   if (isInJava) {
  66     frame ret_frame = os::fetch_frame_from_context(ucontext);
  67     if (ret_frame.pc() == NULL || ret_frame.sp() == NULL ) {
  68       // CONTEXT wasn't useful
  69       return false;
  70     }
  71 
  72     if (MetaspaceShared::is_in_trampoline_frame(ret_frame.pc())) {
  73       // In the middle of a trampoline call. Bail out for safety.
  74       // This happens rarely so shouldn't affect profiling.
  75       return false;
  76     }
  77 
  78     if (!ret_frame.safe_for_sender(jt)) {
  79 #if COMPILER2_OR_JVMCI
  80       // C2 and JVMCI use ebp as a general register see if NULL fp helps
  81       frame ret_frame2(ret_frame.sp(), NULL, ret_frame.pc());
  82       if (!ret_frame2.safe_for_sender(jt)) {
  83         // nothing else to try if the frame isn't good
  84         return false;
  85       }
  86       ret_frame = ret_frame2;
  87 #else
  88       // nothing else to try if the frame isn't good
  89       return false;
  90 #endif // COMPILER2_OR_JVMCI
  91     }
  92     *fr_addr = ret_frame;
  93     return true;
  94   }
  95 
  96   // nothing else to try
  97   return false;
  98 }
  99 
 100 void JavaThread::cache_global_variables() { }