aoqi@0: /*
aoqi@0:  * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  *
aoqi@0:  */
aoqi@0: 
aoqi@0: #include "precompiled.hpp"
aoqi@0: #include "runtime/frame.inline.hpp"
aoqi@0: #include "runtime/thread.inline.hpp"
aoqi@0: 
aoqi@0: // For Forte Analyzer AsyncGetCallTrace profiling support - thread is
aoqi@0: // currently interrupted by SIGPROF
aoqi@0: //
aoqi@0: // NOTE: On Solaris, register windows are flushed in the signal handler
aoqi@0: // except for possibly the top frame.
aoqi@0: //
aoqi@0: bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr,
aoqi@0:   void* ucontext, bool isInJava) {
aoqi@0: 
aoqi@0:   assert(Thread::current() == this, "caller must be current thread");
aoqi@0:   return pd_get_top_frame(fr_addr, ucontext, isInJava, true);
aoqi@0: }
aoqi@0: 
aoqi@0: bool JavaThread::pd_get_top_frame_for_profiling(frame* fr_addr, void* ucontext, bool isInJava) {
aoqi@0:   // get ucontext somehow
aoqi@0:   return pd_get_top_frame(fr_addr, ucontext, isInJava, false);
aoqi@0: }
aoqi@0: 
aoqi@0: bool JavaThread::pd_get_top_frame(frame* fr_addr,
aoqi@0:   void* ucontext, bool isInJava, bool makeWalkable) {
aoqi@0:   assert(this->is_Java_thread(), "must be JavaThread");
aoqi@0: 
aoqi@0:   JavaThread* jt = (JavaThread *)this;
aoqi@0: 
aoqi@0:   if (!isInJava && makeWalkable) {
aoqi@0:     // make_walkable flushes register windows and grabs last_Java_pc
aoqi@0:     // which can not be done if the ucontext sp matches last_Java_sp
aoqi@0:     // stack walking utilities assume last_Java_pc set if marked flushed
aoqi@0:     jt->frame_anchor()->make_walkable(jt);
aoqi@0:   }
aoqi@0: 
aoqi@0:   // If we have a walkable last_Java_frame, then we should use it
aoqi@0:   // even if isInJava == true. It should be more reliable than
aoqi@0:   // ucontext info.
aoqi@0:   if (jt->has_last_Java_frame() && jt->frame_anchor()->walkable()) {
aoqi@0:     *fr_addr = jt->pd_last_frame();
aoqi@0:     return true;
aoqi@0:   }
aoqi@0: 
aoqi@0:   ucontext_t* uc = (ucontext_t*) ucontext;
aoqi@0: 
aoqi@0:   // At this point, we don't have a walkable last_Java_frame, so
aoqi@0:   // we try to glean some information out of the ucontext.
aoqi@0:   intptr_t* ret_sp;
aoqi@0:   ExtendedPC addr = os::Solaris::fetch_frame_from_ucontext(this, uc,
aoqi@0:     &ret_sp, NULL /* ret_fp only used on Solaris X86 */);
aoqi@0:   if (addr.pc() == NULL || ret_sp == NULL) {
aoqi@0:     // ucontext wasn't useful
aoqi@0:     return false;
aoqi@0:   }
aoqi@0: 
aoqi@0:   frame ret_frame(ret_sp, frame::unpatchable, addr.pc());
aoqi@0: 
aoqi@0:   // we were running Java code when SIGPROF came in
aoqi@0:   if (isInJava) {
aoqi@0: 
aoqi@0: 
aoqi@0:     // If the frame we got is safe then it is most certainly valid
aoqi@0:     if (ret_frame.safe_for_sender(jt)) {
aoqi@0:       *fr_addr = ret_frame;
aoqi@0:       return true;
aoqi@0:     }
aoqi@0: 
aoqi@0:     // If it isn't safe then we can try several things to try and get
aoqi@0:     // a good starting point.
aoqi@0:     //
aoqi@0:     // On sparc the frames are almost certainly walkable in the sense
aoqi@0:     // of sp/fp linkages. However because of recycling of windows if
aoqi@0:     // a piece of code does multiple save's where the initial save creates
aoqi@0:     // a real frame with a return pc and the succeeding save's are used to
aoqi@0:     // simply get free registers and have no real pc then the pc linkage on these
aoqi@0:     // "inner" temporary frames will be bogus.
aoqi@0:     // Since there is in general only a nesting level like
aoqi@0:     // this one deep in general we'll try and unwind such an "inner" frame
aoqi@0:     // here ourselves and see if it makes sense
aoqi@0: 
aoqi@0:     frame unwind_frame(ret_frame.fp(), frame::unpatchable, addr.pc());
aoqi@0: 
aoqi@0:     if (unwind_frame.safe_for_sender(jt)) {
aoqi@0:       *fr_addr = unwind_frame;
aoqi@0:       return true;
aoqi@0:     }
aoqi@0: 
aoqi@0:     // Well that didn't work. Most likely we're toast on this tick
aoqi@0:     // The previous code would try this. I think it is dubious in light
aoqi@0:     // of changes to safe_for_sender and the unwind trick above but
aoqi@0:     // if it gets us a safe frame who wants to argue.
aoqi@0: 
aoqi@0:     // If we have a last_Java_sp, then the SIGPROF signal caught us
aoqi@0:     // right when we were transitioning from _thread_in_Java to a new
aoqi@0:     // JavaThreadState. We use last_Java_sp instead of the sp from
aoqi@0:     // the ucontext since it should be more reliable.
aoqi@0: 
aoqi@0:     if (jt->has_last_Java_frame()) {
aoqi@0:       ret_sp = jt->last_Java_sp();
aoqi@0:       frame ret_frame2(ret_sp, frame::unpatchable, addr.pc());
aoqi@0:       if (ret_frame2.safe_for_sender(jt)) {
aoqi@0:         *fr_addr = ret_frame2;
aoqi@0:         return true;
aoqi@0:       }
aoqi@0:     }
aoqi@0: 
aoqi@0:     // This is the best we can do. We will only be able to decode the top frame
aoqi@0: 
aoqi@0:     *fr_addr = ret_frame;
aoqi@0:     return true;
aoqi@0:   }
aoqi@0: 
aoqi@0:   // At this point, we know we weren't running Java code. We might
aoqi@0:   // have a last_Java_sp, but we don't have a walkable frame.
aoqi@0:   // However, we might still be able to construct something useful
aoqi@0:   // if the thread was running native code.
aoqi@0:   if (jt->has_last_Java_frame()) {
aoqi@0:     assert(!jt->frame_anchor()->walkable(), "case covered above");
aoqi@0: 
aoqi@0:     frame ret_frame(jt->last_Java_sp(), frame::unpatchable, addr.pc());
aoqi@0:     *fr_addr = ret_frame;
aoqi@0:     return true;
aoqi@0:   }
aoqi@0: 
aoqi@0:   // nothing else to try but what we found initially
aoqi@0: 
aoqi@0:   *fr_addr = ret_frame;
aoqi@0:   return true;
aoqi@0: }
aoqi@0: 
aoqi@0: void JavaThread::cache_global_variables() { }
aoqi@0: