/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
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*/
#include "precompiled.hpp"
#include "runtime/frame.inline.hpp"
#include "thread_solaris.inline.hpp"
// For Forte Analyzer AsyncGetCallTrace profiling support - thread is
// currently interrupted by SIGPROF
//
// NOTE: On Solaris, register windows are flushed in the signal handler
// except for possibly the top frame.
//
}
// get ucontext somehow
}
if (!isInJava && makeWalkable) {
// make_walkable flushes register windows and grabs last_Java_pc
// which can not be done if the ucontext sp matches last_Java_sp
// stack walking utilities assume last_Java_pc set if marked flushed
}
// If we have a walkable last_Java_frame, then we should use it
// even if isInJava == true. It should be more reliable than
// ucontext info.
return true;
}
// At this point, we don't have a walkable last_Java_frame, so
// we try to glean some information out of the ucontext.
// ucontext wasn't useful
return false;
}
// we were running Java code when SIGPROF came in
if (isInJava) {
// If the frame we got is safe then it is most certainly valid
return true;
}
// If it isn't safe then we can try several things to try and get
// a good starting point.
//
// On sparc the frames are almost certainly walkable in the sense
// a piece of code does multiple save's where the initial save creates
// a real frame with a return pc and the succeeding save's are used to
// simply get free registers and have no real pc then the pc linkage on these
// "inner" temporary frames will be bogus.
// Since there is in general only a nesting level like
// this one deep in general we'll try and unwind such an "inner" frame
// here ourselves and see if it makes sense
*fr_addr = unwind_frame;
return true;
}
// Well that didn't work. Most likely we're toast on this tick
// The previous code would try this. I think it is dubious in light
// of changes to safe_for_sender and the unwind trick above but
// if it gets us a safe frame who wants to argue.
// If we have a last_Java_sp, then the SIGPROF signal caught us
// right when we were transitioning from _thread_in_Java to a new
// JavaThreadState. We use last_Java_sp instead of the sp from
// the ucontext since it should be more reliable.
if (jt->has_last_Java_frame()) {
*fr_addr = ret_frame2;
return true;
}
}
// This is the best we can do. We will only be able to decode the top frame
return true;
}
// At this point, we know we weren't running Java code. We might
// have a last_Java_sp, but we don't have a walkable frame.
// However, we might still be able to construct something useful
// if the thread was running native code.
if (jt->has_last_Java_frame()) {
return true;
}
// nothing else to try but what we found initially
return true;
}