1879N/A * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved. 0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 0N/A * This code is free software; you can redistribute it and/or modify it 0N/A * under the terms of the GNU General Public License version 2 only, as 0N/A * published by the Free Software Foundation. 0N/A * This code is distributed in the hope that it will be useful, but WITHOUT 0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 0N/A * version 2 for more details (a copy is included in the LICENSE file that 0N/A * accompanied this code). 0N/A * You should have received a copy of the GNU General Public License version 0N/A * 2 along with this work; if not, write to the Free Software Foundation, 0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 1472N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 0N/A// For Forte Analyzer AsyncGetCallTrace profiling support - thread is 0N/A// currently interrupted by SIGPROF 0N/A// NOTE: On Solaris, register windows are flushed in the signal handler 0N/A// except for possibly the top frame. 0N/A // make_walkable flushes register windows and grabs last_Java_pc 0N/A // which can not be done if the ucontext sp matches last_Java_sp 0N/A // stack walking utilities assume last_Java_pc set if marked flushed 0N/A // If we have a walkable last_Java_frame, then we should use it 0N/A // even if isInJava == true. It should be more reliable than 0N/A // At this point, we don't have a walkable last_Java_frame, so 0N/A // we try to glean some information out of the ucontext. 0N/A // ucontext wasn't useful 0N/A // we were running Java code when SIGPROF came in 107N/A // If the frame we got is safe then it is most certainly valid 107N/A // If it isn't safe then we can try several things to try and get 107N/A // a good starting point. 107N/A // On sparc the frames are almost certainly walkable in the sense 107N/A // of sp/fp linkages. However because of recycling of windows if 107N/A // a piece of code does multiple save's where the initial save creates 107N/A // a real frame with a return pc and the succeeding save's are used to 107N/A // simply get free registers and have no real pc then the pc linkage on these 107N/A // "inner" temporary frames will be bogus. 107N/A // Since there is in general only a nesting level like 107N/A // this one deep in general we'll try and unwind such an "inner" frame 107N/A // here ourselves and see if it makes sense 107N/A // Well that didn't work. Most likely we're toast on this tick 107N/A // The previous code would try this. I think it is dubious in light 107N/A // of changes to safe_for_sender and the unwind trick above but 107N/A // if it gets us a safe frame who wants to argue. 0N/A // If we have a last_Java_sp, then the SIGPROF signal caught us 0N/A // right when we were transitioning from _thread_in_Java to a new 0N/A // JavaThreadState. We use last_Java_sp instead of the sp from 0N/A // the ucontext since it should be more reliable. 107N/A // This is the best we can do. We will only be able to decode the top frame 0N/A // At this point, we know we weren't running Java code. We might 0N/A // have a last_Java_sp, but we don't have a walkable frame. 0N/A // However, we might still be able to construct something useful 0N/A // if the thread was running native code. 107N/A // nothing else to try but what we found initially