thread_linux_sparc.cpp revision 196:d1605aabd0a1 
1/*
2 * Copyright 2003-2008 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25#include "incls/_precompiled.incl"
26#include "incls/_thread_linux_sparc.cpp.incl"
27
28// For Forte Analyzer AsyncGetCallTrace profiling support - thread is
29// currently interrupted by SIGPROF
30bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr,
31                                                     void* ucontext,
32                                                     bool isInJava) {
33  assert(Thread::current() == this, "caller must be current thread");
34  assert(this->is_Java_thread(), "must be JavaThread");
35
36  JavaThread* jt = (JavaThread *)this;
37
38  if (!isInJava) {
39    // make_walkable flushes register windows and grabs last_Java_pc
40    // which can not be done if the ucontext sp matches last_Java_sp
41    // stack walking utilities assume last_Java_pc set if marked flushed
42    jt->frame_anchor()->make_walkable(jt);
43  }
44
45  // If we have a walkable last_Java_frame, then we should use it
46  // even if isInJava == true. It should be more reliable than
47  // ucontext info.
48  if (jt->has_last_Java_frame() && jt->frame_anchor()->walkable()) {
49    *fr_addr = jt->pd_last_frame();
50    return true;
51  }
52
53  ucontext_t* uc = (ucontext_t*) ucontext;
54
55  // At this point, we don't have a walkable last_Java_frame, so
56  // we try to glean some information out of the ucontext.
57  intptr_t* ret_sp;
58  ExtendedPC addr =
59    os::fetch_frame_from_context(uc, &ret_sp,
60                                 NULL /* ret_fp only used on X86 */);
61  if (addr.pc() == NULL || ret_sp == NULL) {
62    // ucontext wasn't useful
63    return false;
64  }
65
66  // we were running Java code when SIGPROF came in
67  if (isInJava) {
68    // If we have a last_Java_sp, then the SIGPROF signal caught us
69    // right when we were transitioning from _thread_in_Java to a new
70    // JavaThreadState. We use last_Java_sp instead of the sp from
71    // the ucontext since it should be more reliable.
72    if (jt->has_last_Java_frame()) {
73      ret_sp = jt->last_Java_sp();
74    }
75    // Implied else: we don't have a last_Java_sp so we use what we
76    // got from the ucontext.
77
78    frame ret_frame(ret_sp, frame::unpatchable, addr.pc());
79    if (!ret_frame.safe_for_sender(jt)) {
80      // nothing else to try if the frame isn't good
81      return false;
82    }
83    *fr_addr = ret_frame;
84    return true;
85  }
86
87  // At this point, we know we weren't running Java code. We might
88  // have a last_Java_sp, but we don't have a walkable frame.
89  // However, we might still be able to construct something useful
90  // if the thread was running native code.
91  if (jt->has_last_Java_frame()) {
92    assert(!jt->frame_anchor()->walkable(), "case covered above");
93
94    if (jt->thread_state() == _thread_in_native) {
95      frame ret_frame(jt->last_Java_sp(), frame::unpatchable, addr.pc());
96      if (!ret_frame.safe_for_sender(jt)) {
97        // nothing else to try if the frame isn't good
98        return false;
99      }
100      *fr_addr = ret_frame;
101      return true;
102    }
103  }
104
105  // nothing else to try
106  return false;
107}
108