1 /*
 2  * Copyright (c) 2011, 2026, 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
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24 
25 #ifndef SHARE_JFR_RECORDER_STACKTRACE_JFRVFRAMESTREAM_INLINE_HPP
26 #define SHARE_JFR_RECORDER_STACKTRACE_JFRVFRAMESTREAM_INLINE_HPP
27 
28 #include "jfr/recorder/stacktrace/jfrVframeStream.hpp"
29 
30 #include "runtime/continuationEntry.inline.hpp"
31 #include "runtime/javaThread.hpp"
32 #include "runtime/registerMap.hpp"
33 #include "runtime/stackWatermarkSet.inline.hpp"
34 #include "runtime/vframe.inline.hpp"
35 
36 inline RegisterMap::WalkContinuation JfrVframeStream::walk_continuation(JavaThread* jt) {
37   // NOTE: WalkContinuation::skip, because of interactions with ZGC relocation
38   //       and load barriers. This code is run while generating stack traces for
39   //       the ZPage allocation event, even when ZGC is relocating  objects.
40   //       When ZGC is relocating, it is forbidden to run code that performs
41   //       load barriers. With WalkContinuation::include, we visit heap stack
42   //       chunks and could be using load barriers.
43   //
44   // NOTE: Shenandoah GC also seems to require this check - actual details as to why
45   //       is unknown but to be filled in by others.
46   return ((UseZGC || UseShenandoahGC) && !StackWatermarkSet::processing_started(jt))
47     ? RegisterMap::WalkContinuation::skip
48     : RegisterMap::WalkContinuation::include;
49 }
50 
51 inline JfrVframeStream::JfrVframeStream(JavaThread* jt, const frame& fr, bool in_continuation, bool stop_at_java_call_stub) :
52   vframeStreamCommon(jt, RegisterMap::UpdateMap::skip, RegisterMap::ProcessFrames::skip, walk_continuation(jt)),
53   _vthread(in_continuation) {
54   assert(!_vthread || JfrThreadLocal::is_vthread(jt), "invariant");
55   if (in_continuation) {
56     _cont_entry = jt->last_continuation();
57     assert(_cont_entry != nullptr, "invariant");
58   }
59   _frame = fr;
60   _stop_at_java_call_stub = stop_at_java_call_stub;
61   while (!fill_from_frame()) {
62     _frame = _frame.sender(&_reg_map);
63   }
64 }
65 
66 inline void JfrVframeStream::next_frame() {
67   do {
68     if (_vthread && Continuation::is_continuation_enterSpecial(_frame)) {
69       if (_cont_entry->is_virtual_thread()) {
70         // An entry of a vthread continuation is a termination point.
71         _mode = at_end_mode;
72         break;
73       }
74       _cont_entry = _cont_entry->parent();
75     }
76 
77     _frame = _frame.sender(&_reg_map);
78 
79   } while (!fill_from_frame());
80 }
81 
82 inline void JfrVframeStream::next_vframe() {
83   // handle frames with inlining
84   if (_mode == compiled_mode && fill_in_compiled_inlined_sender()) {
85     return;
86   }
87   next_frame();
88 }
89 
90 inline int JfrVframeStream::normalized_bci() const {
91   const int value = bci();
92   return value == InvocationEntryBci ? 0 : value;
93 }
94 
95 #endif // SHARE_JFR_RECORDER_STACKTRACE_JFRVFRAMESTREAM_INLINE_HPP