1 /*
2 * Copyright (c) 2022, 2025, 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
21 * questions.
22 *
23 */
24
25 #include "code/compiledIC.hpp"
26 #include "code/nmethod.hpp"
27 #include "oops/method.inline.hpp"
28 #include "runtime/continuation.hpp"
29 #include "runtime/continuationEntry.inline.hpp"
30 #include "runtime/continuationHelper.inline.hpp"
31 #include "runtime/frame.inline.hpp"
32 #include "runtime/javaThread.hpp"
33 #include "runtime/stackFrameStream.inline.hpp"
34 #include "runtime/stackWatermarkSet.inline.hpp"
35 #include "runtime/stubRoutines.hpp"
36
37 int ContinuationEntry::_return_pc_offset = 0;
38 int ContinuationEntry::_thaw_call_pc_offset = 0;
39 int ContinuationEntry::_cleanup_offset = 0;
40 address ContinuationEntry::_return_pc = nullptr;
41 address ContinuationEntry::_thaw_call_pc = nullptr;
42 address ContinuationEntry::_cleanup_pc = nullptr;
43 nmethod* ContinuationEntry::_enter_special = nullptr;
44 int ContinuationEntry::_interpreted_entry_offset = 0;
45
46 void ContinuationEntry::set_enter_code(nmethod* nm, int interpreted_entry_offset) {
47 assert(_return_pc_offset != 0, "");
48 _return_pc = nm->code_begin() + _return_pc_offset;
49 _thaw_call_pc = nm->code_begin() + _thaw_call_pc_offset;
50 _cleanup_pc = nm->code_begin() + _cleanup_offset;
51
52 _enter_special = nm;
53 _interpreted_entry_offset = interpreted_entry_offset;
54
55 assert(_enter_special->code_contains(compiled_entry()), "entry not in enterSpecial");
56 assert(_enter_special->code_contains(interpreted_entry()), "entry not in enterSpecial");
57 assert(interpreted_entry() < compiled_entry(), "unexpected code layout");
58 }
59
60 address ContinuationEntry::compiled_entry() {
61 return _enter_special->verified_entry_point();
62 }
63
64 address ContinuationEntry::interpreted_entry() {
65 return _enter_special->code_begin() + _interpreted_entry_offset;
66 }
67
68 bool ContinuationEntry::is_interpreted_call(address call_address) {
69 assert(_enter_special->code_contains(call_address), "call not in enterSpecial");
70 assert(call_address >= interpreted_entry(), "unexpected location");
71 return call_address < compiled_entry();
72 }
73
74 ContinuationEntry* ContinuationEntry::from_frame(const frame& f) {
75 assert(Continuation::is_continuation_enterSpecial(f), "");
76 return (ContinuationEntry*)f.unextended_sp();
77 }
78
79 NOINLINE static void flush_stack_processing(JavaThread* thread, intptr_t* sp) {
80 log_develop_trace(continuations)("flush_stack_processing");
81 for (StackFrameStream fst(thread, true, true); fst.current()->sp() <= sp; fst.next()) {
82 ;
83 }
84 }
85
86 inline void maybe_flush_stack_processing(JavaThread* thread, intptr_t* sp) {
87 StackWatermark* sw;
88 uintptr_t watermark;
89 if ((sw = StackWatermarkSet::get(thread, StackWatermarkKind::gc)) != nullptr
90 && (watermark = sw->watermark()) != 0
91 && watermark <= (uintptr_t)sp) {
92 flush_stack_processing(thread, sp);
93 }
94 }
95
96 void ContinuationEntry::flush_stack_processing(JavaThread* thread) const {
97 maybe_flush_stack_processing(thread, (intptr_t*)((uintptr_t)entry_sp() + ContinuationEntry::size()));
98 }
99
100 #ifndef PRODUCT
101 void ContinuationEntry::describe(FrameValues& values, int frame_no) const {
102 address usp = (address)this;
103 values.describe(frame_no, (intptr_t*)(usp + in_bytes(ContinuationEntry::parent_offset())), "parent");
104 values.describe(frame_no, (intptr_t*)(usp + in_bytes(ContinuationEntry::cont_offset())), "continuation");
105 values.describe(frame_no, (intptr_t*)(usp + in_bytes(ContinuationEntry::flags_offset())), "flags");
106 values.describe(frame_no, (intptr_t*)(usp + in_bytes(ContinuationEntry::chunk_offset())), "chunk");
107 values.describe(frame_no, (intptr_t*)(usp + in_bytes(ContinuationEntry::argsize_offset())), "argsize");
108 values.describe(frame_no, (intptr_t*)(usp + in_bytes(ContinuationEntry::pin_count_offset())), "pin_count");
109 values.describe(frame_no, (intptr_t*)(usp + in_bytes(ContinuationEntry::parent_cont_fastpath_offset())), "parent fastpath");
110 values.describe(frame_no, (intptr_t*)(usp + in_bytes(ContinuationEntry::parent_held_monitor_count_offset())), "parent held monitor count");
111 }
112 #endif
113
114 #ifdef ASSERT
115 bool ContinuationEntry::assert_entry_frame_laid_out(JavaThread* thread) {
116 assert(thread->has_last_Java_frame(), "Wrong place to use this assertion");
117
118 ContinuationEntry* entry = thread->last_continuation();
119 assert(entry != nullptr, "");
120
121 intptr_t* unextended_sp = entry->entry_sp();
122 intptr_t* sp;
123 if (entry->argsize() > 0) {
124 sp = entry->bottom_sender_sp();
125 } else {
126 sp = unextended_sp;
127 bool interpreted_bottom = false;
128 RegisterMap map(thread,
129 RegisterMap::UpdateMap::skip,
130 RegisterMap::ProcessFrames::skip,
131 RegisterMap::WalkContinuation::skip);
132 frame f;
133 for (f = thread->last_frame();
134 !f.is_first_frame() && f.sp() <= unextended_sp && !Continuation::is_continuation_enterSpecial(f);
135 f = f.sender(&map)) {
136 interpreted_bottom = f.is_interpreted_frame();
137 }
138 assert(Continuation::is_continuation_enterSpecial(f), "");
139 sp = interpreted_bottom ? f.sp() : entry->bottom_sender_sp();
140 }
141
142 assert(sp != nullptr, "");
143 assert(sp <= entry->entry_sp(), "");
144 address pc = ContinuationHelper::return_address_at(
145 sp - frame::sender_sp_ret_address_offset());
146
147 if (pc != StubRoutines::cont_returnBarrier()) {
148 CodeBlob* cb = pc != nullptr ? CodeCache::find_blob(pc) : nullptr;
149 assert(cb != nullptr, "sp: " INTPTR_FORMAT " pc: " INTPTR_FORMAT, p2i(sp), p2i(pc));
150 assert(cb->as_nmethod()->method()->is_continuation_enter_intrinsic(), "");
151 }
152
153 return true;
154 }
155 #endif // ASSERT