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 nmethod* ContinuationEntry::_do_yield = nullptr;
45 int ContinuationEntry::_interpreted_entry_offset = 0;
46
47 void ContinuationEntry::set_enter_code(nmethod* nm, int interpreted_entry_offset) {
48 assert(_return_pc_offset != 0, "");
49 assert(_thaw_call_pc_offset != 0, "");
50 _return_pc = nm->code_begin() + _return_pc_offset;
51 _thaw_call_pc = nm->code_begin() + _thaw_call_pc_offset;
52 _cleanup_pc = nm->code_begin() + _cleanup_offset;
53
54 _enter_special = nm;
55 _interpreted_entry_offset = interpreted_entry_offset;
56
57 assert(_enter_special->code_contains(compiled_entry()), "entry not in enterSpecial");
58 assert(_enter_special->code_contains(interpreted_entry()), "entry not in enterSpecial");
59 assert(interpreted_entry() < compiled_entry(), "unexpected code layout");
60 }
61
62 void ContinuationEntry::set_yield_code(nmethod* nm) {
63 _do_yield = nm;
64 }
65
66 address ContinuationEntry::compiled_entry() {
67 return _enter_special->verified_entry_point();
68 }
69
70 address ContinuationEntry::interpreted_entry() {
71 return _enter_special->code_begin() + _interpreted_entry_offset;
72 }
73
74 bool ContinuationEntry::is_interpreted_call(address call_address) {
75 assert(_enter_special->code_contains(call_address), "call not in enterSpecial");
76 assert(call_address >= interpreted_entry(), "unexpected location");
77 return call_address < compiled_entry();
78 }
79
80 ContinuationEntry* ContinuationEntry::from_frame(const frame& f) {
81 assert(Continuation::is_continuation_enterSpecial(f), "");
82 return (ContinuationEntry*)f.unextended_sp();
83 }
84
85 NOINLINE static void flush_stack_processing(JavaThread* thread, intptr_t* sp) {
86 log_develop_trace(continuations)("flush_stack_processing");
87 for (StackFrameStream fst(thread, true, true); fst.current()->sp() <= sp; fst.next()) {
88 ;
89 }
90 }
91
92 inline void maybe_flush_stack_processing(JavaThread* thread, intptr_t* sp) {
93 StackWatermark* sw;
94 uintptr_t watermark;
95 if ((sw = StackWatermarkSet::get(thread, StackWatermarkKind::gc)) != nullptr
96 && (watermark = sw->watermark()) != 0
97 && watermark <= (uintptr_t)sp) {
98 flush_stack_processing(thread, sp);
99 }
100 }
101
102 void ContinuationEntry::flush_stack_processing(JavaThread* thread) const {
103 maybe_flush_stack_processing(thread, (intptr_t*)((uintptr_t)entry_sp() + ContinuationEntry::size()));
104 }
105
106 #ifndef PRODUCT
107 void ContinuationEntry::describe(FrameValues& values, int frame_no) const {
108 address usp = (address)this;
109 values.describe(frame_no, (intptr_t*)(usp + in_bytes(ContinuationEntry::parent_offset())), "parent");
110 values.describe(frame_no, (intptr_t*)(usp + in_bytes(ContinuationEntry::cont_offset())), "continuation");
111 values.describe(frame_no, (intptr_t*)(usp + in_bytes(ContinuationEntry::flags_offset())), "flags");
112 values.describe(frame_no, (intptr_t*)(usp + in_bytes(ContinuationEntry::chunk_offset())), "chunk");
113 values.describe(frame_no, (intptr_t*)(usp + in_bytes(ContinuationEntry::argsize_offset())), "argsize");
114 values.describe(frame_no, (intptr_t*)(usp + in_bytes(ContinuationEntry::pin_count_offset())), "pin_count");
115 values.describe(frame_no, (intptr_t*)(usp + in_bytes(ContinuationEntry::parent_cont_fastpath_offset())), "parent fastpath");
116 values.describe(frame_no, (intptr_t*)(usp + in_bytes(ContinuationEntry::parent_held_monitor_count_offset())), "parent held monitor count");
117 }
118 #endif
119
120 #ifdef ASSERT
121 bool ContinuationEntry::assert_entry_frame_laid_out(JavaThread* thread, bool preempted) {
122 assert(thread->has_last_Java_frame(), "Wrong place to use this assertion");
123
124 if (preempted) return true;
125
126 ContinuationEntry* entry = thread->last_continuation();
127 assert(entry != nullptr, "");
128
129 intptr_t* unextended_sp = entry->entry_sp();
130 intptr_t* sp;
131 if (entry->argsize() > 0) {
132 sp = entry->bottom_sender_sp();
133 } else {
134 sp = unextended_sp;
135 bool interpreted_bottom = false;
136 RegisterMap map(thread,
137 RegisterMap::UpdateMap::skip,
138 RegisterMap::ProcessFrames::skip,
139 RegisterMap::WalkContinuation::skip);
140 frame f;
141 for (f = thread->last_frame();
142 !f.is_first_frame() && f.sp() <= unextended_sp && !Continuation::is_continuation_enterSpecial(f);
143 f = f.sender(&map)) {
144 interpreted_bottom = f.is_interpreted_frame();
145 }
146 assert(Continuation::is_continuation_enterSpecial(f), "");
147 sp = interpreted_bottom ? f.sp() : entry->bottom_sender_sp();
148 }
149
150 assert(sp != nullptr, "");
151 assert(sp <= entry->entry_sp(), "");
152 address pc = ContinuationHelper::return_address_at(
153 sp - frame::sender_sp_ret_address_offset());
154
155 if (pc != StubRoutines::cont_returnBarrier()) {
156 CodeBlob* cb = pc != nullptr ? CodeCache::find_blob(pc) : nullptr;
157 assert(cb != nullptr, "sp: " INTPTR_FORMAT " pc: " INTPTR_FORMAT, p2i(sp), p2i(pc));
158 assert(cb->as_nmethod()->method()->is_continuation_enter_intrinsic(), "");
159 }
160
161 return true;
162 }
163 #endif // ASSERT