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 #ifndef SHARE_VM_RUNTIME_CONTINUATIONENTRY_HPP
26 #define SHARE_VM_RUNTIME_CONTINUATIONENTRY_HPP
27
28 #include "oops/oop.hpp"
29 #include "oops/oopsHierarchy.hpp"
30 #include "runtime/continuation.hpp"
31 #include "utilities/sizes.hpp"
32
33 #include CPU_HEADER(continuationEntry)
34
35 class JavaThread;
36 class nmethod;
37 class OopMap;
38 class RegisterMap;
39
40 // Metadata stored in the continuation entry frame
41 class ContinuationEntry {
42 friend class JVMCIVMStructs;
43 ContinuationEntryPD _pd;
44 #ifdef ASSERT
45 private:
46 static const int COOKIE_VALUE = 0x1234;
47 int cookie;
48
49 public:
50 static int cookie_value() { return COOKIE_VALUE; }
51 static ByteSize cookie_offset() { return byte_offset_of(ContinuationEntry, cookie); }
52
53 void verify_cookie() {
54 assert(cookie == COOKIE_VALUE, "Bad cookie: %#x, expected: %#x", cookie, COOKIE_VALUE);
55 }
56 #endif
57
58 public:
59 static int _return_pc_offset; // friend gen_continuation_enter
60 static int _thaw_call_pc_offset;
61 static int _cleanup_offset;
62
63 static void set_enter_code(nmethod* nm, int interpreted_entry_offset);
64 static void set_yield_code(nmethod* nm);
65 static bool is_interpreted_call(address call_address);
66
67 private:
68 static address _return_pc;
69 static address _thaw_call_pc;
70 static address _cleanup_pc;
71 static nmethod* _enter_special;
72 static nmethod* _do_yield;
73 static int _interpreted_entry_offset;
74
75 private:
76 ContinuationEntry* _parent;
77 oopDesc* _cont;
78 oopDesc* _chunk;
79 int _flags;
80 // Size in words of the stack arguments of the bottom frame on stack if compiled 0 otherwise.
81 // The caller (if there is one) is the still frozen top frame in the StackChunk.
82 int _argsize;
83 intptr_t* _parent_cont_fastpath;
84 #ifdef _LP64
85 int64_t _parent_held_monitor_count;
86 #else
87 int32_t _parent_held_monitor_count;
88 #endif
89 uint32_t _pin_count;
90
91 public:
92 static ByteSize parent_offset() { return byte_offset_of(ContinuationEntry, _parent); }
93 static ByteSize cont_offset() { return byte_offset_of(ContinuationEntry, _cont); }
94 static ByteSize chunk_offset() { return byte_offset_of(ContinuationEntry, _chunk); }
95 static ByteSize flags_offset() { return byte_offset_of(ContinuationEntry, _flags); }
96 static ByteSize argsize_offset() { return byte_offset_of(ContinuationEntry, _argsize); }
97 static ByteSize pin_count_offset(){ return byte_offset_of(ContinuationEntry, _pin_count); }
98 static ByteSize parent_cont_fastpath_offset() { return byte_offset_of(ContinuationEntry, _parent_cont_fastpath); }
99 static ByteSize parent_held_monitor_count_offset() { return byte_offset_of(ContinuationEntry, _parent_held_monitor_count); }
100
101 static address return_pc() { return _return_pc; }
102 static address return_pc_address() { return (address)&_return_pc; }
103
104 public:
105 static size_t size() { return align_up((int)sizeof(ContinuationEntry), 2*wordSize); }
106
107 ContinuationEntry* parent() const { return _parent; }
108 int64_t parent_held_monitor_count() const { return (int64_t)_parent_held_monitor_count; }
109
110 static address entry_pc() { return _return_pc; }
111 intptr_t* entry_sp() const { return (intptr_t*)this; }
112 intptr_t* entry_fp() const;
113
114 static address thaw_call_pc_address() { return (address)&_thaw_call_pc; }
115 static address cleanup_pc() { return _cleanup_pc; }
116
117 static address compiled_entry();
118 static address interpreted_entry();
119
120 static nmethod* do_yield_nmethod() {
121 assert(_do_yield != nullptr, "oops");
122 return _do_yield;
123 }
124
125 int argsize() const { return _argsize; }
126 void set_argsize(int value) { _argsize = value; }
127
128 bool is_pinned() { return _pin_count > 0; }
129 bool pin() {
130 if (_pin_count == UINT32_MAX) return false;
131 _pin_count++;
132 return true;
133 }
134 bool unpin() {
135 if (_pin_count == 0) return false;
136 _pin_count--;
137 return true;
138 }
139
140 intptr_t* parent_cont_fastpath() const { return _parent_cont_fastpath; }
141 void set_parent_cont_fastpath(intptr_t* x) { _parent_cont_fastpath = x; }
142
143 static ContinuationEntry* from_frame(const frame& f);
144 frame to_frame() const;
145 void update_register_map(RegisterMap* map) const;
146 void flush_stack_processing(JavaThread* thread) const;
147
148 inline intptr_t* bottom_sender_sp() const;
149 inline oop cont_oop(const JavaThread* thread) const;
150 inline oop scope(const JavaThread* thread) const;
151 inline static oop cont_oop_or_null(const ContinuationEntry* ce, const JavaThread* thread);
152
153 oop* cont_addr() { return (oop*)&_cont; }
154 oop* chunk_addr() { return (oop*)&_chunk; }
155
156 bool is_virtual_thread() const { return _flags != 0; }
157
158 #ifndef PRODUCT
159 void describe(FrameValues& values, int frame_no) const;
160 #endif
161
162 #ifdef ASSERT
163 static bool assert_entry_frame_laid_out(JavaThread* thread, bool preempted = false);
164 #endif
165 };
166
167 #endif // SHARE_VM_RUNTIME_CONTINUATIONENTRY_HPP