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 bool is_interpreted_call(address call_address);
65
66 private:
67 static address _return_pc;
68 static address _thaw_call_pc;
69 static address _cleanup_pc;
70 static nmethod* _enter_special;
71 static int _interpreted_entry_offset;
72
73 private:
74 ContinuationEntry* _parent;
75 oopDesc* _cont;
76 oopDesc* _chunk;
77 int _flags;
78 // Size in words of the stack arguments of the bottom frame on stack if compiled 0 otherwise.
79 // The caller (if there is one) is the still frozen top frame in the StackChunk.
80 int _argsize;
81 intptr_t* _parent_cont_fastpath;
82 uint32_t _pin_count;
83
84 public:
85 static ByteSize parent_offset() { return byte_offset_of(ContinuationEntry, _parent); }
86 static ByteSize cont_offset() { return byte_offset_of(ContinuationEntry, _cont); }
87 static ByteSize chunk_offset() { return byte_offset_of(ContinuationEntry, _chunk); }
88 static ByteSize flags_offset() { return byte_offset_of(ContinuationEntry, _flags); }
89 static ByteSize argsize_offset() { return byte_offset_of(ContinuationEntry, _argsize); }
90 static ByteSize pin_count_offset(){ return byte_offset_of(ContinuationEntry, _pin_count); }
91 static ByteSize parent_cont_fastpath_offset() { return byte_offset_of(ContinuationEntry, _parent_cont_fastpath); }
92
93 static address return_pc() { return _return_pc; }
94 static address return_pc_address() { return (address)&_return_pc; }
95
96 public:
97 static size_t size() { return align_up((int)sizeof(ContinuationEntry), 2*wordSize); }
98
99 ContinuationEntry* parent() const { return _parent; }
100
101 static address entry_pc() { return _return_pc; }
102 intptr_t* entry_sp() const { return (intptr_t*)this; }
103 intptr_t* entry_fp() const;
104
105 static address thaw_call_pc_address() { return (address)&_thaw_call_pc; }
106 static address cleanup_pc() { return _cleanup_pc; }
107
108 static address compiled_entry();
109 static address interpreted_entry();
110
111 int argsize() const { return _argsize; }
112 void set_argsize(int value) { _argsize = value; }
113
114 bool is_pinned() { return _pin_count > 0; }
115 bool pin() {
116 if (_pin_count == UINT32_MAX) return false;
117 _pin_count++;
118 return true;
119 }
120 bool unpin() {
121 if (_pin_count == 0) return false;
122 _pin_count--;
123 return true;
124 }
125
126 intptr_t* parent_cont_fastpath() const { return _parent_cont_fastpath; }
127 void set_parent_cont_fastpath(intptr_t* x) { _parent_cont_fastpath = x; }
128
129 static ContinuationEntry* from_frame(const frame& f);
130 frame to_frame() const;
131 void update_register_map(RegisterMap* map) const;
132 void flush_stack_processing(JavaThread* thread) const;
133
134 inline intptr_t* bottom_sender_sp() const;
135 inline oop cont_oop(const JavaThread* thread) const;
136 inline oop scope(const JavaThread* thread) const;
137 inline static oop cont_oop_or_null(const ContinuationEntry* ce, const JavaThread* thread);
138
139 oop* cont_addr() { return (oop*)&_cont; }
140 oop* chunk_addr() { return (oop*)&_chunk; }
141
142 bool is_virtual_thread() const { return _flags != 0; }
143
144 #ifndef PRODUCT
145 void describe(FrameValues& values, int frame_no) const;
146 #endif
147
148 #ifdef ASSERT
149 static bool assert_entry_frame_laid_out(JavaThread* thread, bool preempted = false);
150 #endif
151 };
152
153 #endif // SHARE_VM_RUNTIME_CONTINUATIONENTRY_HPP