1 /*
2 * Copyright (c) 1997, 2024, 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.
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23 */
24
25 #ifndef SHARE_CODE_COMPILEDIC_HPP
26 #define SHARE_CODE_COMPILEDIC_HPP
27
28 #include "code/nativeInst.hpp"
29 #include "interpreter/linkResolver.hpp"
30 #include "runtime/safepointVerifiers.hpp"
31 #include "opto/c2_MacroAssembler.hpp"
32
33 //-----------------------------------------------------------------------------
34 // The CompiledIC represents a compiled inline cache.
35 //
36 // It's safe to transition from any state to any state. Typically an inline cache starts
37 // in the clean state, meaning it will resolve the call when called. Then it typically
38 // transitions to monomorphic, assuming the first dynamic receiver will be the only one
39 // observed. If that speculation fails, we transition to megamorphic.
40 //
41 class CompiledIC;
42 class CompiledICProtectionBehaviour;
43 class nmethod;
44
45 class CompiledICLocker: public StackObj {
46 nmethod* _method;
47 CompiledICProtectionBehaviour* _behaviour;
48 bool _locked;
49 NoSafepointVerifier _nsv;
50
51 public:
52 CompiledICLocker(nmethod* method);
53 ~CompiledICLocker();
54 static bool is_safe(nmethod* method);
55 static bool is_safe(address code);
56 };
57
58 // A CompiledICData is a helper object for the inline cache implementation.
59 // It comprises:
60 // (1) The first receiver klass and its selected method
61 // (2) Itable call metadata
62
63 class CompiledICData : public CHeapObj<mtCode> {
64 friend class VMStructs;
65 friend class JVMCIVMStructs;
66
67 Method* volatile _speculated_method;
68 uintptr_t volatile _speculated_klass;
69 Klass* _itable_defc_klass;
70 Klass* _itable_refc_klass;
71 bool _is_initialized;
72
73 bool is_speculated_klass_unloaded() const;
74
75 public:
76 // Constructor
77 CompiledICData();
78
79 // accessors
80 Klass* speculated_klass() const;
81 Method* speculated_method() const { return _speculated_method; }
82 Klass* itable_defc_klass() const { return _itable_defc_klass; }
83 Klass* itable_refc_klass() const { return _itable_refc_klass; }
84
85 static ByteSize speculated_method_offset() { return byte_offset_of(CompiledICData, _speculated_method); }
86 static ByteSize speculated_klass_offset() { return byte_offset_of(CompiledICData, _speculated_klass); }
87
88 static ByteSize itable_defc_klass_offset() { return byte_offset_of(CompiledICData, _itable_defc_klass); }
89 static ByteSize itable_refc_klass_offset() { return byte_offset_of(CompiledICData, _itable_refc_klass); }
90
91 void initialize(CallInfo* call_info, Klass* receiver_klass);
92
93 bool is_initialized() const { return _is_initialized; }
94
95 // GC Support
96 void clean_metadata();
97 void metadata_do(MetadataClosure* cl);
98 };
99
100 class CompiledIC: public ResourceObj {
101 private:
102 nmethod* _method;
103 CompiledICData* _data;
104 NativeCall* _call;
105
106 CompiledIC(RelocIterator* iter);
107
108 // CompiledICData wrappers
109 void ensure_initialized(CallInfo* call_info, Klass* receiver_klass);
110 bool is_speculated_klass(Klass* receiver_klass);
111
112 // Inline cache states
113 void set_to_monomorphic();
114 void set_to_megamorphic(CallInfo* call_info);
115
116 public:
117 // conversion (machine PC to CompiledIC*)
118 friend CompiledIC* CompiledIC_before(nmethod* nm, address return_addr);
119 friend CompiledIC* CompiledIC_at(nmethod* nm, address call_site);
120 friend CompiledIC* CompiledIC_at(Relocation* call_site);
121 friend CompiledIC* CompiledIC_at(RelocIterator* reloc_iter);
122
123 CompiledICData* data() const;
124
125 // State
126 bool is_clean() const;
127 bool is_monomorphic() const;
128 bool is_megamorphic() const;
129
130 address end_of_call() const { return _call->return_address(); }
131
132 // MT-safe patching of inline caches. Note: Only safe to call is_xxx when holding the CompiledICLocker
133 // so you are guaranteed that no patching takes place. The same goes for verify.
134 void set_to_clean();
135 void update(CallInfo* call_info, Klass* receiver_klass);
136
137 // GC support
138 void clean_metadata();
139 void metadata_do(MetadataClosure* cl);
140
141 // Location
142 address instruction_address() const { return _call->instruction_address(); }
143 address destination() const { return _call->destination(); }
144
145 // Misc
146 void print() PRODUCT_RETURN;
147 void verify() PRODUCT_RETURN;
148 };
149
150 CompiledIC* CompiledIC_before(nmethod* nm, address return_addr);
151 CompiledIC* CompiledIC_at(nmethod* nm, address call_site);
152 CompiledIC* CompiledIC_at(Relocation* call_site);
153 CompiledIC* CompiledIC_at(RelocIterator* reloc_iter);
154
155 //-----------------------------------------------------------------------------
156 // The CompiledDirectCall represents a call to a method in the compiled code
157 //
158 //
159 // -----<----- Clean ----->-----
160 // / \
161 // / \
162 // compilled code <------------> interpreted code
163 //
164 // Clean: Calls directly to runtime method for fixup
165 // Compiled code: Calls directly to compiled code
166 // Interpreted code: Calls to stub that set Method* reference
167 //
168 //
169
170 class CompiledDirectCall : public ResourceObj {
171 private:
172 friend class CompiledIC;
173 friend class DirectNativeCallWrapper;
174
175 // Also used by CompiledIC
176 void set_to_interpreted(const methodHandle& callee, address entry);
177 void verify_mt_safe(const methodHandle& callee, address entry,
178 NativeMovConstReg* method_holder,
179 NativeJump* jump) PRODUCT_RETURN;
180 address instruction_address() const { return _call->instruction_address(); }
181 void set_destination_mt_safe(address dest) { _call->set_destination_mt_safe(dest); }
182
183 NativeCall* _call;
184
185 CompiledDirectCall(NativeCall* call) : _call(call) {}
186
187 public:
188 // Returns null if CodeBuffer::expand fails
189 static address emit_to_interp_stub(MacroAssembler *masm, address mark = nullptr);
190 static int to_interp_stub_size();
191 static int to_trampoline_stub_size();
192 static int reloc_to_interp_stub();
193
194 static inline CompiledDirectCall* before(address return_addr) {
195 CompiledDirectCall* st = new CompiledDirectCall(nativeCall_before(return_addr));
196 st->verify();
197 return st;
198 }
199
200 static inline CompiledDirectCall* at(address native_call) {
201 CompiledDirectCall* st = new CompiledDirectCall(nativeCall_at(native_call));
202 st->verify();
203 return st;
204 }
205
206 static inline CompiledDirectCall* at(Relocation* call_site) {
207 return at(call_site->addr());
208 }
209
210 // Delegation
211 address destination() const { return _call->destination(); }
212 address end_of_call() const { return _call->return_address(); }
213
214 // Clean static call (will force resolving on next use)
215 void set_to_clean();
216
217 void set(const methodHandle& callee_method);
218
219 // State
220 bool is_clean() const;
221 bool is_call_to_interpreted() const;
222 bool is_call_to_compiled() const;
223
224 // Stub support
225 static address find_stub_for(address instruction);
226 address find_stub();
227 static void set_stub_to_clean(static_stub_Relocation* static_stub);
228
229 // Misc.
230 void print() PRODUCT_RETURN;
231 void verify() PRODUCT_RETURN;
232 };
233
234 #endif // SHARE_CODE_COMPILEDIC_HPP