1 /*
2 * Copyright (c) 1997, 2023, 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 *
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16 * 2 along with this work; if not, write to the Free Software Foundation,
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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 "oops/compiledICHolder.hpp"
31 #include "runtime/safepointVerifiers.hpp"
32
33 //-----------------------------------------------------------------------------
34 // The CompiledIC represents a compiled inline cache.
35 //
36 // In order to make patching of the inline cache MT-safe, we only allow the following
37 // transitions (when not at a safepoint):
38 //
39 //
40 // [1] --<-- Clean -->--- [1]
41 // / (null) \
42 // / \ /-<-\
43 // / [2] \ / \
44 // Interpreted ---------> Monomorphic | [3]
45 // (CompiledICHolder*) (Klass*) |
46 // \ / \ /
47 // [4] \ / [4] \->-/
48 // \->- Megamorphic -<-/
49 // (CompiledICHolder*)
50 //
51 // The text in parentheses () refers to the value of the inline cache receiver (mov instruction)
52 //
53 // The numbers in square brackets refer to the kind of transition:
54 // [1]: Initial fixup. Receiver it found from debug information
55 // [2]: Compilation of a method
56 // [3]: Recompilation of a method (note: only entry is changed. The Klass* must stay the same)
57 // [4]: Inline cache miss. We go directly to megamorphic call.
58 //
59 // The class automatically inserts transition stubs (using the InlineCacheBuffer) when an MT-unsafe
60 // transition is made to a stub.
61 //
62 class CompiledIC;
63 class CompiledICProtectionBehaviour;
64 class CompiledMethod;
65 class ICStub;
66
67 class CompiledICLocker: public StackObj {
68 CompiledMethod* _method;
69 CompiledICProtectionBehaviour* _behaviour;
70 bool _locked;
71 NoSafepointVerifier _nsv;
72
73 public:
74 CompiledICLocker(CompiledMethod* method);
75 ~CompiledICLocker();
76 static bool is_safe(CompiledMethod* method);
77 static bool is_safe(address code);
78 };
79
80 class CompiledICInfo : public StackObj {
81 private:
82 address _entry; // entry point for call
83 void* _cached_value; // Value of cached_value (either in stub or inline cache)
84 bool _is_icholder; // Is the cached value a CompiledICHolder*
85 bool _is_optimized; // it is an optimized virtual call (i.e., can be statically bound)
86 bool _to_interpreter; // Call it to interpreter
87 bool _release_icholder;
88 public:
89 address entry() const { return _entry; }
90 Metadata* cached_metadata() const { assert(!_is_icholder, ""); return (Metadata*)_cached_value; }
91 CompiledICHolder* claim_cached_icholder() {
92 assert(_is_icholder, "");
93 assert(_cached_value != nullptr, "must be non-null");
94 _release_icholder = false;
95 CompiledICHolder* icholder = (CompiledICHolder*)_cached_value;
96 icholder->claim();
97 return icholder;
98 }
99 bool is_optimized() const { return _is_optimized; }
100 bool to_interpreter() const { return _to_interpreter; }
101
102 void set_compiled_entry(address entry, Klass* klass, bool is_optimized) {
103 _entry = entry;
104 _cached_value = (void*)klass;
105 _to_interpreter = false;
106 _is_icholder = false;
107 _is_optimized = is_optimized;
108 _release_icholder = false;
109 }
110
111 void set_interpreter_entry(address entry, Method* method) {
112 _entry = entry;
113 _cached_value = (void*)method;
114 _to_interpreter = true;
115 _is_icholder = false;
116 _is_optimized = true;
117 _release_icholder = false;
118 }
119
120 void set_icholder_entry(address entry, CompiledICHolder* icholder) {
121 _entry = entry;
122 _cached_value = (void*)icholder;
123 _to_interpreter = true;
124 _is_icholder = true;
125 _is_optimized = false;
126 _release_icholder = true;
127 }
128
129 CompiledICInfo(): _entry(nullptr), _cached_value(nullptr), _is_icholder(false),
130 _is_optimized(false), _to_interpreter(false), _release_icholder(false) {
131 }
132 ~CompiledICInfo() {
133 // In rare cases the info is computed but not used, so release any
134 // CompiledICHolder* that was created
135 if (_release_icholder) {
136 assert(_is_icholder, "must be");
137 CompiledICHolder* icholder = (CompiledICHolder*)_cached_value;
138 icholder->claim();
139 delete icholder;
140 }
141 }
142 };
143
144 class NativeCallWrapper: public ResourceObj {
145 public:
146 virtual address destination() const = 0;
147 virtual address instruction_address() const = 0;
148 virtual address next_instruction_address() const = 0;
149 virtual address return_address() const = 0;
150 virtual address get_resolve_call_stub(bool is_optimized) const = 0;
151 virtual void set_destination_mt_safe(address dest) = 0;
152 virtual void set_to_interpreted(const methodHandle& method, CompiledICInfo& info) = 0;
153 virtual void verify() const = 0;
154 virtual void verify_resolve_call(address dest) const = 0;
155
156 virtual bool is_call_to_interpreted(address dest) const = 0;
157 virtual bool is_safe_for_patching() const = 0;
158
159 virtual NativeInstruction* get_load_instruction(virtual_call_Relocation* r) const = 0;
160
161 virtual void *get_data(NativeInstruction* instruction) const = 0;
162 virtual void set_data(NativeInstruction* instruction, intptr_t data) = 0;
163 };
164
165 class CompiledIC: public ResourceObj {
166 friend class InlineCacheBuffer;
167 friend class ICStub;
168
169 private:
170 NativeCallWrapper* _call;
171 NativeInstruction* _value; // patchable value cell for this IC
172 bool _is_optimized; // an optimized virtual call (i.e., no compiled IC)
173 CompiledMethod* _method;
174
175 CompiledIC(CompiledMethod* cm, NativeCall* ic_call);
176 CompiledIC(RelocIterator* iter);
177
178 void initialize_from_iter(RelocIterator* iter);
179
180 static bool is_icholder_entry(address entry);
181
182 // low-level inline-cache manipulation. Cannot be accessed directly, since it might not be MT-safe
183 // to change an inline-cache. These changes the underlying inline-cache directly. They *newer* make
184 // changes to a transition stub.
185 void internal_set_ic_destination(address entry_point, bool is_icstub, void* cache, bool is_icholder);
186 void set_ic_destination(ICStub* stub);
187 void set_ic_destination(address entry_point) {
188 assert(_is_optimized, "use set_ic_destination_and_value instead");
189 internal_set_ic_destination(entry_point, false, nullptr, false);
190 }
191 // This only for use by ICStubs where the type of the value isn't known
192 void set_ic_destination_and_value(address entry_point, void* value) {
193 internal_set_ic_destination(entry_point, false, value, is_icholder_entry(entry_point));
194 }
195 void set_ic_destination_and_value(address entry_point, Metadata* value) {
196 internal_set_ic_destination(entry_point, false, value, false);
197 }
198 void set_ic_destination_and_value(address entry_point, CompiledICHolder* value) {
199 internal_set_ic_destination(entry_point, false, value, true);
200 }
201
202 // Reads the location of the transition stub. This will fail with an assertion, if no transition stub is
203 // associated with the inline cache.
204 address stub_address() const;
205 bool is_in_transition_state() const; // Use InlineCacheBuffer
206
207 public:
208 // conversion (machine PC to CompiledIC*)
209 friend CompiledIC* CompiledIC_before(CompiledMethod* nm, address return_addr);
210 friend CompiledIC* CompiledIC_at(CompiledMethod* nm, address call_site);
211 friend CompiledIC* CompiledIC_at(Relocation* call_site);
212 friend CompiledIC* CompiledIC_at(RelocIterator* reloc_iter);
213
214 static bool is_icholder_call_site(virtual_call_Relocation* call_site, const CompiledMethod* cm);
215
216 // Return the cached_metadata/destination associated with this inline cache. If the cache currently points
217 // to a transition stub, it will read the values from the transition stub.
218 void* cached_value() const;
219 CompiledICHolder* cached_icholder() const {
220 assert(is_icholder_call(), "must be");
221 return (CompiledICHolder*) cached_value();
222 }
223 Metadata* cached_metadata() const {
224 assert(!is_icholder_call(), "must be");
225 return (Metadata*) cached_value();
226 }
227
228 void* get_data() const {
229 return _call->get_data(_value);
230 }
231
232 void set_data(intptr_t data) {
233 _call->set_data(_value, data);
234 }
235
236 address ic_destination() const;
237
238 bool is_optimized() const { return _is_optimized; }
239
240 // State
241 bool is_clean() const;
242 bool is_megamorphic() const;
243 bool is_call_to_compiled() const;
244 bool is_call_to_interpreted() const;
245
246 bool is_icholder_call() const;
247
248 address end_of_call() const { return _call->return_address(); }
249
250 // MT-safe patching of inline caches. Note: Only safe to call is_xxx when holding the CompiledIC_ock
251 // so you are guaranteed that no patching takes place. The same goes for verify.
252 //
253 // Note: We do not provide any direct access to the stub code, to prevent parts of the code
254 // to manipulate the inline cache in MT-unsafe ways.
255 //
256 // They all takes a TRAP argument, since they can cause a GC if the inline-cache buffer is full.
257 //
258 bool set_to_clean(bool in_use = true);
259 bool set_to_monomorphic(CompiledICInfo& info);
260 void clear_ic_stub();
261
262 // Returns true if successful and false otherwise. The call can fail if memory
263 // allocation in the code cache fails, or ic stub refill is required.
264 bool set_to_megamorphic(CallInfo* call_info, Bytecodes::Code bytecode, bool& needs_ic_stub_refill, TRAPS);
265
266 static void compute_monomorphic_entry(const methodHandle& method, Klass* receiver_klass,
267 bool is_optimized, bool static_bound, bool caller_is_nmethod,
268 CompiledICInfo& info, TRAPS);
269
270 // Location
271 address instruction_address() const { return _call->instruction_address(); }
272
273 // Misc
274 void print() PRODUCT_RETURN;
275 void print_compiled_ic() PRODUCT_RETURN;
276 void verify() PRODUCT_RETURN;
277 };
278
279 inline CompiledIC* CompiledIC_before(CompiledMethod* nm, address return_addr) {
280 CompiledIC* c_ic = new CompiledIC(nm, nativeCall_before(return_addr));
281 c_ic->verify();
282 return c_ic;
283 }
284
285 inline CompiledIC* CompiledIC_at(CompiledMethod* nm, address call_site) {
286 CompiledIC* c_ic = new CompiledIC(nm, nativeCall_at(call_site));
287 c_ic->verify();
288 return c_ic;
289 }
290
291 inline CompiledIC* CompiledIC_at(Relocation* call_site) {
292 assert(call_site->type() == relocInfo::virtual_call_type ||
293 call_site->type() == relocInfo::opt_virtual_call_type, "wrong reloc. info");
294 CompiledIC* c_ic = new CompiledIC(call_site->code(), nativeCall_at(call_site->addr()));
295 c_ic->verify();
296 return c_ic;
297 }
298
299 inline CompiledIC* CompiledIC_at(RelocIterator* reloc_iter) {
300 assert(reloc_iter->type() == relocInfo::virtual_call_type ||
301 reloc_iter->type() == relocInfo::opt_virtual_call_type, "wrong reloc. info");
302 CompiledIC* c_ic = new CompiledIC(reloc_iter);
303 c_ic->verify();
304 return c_ic;
305 }
306
307 //-----------------------------------------------------------------------------
308 // The CompiledStaticCall represents a call to a static method in the compiled
309 //
310 // Transition diagram of a static call site is somewhat simpler than for an inlined cache:
311 //
312 //
313 // -----<----- Clean ----->-----
314 // / \
315 // / \
316 // compilled code <------------> interpreted code
317 //
318 // Clean: Calls directly to runtime method for fixup
319 // Compiled code: Calls directly to compiled code
320 // Interpreted code: Calls to stub that set Method* reference
321 //
322 //
323
324 class StaticCallInfo {
325 private:
326 address _entry; // Entrypoint
327 methodHandle _callee; // Callee (used when calling interpreter)
328 bool _to_interpreter; // call to interpreted method (otherwise compiled)
329
330 friend class CompiledStaticCall;
331 friend class CompiledDirectStaticCall;
332 friend class CompiledPltStaticCall;
333 public:
334 address entry() const { return _entry; }
335 methodHandle callee() const { return _callee; }
336 };
337
338 class CompiledStaticCall : public ResourceObj {
339 public:
340 // Code
341
342 // Returns null if CodeBuffer::expand fails
343 static address emit_to_interp_stub(CodeBuffer &cbuf, address mark = nullptr);
344 static int to_interp_stub_size();
345 static int to_trampoline_stub_size();
346 static int reloc_to_interp_stub();
347
348 // Compute entry point given a method
349 static void compute_entry(const methodHandle& m, bool caller_is_nmethod, StaticCallInfo& info);
350 void compute_entry_for_continuation_entry(const methodHandle& m, StaticCallInfo& info);
351
352 public:
353 // Clean static call (will force resolving on next use)
354 virtual address destination() const = 0;
355
356 // Clean static call (will force resolving on next use)
357 bool set_to_clean(bool in_use = true);
358
359 // Set state. The entry must be the same, as computed by compute_entry.
360 // Computation and setting is split up, since the actions are separate during
361 // a OptoRuntime::resolve_xxx.
362 void set(const StaticCallInfo& info);
363
364 // State
365 bool is_clean() const;
366 bool is_call_to_compiled() const;
367 virtual bool is_call_to_interpreted() const = 0;
368
369 virtual address instruction_address() const = 0;
370 virtual address end_of_call() const = 0;
371 protected:
372 virtual address resolve_call_stub() const = 0;
373 virtual void set_destination_mt_safe(address dest) = 0;
374 virtual void set_to_interpreted(const methodHandle& callee, address entry) = 0;
375 virtual const char* name() const = 0;
376
377 void set_to_compiled(address entry);
378 };
379
380 class CompiledDirectStaticCall : public CompiledStaticCall {
381 private:
382 friend class CompiledIC;
383 friend class DirectNativeCallWrapper;
384
385 // Also used by CompiledIC
386 void set_to_interpreted(const methodHandle& callee, address entry);
387 void verify_mt_safe(const methodHandle& callee, address entry,
388 NativeMovConstReg* method_holder,
389 NativeJump* jump) PRODUCT_RETURN;
390 address instruction_address() const { return _call->instruction_address(); }
391 void set_destination_mt_safe(address dest) { _call->set_destination_mt_safe(dest); }
392
393 NativeCall* _call;
394
395 CompiledDirectStaticCall(NativeCall* call) : _call(call) {}
396
397 public:
398 static inline CompiledDirectStaticCall* before(address return_addr) {
399 CompiledDirectStaticCall* st = new CompiledDirectStaticCall(nativeCall_before(return_addr));
400 st->verify();
401 return st;
402 }
403
404 static inline CompiledDirectStaticCall* at(address native_call) {
405 CompiledDirectStaticCall* st = new CompiledDirectStaticCall(nativeCall_at(native_call));
406 st->verify();
407 return st;
408 }
409
410 static inline CompiledDirectStaticCall* at(Relocation* call_site) {
411 return at(call_site->addr());
412 }
413
414 // Delegation
415 address destination() const { return _call->destination(); }
416 address end_of_call() const { return _call->return_address(); }
417
418 // State
419 virtual bool is_call_to_interpreted() const;
420
421 // Stub support
422 static address find_stub_for(address instruction);
423 address find_stub();
424 static void set_stub_to_clean(static_stub_Relocation* static_stub);
425
426 // Misc.
427 void print() PRODUCT_RETURN;
428 void verify() PRODUCT_RETURN;
429
430 protected:
431 virtual address resolve_call_stub() const;
432 virtual const char* name() const { return "CompiledDirectStaticCall"; }
433 };
434
435 #endif // SHARE_CODE_COMPILEDIC_HPP