1 /*
2 * Copyright (c) 1997, 2005, 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.
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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 //-----------------------------------------------------------------------------
26 // The CompiledIC represents a compiled inline cache.
27 //
28 // In order to make patching of the inline cache MT-safe, we only allow the following
29 // transitions (when not at a safepoint):
30 //
31 //
32 // [1] --<-- Clean -->--- [1]
33 // / (null) \
34 // / \ /-<-\
35 // / [2] \ / \
36 // Interpreted ---------> Monomorphic | [3]
37 // (compiledICHolderOop) (klassOop) |
38 // \ / \ /
39 // [4] \ / [4] \->-/
40 // \->- Megamorphic -<-/
41 // (methodOop)
42 //
43 // The text in paranteses () refere to the value of the inline cache receiver (mov instruction)
44 //
45 // The numbers in square brackets refere to the kind of transition:
46 // [1]: Initial fixup. Receiver it found from debug information
47 // [2]: Compilation of a method
48 // [3]: Recompilation of a method (note: only entry is changed. The klassOop must stay the same)
49 // [4]: Inline cache miss. We go directly to megamorphic call.
50 //
51 // The class automatically inserts transition stubs (using the InlineCacheBuffer) when an MT-unsafe
52 // transition is made to a stub.
53 //
54 class CompiledIC;
55
56 class CompiledICInfo {
57 friend class CompiledIC;
58 private:
59 address _entry; // entry point for call
60 Handle _cached_oop; // Value of cached_oop (either in stub or inline cache)
61 bool _is_optimized; // it is an optimized virtual call (i.e., can be statically bound)
62 bool _to_interpreter; // Call it to interpreter
63 public:
64 address entry() const { return _entry; }
65 Handle cached_oop() const { return _cached_oop; }
66 bool is_optimized() const { return _is_optimized; }
67 };
68
69 class CompiledIC: public ResourceObj {
70 friend class InlineCacheBuffer;
71 friend class ICStub;
72
73
74 private:
75 NativeCall* _ic_call; // the call instruction
76 oop* _oop_addr; // patchable oop cell for this IC
77 RelocIterator _oops; // iteration over any and all set-oop instructions
78 bool _is_optimized; // an optimized virtual call (i.e., no compiled IC)
79
80 CompiledIC(NativeCall* ic_call);
81 CompiledIC(Relocation* ic_reloc); // Must be of virtual_call_type/opt_virtual_call_type
82
83 // low-level inline-cache manipulation. Cannot be accessed directly, since it might not be MT-safe
84 // to change an inline-cache. These changes the underlying inline-cache directly. They *newer* make
85 // changes to a transition stub.
86 void set_ic_destination(address entry_point);
87 void set_cached_oop(oop cache);
88
89 // Reads the location of the transition stub. This will fail with an assertion, if no transition stub is
90 // associated with the inline cache.
91 address stub_address() const;
92 bool is_in_transition_state() const; // Use InlineCacheBuffer
93
94 public:
95 // conversion (machine PC to CompiledIC*)
96 friend CompiledIC* CompiledIC_before(address return_addr);
97 friend CompiledIC* CompiledIC_at(address call_site);
98 friend CompiledIC* CompiledIC_at(Relocation* call_site);
99
100 // Return the cached_oop/destination associated with this inline cache. If the cache currently points
101 // to a transition stub, it will read the values from the transition stub.
102 oop cached_oop() const;
103 address ic_destination() const;
104
105 bool is_optimized() const { return _is_optimized; }
106
107 // State
108 bool is_clean() const;
109 bool is_megamorphic() const;
110 bool is_call_to_compiled() const;
111 bool is_call_to_interpreted() const;
112
113 address end_of_call() { return _ic_call->return_address(); }
114
115 // MT-safe patching of inline caches. Note: Only safe to call is_xxx when holding the CompiledIC_ock
116 // so you are guaranteed that no patching takes place. The same goes for verify.
117 //
118 // Note: We do not provide any direct access to the stub code, to prevent parts of the code
119 // to manipulate the inline cache in MT-unsafe ways.
120 //
121 // They all takes a TRAP argument, since they can cause a GC if the inline-cache buffer is full.
122 //
123 void set_to_clean(); // Can only be called during a safepoint operation
124 void set_to_monomorphic(const CompiledICInfo& info);
125 void set_to_megamorphic(CallInfo* call_info, Bytecodes::Code bytecode, TRAPS);
126
127 static void compute_monomorphic_entry(methodHandle method, KlassHandle receiver_klass,
128 bool is_optimized, bool static_bound, CompiledICInfo& info, TRAPS);
129
130 // Location
131 address instruction_address() const { return _ic_call->instruction_address(); }
132
133 // Misc
134 void print() PRODUCT_RETURN;
135 void print_compiled_ic() PRODUCT_RETURN;
136 void verify() PRODUCT_RETURN;
137 };
138
139 inline CompiledIC* CompiledIC_before(address return_addr) {
140 CompiledIC* c_ic = new CompiledIC(nativeCall_before(return_addr));
141 c_ic->verify();
142 return c_ic;
143 }
144
145 inline CompiledIC* CompiledIC_at(address call_site) {
146 CompiledIC* c_ic = new CompiledIC(nativeCall_at(call_site));
147 c_ic->verify();
148 return c_ic;
149 }
150
151 inline CompiledIC* CompiledIC_at(Relocation* call_site) {
152 CompiledIC* c_ic = new CompiledIC(call_site);
153 c_ic->verify();
154 return c_ic;
155 }
156
157
158 //-----------------------------------------------------------------------------
159 // The CompiledStaticCall represents a call to a static method in the compiled
160 //
161 // Transition diagram of a static call site is somewhat simpler than for an inlined cache:
162 //
163 //
164 // -----<----- Clean ----->-----
165 // / \
166 // / \
167 // compilled code <------------> interpreted code
168 //
169 // Clean: Calls directly to runtime method for fixup
170 // Compiled code: Calls directly to compiled code
171 // Interpreted code: Calls to stub that set methodOop reference
172 //
173 //
174 class CompiledStaticCall;
175
176 class StaticCallInfo {
177 private:
178 address _entry; // Entrypoint
179 methodHandle _callee; // Callee (used when calling interpreter)
180 bool _to_interpreter; // call to interpreted method (otherwise compiled)
181
182 friend class CompiledStaticCall;
183 public:
184 address entry() const { return _entry; }
185 methodHandle callee() const { return _callee; }
186 };
187
188
189 class CompiledStaticCall: public NativeCall {
190 friend class CompiledIC;
191
192 // Also used by CompiledIC
193 void set_to_interpreted(methodHandle callee, address entry);
194 bool is_optimized_virtual();
195
196 public:
197 friend CompiledStaticCall* compiledStaticCall_before(address return_addr);
198 friend CompiledStaticCall* compiledStaticCall_at(address native_call);
199 friend CompiledStaticCall* compiledStaticCall_at(Relocation* call_site);
200
201 // State
202 bool is_clean() const;
203 bool is_call_to_compiled() const;
204 bool is_call_to_interpreted() const;
205
206 // Clean static call (will force resolving on next use)
207 void set_to_clean();
208
209 // Set state. The entry must be the same, as computed by compute_entry.
210 // Computation and setting is split up, since the actions are separate during
211 // a OptoRuntime::resolve_xxx.
212 void set(const StaticCallInfo& info);
213
214 // Compute entry point given a method
215 static void compute_entry(methodHandle m, StaticCallInfo& info);
216
217 // Stub support
218 address find_stub();
219 static void set_stub_to_clean(static_stub_Relocation* static_stub);
220
221 // Misc.
222 void print() PRODUCT_RETURN;
223 void verify() PRODUCT_RETURN;
224 };
225
226
227 inline CompiledStaticCall* compiledStaticCall_before(address return_addr) {
228 CompiledStaticCall* st = (CompiledStaticCall*)nativeCall_before(return_addr);
229 st->verify();
230 return st;
231 }
232
233 inline CompiledStaticCall* compiledStaticCall_at(address native_call) {
234 CompiledStaticCall* st = (CompiledStaticCall*)native_call;
235 st->verify();
236 return st;
237 }
238
239 inline CompiledStaticCall* compiledStaticCall_at(Relocation* call_site) {
240 return compiledStaticCall_at(call_site->addr());
241 }