|
1 /* |
|
2 * Copyright (c) 1997, 2016, 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_CODE_STUBS_HPP |
|
26 #define SHARE_VM_CODE_STUBS_HPP |
|
27 |
|
28 #include "asm/codeBuffer.hpp" |
|
29 #include "memory/allocation.hpp" |
|
30 |
|
31 // The classes in this file provide a simple framework for the |
|
32 // management of little pieces of machine code - or stubs - |
|
33 // created on the fly and frequently discarded. In this frame- |
|
34 // work stubs are stored in a queue. |
|
35 |
|
36 |
|
37 // Stub serves as abstract base class. A concrete stub |
|
38 // implementation is a subclass of Stub, implementing |
|
39 // all (non-virtual!) functions required sketched out |
|
40 // in the Stub class. |
|
41 // |
|
42 // A concrete stub layout may look like this (both data |
|
43 // and code sections could be empty as well): |
|
44 // |
|
45 // ________ |
|
46 // stub -->| | <--+ |
|
47 // | data | | |
|
48 // |________| | |
|
49 // code_begin -->| | | |
|
50 // | | | |
|
51 // | code | | size |
|
52 // | | | |
|
53 // |________| | |
|
54 // code_end -->| | | |
|
55 // | data | | |
|
56 // |________| | |
|
57 // <--+ |
|
58 |
|
59 |
|
60 class Stub VALUE_OBJ_CLASS_SPEC { |
|
61 public: |
|
62 // Initialization/finalization |
|
63 void initialize(int size, |
|
64 CodeStrings& strings) { ShouldNotCallThis(); } // called to initialize/specify the stub's size |
|
65 void finalize() { ShouldNotCallThis(); } // called before the stub is deallocated |
|
66 |
|
67 // General info/converters |
|
68 int size() const { ShouldNotCallThis(); return 0; } // must return the size provided by initialize |
|
69 static int code_size_to_size(int code_size) { ShouldNotCallThis(); return 0; } // computes the size given the code size |
|
70 |
|
71 // Code info |
|
72 address code_begin() const { ShouldNotCallThis(); return NULL; } // points to the first byte of the code |
|
73 address code_end() const { ShouldNotCallThis(); return NULL; } // points to the first byte after the code |
|
74 |
|
75 // Debugging |
|
76 void verify() { ShouldNotCallThis(); } // verifies the Stub |
|
77 void print() { ShouldNotCallThis(); } // prints some information about the stub |
|
78 }; |
|
79 |
|
80 |
|
81 // A stub interface defines the interface between a stub queue |
|
82 // and the stubs it queues. In order to avoid a vtable and |
|
83 // (and thus the extra word) in each stub, a concrete stub |
|
84 // interface object is created and associated with a stub |
|
85 // buffer which in turn uses the stub interface to interact |
|
86 // with its stubs. |
|
87 // |
|
88 // StubInterface serves as an abstract base class. A concrete |
|
89 // stub interface implementation is a subclass of StubInterface, |
|
90 // forwarding its virtual function calls to non-virtual calls |
|
91 // of the concrete stub (see also macro below). There's exactly |
|
92 // one stub interface instance required per stub queue. |
|
93 |
|
94 class StubInterface: public CHeapObj<mtCode> { |
|
95 public: |
|
96 // Initialization/finalization |
|
97 virtual void initialize(Stub* self, int size, |
|
98 CodeStrings& strings) = 0; // called after creation (called twice if allocated via (request, commit)) |
|
99 virtual void finalize(Stub* self) = 0; // called before deallocation |
|
100 |
|
101 // General info/converters |
|
102 virtual int size(Stub* self) const = 0; // the total size of the stub in bytes (must be a multiple of CodeEntryAlignment) |
|
103 virtual int code_size_to_size(int code_size) const = 0; // computes the total stub size in bytes given the code size in bytes |
|
104 |
|
105 // Code info |
|
106 virtual address code_begin(Stub* self) const = 0; // points to the first code byte |
|
107 virtual address code_end(Stub* self) const = 0; // points to the first byte after the code |
|
108 |
|
109 // Debugging |
|
110 virtual void verify(Stub* self) = 0; // verifies the stub |
|
111 virtual void print(Stub* self) = 0; // prints information about the stub |
|
112 }; |
|
113 |
|
114 |
|
115 // DEF_STUB_INTERFACE is used to create a concrete stub interface |
|
116 // class, forwarding stub interface calls to the corresponding |
|
117 // stub calls. |
|
118 |
|
119 #define DEF_STUB_INTERFACE(stub) \ |
|
120 class stub##Interface: public StubInterface { \ |
|
121 private: \ |
|
122 static stub* cast(Stub* self) { return (stub*)self; } \ |
|
123 \ |
|
124 public: \ |
|
125 /* Initialization/finalization */ \ |
|
126 virtual void initialize(Stub* self, int size, \ |
|
127 CodeStrings& strings) { cast(self)->initialize(size, strings); } \ |
|
128 virtual void finalize(Stub* self) { cast(self)->finalize(); } \ |
|
129 \ |
|
130 /* General info */ \ |
|
131 virtual int size(Stub* self) const { return cast(self)->size(); } \ |
|
132 virtual int code_size_to_size(int code_size) const { return stub::code_size_to_size(code_size); } \ |
|
133 \ |
|
134 /* Code info */ \ |
|
135 virtual address code_begin(Stub* self) const { return cast(self)->code_begin(); } \ |
|
136 virtual address code_end(Stub* self) const { return cast(self)->code_end(); } \ |
|
137 \ |
|
138 /* Debugging */ \ |
|
139 virtual void verify(Stub* self) { cast(self)->verify(); } \ |
|
140 virtual void print(Stub* self) { cast(self)->print(); } \ |
|
141 }; |
|
142 |
|
143 |
|
144 // A StubQueue maintains a queue of stubs. |
|
145 // Note: All sizes (spaces) are given in bytes. |
|
146 |
|
147 class StubQueue: public CHeapObj<mtCode> { |
|
148 friend class VMStructs; |
|
149 private: |
|
150 StubInterface* _stub_interface; // the interface prototype |
|
151 address _stub_buffer; // where all stubs are stored |
|
152 int _buffer_size; // the buffer size in bytes |
|
153 int _buffer_limit; // the (byte) index of the actual buffer limit (_buffer_limit <= _buffer_size) |
|
154 int _queue_begin; // the (byte) index of the first queue entry (word-aligned) |
|
155 int _queue_end; // the (byte) index of the first entry after the queue (word-aligned) |
|
156 int _number_of_stubs; // the number of buffered stubs |
|
157 Mutex* const _mutex; // the lock used for a (request, commit) transaction |
|
158 |
|
159 void check_index(int i) const { assert(0 <= i && i < _buffer_limit && i % CodeEntryAlignment == 0, "illegal index"); } |
|
160 bool is_contiguous() const { return _queue_begin <= _queue_end; } |
|
161 int index_of(Stub* s) const { int i = (address)s - _stub_buffer; check_index(i); return i; } |
|
162 Stub* stub_at(int i) const { check_index(i); return (Stub*)(_stub_buffer + i); } |
|
163 Stub* current_stub() const { return stub_at(_queue_end); } |
|
164 |
|
165 // Stub functionality accessed via interface |
|
166 void stub_initialize(Stub* s, int size, |
|
167 CodeStrings& strings) { assert(size % CodeEntryAlignment == 0, "size not aligned"); _stub_interface->initialize(s, size, strings); } |
|
168 void stub_finalize(Stub* s) { _stub_interface->finalize(s); } |
|
169 int stub_size(Stub* s) const { return _stub_interface->size(s); } |
|
170 bool stub_contains(Stub* s, address pc) const { return _stub_interface->code_begin(s) <= pc && pc < _stub_interface->code_end(s); } |
|
171 int stub_code_size_to_size(int code_size) const { return _stub_interface->code_size_to_size(code_size); } |
|
172 void stub_verify(Stub* s) { _stub_interface->verify(s); } |
|
173 void stub_print(Stub* s) { _stub_interface->print(s); } |
|
174 |
|
175 static void register_queue(StubQueue*); |
|
176 |
|
177 public: |
|
178 StubQueue(StubInterface* stub_interface, int buffer_size, Mutex* lock, |
|
179 const char* name); |
|
180 ~StubQueue(); |
|
181 |
|
182 // General queue info |
|
183 bool is_empty() const { return _queue_begin == _queue_end; } |
|
184 int total_space() const { return _buffer_size - 1; } |
|
185 int available_space() const { int d = _queue_begin - _queue_end - 1; return d < 0 ? d + _buffer_size : d; } |
|
186 int used_space() const { return total_space() - available_space(); } |
|
187 int number_of_stubs() const { return _number_of_stubs; } |
|
188 bool contains(address pc) const { return _stub_buffer <= pc && pc < _stub_buffer + _buffer_limit; } |
|
189 Stub* stub_containing(address pc) const; |
|
190 address code_start() const { return _stub_buffer; } |
|
191 address code_end() const { return _stub_buffer + _buffer_limit; } |
|
192 |
|
193 // Stub allocation (atomic transactions) |
|
194 Stub* request_committed(int code_size); // request a stub that provides exactly code_size space for code |
|
195 Stub* request(int requested_code_size); // request a stub with a (maximum) code space - locks the queue |
|
196 void commit (int committed_code_size, |
|
197 CodeStrings& strings); // commit the previously requested stub - unlocks the queue |
|
198 |
|
199 // Stub deallocation |
|
200 void remove_first(); // remove the first stub in the queue |
|
201 void remove_first(int n); // remove the first n stubs in the queue |
|
202 void remove_all(); // remove all stubs in the queue |
|
203 |
|
204 // Iteration |
|
205 static void queues_do(void f(StubQueue* s)); // call f with each StubQueue |
|
206 void stubs_do(void f(Stub* s)); // call f with all stubs |
|
207 Stub* first() const { return number_of_stubs() > 0 ? stub_at(_queue_begin) : NULL; } |
|
208 Stub* next(Stub* s) const { int i = index_of(s) + stub_size(s); |
|
209 if (i == _buffer_limit) i = 0; |
|
210 return (i == _queue_end) ? NULL : stub_at(i); |
|
211 } |
|
212 |
|
213 address stub_code_begin(Stub* s) const { return _stub_interface->code_begin(s); } |
|
214 address stub_code_end(Stub* s) const { return _stub_interface->code_end(s); } |
|
215 |
|
216 // Debugging/printing |
|
217 void verify(); // verifies the stub queue |
|
218 void print(); // prints information about the stub queue |
|
219 |
|
220 }; |
|
221 |
|
222 #endif // SHARE_VM_CODE_STUBS_HPP |