icBuffer.hpp revision 5776:de6a9e811145 
1/*
2 * Copyright (c) 1997, 2013, 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_VM_CODE_ICBUFFER_HPP
26#define SHARE_VM_CODE_ICBUFFER_HPP
27
28#include "asm/codeBuffer.hpp"
29#include "code/stubs.hpp"
30#include "interpreter/bytecodes.hpp"
31#include "memory/allocation.hpp"
32
33//
34// For CompiledIC's:
35//
36// In cases where we do not have MT-safe state transformation,
37// we go to a transition state, using ICStubs. At a safepoint,
38// the inline caches are transferred from the transitional code:
39//
40//    instruction_address --> 01 set xxx_oop, Ginline_cache_klass
41//                            23 jump_to Gtemp, yyyy
42//                            4  nop
43
44class ICStub: public Stub {
45 private:
46  int                 _size;       // total size of the stub incl. code
47  address             _ic_site;    // points at call instruction of owning ic-buffer
48  /* stub code follows here */
49 protected:
50  friend class ICStubInterface;
51  // This will be called only by ICStubInterface
52  void    initialize(int size,
53                     CodeStrings strings)        { _size = size; _ic_site = NULL; }
54  void    finalize(); // called when a method is removed
55
56  // General info
57  int     size() const                           { return _size; }
58  static  int code_size_to_size(int code_size)   { return round_to(sizeof(ICStub), CodeEntryAlignment) + code_size; }
59
60 public:
61  // Creation
62  void set_stub(CompiledIC *ic, void* cached_value, address dest_addr);
63
64  // Code info
65  address code_begin() const                     { return (address)this + round_to(sizeof(ICStub), CodeEntryAlignment); }
66  address code_end() const                       { return (address)this + size(); }
67
68  // Call site info
69  address ic_site() const                        { return _ic_site; }
70  void    clear();
71  bool    is_empty() const                       { return _ic_site == NULL; }
72
73  // stub info
74  address destination() const;  // destination of jump instruction
75  void* cached_value() const;   // cached_value for stub
76
77  // Debugging
78  void    verify()            PRODUCT_RETURN;
79  void    print()             PRODUCT_RETURN;
80
81  // Creation
82  friend ICStub* ICStub_from_destination_address(address destination_address);
83};
84
85// ICStub Creation
86inline ICStub* ICStub_from_destination_address(address destination_address) {
87  ICStub* stub = (ICStub*) (destination_address - round_to(sizeof(ICStub), CodeEntryAlignment));
88  #ifdef ASSERT
89  stub->verify();
90  #endif
91  return stub;
92}
93
94class InlineCacheBuffer: public AllStatic {
95 private:
96  // friends
97  friend class ICStub;
98
99  static int ic_stub_code_size();
100
101  static StubQueue* _buffer;
102  static ICStub*    _next_stub;
103
104  static CompiledICHolder* _pending_released;
105  static int _pending_count;
106
107  static StubQueue* buffer()                         { return _buffer;         }
108  static void       set_next_stub(ICStub* next_stub) { _next_stub = next_stub; }
109  static ICStub*    get_next_stub()                  { return _next_stub;      }
110
111  static void       init_next_stub();
112
113  static ICStub* new_ic_stub();
114
115
116  // Machine-dependent implementation of ICBuffer
117  static void    assemble_ic_buffer_code(address code_begin, void* cached_value, address entry_point);
118  static address ic_buffer_entry_point  (address code_begin);
119  static void*   ic_buffer_cached_value (address code_begin);
120
121 public:
122
123    // Initialization; must be called before first usage
124  static void initialize();
125
126  // Access
127  static bool contains(address instruction_address);
128
129    // removes the ICStubs after backpatching
130  static void update_inline_caches();
131
132  // for debugging
133  static bool is_empty();
134
135  static void release_pending_icholders();
136  static void queue_for_release(CompiledICHolder* icholder);
137  static int pending_icholder_count() { return _pending_count; }
138
139  // New interface
140  static void    create_transition_stub(CompiledIC *ic, void* cached_value, address entry);
141  static address ic_destination_for(CompiledIC *ic);
142  static void*   cached_value_for(CompiledIC *ic);
143};
144
145#endif // SHARE_VM_CODE_ICBUFFER_HPP
146