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.
22 *
23 */
24
25 #ifndef SHARE_VM_CODE_CODECACHE_HPP
26 #define SHARE_VM_CODE_CODECACHE_HPP
27
28 #include "code/codeBlob.hpp"
29 #include "memory/allocation.hpp"
30 #include "memory/heap.hpp"
31 #include "oops/instanceKlass.hpp"
32 #include "oops/oopsHierarchy.hpp"
33
34 // The CodeCache implements the code cache for various pieces of generated
35 // code, e.g., compiled java methods, runtime stubs, transition frames, etc.
36 // The entries in the CodeCache are all CodeBlob's.
37
38 // Implementation:
39 // - Each CodeBlob occupies one chunk of memory.
40 // - Like the offset table in oldspace the zone has at table for
41 // locating a method given a addess of an instruction.
42
43 class OopClosure;
44 class DepChange;
45
46 class CodeCache : AllStatic {
47 friend class VMStructs;
48 private:
49 // CodeHeap is malloc()'ed at startup and never deleted during shutdown,
50 // so that the generated assembly code is always there when it's needed.
51 // This may cause memory leak, but is necessary, for now. See 4423824,
52 // 4422213 or 4436291 for details.
53 static CodeHeap * _heap;
54 static int _number_of_blobs;
55 static int _number_of_adapters;
56 static int _number_of_nmethods;
57 static int _number_of_nmethods_with_dependencies;
58 static bool _needs_cache_clean;
59 static nmethod* _scavenge_root_nmethods; // linked via nm->scavenge_root_link()
60 static nmethod* _saved_nmethods; // Linked list of speculatively disconnected nmethods.
61
62 static void verify_if_often() PRODUCT_RETURN;
63
64 static void mark_scavenge_root_nmethods() PRODUCT_RETURN;
65 static void verify_perm_nmethods(CodeBlobClosure* f_or_null) PRODUCT_RETURN;
66
67 static int _codemem_full_count;
68
69 static void print_details();
70 static void print_content();
71 static void print_oop_map_usage();
72 static void print_dependency_checking_time();
73
74 public:
75
76 // Initialization
77 static void initialize();
78 static void init_printing_options(const char* options);
79
80 static void report_codemem_full();
81
82 // Allocation/administration
83 static CodeBlob* allocate(int size, bool is_critical = false); // allocates a new CodeBlob
84 static void commit(CodeBlob* cb); // called when the allocated CodeBlob has been filled
85 static int alignment_unit(); // guaranteed alignment of all CodeBlobs
86 static int alignment_offset(); // guaranteed offset of first CodeBlob byte within alignment unit (i.e., allocation header)
87 static void free(CodeBlob* cb); // frees a CodeBlob
88 static void flush(); // flushes all CodeBlobs
89 static bool contains(void *p); // returns whether p is included
90 static void blobs_do(void f(CodeBlob* cb)); // iterates over all CodeBlobs
91 static void blobs_do(CodeBlobClosure* f); // iterates over all CodeBlobs
92 static void nmethods_do(void f(nmethod* nm)); // iterates over all nmethods
93 static void alive_nmethods_do(void f(nmethod* nm)); // iterates over all alive nmethods
94
95 // Lookup
96 static CodeBlob* find_blob(void* start);
97 static nmethod* find_nmethod(void* start);
98
99 // Lookup that does not fail if you lookup a zombie method (if you call this, be sure to know
100 // what you are doing)
101 static CodeBlob* find_blob_unsafe(void* start) {
102 // NMT can walk the stack before code cache is created
103 if (_heap == NULL) return NULL;
104
105 CodeBlob* result = (CodeBlob*)_heap->find_start(start);
106 // this assert is too strong because the heap code will return the
107 // heapblock containing start. That block can often be larger than
108 // the codeBlob itself. If you look up an address that is within
109 // the heapblock but not in the codeBlob you will assert.
110 //
111 // Most things will not lookup such bad addresses. However
112 // AsyncGetCallTrace can see intermediate frames and get that kind
113 // of invalid address and so can a developer using hsfind.
114 //
115 // The more correct answer is to return NULL if blob_contains() returns
116 // false.
117 // assert(result == NULL || result->blob_contains((address)start), "found wrong CodeBlob");
118
119 if (result != NULL && !result->blob_contains((address)start)) {
120 result = NULL;
121 }
122 return result;
123 }
124
125 // Iteration
126 static CodeBlob* first();
127 static CodeBlob* next (CodeBlob* cb);
128 static CodeBlob* alive(CodeBlob *cb);
129 static nmethod* alive_nmethod(CodeBlob *cb);
130 static nmethod* first_nmethod();
131 static nmethod* next_nmethod (CodeBlob* cb);
132 static int nof_blobs() { return _number_of_blobs; }
133 static int nof_adapters() { return _number_of_adapters; }
134 static int nof_nmethods() { return _number_of_nmethods; }
135
136 // GC support
137 static void gc_epilogue();
138 static void gc_prologue();
139 static void verify_oops();
140 // If "unloading_occurred" is true, then unloads (i.e., breaks root links
141 // to) any unmarked codeBlobs in the cache. Sets "marked_for_unloading"
142 // to "true" iff some code got unloaded.
143 static void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);
144 static void oops_do(OopClosure* f) {
145 CodeBlobToOopClosure oopc(f, /*do_marking=*/ false);
146 blobs_do(&oopc);
147 }
148 static void asserted_non_scavengable_nmethods_do(CodeBlobClosure* f = NULL) PRODUCT_RETURN;
149 static void scavenge_root_nmethods_do(CodeBlobClosure* f);
150
151 static nmethod* scavenge_root_nmethods() { return _scavenge_root_nmethods; }
152 static void set_scavenge_root_nmethods(nmethod* nm) { _scavenge_root_nmethods = nm; }
153 static void add_scavenge_root_nmethod(nmethod* nm);
154 static void drop_scavenge_root_nmethod(nmethod* nm);
155 static void prune_scavenge_root_nmethods();
156
157 // Printing/debugging
158 static void print(); // prints summary
159 static void verify(); // verifies the code cache
160 static void print_trace(const char* event, CodeBlob* cb, int size = 0) PRODUCT_RETURN;
161 static void print_summary(outputStream* st, bool detailed = true); // Prints a summary of the code cache usage
162 static void log_state(outputStream* st);
163
164 // The full limits of the codeCache
165 static address low_bound() { return (address) _heap->low_boundary(); }
166 static address high_bound() { return (address) _heap->high_boundary(); }
167 static address high() { return (address) _heap->high(); }
168
169 // Profiling
170 static address first_address(); // first address used for CodeBlobs
171 static address last_address(); // last address used for CodeBlobs
172 static size_t capacity() { return _heap->capacity(); }
173 static size_t max_capacity() { return _heap->max_capacity(); }
174 static size_t unallocated_capacity() { return _heap->unallocated_capacity(); }
175 static bool needs_flushing() { return unallocated_capacity() < CodeCacheFlushingMinimumFreeSpace; }
176 static double reverse_free_ratio();
177
178 static bool needs_cache_clean() { return _needs_cache_clean; }
179 static void set_needs_cache_clean(bool v) { _needs_cache_clean = v; }
180 static void clear_inline_caches(); // clear all inline caches
181
182 static nmethod* reanimate_saved_code(Method* m);
183 static void remove_saved_code(nmethod* nm);
184 static void speculatively_disconnect(nmethod* nm);
185
186 // Deoptimization
187 static int mark_for_deoptimization(DepChange& changes);
188 #ifdef HOTSWAP
189 static int mark_for_evol_deoptimization(instanceKlassHandle dependee);
190 #endif // HOTSWAP
191
192 static void mark_all_nmethods_for_deoptimization();
193 static int mark_for_deoptimization(Method* dependee);
194 static void make_marked_nmethods_zombies();
195 static void make_marked_nmethods_not_entrant();
196
197 // tells how many nmethods have dependencies
198 static int number_of_nmethods_with_dependencies();
199
200 static int get_codemem_full_count() { return _codemem_full_count; }
201 };
202
203 #endif // SHARE_VM_CODE_CODECACHE_HPP