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 #include "runtime/safepoint.hpp"
34
35 // The CodeCache implements the code cache for various pieces of generated
36 // code, e.g., compiled java methods, runtime stubs, transition frames, etc.
37 // The entries in the CodeCache are all CodeBlob's.
38
39 // Implementation:
40 // - Each CodeBlob occupies one chunk of memory.
41 // - Like the offset table in oldspace the zone has at table for
42 // locating a method given a addess of an instruction.
43
44 class OopClosure;
45 class DepChange;
46
47 class ParallelCodeCacheIterator VALUE_OBJ_CLASS_SPEC {
48 friend class CodeCache;
49 private:
50 volatile int _claimed_idx;
51 volatile bool _finished;
52 public:
53 ParallelCodeCacheIterator();
54 void parallel_blobs_do(CodeBlobClosure* f);
55 };
56
57 class CodeCache : AllStatic {
58 friend class VMStructs;
59 private:
60 // CodeHeap is malloc()'ed at startup and never deleted during shutdown,
61 // so that the generated assembly code is always there when it's needed.
62 // This may cause memory leak, but is necessary, for now. See 4423824,
63 // 4422213 or 4436291 for details.
64 static CodeHeap * _heap;
65 static int _number_of_blobs;
66 static int _number_of_adapters;
67 static int _number_of_nmethods;
68 static int _number_of_nmethods_with_dependencies;
69 static bool _needs_cache_clean;
70 static nmethod* _scavenge_root_nmethods; // linked via nm->scavenge_root_link()
71
72 static void verify_if_often() PRODUCT_RETURN;
73
74 static void mark_scavenge_root_nmethods() PRODUCT_RETURN;
75 static void verify_perm_nmethods(CodeBlobClosure* f_or_null) PRODUCT_RETURN;
76
77 static int _codemem_full_count;
78
79 public:
80
81 // Initialization
82 static void initialize();
83
84 static void report_codemem_full();
85
86 // Allocation/administration
87 static CodeBlob* allocate(int size, bool is_critical = false); // allocates a new CodeBlob
88 static void commit(CodeBlob* cb); // called when the allocated CodeBlob has been filled
89 static int alignment_unit(); // guaranteed alignment of all CodeBlobs
90 static int alignment_offset(); // guaranteed offset of first CodeBlob byte within alignment unit (i.e., allocation header)
91 static void free(CodeBlob* cb); // frees a CodeBlob
92 static void flush(); // flushes all CodeBlobs
93 static bool contains(void *p); // returns whether p is included
94 static void blobs_do(void f(CodeBlob* cb)); // iterates over all CodeBlobs
95 static void blobs_do(CodeBlobClosure* f); // iterates over all CodeBlobs
96 static void nmethods_do(void f(nmethod* nm)); // iterates over all nmethods
97 static void alive_nmethods_do(void f(nmethod* nm)); // iterates over all alive nmethods
98
99 // Lookup
100 static CodeBlob* find_blob(void* start);
101 static nmethod* find_nmethod(void* start);
102
103 // Lookup that does not fail if you lookup a zombie method (if you call this, be sure to know
104 // what you are doing)
105 static CodeBlob* find_blob_unsafe(void* start) {
106 // NMT can walk the stack before code cache is created
107 if (_heap == NULL) return NULL;
108
109 CodeBlob* result = (CodeBlob*)_heap->find_start(start);
110 // this assert is too strong because the heap code will return the
111 // heapblock containing start. That block can often be larger than
112 // the codeBlob itself. If you look up an address that is within
113 // the heapblock but not in the codeBlob you will assert.
114 //
115 // Most things will not lookup such bad addresses. However
116 // AsyncGetCallTrace can see intermediate frames and get that kind
117 // of invalid address and so can a developer using hsfind.
118 //
119 // The more correct answer is to return NULL if blob_contains() returns
120 // false.
121 // assert(result == NULL || result->blob_contains((address)start), "found wrong CodeBlob");
122
123 if (result != NULL && !result->blob_contains((address)start)) {
124 result = NULL;
125 }
126 return result;
127 }
128
129 // Iteration
130 static CodeBlob* first();
131 static CodeBlob* next (CodeBlob* cb);
132 static CodeBlob* alive(CodeBlob *cb);
133 static nmethod* alive_nmethod(CodeBlob *cb);
134 static nmethod* first_nmethod();
135 static nmethod* next_nmethod (CodeBlob* cb);
136 static int nof_blobs() { return _number_of_blobs; }
137 static int nof_adapters() { return _number_of_adapters; }
138 static int nof_nmethods() { return _number_of_nmethods; }
139
140 // GC support
141 static void gc_epilogue();
142 static void gc_prologue();
143 static void verify_oops();
144
145 // Parallel GC support
146 static ParallelCodeCacheIterator parallel_iterator() {
147 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint");
148 return ParallelCodeCacheIterator();
149 }
150
151 // If "unloading_occurred" is true, then unloads (i.e., breaks root links
152 // to) any unmarked codeBlobs in the cache. Sets "marked_for_unloading"
153 // to "true" iff some code got unloaded.
154 static void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);
155 static void asserted_non_scavengable_nmethods_do(CodeBlobClosure* f = NULL) PRODUCT_RETURN;
156 static void scavenge_root_nmethods_do(CodeBlobClosure* f);
157
158 static nmethod* scavenge_root_nmethods() { return _scavenge_root_nmethods; }
159 static void set_scavenge_root_nmethods(nmethod* nm) { _scavenge_root_nmethods = nm; }
160 static void add_scavenge_root_nmethod(nmethod* nm);
161 static void drop_scavenge_root_nmethod(nmethod* nm);
162 static void prune_scavenge_root_nmethods();
163
164 // Printing/debugging
165 static void print(); // prints summary
166 static void print_internals();
167 static void verify(); // verifies the code cache
168 static void print_trace(const char* event, CodeBlob* cb, int size = 0) PRODUCT_RETURN;
169 static void print_summary(outputStream* st, bool detailed = true); // Prints a summary of the code cache usage
170 static void log_state(outputStream* st);
171
172 // The full limits of the codeCache
173 static address low_bound() { return (address) _heap->low_boundary(); }
174 static address high_bound() { return (address) _heap->high_boundary(); }
175 static address high() { return (address) _heap->high(); }
176
177 // Profiling
178 static address first_address(); // first address used for CodeBlobs
179 static address last_address(); // last address used for CodeBlobs
180 static size_t capacity() { return _heap->capacity(); }
181 static size_t max_capacity() { return _heap->max_capacity(); }
182 static size_t unallocated_capacity() { return _heap->unallocated_capacity(); }
183 static double reverse_free_ratio();
184
185 static bool needs_cache_clean() { return _needs_cache_clean; }
186 static void set_needs_cache_clean(bool v) { _needs_cache_clean = v; }
187 static void clear_inline_caches(); // clear all inline caches
188
189 static void verify_clean_inline_caches();
190 static void verify_icholder_relocations();
191
192 // Deoptimization
193 static int mark_for_deoptimization(DepChange& changes);
194 #ifdef HOTSWAP
195 static int mark_for_evol_deoptimization(instanceKlassHandle dependee);
196 #endif // HOTSWAP
197
198 static void mark_all_nmethods_for_deoptimization();
199 static int mark_for_deoptimization(Method* dependee);
200 static void make_marked_nmethods_not_entrant();
201
202 // tells how many nmethods have dependencies
203 static int number_of_nmethods_with_dependencies();
204
205 static int get_codemem_full_count() { return _codemem_full_count; }
206 };
207
208 #endif // SHARE_VM_CODE_CODECACHE_HPP