Wed, 02 Jul 2008 12:55:16 -0700
6719955: Update copyright year
Summary: Update copyright year for files that have been modified in 2008
Reviewed-by: ohair, tbell
1 /*
2 * Copyright 1997-2008 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
25 // The CodeCache implements the code cache for various pieces of generated
26 // code, e.g., compiled java methods, runtime stubs, transition frames, etc.
27 // The entries in the CodeCache are all CodeBlob's.
29 // Implementation:
30 // - Each CodeBlob occupies one chunk of memory.
31 // - Like the offset table in oldspace the zone has at table for
32 // locating a method given a addess of an instruction.
34 class OopClosure;
35 class DepChange;
37 class CodeCache : AllStatic {
38 friend class VMStructs;
39 private:
40 // CodeHeap is malloc()'ed at startup and never deleted during shutdown,
41 // so that the generated assembly code is always there when it's needed.
42 // This may cause memory leak, but is necessary, for now. See 4423824,
43 // 4422213 or 4436291 for details.
44 static CodeHeap * _heap;
45 static int _number_of_blobs;
46 static int _number_of_nmethods_with_dependencies;
47 static bool _needs_cache_clean;
49 static void verify_if_often() PRODUCT_RETURN;
50 public:
52 // Initialization
53 static void initialize();
55 // Allocation/administration
56 static CodeBlob* allocate(int size); // allocates a new CodeBlob
57 static void commit(CodeBlob* cb); // called when the allocated CodeBlob has been filled
58 static int alignment_unit(); // guaranteed alignment of all CodeBlobs
59 static int alignment_offset(); // guaranteed offset of first CodeBlob byte within alignment unit (i.e., allocation header)
60 static void free(CodeBlob* cb); // frees a CodeBlob
61 static void flush(); // flushes all CodeBlobs
62 static bool contains(void *p); // returns whether p is included
63 static void blobs_do(void f(CodeBlob* cb)); // iterates over all CodeBlobs
64 static void nmethods_do(void f(nmethod* nm)); // iterates over all nmethods
66 // Lookup
67 static CodeBlob* find_blob(void* start);
68 static nmethod* find_nmethod(void* start);
70 // Lookup that does not fail if you lookup a zombie method (if you call this, be sure to know
71 // what you are doing)
72 static CodeBlob* find_blob_unsafe(void* start) {
73 CodeBlob* result = (CodeBlob*)_heap->find_start(start);
74 // this assert is too strong because the heap code will return the
75 // heapblock containing start. That block can often be larger than
76 // the codeBlob itself. If you look up an address that is within
77 // the heapblock but not in the codeBlob you will assert.
78 //
79 // Most things will not lookup such bad addresses. However
80 // AsyncGetCallTrace can see intermediate frames and get that kind
81 // of invalid address and so can a developer using hsfind.
82 //
83 // The more correct answer is to return NULL if blob_contains() returns
84 // false.
85 // assert(result == NULL || result->blob_contains((address)start), "found wrong CodeBlob");
87 if (result != NULL && !result->blob_contains((address)start)) {
88 result = NULL;
89 }
90 return result;
91 }
93 // Iteration
94 static CodeBlob* first();
95 static CodeBlob* next (CodeBlob* cb);
96 static CodeBlob* alive(CodeBlob *cb);
97 static nmethod* alive_nmethod(CodeBlob *cb);
98 static int nof_blobs() { return _number_of_blobs; }
100 // GC support
101 static void gc_epilogue();
102 static void gc_prologue();
103 // If "unloading_occurred" is true, then unloads (i.e., breaks root links
104 // to) any unmarked codeBlobs in the cache. Sets "marked_for_unloading"
105 // to "true" iff some code got unloaded.
106 static void do_unloading(BoolObjectClosure* is_alive,
107 OopClosure* keep_alive,
108 bool unloading_occurred);
109 static void oops_do(OopClosure* f);
111 // Printing/debugging
112 static void print() PRODUCT_RETURN; // prints summary
113 static void print_internals();
114 static void verify(); // verifies the code cache
116 // The full limits of the codeCache
117 static address low_bound() { return (address) _heap->low_boundary(); }
118 static address high_bound() { return (address) _heap->high_boundary(); }
120 // Profiling
121 static address first_address(); // first address used for CodeBlobs
122 static address last_address(); // last address used for CodeBlobs
123 static size_t capacity() { return _heap->capacity(); }
124 static size_t max_capacity() { return _heap->max_capacity(); }
125 static size_t unallocated_capacity() { return _heap->unallocated_capacity(); }
127 static bool needs_cache_clean() { return _needs_cache_clean; }
128 static void set_needs_cache_clean(bool v) { _needs_cache_clean = v; }
129 static void clear_inline_caches(); // clear all inline caches
131 // Deoptimization
132 static int mark_for_deoptimization(DepChange& changes);
133 #ifdef HOTSWAP
134 static int mark_for_evol_deoptimization(instanceKlassHandle dependee);
135 #endif // HOTSWAP
137 static void mark_all_nmethods_for_deoptimization();
138 static int mark_for_deoptimization(methodOop dependee);
139 static void make_marked_nmethods_zombies();
140 static void make_marked_nmethods_not_entrant();
142 // tells how many nmethods have dependencies
143 static int number_of_nmethods_with_dependencies();
144 };