1 // Copyright 2012 the V8 project authors. All rights reserved.
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3 // modification, are permitted provided that the following conditions are
6 // * Redistributions of source code must retain the above copyright
7 // notice, this list of conditions and the following disclaimer.
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28 #ifndef V8_COMPILATION_CACHE_H_
29 #define V8_COMPILATION_CACHE_H_
34 // The compilation cache consists of several generational sub-caches which uses
35 // this class as a base class. A sub-cache contains a compilation cache tables
36 // for each generation of the sub-cache. Since the same source code string has
37 // different compiled code for scripts and evals, we use separate sub-caches
38 // for different compilation modes, to avoid retrieving the wrong result.
39 class CompilationSubCache {
41 CompilationSubCache(Isolate* isolate, int generations)
43 generations_(generations) {
44 tables_ = NewArray<Object*>(generations);
47 ~CompilationSubCache() { DeleteArray(tables_); }
49 // Index for the first generation in the cache.
50 static const int kFirstGeneration = 0;
52 // Get the compilation cache tables for a specific generation.
53 Handle<CompilationCacheTable> GetTable(int generation);
55 // Accessors for first generation.
56 Handle<CompilationCacheTable> GetFirstTable() {
57 return GetTable(kFirstGeneration);
59 void SetFirstTable(Handle<CompilationCacheTable> value) {
60 ASSERT(kFirstGeneration < generations_);
61 tables_[kFirstGeneration] = *value;
64 // Age the sub-cache by evicting the oldest generation and creating a new
69 void Iterate(ObjectVisitor* v);
70 void IterateFunctions(ObjectVisitor* v);
72 // Clear this sub-cache evicting all its content.
75 // Remove given shared function info from sub-cache.
76 void Remove(Handle<SharedFunctionInfo> function_info);
78 // Number of generations in this sub-cache.
79 inline int generations() { return generations_; }
82 Isolate* isolate() { return isolate_; }
86 int generations_; // Number of generations.
87 Object** tables_; // Compilation cache tables - one for each generation.
89 DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationSubCache);
93 // Sub-cache for scripts.
94 class CompilationCacheScript : public CompilationSubCache {
96 CompilationCacheScript(Isolate* isolate, int generations);
98 Handle<SharedFunctionInfo> Lookup(Handle<String> source,
102 bool is_shared_cross_origin,
103 Handle<Context> context);
104 void Put(Handle<String> source,
105 Handle<Context> context,
106 Handle<SharedFunctionInfo> function_info);
109 MUST_USE_RESULT MaybeObject* TryTablePut(
110 Handle<String> source,
111 Handle<Context> context,
112 Handle<SharedFunctionInfo> function_info);
114 // Note: Returns a new hash table if operation results in expansion.
115 Handle<CompilationCacheTable> TablePut(
116 Handle<String> source,
117 Handle<Context> context,
118 Handle<SharedFunctionInfo> function_info);
120 bool HasOrigin(Handle<SharedFunctionInfo> function_info,
124 bool is_shared_cross_origin);
126 void* script_histogram_;
127 bool script_histogram_initialized_;
129 DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheScript);
133 // Sub-cache for eval scripts. Two caches for eval are used. One for eval calls
134 // in native contexts and one for eval calls in other contexts. The cache
135 // considers the following pieces of information when checking for matching
137 // 1. The source string.
138 // 2. The shared function info of the calling function.
139 // 3. Whether the source should be compiled as strict code or as non-strict
141 // Note: Currently there are clients of CompileEval that always compile
142 // non-strict code even if the calling function is a strict mode function.
143 // More specifically these are the CompileString, DebugEvaluate and
144 // DebugEvaluateGlobal runtime functions.
145 // 4. The start position of the calling scope.
146 class CompilationCacheEval: public CompilationSubCache {
148 CompilationCacheEval(Isolate* isolate, int generations)
149 : CompilationSubCache(isolate, generations) { }
151 Handle<SharedFunctionInfo> Lookup(Handle<String> source,
152 Handle<Context> context,
153 LanguageMode language_mode,
156 void Put(Handle<String> source,
157 Handle<Context> context,
158 Handle<SharedFunctionInfo> function_info,
162 MUST_USE_RESULT MaybeObject* TryTablePut(
163 Handle<String> source,
164 Handle<Context> context,
165 Handle<SharedFunctionInfo> function_info,
168 // Note: Returns a new hash table if operation results in expansion.
169 Handle<CompilationCacheTable> TablePut(
170 Handle<String> source,
171 Handle<Context> context,
172 Handle<SharedFunctionInfo> function_info,
175 DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheEval);
179 // Sub-cache for regular expressions.
180 class CompilationCacheRegExp: public CompilationSubCache {
182 CompilationCacheRegExp(Isolate* isolate, int generations)
183 : CompilationSubCache(isolate, generations) { }
185 Handle<FixedArray> Lookup(Handle<String> source, JSRegExp::Flags flags);
187 void Put(Handle<String> source,
188 JSRegExp::Flags flags,
189 Handle<FixedArray> data);
191 MUST_USE_RESULT MaybeObject* TryTablePut(Handle<String> source,
192 JSRegExp::Flags flags,
193 Handle<FixedArray> data);
195 // Note: Returns a new hash table if operation results in expansion.
196 Handle<CompilationCacheTable> TablePut(Handle<String> source,
197 JSRegExp::Flags flags,
198 Handle<FixedArray> data);
200 DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheRegExp);
204 // The compilation cache keeps shared function infos for compiled
205 // scripts and evals. The shared function infos are looked up using
206 // the source string as the key. For regular expressions the
207 // compilation data is cached.
208 class CompilationCache {
210 // Finds the script shared function info for a source
211 // string. Returns an empty handle if the cache doesn't contain a
212 // script for the given source string with the right origin.
213 Handle<SharedFunctionInfo> LookupScript(Handle<String> source,
217 bool is_shared_cross_origin,
218 Handle<Context> context);
220 // Finds the shared function info for a source string for eval in a
221 // given context. Returns an empty handle if the cache doesn't
222 // contain a script for the given source string.
223 Handle<SharedFunctionInfo> LookupEval(Handle<String> source,
224 Handle<Context> context,
226 LanguageMode language_mode,
229 // Returns the regexp data associated with the given regexp if it
230 // is in cache, otherwise an empty handle.
231 Handle<FixedArray> LookupRegExp(Handle<String> source,
232 JSRegExp::Flags flags);
234 // Associate the (source, kind) pair to the shared function
235 // info. This may overwrite an existing mapping.
236 void PutScript(Handle<String> source,
237 Handle<Context> context,
238 Handle<SharedFunctionInfo> function_info);
240 // Associate the (source, context->closure()->shared(), kind) triple
241 // with the shared function info. This may overwrite an existing mapping.
242 void PutEval(Handle<String> source,
243 Handle<Context> context,
245 Handle<SharedFunctionInfo> function_info,
248 // Associate the (source, flags) pair to the given regexp data.
249 // This may overwrite an existing mapping.
250 void PutRegExp(Handle<String> source,
251 JSRegExp::Flags flags,
252 Handle<FixedArray> data);
254 // Clear the cache - also used to initialize the cache at startup.
257 // Remove given shared function info from all caches.
258 void Remove(Handle<SharedFunctionInfo> function_info);
261 void Iterate(ObjectVisitor* v);
262 void IterateFunctions(ObjectVisitor* v);
264 // Notify the cache that a mark-sweep garbage collection is about to
265 // take place. This is used to retire entries from the cache to
266 // avoid keeping them alive too long without using them.
267 void MarkCompactPrologue();
269 // Enable/disable compilation cache. Used by debugger to disable compilation
270 // cache during debugging to make sure new scripts are always compiled.
275 explicit CompilationCache(Isolate* isolate);
278 HashMap* EagerOptimizingSet();
280 // The number of sub caches covering the different types to cache.
281 static const int kSubCacheCount = 4;
283 bool IsEnabled() { return FLAG_compilation_cache && enabled_; }
285 Isolate* isolate() { return isolate_; }
289 CompilationCacheScript script_;
290 CompilationCacheEval eval_global_;
291 CompilationCacheEval eval_contextual_;
292 CompilationCacheRegExp reg_exp_;
293 CompilationSubCache* subcaches_[kSubCacheCount];
295 // Current enable state of the compilation cache.
298 friend class Isolate;
300 DISALLOW_COPY_AND_ASSIGN(CompilationCache);
304 } } // namespace v8::internal
306 #endif // V8_COMPILATION_CACHE_H_