1// Copyright 2011 the V8 project authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5#include "src/compilation-cache.h" 6 7#include "src/assembler.h" 8#include "src/counters.h" 9#include "src/factory.h" 10#include "src/objects-inl.h" 11 12namespace v8 { 13namespace internal { 14 15 16// The number of generations for each sub cache. 17static const int kRegExpGenerations = 2; 18 19// Initial size of each compilation cache table allocated. 20static const int kInitialCacheSize = 64; 21 22 23CompilationCache::CompilationCache(Isolate* isolate) 24 : isolate_(isolate), 25 script_(isolate, 1), 26 eval_global_(isolate, 1), 27 eval_contextual_(isolate, 1), 28 reg_exp_(isolate, kRegExpGenerations), 29 enabled_(true) { 30 CompilationSubCache* subcaches[kSubCacheCount] = 31 {&script_, &eval_global_, &eval_contextual_, ®_exp_}; 32 for (int i = 0; i < kSubCacheCount; ++i) { 33 subcaches_[i] = subcaches[i]; 34 } 35} 36 37 38CompilationCache::~CompilationCache() {} 39 40 41Handle<CompilationCacheTable> CompilationSubCache::GetTable(int generation) { 42 DCHECK(generation < generations_); 43 Handle<CompilationCacheTable> result; 44 if (tables_[generation]->IsUndefined(isolate())) { 45 result = CompilationCacheTable::New(isolate(), kInitialCacheSize); 46 tables_[generation] = *result; 47 } else { 48 CompilationCacheTable* table = 49 CompilationCacheTable::cast(tables_[generation]); 50 result = Handle<CompilationCacheTable>(table, isolate()); 51 } 52 return result; 53} 54 55 56void CompilationSubCache::Age() { 57 // Don't directly age single-generation caches. 58 if (generations_ == 1) { 59 if (!tables_[0]->IsUndefined(isolate())) { 60 CompilationCacheTable::cast(tables_[0])->Age(); 61 } 62 return; 63 } 64 65 // Age the generations implicitly killing off the oldest. 66 for (int i = generations_ - 1; i > 0; i--) { 67 tables_[i] = tables_[i - 1]; 68 } 69 70 // Set the first generation as unborn. 71 tables_[0] = isolate()->heap()->undefined_value(); 72} 73 74 75void CompilationSubCache::IterateFunctions(ObjectVisitor* v) { 76 Object* undefined = isolate()->heap()->undefined_value(); 77 for (int i = 0; i < generations_; i++) { 78 if (tables_[i] != undefined) { 79 reinterpret_cast<CompilationCacheTable*>(tables_[i])->IterateElements(v); 80 } 81 } 82} 83 84 85void CompilationSubCache::Iterate(ObjectVisitor* v) { 86 v->VisitPointers(&tables_[0], &tables_[generations_]); 87} 88 89 90void CompilationSubCache::Clear() { 91 MemsetPointer(tables_, isolate()->heap()->undefined_value(), generations_); 92} 93 94 95void CompilationSubCache::Remove(Handle<SharedFunctionInfo> function_info) { 96 // Probe the script generation tables. Make sure not to leak handles 97 // into the caller's handle scope. 98 { HandleScope scope(isolate()); 99 for (int generation = 0; generation < generations(); generation++) { 100 Handle<CompilationCacheTable> table = GetTable(generation); 101 table->Remove(*function_info); 102 } 103 } 104} 105 106 107CompilationCacheScript::CompilationCacheScript(Isolate* isolate, 108 int generations) 109 : CompilationSubCache(isolate, generations) {} 110 111 112// We only re-use a cached function for some script source code if the 113// script originates from the same place. This is to avoid issues 114// when reporting errors, etc. 115bool CompilationCacheScript::HasOrigin(Handle<SharedFunctionInfo> function_info, 116 Handle<Object> name, int line_offset, 117 int column_offset, 118 ScriptOriginOptions resource_options) { 119 Handle<Script> script = 120 Handle<Script>(Script::cast(function_info->script()), isolate()); 121 // If the script name isn't set, the boilerplate script should have 122 // an undefined name to have the same origin. 123 if (name.is_null()) { 124 return script->name()->IsUndefined(isolate()); 125 } 126 // Do the fast bailout checks first. 127 if (line_offset != script->line_offset()) return false; 128 if (column_offset != script->column_offset()) return false; 129 // Check that both names are strings. If not, no match. 130 if (!name->IsString() || !script->name()->IsString()) return false; 131 // Are the origin_options same? 132 if (resource_options.Flags() != script->origin_options().Flags()) 133 return false; 134 // Compare the two name strings for equality. 135 return String::Equals(Handle<String>::cast(name), 136 Handle<String>(String::cast(script->name()))); 137} 138 139 140// TODO(245): Need to allow identical code from different contexts to 141// be cached in the same script generation. Currently the first use 142// will be cached, but subsequent code from different source / line 143// won't. 144Handle<SharedFunctionInfo> CompilationCacheScript::Lookup( 145 Handle<String> source, Handle<Object> name, int line_offset, 146 int column_offset, ScriptOriginOptions resource_options, 147 Handle<Context> context, LanguageMode language_mode) { 148 Object* result = NULL; 149 int generation; 150 151 // Probe the script generation tables. Make sure not to leak handles 152 // into the caller's handle scope. 153 { HandleScope scope(isolate()); 154 for (generation = 0; generation < generations(); generation++) { 155 Handle<CompilationCacheTable> table = GetTable(generation); 156 Handle<Object> probe = table->Lookup(source, context, language_mode); 157 if (probe->IsSharedFunctionInfo()) { 158 Handle<SharedFunctionInfo> function_info = 159 Handle<SharedFunctionInfo>::cast(probe); 160 // Break when we've found a suitable shared function info that 161 // matches the origin. 162 if (HasOrigin(function_info, name, line_offset, column_offset, 163 resource_options)) { 164 result = *function_info; 165 break; 166 } 167 } 168 } 169 } 170 171 // Once outside the manacles of the handle scope, we need to recheck 172 // to see if we actually found a cached script. If so, we return a 173 // handle created in the caller's handle scope. 174 if (result != NULL) { 175 Handle<SharedFunctionInfo> shared(SharedFunctionInfo::cast(result), 176 isolate()); 177 DCHECK( 178 HasOrigin(shared, name, line_offset, column_offset, resource_options)); 179 // If the script was found in a later generation, we promote it to 180 // the first generation to let it survive longer in the cache. 181 if (generation != 0) Put(source, context, language_mode, shared); 182 isolate()->counters()->compilation_cache_hits()->Increment(); 183 return shared; 184 } else { 185 isolate()->counters()->compilation_cache_misses()->Increment(); 186 return Handle<SharedFunctionInfo>::null(); 187 } 188} 189 190 191void CompilationCacheScript::Put(Handle<String> source, 192 Handle<Context> context, 193 LanguageMode language_mode, 194 Handle<SharedFunctionInfo> function_info) { 195 HandleScope scope(isolate()); 196 Handle<CompilationCacheTable> table = GetFirstTable(); 197 SetFirstTable(CompilationCacheTable::Put(table, source, context, 198 language_mode, function_info)); 199} 200 201 202MaybeHandle<SharedFunctionInfo> CompilationCacheEval::Lookup( 203 Handle<String> source, Handle<SharedFunctionInfo> outer_info, 204 LanguageMode language_mode, int scope_position) { 205 HandleScope scope(isolate()); 206 // Make sure not to leak the table into the surrounding handle 207 // scope. Otherwise, we risk keeping old tables around even after 208 // having cleared the cache. 209 Handle<Object> result = isolate()->factory()->undefined_value(); 210 int generation; 211 for (generation = 0; generation < generations(); generation++) { 212 Handle<CompilationCacheTable> table = GetTable(generation); 213 result = 214 table->LookupEval(source, outer_info, language_mode, scope_position); 215 if (result->IsSharedFunctionInfo()) break; 216 } 217 if (result->IsSharedFunctionInfo()) { 218 Handle<SharedFunctionInfo> function_info = 219 Handle<SharedFunctionInfo>::cast(result); 220 if (generation != 0) { 221 Put(source, outer_info, function_info, scope_position); 222 } 223 isolate()->counters()->compilation_cache_hits()->Increment(); 224 return scope.CloseAndEscape(function_info); 225 } else { 226 isolate()->counters()->compilation_cache_misses()->Increment(); 227 return MaybeHandle<SharedFunctionInfo>(); 228 } 229} 230 231 232void CompilationCacheEval::Put(Handle<String> source, 233 Handle<SharedFunctionInfo> outer_info, 234 Handle<SharedFunctionInfo> function_info, 235 int scope_position) { 236 HandleScope scope(isolate()); 237 Handle<CompilationCacheTable> table = GetFirstTable(); 238 table = CompilationCacheTable::PutEval(table, source, outer_info, 239 function_info, scope_position); 240 SetFirstTable(table); 241} 242 243 244MaybeHandle<FixedArray> CompilationCacheRegExp::Lookup( 245 Handle<String> source, 246 JSRegExp::Flags flags) { 247 HandleScope scope(isolate()); 248 // Make sure not to leak the table into the surrounding handle 249 // scope. Otherwise, we risk keeping old tables around even after 250 // having cleared the cache. 251 Handle<Object> result = isolate()->factory()->undefined_value(); 252 int generation; 253 for (generation = 0; generation < generations(); generation++) { 254 Handle<CompilationCacheTable> table = GetTable(generation); 255 result = table->LookupRegExp(source, flags); 256 if (result->IsFixedArray()) break; 257 } 258 if (result->IsFixedArray()) { 259 Handle<FixedArray> data = Handle<FixedArray>::cast(result); 260 if (generation != 0) { 261 Put(source, flags, data); 262 } 263 isolate()->counters()->compilation_cache_hits()->Increment(); 264 return scope.CloseAndEscape(data); 265 } else { 266 isolate()->counters()->compilation_cache_misses()->Increment(); 267 return MaybeHandle<FixedArray>(); 268 } 269} 270 271 272void CompilationCacheRegExp::Put(Handle<String> source, 273 JSRegExp::Flags flags, 274 Handle<FixedArray> data) { 275 HandleScope scope(isolate()); 276 Handle<CompilationCacheTable> table = GetFirstTable(); 277 SetFirstTable(CompilationCacheTable::PutRegExp(table, source, flags, data)); 278} 279 280 281void CompilationCache::Remove(Handle<SharedFunctionInfo> function_info) { 282 if (!IsEnabled()) return; 283 284 eval_global_.Remove(function_info); 285 eval_contextual_.Remove(function_info); 286 script_.Remove(function_info); 287} 288 289 290MaybeHandle<SharedFunctionInfo> CompilationCache::LookupScript( 291 Handle<String> source, Handle<Object> name, int line_offset, 292 int column_offset, ScriptOriginOptions resource_options, 293 Handle<Context> context, LanguageMode language_mode) { 294 if (!IsEnabled()) return MaybeHandle<SharedFunctionInfo>(); 295 296 return script_.Lookup(source, name, line_offset, column_offset, 297 resource_options, context, language_mode); 298} 299 300 301MaybeHandle<SharedFunctionInfo> CompilationCache::LookupEval( 302 Handle<String> source, Handle<SharedFunctionInfo> outer_info, 303 Handle<Context> context, LanguageMode language_mode, int scope_position) { 304 if (!IsEnabled()) return MaybeHandle<SharedFunctionInfo>(); 305 306 MaybeHandle<SharedFunctionInfo> result; 307 if (context->IsNativeContext()) { 308 result = 309 eval_global_.Lookup(source, outer_info, language_mode, scope_position); 310 } else { 311 DCHECK(scope_position != RelocInfo::kNoPosition); 312 result = eval_contextual_.Lookup(source, outer_info, language_mode, 313 scope_position); 314 } 315 return result; 316} 317 318 319MaybeHandle<FixedArray> CompilationCache::LookupRegExp(Handle<String> source, 320 JSRegExp::Flags flags) { 321 if (!IsEnabled()) return MaybeHandle<FixedArray>(); 322 323 return reg_exp_.Lookup(source, flags); 324} 325 326 327void CompilationCache::PutScript(Handle<String> source, 328 Handle<Context> context, 329 LanguageMode language_mode, 330 Handle<SharedFunctionInfo> function_info) { 331 if (!IsEnabled()) return; 332 333 script_.Put(source, context, language_mode, function_info); 334} 335 336 337void CompilationCache::PutEval(Handle<String> source, 338 Handle<SharedFunctionInfo> outer_info, 339 Handle<Context> context, 340 Handle<SharedFunctionInfo> function_info, 341 int scope_position) { 342 if (!IsEnabled()) return; 343 344 HandleScope scope(isolate()); 345 if (context->IsNativeContext()) { 346 eval_global_.Put(source, outer_info, function_info, scope_position); 347 } else { 348 DCHECK(scope_position != RelocInfo::kNoPosition); 349 eval_contextual_.Put(source, outer_info, function_info, scope_position); 350 } 351} 352 353 354 355void CompilationCache::PutRegExp(Handle<String> source, 356 JSRegExp::Flags flags, 357 Handle<FixedArray> data) { 358 if (!IsEnabled()) { 359 return; 360 } 361 362 reg_exp_.Put(source, flags, data); 363} 364 365 366void CompilationCache::Clear() { 367 for (int i = 0; i < kSubCacheCount; i++) { 368 subcaches_[i]->Clear(); 369 } 370} 371 372 373void CompilationCache::Iterate(ObjectVisitor* v) { 374 for (int i = 0; i < kSubCacheCount; i++) { 375 subcaches_[i]->Iterate(v); 376 } 377} 378 379 380void CompilationCache::IterateFunctions(ObjectVisitor* v) { 381 for (int i = 0; i < kSubCacheCount; i++) { 382 subcaches_[i]->IterateFunctions(v); 383 } 384} 385 386 387void CompilationCache::MarkCompactPrologue() { 388 for (int i = 0; i < kSubCacheCount; i++) { 389 subcaches_[i]->Age(); 390 } 391} 392 393 394void CompilationCache::Enable() { 395 enabled_ = true; 396} 397 398 399void CompilationCache::Disable() { 400 enabled_ = false; 401 Clear(); 402} 403 404 405} // namespace internal 406} // namespace v8 407