| // Copyright 2008 the V8 project authors. All rights reserved. |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following |
| // disclaimer in the documentation and/or other materials provided |
| // with the distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived |
| // from this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #include "v8.h" |
| |
| #include "compilation-cache.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| // The number of sub caches covering the different types to cache. |
| static const int kSubCacheCount = 4; |
| |
| // The number of generations for each sub cache. |
| // The number of ScriptGenerations is carefully chosen based on histograms. |
| // See issue 458: http://code.google.com/p/v8/issues/detail?id=458 |
| static const int kScriptGenerations = 5; |
| static const int kEvalGlobalGenerations = 2; |
| static const int kEvalContextualGenerations = 2; |
| static const int kRegExpGenerations = 2; |
| |
| // Initial size of each compilation cache table allocated. |
| static const int kInitialCacheSize = 64; |
| |
| // Index for the first generation in the cache. |
| static const int kFirstGeneration = 0; |
| |
| // The compilation cache consists of several generational sub-caches which uses |
| // this class as a base class. A sub-cache contains a compilation cache tables |
| // for each generation of the sub-cache. Since the same source code string has |
| // different compiled code for scripts and evals, we use separate sub-caches |
| // for different compilation modes, to avoid retrieving the wrong result. |
| class CompilationSubCache { |
| public: |
| explicit CompilationSubCache(int generations): generations_(generations) { |
| tables_ = NewArray<Object*>(generations); |
| } |
| |
| ~CompilationSubCache() { DeleteArray(tables_); } |
| |
| // Get the compilation cache tables for a specific generation. |
| Handle<CompilationCacheTable> GetTable(int generation); |
| |
| // Accessors for first generation. |
| Handle<CompilationCacheTable> GetFirstTable() { |
| return GetTable(kFirstGeneration); |
| } |
| void SetFirstTable(Handle<CompilationCacheTable> value) { |
| ASSERT(kFirstGeneration < generations_); |
| tables_[kFirstGeneration] = *value; |
| } |
| |
| // Age the sub-cache by evicting the oldest generation and creating a new |
| // young generation. |
| void Age(); |
| |
| // GC support. |
| void Iterate(ObjectVisitor* v); |
| |
| // Clear this sub-cache evicting all its content. |
| void Clear(); |
| |
| // Number of generations in this sub-cache. |
| inline int generations() { return generations_; } |
| |
| private: |
| int generations_; // Number of generations. |
| Object** tables_; // Compilation cache tables - one for each generation. |
| |
| DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationSubCache); |
| }; |
| |
| |
| // Sub-cache for scripts. |
| class CompilationCacheScript : public CompilationSubCache { |
| public: |
| explicit CompilationCacheScript(int generations) |
| : CompilationSubCache(generations) { } |
| |
| Handle<JSFunction> Lookup(Handle<String> source, |
| Handle<Object> name, |
| int line_offset, |
| int column_offset); |
| void Put(Handle<String> source, Handle<JSFunction> boilerplate); |
| |
| private: |
| // Note: Returns a new hash table if operation results in expansion. |
| Handle<CompilationCacheTable> TablePut(Handle<String> source, |
| Handle<JSFunction> boilerplate); |
| |
| bool HasOrigin(Handle<JSFunction> boilerplate, |
| Handle<Object> name, |
| int line_offset, |
| int column_offset); |
| |
| DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheScript); |
| }; |
| |
| |
| // Sub-cache for eval scripts. |
| class CompilationCacheEval: public CompilationSubCache { |
| public: |
| explicit CompilationCacheEval(int generations) |
| : CompilationSubCache(generations) { } |
| |
| Handle<JSFunction> Lookup(Handle<String> source, Handle<Context> context); |
| |
| void Put(Handle<String> source, |
| Handle<Context> context, |
| Handle<JSFunction> boilerplate); |
| |
| private: |
| // Note: Returns a new hash table if operation results in expansion. |
| Handle<CompilationCacheTable> TablePut(Handle<String> source, |
| Handle<Context> context, |
| Handle<JSFunction> boilerplate); |
| |
| DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheEval); |
| }; |
| |
| |
| // Sub-cache for regular expressions. |
| class CompilationCacheRegExp: public CompilationSubCache { |
| public: |
| explicit CompilationCacheRegExp(int generations) |
| : CompilationSubCache(generations) { } |
| |
| Handle<FixedArray> Lookup(Handle<String> source, JSRegExp::Flags flags); |
| |
| void Put(Handle<String> source, |
| JSRegExp::Flags flags, |
| Handle<FixedArray> data); |
| private: |
| // Note: Returns a new hash table if operation results in expansion. |
| Handle<CompilationCacheTable> TablePut(Handle<String> source, |
| JSRegExp::Flags flags, |
| Handle<FixedArray> data); |
| |
| DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheRegExp); |
| }; |
| |
| |
| // Statically allocate all the sub-caches. |
| static CompilationCacheScript script(kScriptGenerations); |
| static CompilationCacheEval eval_global(kEvalGlobalGenerations); |
| static CompilationCacheEval eval_contextual(kEvalContextualGenerations); |
| static CompilationCacheRegExp reg_exp(kRegExpGenerations); |
| static CompilationSubCache* subcaches[kSubCacheCount] = |
| {&script, &eval_global, &eval_contextual, ®_exp}; |
| |
| |
| // Current enable state of the compilation cache. |
| static bool enabled = true; |
| static inline bool IsEnabled() { |
| return FLAG_compilation_cache && enabled; |
| } |
| |
| |
| static Handle<CompilationCacheTable> AllocateTable(int size) { |
| CALL_HEAP_FUNCTION(CompilationCacheTable::Allocate(size), |
| CompilationCacheTable); |
| } |
| |
| |
| Handle<CompilationCacheTable> CompilationSubCache::GetTable(int generation) { |
| ASSERT(generation < generations_); |
| Handle<CompilationCacheTable> result; |
| if (tables_[generation]->IsUndefined()) { |
| result = AllocateTable(kInitialCacheSize); |
| tables_[generation] = *result; |
| } else { |
| CompilationCacheTable* table = |
| CompilationCacheTable::cast(tables_[generation]); |
| result = Handle<CompilationCacheTable>(table); |
| } |
| return result; |
| } |
| |
| |
| void CompilationSubCache::Age() { |
| // Age the generations implicitly killing off the oldest. |
| for (int i = generations_ - 1; i > 0; i--) { |
| tables_[i] = tables_[i - 1]; |
| } |
| |
| // Set the first generation as unborn. |
| tables_[0] = Heap::undefined_value(); |
| } |
| |
| |
| void CompilationSubCache::Iterate(ObjectVisitor* v) { |
| v->VisitPointers(&tables_[0], &tables_[generations_]); |
| } |
| |
| |
| void CompilationSubCache::Clear() { |
| for (int i = 0; i < generations_; i++) { |
| tables_[i] = Heap::undefined_value(); |
| } |
| } |
| |
| |
| // We only re-use a cached function for some script source code if the |
| // script originates from the same place. This is to avoid issues |
| // when reporting errors, etc. |
| bool CompilationCacheScript::HasOrigin(Handle<JSFunction> boilerplate, |
| Handle<Object> name, |
| int line_offset, |
| int column_offset) { |
| Handle<Script> script = |
| Handle<Script>(Script::cast(boilerplate->shared()->script())); |
| // If the script name isn't set, the boilerplate script should have |
| // an undefined name to have the same origin. |
| if (name.is_null()) { |
| return script->name()->IsUndefined(); |
| } |
| // Do the fast bailout checks first. |
| if (line_offset != script->line_offset()->value()) return false; |
| if (column_offset != script->column_offset()->value()) return false; |
| // Check that both names are strings. If not, no match. |
| if (!name->IsString() || !script->name()->IsString()) return false; |
| // Compare the two name strings for equality. |
| return String::cast(*name)->Equals(String::cast(script->name())); |
| } |
| |
| |
| // TODO(245): Need to allow identical code from different contexts to |
| // be cached in the same script generation. Currently the first use |
| // will be cached, but subsequent code from different source / line |
| // won't. |
| Handle<JSFunction> CompilationCacheScript::Lookup(Handle<String> source, |
| Handle<Object> name, |
| int line_offset, |
| int column_offset) { |
| Object* result = NULL; |
| int generation; |
| |
| // Probe the script generation tables. Make sure not to leak handles |
| // into the caller's handle scope. |
| { HandleScope scope; |
| for (generation = 0; generation < generations(); generation++) { |
| Handle<CompilationCacheTable> table = GetTable(generation); |
| Handle<Object> probe(table->Lookup(*source)); |
| if (probe->IsJSFunction()) { |
| Handle<JSFunction> boilerplate = Handle<JSFunction>::cast(probe); |
| // Break when we've found a suitable boilerplate function that |
| // matches the origin. |
| if (HasOrigin(boilerplate, name, line_offset, column_offset)) { |
| result = *boilerplate; |
| break; |
| } |
| } |
| } |
| } |
| |
| static void* script_histogram = StatsTable::CreateHistogram( |
| "V8.ScriptCache", |
| 0, |
| kScriptGenerations, |
| kScriptGenerations + 1); |
| |
| if (script_histogram != NULL) { |
| // The level NUMBER_OF_SCRIPT_GENERATIONS is equivalent to a cache miss. |
| StatsTable::AddHistogramSample(script_histogram, generation); |
| } |
| |
| // Once outside the manacles of the handle scope, we need to recheck |
| // to see if we actually found a cached script. If so, we return a |
| // handle created in the caller's handle scope. |
| if (result != NULL) { |
| Handle<JSFunction> boilerplate(JSFunction::cast(result)); |
| ASSERT(HasOrigin(boilerplate, name, line_offset, column_offset)); |
| // If the script was found in a later generation, we promote it to |
| // the first generation to let it survive longer in the cache. |
| if (generation != 0) Put(source, boilerplate); |
| Counters::compilation_cache_hits.Increment(); |
| return boilerplate; |
| } else { |
| Counters::compilation_cache_misses.Increment(); |
| return Handle<JSFunction>::null(); |
| } |
| } |
| |
| |
| Handle<CompilationCacheTable> CompilationCacheScript::TablePut( |
| Handle<String> source, |
| Handle<JSFunction> boilerplate) { |
| CALL_HEAP_FUNCTION(GetFirstTable()->Put(*source, *boilerplate), |
| CompilationCacheTable); |
| } |
| |
| |
| void CompilationCacheScript::Put(Handle<String> source, |
| Handle<JSFunction> boilerplate) { |
| HandleScope scope; |
| ASSERT(boilerplate->IsBoilerplate()); |
| SetFirstTable(TablePut(source, boilerplate)); |
| } |
| |
| |
| Handle<JSFunction> CompilationCacheEval::Lookup(Handle<String> source, |
| Handle<Context> context) { |
| // Make sure not to leak the table into the surrounding handle |
| // scope. Otherwise, we risk keeping old tables around even after |
| // having cleared the cache. |
| Object* result = NULL; |
| int generation; |
| { HandleScope scope; |
| for (generation = 0; generation < generations(); generation++) { |
| Handle<CompilationCacheTable> table = GetTable(generation); |
| result = table->LookupEval(*source, *context); |
| if (result->IsJSFunction()) { |
| break; |
| } |
| } |
| } |
| if (result->IsJSFunction()) { |
| Handle<JSFunction> boilerplate(JSFunction::cast(result)); |
| if (generation != 0) { |
| Put(source, context, boilerplate); |
| } |
| Counters::compilation_cache_hits.Increment(); |
| return boilerplate; |
| } else { |
| Counters::compilation_cache_misses.Increment(); |
| return Handle<JSFunction>::null(); |
| } |
| } |
| |
| |
| Handle<CompilationCacheTable> CompilationCacheEval::TablePut( |
| Handle<String> source, |
| Handle<Context> context, |
| Handle<JSFunction> boilerplate) { |
| CALL_HEAP_FUNCTION(GetFirstTable()->PutEval(*source, *context, *boilerplate), |
| CompilationCacheTable); |
| } |
| |
| |
| void CompilationCacheEval::Put(Handle<String> source, |
| Handle<Context> context, |
| Handle<JSFunction> boilerplate) { |
| HandleScope scope; |
| ASSERT(boilerplate->IsBoilerplate()); |
| SetFirstTable(TablePut(source, context, boilerplate)); |
| } |
| |
| |
| Handle<FixedArray> CompilationCacheRegExp::Lookup(Handle<String> source, |
| JSRegExp::Flags flags) { |
| // Make sure not to leak the table into the surrounding handle |
| // scope. Otherwise, we risk keeping old tables around even after |
| // having cleared the cache. |
| Object* result = NULL; |
| int generation; |
| { HandleScope scope; |
| for (generation = 0; generation < generations(); generation++) { |
| Handle<CompilationCacheTable> table = GetTable(generation); |
| result = table->LookupRegExp(*source, flags); |
| if (result->IsFixedArray()) { |
| break; |
| } |
| } |
| } |
| if (result->IsFixedArray()) { |
| Handle<FixedArray> data(FixedArray::cast(result)); |
| if (generation != 0) { |
| Put(source, flags, data); |
| } |
| Counters::compilation_cache_hits.Increment(); |
| return data; |
| } else { |
| Counters::compilation_cache_misses.Increment(); |
| return Handle<FixedArray>::null(); |
| } |
| } |
| |
| |
| Handle<CompilationCacheTable> CompilationCacheRegExp::TablePut( |
| Handle<String> source, |
| JSRegExp::Flags flags, |
| Handle<FixedArray> data) { |
| CALL_HEAP_FUNCTION(GetFirstTable()->PutRegExp(*source, flags, *data), |
| CompilationCacheTable); |
| } |
| |
| |
| void CompilationCacheRegExp::Put(Handle<String> source, |
| JSRegExp::Flags flags, |
| Handle<FixedArray> data) { |
| HandleScope scope; |
| SetFirstTable(TablePut(source, flags, data)); |
| } |
| |
| |
| Handle<JSFunction> CompilationCache::LookupScript(Handle<String> source, |
| Handle<Object> name, |
| int line_offset, |
| int column_offset) { |
| if (!IsEnabled()) { |
| return Handle<JSFunction>::null(); |
| } |
| |
| return script.Lookup(source, name, line_offset, column_offset); |
| } |
| |
| |
| Handle<JSFunction> CompilationCache::LookupEval(Handle<String> source, |
| Handle<Context> context, |
| bool is_global) { |
| if (!IsEnabled()) { |
| return Handle<JSFunction>::null(); |
| } |
| |
| Handle<JSFunction> result; |
| if (is_global) { |
| result = eval_global.Lookup(source, context); |
| } else { |
| result = eval_contextual.Lookup(source, context); |
| } |
| return result; |
| } |
| |
| |
| Handle<FixedArray> CompilationCache::LookupRegExp(Handle<String> source, |
| JSRegExp::Flags flags) { |
| if (!IsEnabled()) { |
| return Handle<FixedArray>::null(); |
| } |
| |
| return reg_exp.Lookup(source, flags); |
| } |
| |
| |
| void CompilationCache::PutScript(Handle<String> source, |
| Handle<JSFunction> boilerplate) { |
| if (!IsEnabled()) { |
| return; |
| } |
| |
| ASSERT(boilerplate->IsBoilerplate()); |
| script.Put(source, boilerplate); |
| } |
| |
| |
| void CompilationCache::PutEval(Handle<String> source, |
| Handle<Context> context, |
| bool is_global, |
| Handle<JSFunction> boilerplate) { |
| if (!IsEnabled()) { |
| return; |
| } |
| |
| HandleScope scope; |
| ASSERT(boilerplate->IsBoilerplate()); |
| if (is_global) { |
| eval_global.Put(source, context, boilerplate); |
| } else { |
| eval_contextual.Put(source, context, boilerplate); |
| } |
| } |
| |
| |
| |
| void CompilationCache::PutRegExp(Handle<String> source, |
| JSRegExp::Flags flags, |
| Handle<FixedArray> data) { |
| if (!IsEnabled()) { |
| return; |
| } |
| |
| reg_exp.Put(source, flags, data); |
| } |
| |
| |
| void CompilationCache::Clear() { |
| for (int i = 0; i < kSubCacheCount; i++) { |
| subcaches[i]->Clear(); |
| } |
| } |
| |
| |
| void CompilationCache::Iterate(ObjectVisitor* v) { |
| for (int i = 0; i < kSubCacheCount; i++) { |
| subcaches[i]->Iterate(v); |
| } |
| } |
| |
| |
| void CompilationCache::MarkCompactPrologue() { |
| for (int i = 0; i < kSubCacheCount; i++) { |
| subcaches[i]->Age(); |
| } |
| } |
| |
| |
| void CompilationCache::Enable() { |
| enabled = true; |
| } |
| |
| |
| void CompilationCache::Disable() { |
| enabled = false; |
| Clear(); |
| } |
| |
| |
| } } // namespace v8::internal |