v8/src/compilation-cache.h
2011-11-14 08:58:47 +00:00

297 lines
11 KiB
C++

// Copyright 2011 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.
#ifndef V8_COMPILATION_CACHE_H_
#define V8_COMPILATION_CACHE_H_
namespace v8 {
namespace internal {
class HashMap;
// 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:
CompilationSubCache(Isolate* isolate, int generations)
: isolate_(isolate),
generations_(generations) {
tables_ = NewArray<Object*>(generations);
}
~CompilationSubCache() { DeleteArray(tables_); }
// Index for the first generation in the cache.
static const int kFirstGeneration = 0;
// 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);
void IterateFunctions(ObjectVisitor* v);
// Clear this sub-cache evicting all its content.
void Clear();
// Remove given shared function info from sub-cache.
void Remove(Handle<SharedFunctionInfo> function_info);
// Number of generations in this sub-cache.
inline int generations() { return generations_; }
protected:
Isolate* isolate() { return isolate_; }
private:
Isolate* isolate_;
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:
CompilationCacheScript(Isolate* isolate, int generations);
Handle<SharedFunctionInfo> Lookup(Handle<String> source,
Handle<Object> name,
int line_offset,
int column_offset);
void Put(Handle<String> source, Handle<SharedFunctionInfo> function_info);
private:
MUST_USE_RESULT MaybeObject* TryTablePut(
Handle<String> source, Handle<SharedFunctionInfo> function_info);
// Note: Returns a new hash table if operation results in expansion.
Handle<CompilationCacheTable> TablePut(
Handle<String> source, Handle<SharedFunctionInfo> function_info);
bool HasOrigin(Handle<SharedFunctionInfo> function_info,
Handle<Object> name,
int line_offset,
int column_offset);
void* script_histogram_;
bool script_histogram_initialized_;
DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheScript);
};
// Sub-cache for eval scripts. Two caches for eval are used. One for eval calls
// in global contexts and one for eval calls in other contexts. The cache
// considers the following pieces of information when checking for matching
// entries:
// 1. The source string.
// 2. The shared function info of the calling function.
// 3. Whether the source should be compiled as strict code or as non-strict
// code.
// Note: Currently there are clients of CompileEval that always compile
// non-strict code even if the calling function is a strict mode function.
// More specifically these are the CompileString, DebugEvaluate and
// DebugEvaluateGlobal runtime functions.
// 4. The start position of the calling scope.
class CompilationCacheEval: public CompilationSubCache {
public:
CompilationCacheEval(Isolate* isolate, int generations)
: CompilationSubCache(isolate, generations) { }
Handle<SharedFunctionInfo> Lookup(Handle<String> source,
Handle<Context> context,
StrictModeFlag strict_mode,
int scope_position);
void Put(Handle<String> source,
Handle<Context> context,
Handle<SharedFunctionInfo> function_info,
int scope_position);
private:
MUST_USE_RESULT MaybeObject* TryTablePut(
Handle<String> source,
Handle<Context> context,
Handle<SharedFunctionInfo> function_info,
int scope_position);
// Note: Returns a new hash table if operation results in expansion.
Handle<CompilationCacheTable> TablePut(
Handle<String> source,
Handle<Context> context,
Handle<SharedFunctionInfo> function_info,
int scope_position);
DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheEval);
};
// Sub-cache for regular expressions.
class CompilationCacheRegExp: public CompilationSubCache {
public:
CompilationCacheRegExp(Isolate* isolate, int generations)
: CompilationSubCache(isolate, generations) { }
Handle<FixedArray> Lookup(Handle<String> source, JSRegExp::Flags flags);
void Put(Handle<String> source,
JSRegExp::Flags flags,
Handle<FixedArray> data);
private:
MUST_USE_RESULT MaybeObject* TryTablePut(Handle<String> source,
JSRegExp::Flags flags,
Handle<FixedArray> data);
// 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);
};
// The compilation cache keeps shared function infos for compiled
// scripts and evals. The shared function infos are looked up using
// the source string as the key. For regular expressions the
// compilation data is cached.
class CompilationCache {
public:
// Finds the script shared function info for a source
// string. Returns an empty handle if the cache doesn't contain a
// script for the given source string with the right origin.
Handle<SharedFunctionInfo> LookupScript(Handle<String> source,
Handle<Object> name,
int line_offset,
int column_offset);
// Finds the shared function info for a source string for eval in a
// given context. Returns an empty handle if the cache doesn't
// contain a script for the given source string.
Handle<SharedFunctionInfo> LookupEval(Handle<String> source,
Handle<Context> context,
bool is_global,
StrictModeFlag strict_mode,
int scope_position);
// Returns the regexp data associated with the given regexp if it
// is in cache, otherwise an empty handle.
Handle<FixedArray> LookupRegExp(Handle<String> source,
JSRegExp::Flags flags);
// Associate the (source, kind) pair to the shared function
// info. This may overwrite an existing mapping.
void PutScript(Handle<String> source,
Handle<SharedFunctionInfo> function_info);
// Associate the (source, context->closure()->shared(), kind) triple
// with the shared function info. This may overwrite an existing mapping.
void PutEval(Handle<String> source,
Handle<Context> context,
bool is_global,
Handle<SharedFunctionInfo> function_info,
int scope_position);
// Associate the (source, flags) pair to the given regexp data.
// This may overwrite an existing mapping.
void PutRegExp(Handle<String> source,
JSRegExp::Flags flags,
Handle<FixedArray> data);
// Clear the cache - also used to initialize the cache at startup.
void Clear();
// Remove given shared function info from all caches.
void Remove(Handle<SharedFunctionInfo> function_info);
// GC support.
void Iterate(ObjectVisitor* v);
void IterateFunctions(ObjectVisitor* v);
// Notify the cache that a mark-sweep garbage collection is about to
// take place. This is used to retire entries from the cache to
// avoid keeping them alive too long without using them.
void MarkCompactPrologue();
// Enable/disable compilation cache. Used by debugger to disable compilation
// cache during debugging to make sure new scripts are always compiled.
void Enable();
void Disable();
private:
explicit CompilationCache(Isolate* isolate);
~CompilationCache();
HashMap* EagerOptimizingSet();
// The number of sub caches covering the different types to cache.
static const int kSubCacheCount = 4;
bool IsEnabled() { return FLAG_compilation_cache && enabled_; }
Isolate* isolate() { return isolate_; }
Isolate* isolate_;
CompilationCacheScript script_;
CompilationCacheEval eval_global_;
CompilationCacheEval eval_contextual_;
CompilationCacheRegExp reg_exp_;
CompilationSubCache* subcaches_[kSubCacheCount];
// Current enable state of the compilation cache.
bool enabled_;
friend class Isolate;
DISALLOW_COPY_AND_ASSIGN(CompilationCache);
};
} } // namespace v8::internal
#endif // V8_COMPILATION_CACHE_H_