// 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.
#include "v8.h"
#include "assembler.h"
#include "compilation-cache.h"
#include "serialize.h"
namespace v8 {
namespace internal {
// 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;
CompilationCache::CompilationCache(Isolate* isolate)
: isolate_(isolate),
script_(isolate, kScriptGenerations),
eval_global_(isolate, kEvalGlobalGenerations),
eval_contextual_(isolate, kEvalContextualGenerations),
reg_exp_(isolate, kRegExpGenerations),
enabled_(true) {
CompilationSubCache* subcaches[kSubCacheCount] =
{&script_, &eval_global_, &eval_contextual_, ®_exp_};
for (int i = 0; i < kSubCacheCount; ++i) {
subcaches_[i] = subcaches[i];
}
}
CompilationCache::~CompilationCache() {}
static Handle<CompilationCacheTable> AllocateTable(Isolate* isolate, int size) {
CALL_HEAP_FUNCTION(isolate,
CompilationCacheTable::Allocate(size),
CompilationCacheTable);
}
Handle<CompilationCacheTable> CompilationSubCache::GetTable(int generation) {
ASSERT(generation < generations_);
Handle<CompilationCacheTable> result;
if (tables_[generation]->IsUndefined()) {
result = AllocateTable(isolate(), kInitialCacheSize);
tables_[generation] = *result;
} else {
CompilationCacheTable* table =
CompilationCacheTable::cast(tables_[generation]);
result = Handle<CompilationCacheTable>(table, isolate());
}
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] = isolate()->heap()->undefined_value();
}
void CompilationSubCache::IterateFunctions(ObjectVisitor* v) {
Object* undefined = isolate()->heap()->raw_unchecked_undefined_value();
for (int i = 0; i < generations_; i++) {
if (tables_[i] != undefined) {
reinterpret_cast<CompilationCacheTable*>(tables_[i])->IterateElements(v);
}
}
}
void CompilationSubCache::Iterate(ObjectVisitor* v) {
v->VisitPointers(&tables_[0], &tables_[generations_]);
}
void CompilationSubCache::Clear() {
MemsetPointer(tables_, isolate()->heap()->undefined_value(), generations_);
}
void CompilationSubCache::Remove(Handle<SharedFunctionInfo> function_info) {
// Probe the script generation tables. Make sure not to leak handles
// into the caller's handle scope.
{ HandleScope scope(isolate());
for (int generation = 0; generation < generations(); generation++) {
Handle<CompilationCacheTable> table = GetTable(generation);
table->Remove(*function_info);
}
}
}
CompilationCacheScript::CompilationCacheScript(Isolate* isolate,
int generations)
: CompilationSubCache(isolate, generations),
script_histogram_(NULL),
script_histogram_initialized_(false) { }
// 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<SharedFunctionInfo> function_info,
Handle<Object> name,
int line_offset,
int column_offset) {
Handle<Script> script =
Handle<Script>(Script::cast(function_info->script()), isolate());
// 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<SharedFunctionInfo> 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(isolate());
for (generation = 0; generation < generations(); generation++) {
Handle<CompilationCacheTable> table = GetTable(generation);
Handle<Object> probe(table->Lookup(*source), isolate());
if (probe->IsSharedFunctionInfo()) {
Handle<SharedFunctionInfo> function_info =
Handle<SharedFunctionInfo>::cast(probe);
// Break when we've found a suitable shared function info that
// matches the origin.
if (HasOrigin(function_info, name, line_offset, column_offset)) {
result = *function_info;
break;
}
}
}
}
if (!script_histogram_initialized_) {
script_histogram_ = isolate()->stats_table()->CreateHistogram(
"V8.ScriptCache",
0,
kScriptGenerations,
kScriptGenerations + 1);
script_histogram_initialized_ = true;
}
if (script_histogram_ != NULL) {
// The level NUMBER_OF_SCRIPT_GENERATIONS is equivalent to a cache miss.
isolate()->stats_table()->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<SharedFunctionInfo> shared(SharedFunctionInfo::cast(result),
isolate());
ASSERT(HasOrigin(shared, 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, shared);
isolate()->counters()->compilation_cache_hits()->Increment();
return shared;
} else {
isolate()->counters()->compilation_cache_misses()->Increment();
return Handle<SharedFunctionInfo>::null();
}
}
MaybeObject* CompilationCacheScript::TryTablePut(
Handle<String> source,
Handle<SharedFunctionInfo> function_info) {
Handle<CompilationCacheTable> table = GetFirstTable();
return table->Put(*source, *function_info);
}
Handle<CompilationCacheTable> CompilationCacheScript::TablePut(
Handle<String> source,
Handle<SharedFunctionInfo> function_info) {
CALL_HEAP_FUNCTION(isolate(),
TryTablePut(source, function_info),
CompilationCacheTable);
}
void CompilationCacheScript::Put(Handle<String> source,
Handle<SharedFunctionInfo> function_info) {
HandleScope scope(isolate());
SetFirstTable(TablePut(source, function_info));
}
Handle<SharedFunctionInfo> CompilationCacheEval::Lookup(
Handle<String> source,
Handle<Context> context,
LanguageMode language_mode,
int scope_position) {
// 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(isolate());
for (generation = 0; generation < generations(); generation++) {
Handle<CompilationCacheTable> table = GetTable(generation);
result = table->LookupEval(
*source, *context, language_mode, scope_position);
if (result->IsSharedFunctionInfo()) {
break;
}
}
}
if (result->IsSharedFunctionInfo()) {
Handle<SharedFunctionInfo>
function_info(SharedFunctionInfo::cast(result), isolate());
if (generation != 0) {
Put(source, context, function_info, scope_position);
}
isolate()->counters()->compilation_cache_hits()->Increment();
return function_info;
} else {
isolate()->counters()->compilation_cache_misses()->Increment();
return Handle<SharedFunctionInfo>::null();
}
}
MaybeObject* CompilationCacheEval::TryTablePut(
Handle<String> source,
Handle<Context> context,
Handle<SharedFunctionInfo> function_info,
int scope_position) {
Handle<CompilationCacheTable> table = GetFirstTable();
return table->PutEval(*source, *context, *function_info, scope_position);
}
Handle<CompilationCacheTable> CompilationCacheEval::TablePut(
Handle<String> source,
Handle<Context> context,
Handle<SharedFunctionInfo> function_info,
int scope_position) {
CALL_HEAP_FUNCTION(isolate(),
TryTablePut(
source, context, function_info, scope_position),
CompilationCacheTable);
}
void CompilationCacheEval::Put(Handle<String> source,
Handle<Context> context,
Handle<SharedFunctionInfo> function_info,
int scope_position) {
HandleScope scope(isolate());
SetFirstTable(TablePut(source, context, function_info, scope_position));
}
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(isolate());
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), isolate());
if (generation != 0) {
Put(source, flags, data);
}
isolate()->counters()->compilation_cache_hits()->Increment();
return data;
} else {
isolate()->counters()->compilation_cache_misses()->Increment();
return Handle<FixedArray>::null();
}
}
MaybeObject* CompilationCacheRegExp::TryTablePut(
Handle<String> source,
JSRegExp::Flags flags,
Handle<FixedArray> data) {
Handle<CompilationCacheTable> table = GetFirstTable();
return table->PutRegExp(*source, flags, *data);
}
Handle<CompilationCacheTable> CompilationCacheRegExp::TablePut(
Handle<String> source,
JSRegExp::Flags flags,
Handle<FixedArray> data) {
CALL_HEAP_FUNCTION(isolate(),
TryTablePut(source, flags, data),
CompilationCacheTable);
}
void CompilationCacheRegExp::Put(Handle<String> source,
JSRegExp::Flags flags,
Handle<FixedArray> data) {
HandleScope scope(isolate());
SetFirstTable(TablePut(source, flags, data));
}
void CompilationCache::Remove(Handle<SharedFunctionInfo> function_info) {
if (!IsEnabled()) return;
eval_global_.Remove(function_info);
eval_contextual_.Remove(function_info);
script_.Remove(function_info);
}
Handle<SharedFunctionInfo> CompilationCache::LookupScript(Handle<String> source,
Handle<Object> name,
int line_offset,
int column_offset) {
if (!IsEnabled()) {
return Handle<SharedFunctionInfo>::null();
}
return script_.Lookup(source, name, line_offset, column_offset);
}
Handle<SharedFunctionInfo> CompilationCache::LookupEval(
Handle<String> source,
Handle<Context> context,
bool is_global,
LanguageMode language_mode,
int scope_position) {
if (!IsEnabled()) {
return Handle<SharedFunctionInfo>::null();
}
Handle<SharedFunctionInfo> result;
if (is_global) {
result = eval_global_.Lookup(
source, context, language_mode, scope_position);
} else {
ASSERT(scope_position != RelocInfo::kNoPosition);
result = eval_contextual_.Lookup(
source, context, language_mode, scope_position);
}
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<SharedFunctionInfo> function_info) {
if (!IsEnabled()) {
return;
}
script_.Put(source, function_info);
}
void CompilationCache::PutEval(Handle<String> source,
Handle<Context> context,
bool is_global,
Handle<SharedFunctionInfo> function_info,
int scope_position) {
if (!IsEnabled()) {
return;
}
HandleScope scope(isolate());
if (is_global) {
eval_global_.Put(source, context, function_info, scope_position);
} else {
ASSERT(scope_position != RelocInfo::kNoPosition);
eval_contextual_.Put(source, context, function_info, scope_position);
}
}
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::IterateFunctions(ObjectVisitor* v) {
for (int i = 0; i < kSubCacheCount; i++) {
subcaches_[i]->IterateFunctions(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