v8/src/compilation-cache.cc
kasperl@chromium.org 1daa61fe2d Fix issue 65 by making sure not to leak any of the cache
tables when doing compilation cache operations.
Review URL: http://codereview.chromium.org/1939

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@280 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2008-09-11 13:39:48 +00:00

158 lines
5.7 KiB
C++

// 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 {
enum {
NUMBER_OF_ENTRY_KINDS = CompilationCache::EVAL_CONTEXTUAL + 1
};
// Keep separate tables for the different entry kinds.
static Object* tables[NUMBER_OF_ENTRY_KINDS] = { 0, };
static Handle<CompilationCacheTable> AllocateTable(int size) {
CALL_HEAP_FUNCTION(CompilationCacheTable::Allocate(size),
CompilationCacheTable);
}
static Handle<CompilationCacheTable> GetTable(CompilationCache::Entry entry) {
Handle<CompilationCacheTable> result;
if (tables[entry]->IsUndefined()) {
static const int kInitialCacheSize = 64;
result = AllocateTable(kInitialCacheSize);
tables[entry] = *result;
} else {
CompilationCacheTable* table = CompilationCacheTable::cast(tables[entry]);
result = Handle<CompilationCacheTable>(table);
}
return result;
}
// We only re-use a cached function for some script source code if the
// script originates from the same places. This is to avoid issues
// when reporting errors, etc.
static bool 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()));
}
static Handle<JSFunction> Lookup(Handle<String> source,
CompilationCache::Entry entry) {
// 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;
{ HandleScope scope;
Handle<CompilationCacheTable> table = GetTable(entry);
result = table->Lookup(*source);
}
if (result->IsJSFunction()) {
return Handle<JSFunction>(JSFunction::cast(result));
} else {
return Handle<JSFunction>::null();
}
}
Handle<JSFunction> CompilationCache::LookupScript(Handle<String> source,
Handle<Object> name,
int line_offset,
int column_offset) {
Handle<JSFunction> result = Lookup(source, SCRIPT);
if (result.is_null()) {
Counters::compilation_cache_misses.Increment();
} else if (HasOrigin(result, name, line_offset, column_offset)) {
Counters::compilation_cache_hits.Increment();
} else {
result = Handle<JSFunction>::null();
Counters::compilation_cache_misses.Increment();
}
return result;
}
Handle<JSFunction> CompilationCache::LookupEval(Handle<String> source,
Entry entry) {
ASSERT(entry == EVAL_GLOBAL || entry == EVAL_CONTEXTUAL);
Handle<JSFunction> result = Lookup(source, entry);
if (result.is_null()) {
Counters::compilation_cache_misses.Increment();
} else {
Counters::compilation_cache_hits.Increment();
}
return result;
}
void CompilationCache::Associate(Handle<String> source,
Entry entry,
Handle<JSFunction> boilerplate) {
HandleScope scope;
ASSERT(boilerplate->IsBoilerplate());
Handle<CompilationCacheTable> table = GetTable(entry);
CALL_HEAP_FUNCTION_VOID(table->Put(*source, *boilerplate));
}
void CompilationCache::Clear() {
for (int i = 0; i < NUMBER_OF_ENTRY_KINDS; i++) {
tables[i] = Heap::undefined_value();
}
}
void CompilationCache::Iterate(ObjectVisitor* v) {
v->VisitPointers(&tables[0], &tables[NUMBER_OF_ENTRY_KINDS]);
}
} } // namespace v8::internal