Add option to disable MirrorCache.

R=yurys@chromium.org

Review URL: https://codereview.chromium.org/307383002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21644 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/debug.cc

@@ -2459,17 +2459,17 @@ void Debug::ClearMirrorCache() {
   PostponeInterruptsScope postpone(isolate_);
   HandleScope scope(isolate_);
   ASSERT(isolate_->context() == *Debug::debug_context());
-
-  // Clear the mirror cache.
-  Handle<Object> fun = Object::GetProperty(
-      isolate_,
-      isolate_->global_object(),
-      "ClearMirrorCache").ToHandleChecked();
-  ASSERT(fun->IsJSFunction());
-  Execution::TryCall(Handle<JSFunction>::cast(fun),
-                     Handle<JSObject>(Debug::debug_context()->global_object()),
-                     0,
-                     NULL);
+  Factory* factory = isolate_->factory();
+  JSObject::SetProperty(isolate_->global_object(),
+      factory->NewStringFromAsciiChecked("next_handle_"),
+      handle(Smi::FromInt(0), isolate_),
+      NONE,
+      SLOPPY).Check();
+  JSObject::SetProperty(isolate_->global_object(),
+      factory->NewStringFromAsciiChecked("mirror_cache_"),
+      factory->NewJSArray(0, FAST_ELEMENTS),
+      NONE,
+      SLOPPY).Check();
 }
 
 

src/mirror-debugger.js

@@ -8,6 +8,14 @@ var next_transient_handle_ = -1;
 
 // Mirror cache.
 var mirror_cache_ = [];
+var mirror_cache_enabled_ = true;
+
+
+function ToggleMirrorCache(value) {
+  mirror_cache_enabled_ = value;
+  next_handle_ = 0;
+  mirror_cache_ = [];
+}
 
 
 /**
@@ -44,7 +52,7 @@ function MakeMirror(value, opt_transient) {
   var mirror;
 
   // Look for non transient mirrors in the mirror cache.
-  if (!opt_transient) {
+  if (!opt_transient && mirror_cache_enabled_) {
     for (id in mirror_cache_) {
       mirror = mirror_cache_[id];
       if (mirror.value() === value) {
@@ -88,7 +96,7 @@ function MakeMirror(value, opt_transient) {
     mirror = new ObjectMirror(value, OBJECT_TYPE, opt_transient);
   }
 
-  mirror_cache_[mirror.handle()] = mirror;
+  if (mirror_cache_enabled_) mirror_cache_[mirror.handle()] = mirror;
   return mirror;
 }
 
@@ -101,6 +109,7 @@ function MakeMirror(value, opt_transient) {
  *     undefined if no mirror with the requested handle was found
  */
 function LookupMirror(handle) {
+  if (!mirror_cache_enabled_) throw new Error("Mirror cache is disabled");
   return mirror_cache_[handle];
 }
 
@@ -424,7 +433,7 @@ Mirror.prototype.isScope = function() {
  * Allocate a handle id for this object.
  */
 Mirror.prototype.allocateHandle_ = function() {
-  this.handle_ = next_handle_++;
+  if (mirror_cache_enabled_) this.handle_ = next_handle_++;
 };
 
 

test/mjsunit/debug-toggle-mirror-cache.js

+// Copyright 2014 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.
+
+// Flags: --expose-debug-as debug
+
+var handle1 = debug.MakeMirror(123).handle();
+assertEquals("number", debug.LookupMirror(handle1).type());
+
+debug.ToggleMirrorCache(false);
+var handle2 = debug.MakeMirror(123).handle();
+assertEquals(undefined, handle2);
+assertThrows(function() { debug.LookupMirror(handle2) });
+
+debug.ToggleMirrorCache(true);
+var handle3 = debug.MakeMirror(123).handle();
+assertEquals("number", debug.LookupMirror(handle3).type());

tools/generate-runtime-tests.py

@@ -51,7 +51,7 @@ EXPECTED_FUNCTION_COUNT = 358
 EXPECTED_FUZZABLE_COUNT = 325
 EXPECTED_CCTEST_COUNT = 6
 EXPECTED_UNKNOWN_COUNT = 5
-EXPECTED_BUILTINS_COUNT = 797
+EXPECTED_BUILTINS_COUNT = 798
 
 
 # Don't call these at all.