js/src/jsapi-tests/testGCStoreBufferRemoval.cpp
author Jon Coppeard <jcoppeard@mozilla.com>
Mon, 14 Jan 2019 11:02:35 +0000
changeset 453704 1cebf4f5c850ad22500a360c2742de3c9dd78c81
parent 448963 66eb1f485c1a3ea81372758bc92292c9428b17cd
permissions -rw-r--r--
Bug 1519397 - Factor GC locking RAII classes out of vm/Runtime.h r=pbone

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * vim: set ts=8 sts=2 et sw=2 tw=80:
 */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "gc/Barrier.h"
#include "jsapi-tests/tests.h"

using namespace JS;
using namespace js;

struct AutoIgnoreRootingHazards {
  // Force a nontrivial destructor so the compiler sees the whole RAII scope
  static volatile int depth;
  AutoIgnoreRootingHazards() { depth++; }
  ~AutoIgnoreRootingHazards() { depth--; }
} JS_HAZ_GC_SUPPRESSED;
volatile int AutoIgnoreRootingHazards::depth = 0;

BEGIN_TEST(testGCStoreBufferRemoval) {
  // Sanity check - objects start in the nursery and then become tenured.
  JS_GC(cx);
  JS::RootedObject obj(cx, NurseryObject());
  CHECK(js::gc::IsInsideNursery(obj.get()));
  JS_GC(cx);
  CHECK(!js::gc::IsInsideNursery(obj.get()));
  JS::RootedObject tenuredObject(cx, obj);

  // Hide the horrors herein from the static rooting analysis.
  AutoIgnoreRootingHazards ignore;

  // Test removal of store buffer entries added by HeapPtr<T>.
  {
    JSObject* badObject = reinterpret_cast<JSObject*>(1);
    JSObject* punnedPtr = nullptr;
    HeapPtr<JSObject*>* relocPtr =
        reinterpret_cast<HeapPtr<JSObject*>*>(&punnedPtr);
    new (relocPtr) HeapPtr<JSObject*>;
    *relocPtr = NurseryObject();
    relocPtr->~HeapPtr<JSObject*>();
    punnedPtr = badObject;
    JS_GC(cx);

    new (relocPtr) HeapPtr<JSObject*>;
    *relocPtr = NurseryObject();
    *relocPtr = tenuredObject;
    relocPtr->~HeapPtr<JSObject*>();
    punnedPtr = badObject;
    JS_GC(cx);

    new (relocPtr) HeapPtr<JSObject*>;
    *relocPtr = NurseryObject();
    *relocPtr = nullptr;
    relocPtr->~HeapPtr<JSObject*>();
    punnedPtr = badObject;
    JS_GC(cx);
  }

  // Test removal of store buffer entries added by HeapPtr<Value>.
  {
    Value punnedValue;
    HeapPtr<Value>* relocValue =
        reinterpret_cast<HeapPtr<Value>*>(&punnedValue);
    new (relocValue) HeapPtr<Value>;
    *relocValue = ObjectValue(*NurseryObject());
    relocValue->~HeapPtr<Value>();
    punnedValue = js::PoisonedObjectValue(0x48);
    JS_GC(cx);

    new (relocValue) HeapPtr<Value>;
    *relocValue = ObjectValue(*NurseryObject());
    *relocValue = ObjectValue(*tenuredObject);
    relocValue->~HeapPtr<Value>();
    punnedValue = js::PoisonedObjectValue(0x48);
    JS_GC(cx);

    new (relocValue) HeapPtr<Value>;
    *relocValue = ObjectValue(*NurseryObject());
    *relocValue = NullValue();
    relocValue->~HeapPtr<Value>();
    punnedValue = js::PoisonedObjectValue(0x48);
    JS_GC(cx);
  }

  // Test removal of store buffer entries added by Heap<T>.
  {
    JSObject* badObject = reinterpret_cast<JSObject*>(1);
    JSObject* punnedPtr = nullptr;
    Heap<JSObject*>* heapPtr = reinterpret_cast<Heap<JSObject*>*>(&punnedPtr);
    new (heapPtr) Heap<JSObject*>;
    *heapPtr = NurseryObject();
    heapPtr->~Heap<JSObject*>();
    punnedPtr = badObject;
    JS_GC(cx);

    new (heapPtr) Heap<JSObject*>;
    *heapPtr = NurseryObject();
    *heapPtr = tenuredObject;
    heapPtr->~Heap<JSObject*>();
    punnedPtr = badObject;
    JS_GC(cx);

    new (heapPtr) Heap<JSObject*>;
    *heapPtr = NurseryObject();
    *heapPtr = nullptr;
    heapPtr->~Heap<JSObject*>();
    punnedPtr = badObject;
    JS_GC(cx);
  }

  return true;
}

JSObject* NurseryObject() { return JS_NewPlainObject(cx); }
END_TEST(testGCStoreBufferRemoval)