Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1 | // Copyright 2015 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | // Flags: --allow-natives-syntax --expose-gc |
| 6 | |
| 7 | function Inner() { |
| 8 | this.p1 = 0; |
| 9 | this.p2 = 3; |
| 10 | } |
| 11 | |
| 12 | function Outer() { |
| 13 | this.p3 = 0; |
| 14 | } |
| 15 | |
| 16 | var i1 = new Inner(); |
| 17 | var i2 = new Inner(); |
| 18 | var o1 = new Outer(); |
| 19 | o1.inner = i1; |
| 20 | // o1.map now thinks "inner" has type Inner.map1. |
| 21 | // Deprecate Inner.map1: |
| 22 | i1.p1 = 0.5; |
| 23 | // Let Inner.map1 die by migrating i2 to Inner.map2: |
| 24 | print(i2.p1); |
| 25 | gc(); |
| 26 | // o1.map's descriptor for "inner" is now a cleared WeakCell; |
| 27 | // o1.inner's actual map is Inner.map2. |
| 28 | // Prepare Inner.map3, deprecating Inner.map2. |
| 29 | i2.p2 = 0.5; |
| 30 | // Deprecate o1's map. |
| 31 | var o2 = new Outer(); |
| 32 | o2.p3 = 0.5; |
| 33 | o2.inner = i2; |
| 34 | // o2.map (Outer.map2) now says that o2.inner's type is Inner.map3. |
| 35 | // Migrate o1 to Outer.map2. |
| 36 | print(o1.p3); |
| 37 | // o1.map now thinks that o1.inner has map Inner.map3 just like o2.inner, |
| 38 | // but in fact o1.inner.map is still Inner.map2! |
| 39 | |
| 40 | function loader(o) { |
| 41 | return o.inner.p2; |
| 42 | } |
| 43 | loader(o2); |
| 44 | loader(o2); |
| 45 | %OptimizeFunctionOnNextCall(loader); |
| 46 | assertEquals(0.5, loader(o2)); |
| 47 | assertEquals(3, loader(o1)); |
| 48 | gc(); // Crashes with --verify-heap. |