1 // Copyright 2011 the V8 project authors. All rights reserved. 2 // Redistribution and use in source and binary forms, with or without 3 // modification, are permitted provided that the following conditions are 4 // met: 5 // 6 // * Redistributions of source code must retain the above copyright 7 // notice, this list of conditions and the following disclaimer. 8 // * Redistributions in binary form must reproduce the above 9 // copyright notice, this list of conditions and the following 10 // disclaimer in the documentation and/or other materials provided 11 // with the distribution. 12 // * Neither the name of Google Inc. nor the names of its 13 // contributors may be used to endorse or promote products derived 14 // from this software without specific prior written permission. 15 // 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28 // Regression test of a very rare corner case where left-trimming an 29 // array caused invalid marking bit patterns on lazily swept pages. 30 // 31 // Lazy sweeping was deprecated. We are keeping the test case to make 32 // sure that concurrent sweeping, which relies on similar assumptions 33 // as lazy sweeping works correctly. 34 35 // Flags: --expose-gc --noincremental-marking --max-semi-space-size=1 36 37 (function() { 38 var head = new Array(1); 39 var tail = head; 40 41 // Fill heap to increase old-space size and trigger concurrent sweeping on 42 // some of the old-space pages. 43 for (var i = 0; i < 200; i++) { 44 tail[1] = new Array(1000); 45 tail = tail[1]; 46 } 47 array = new Array(100); 48 gc(); gc(); 49 50 // At this point "array" should have been promoted to old-space and be 51 // located in a concurrently swept page with intact marking bits. Now shift 52 // the array to trigger left-trimming operations. 53 assertEquals(100, array.length); 54 for (var i = 0; i < 50; i++) { 55 array.shift(); 56 } 57 assertEquals(50, array.length); 58 59 // At this point "array" should have been trimmed from the left with 60 // marking bits being correctly transfered to the new object start. 61 // Scavenging operations cause concurrent sweeping to advance and verify 62 // that marking bit patterns are still sane. 63 for (var i = 0; i < 200; i++) { 64 tail[1] = new Array(1000); 65 tail = tail[1]; 66 } 67 })(); 68
