JezK
Edit File: regress-1708.js
// Copyright 2011 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. // Regression test of a very rare corner case where left-trimming an // array caused invalid marking bit patterns on lazily swept pages. // Flags: --expose-gc --noincremental-marking --max-new-space-size 1000 (function() { var head = new Array(1); var tail = head; // Fill heap to increase old-space size and trigger lazy sweeping on // some of the old-space pages. for (var i = 0; i < 200; i++) { tail[1] = new Array(1000); tail = tail[1]; } array = new Array(100); gc(); gc(); // At this point "array" should have been promoted to old-space and be // located in a lazy swept page with intact marking bits. Now shift // the array to trigger left-trimming operations. assertEquals(100, array.length); for (var i = 0; i < 50; i++) { array.shift(); } assertEquals(50, array.length); // At this point "array" should have been trimmed from the left with // marking bits being correctly transfered to the new object start. // Scavenging operations cause lazy sweeping to advance and verify // that marking bit patterns are still sane. for (var i = 0; i < 200; i++) { tail[1] = new Array(1000); tail = tail[1]; } })();