/*

 * Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/**

 * @test

 * @bug 8026775

 * @summary Uncommon trap blob did not bang all the stack shadow pages

 *

 * @run main/othervm compiler.uncommontrap.UncommonTrapStackBang

 */

/*

 * Note: This test does not reproduce the problem with absolute

 * certainty. Empirically the bug reproduces on Windows some 80+% of

 * the time. Setting everything up to fail in 100% of the cases turns

 * out to be tricky at best.

 *

 *

 * The goal of this test is to set up the following stack:

 *

 * doIt()

 * eatStack()

 * ...

 * eatStack()

 * run()

 *

 *

 * When doIt() gets executed it will hit an uncommon trap and expand

 * into a huge interpreter frame. The doIt method then calls the

 * compiled version of StringBuilder.<init>() which does a single

 * stack bang StackShadowPages down.

 *

 * The uncommon trap blob is supposed to prepare for the interpreter

 * by pre-touching stack pages. The bug was that it didn't correctly

 * pre-touch all the stack shadow pages, leaving a "hole" on the stack

 * which raises an exception on Windows when the stack bang in

 * StringBuilder is performed.

 */

package compiler.uncommontrap;

public class UncommonTrapStackBang extends Thread {

    class Foo { }

    public static void main(String[] args) throws Exception {

        doWarmup();

        // Fork off a new thread to increase odds of the stack being unmapped

        UncommonTrapStackBang htsb = new UncommonTrapStackBang();

        htsb.run();

        htsb.join();

    }

    // Make sure:

    //

    // a) StringBuilder.<init>()V is compiled

    // b) doIt() is compiled with an uncommon trap in the unlikely path

    public static void doWarmup() {

        for (int i = 0; i < 100_000; i++) {

            new StringBuilder();

            doIt(false);

        }

    }

    public void run() {

        eatStack(200);

    }

    // Consume some stack to get down to some unused/unmapped pages,

    // then call doIt and provoke the uncommon trap/deoptimization

    private void eatStack(int n) {

        if (n <= 0) {

            doIt(true);

            return;

        }

        eatStack(n - 1);

    }

    static public void doIt(boolean unlikely) {

        int i0;

        int i1;

        int i2;

        int i3;

        int i4;

        int i5;

        int i6;

        int i7;

        int i8;

        int i9;

        int i10;

        int i11;

        int i12;

        int i13;

        int i14;

        int i15;

        int i16;

        int i17;

        int i18;

        int i19;

        int i20;

        int i21;

        int i22;

        int i23;

        int i24;

        int i25;

        int i26;

        int i27;

        int i28;

        int i29;

        int i30;

        int i31;

        int i32;

        int i33;

        int i34;

        int i35;

        int i36;

        int i37;

        int i38;

        int i39;

        int i40;

        int i41;

        int i42;

        int i43;

        int i44;

        int i45;

        int i46;

        int i47;

        int i48;

        int i49;

        int i50;

        int i51;

        int i52;

        int i53;

        int i54;

        int i55;

        int i56;

        int i57;

        int i58;

        int i59;

        int i60;

        int i61;

        int i62;

        int i63;

        int i64;

        int i65;

        int i66;

        int i67;

        int i68;

        int i69;

        int i70;

        int i71;

        int i72;

        int i73;

        int i74;

        int i75;

        int i76;

        int i77;

        int i78;

        int i79;

        int i80;

        int i81;

        int i82;

        int i83;

        int i84;

        int i85;

        int i86;

        int i87;

        int i88;

        int i89;

        int i90;

        int i91;

        int i92;

        int i93;

        int i94;

        int i95;

        int i96;

        int i97;

        int i98;

        int i99;

        int i100;

        int i101;

        int i102;

        int i103;

        int i104;

        int i105;

        int i106;

        int i107;

        int i108;

        int i109;

        int i110;

        int i111;

        int i112;

        int i113;

        int i114;

        int i115;

        int i116;

        int i117;

        int i118;

        int i119;

        int i120;

        int i121;

        int i122;

        int i123;

        int i124;

        int i125;

        int i126;

        int i127;

        int i128;

        int i129;

        int i130;

        int i131;

        int i132;

        int i133;

        int i134;

        int i135;

        int i136;

        int i137;

        int i138;

        int i139;

        int i140;

        int i141;

        int i142;

        int i143;

        int i144;

        int i145;

        int i146;

        int i147;

        int i148;

        int i149;

        int i150;

        int i151;

        int i152;

        int i153;

        int i154;

        int i155;

        int i156;

        int i157;

        int i158;

        int i159;

        int i160;

        int i161;

        int i162;

        int i163;

        int i164;

        int i165;

        int i166;

        int i167;

        int i168;

        int i169;

        int i170;

        int i171;

        int i172;

        int i173;

        int i174;

        int i175;

        int i176;

        int i177;

        int i178;

        int i179;

        int i180;

        int i181;

        int i182;

        int i183;

        int i184;

        int i185;

        int i186;

        int i187;

        int i188;

        int i189;

        int i190;

        int i191;

        int i192;

        int i193;

        int i194;

        int i195;

        int i196;

        int i197;

        int i198;

        int i199;

        int i200;

        int i201;

        int i202;

        int i203;

        int i204;

        int i205;

        int i206;

        int i207;

        int i208;

        int i209;

        int i210;

        int i211;

        int i212;

        int i213;

        int i214;

        int i215;

        int i216;

        int i217;

        int i218;

        int i219;

        int i220;

        int i221;

        int i222;

        int i223;

        int i224;

        int i225;

        int i226;

        int i227;

        int i228;

        int i229;

        int i230;

        int i231;

        int i232;

        int i233;

        int i234;

        int i235;

        int i236;

        int i237;

        int i238;

        int i239;

        int i240;

        int i241;

        int i242;

        int i243;

        int i244;

        int i245;

        int i246;

        int i247;

        int i248;

        int i249;

        int i250;

        int i251;

        int i252;

        int i253;

        int i254;

        int i255;

        int i256;

        int i257;

        int i258;

        int i259;

        int i260;

        int i261;

        int i262;

        int i263;

        int i264;

        int i265;

        int i266;

        int i267;

        int i268;

        int i269;

        int i270;

        int i271;

        int i272;

        int i273;

        int i274;

        int i275;

        int i276;

        int i277;

        int i278;

        int i279;

        int i280;

        int i281;

        int i282;

        int i283;

        int i284;

        int i285;

        int i286;

        int i287;

        int i288;

        int i289;

        int i290;

        int i291;

        int i292;

        int i293;

        int i294;

        int i295;

        int i296;

        int i297;

        int i298;

        int i299;

        int i300;

        int i301;

        int i302;

        int i303;

        int i304;

        int i305;

        int i306;

        int i307;

        int i308;

        int i309;

        int i310;

        int i311;

        int i312;

        int i313;

        int i314;

        int i315;

        int i316;

        int i317;

        int i318;

        int i319;

        int i320;

        int i321;

        int i322;

        int i323;

        int i324;

        int i325;

        int i326;

        int i327;

        int i328;

        int i329;

        int i330;

        int i331;

        int i332;

        int i333;

        int i334;

        int i335;

        int i336;

        int i337;

        int i338;

        int i339;

        int i340;

        int i341;

        int i342;

        int i343;

        int i344;

        int i345;

        int i346;

        int i347;

        int i348;

        int i349;

        int i350;

        int i351;

        int i352;

        int i353;

        int i354;

        int i355;

        int i356;

        int i357;

        int i358;

        int i359;

        int i360;

        int i361;

        int i362;

        int i363;

        int i364;

        int i365;

        int i366;

        int i367;

        int i368;

        int i369;

        int i370;

        int i371;

        int i372;

        int i373;

        int i374;

        int i375;

        int i376;

        int i377;

        int i378;

        int i379;

        int i380;

        int i381;

        int i382;

        int i383;

        int i384;

        int i385;

        int i386;

        int i387;

        int i388;

        int i389;

        int i390;

        int i391;

        int i392;

        int i393;

        int i394;

        int i395;

        int i396;

        int i397;

        int i398;

        int i399;

        int i400;

        int i401;

        int i402;

        int i403;

        int i404;

        int i405;

        int i406;

        int i407;

        int i408;

        int i409;

        int i410;

        int i411;

        int i412;

        int i413;

        int i414;

        int i415;

        int i416;

        int i417;

        int i418;

        int i419;

        int i420;

        int i421;

        int i422;

        int i423;

        int i424;

        int i425;

        int i426;