test/script/basic/JDK-8136544.js

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/**
 * JDK-8136544: Call site switching to megamorphic causes incorrect property read
 *
 * @test
 * @fork
 * @option -Dnashorn.unstable.relink.threshold=8
 * @run
 */

var ScriptContext = Java.type("javax.script.ScriptContext");
var ScriptEngineManager = Java.type("javax.script.ScriptEngineManager");
var m = new ScriptEngineManager();
var e = m.getEngineByName("nashorn");

var scope = e.getBindings(ScriptContext.ENGINE_SCOPE);
var MYVAR = "myvar";

function loopupVar() {
    try {
        e.eval(MYVAR);
        return true;
    } catch (e) {
        return false;
    }
}

// make sure we exercise callsite beyond megamorphic threshold we set
// in this test via nashorn.unstable.relink.threshold property
// In each iteration, callsite is exercised twice (two evals)
// So, LIMIT should be more than 4 to exercise megamorphic callsites.

var LIMIT = 5; // This LIMIT should be more than 4

for (var i = 0; i < LIMIT; i++) {
    // remove the variable and lookup
    delete scope[MYVAR];
    Assert.assertFalse(loopupVar(), "Expected true in iteration " + i);

    // set that variable and check again
    scope[MYVAR] = "foo";
    Assert.assertTrue(loopupVar(), "Expected false in iteration " + i);
}