gc-04.js - mozsearch

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// Storing a Debugger.Object as a key in a WeakMap protects it from GC as long as

// the referent is alive.

var g = newGlobal({newCompartment: true});

var N = g.N = 10;

var dbg = Debugger(g);

var cache = new WeakMap;

var i = 0;

dbg.onDebuggerStatement = function (frame) {

    cache.set(frame.arguments[0], i++);

};

g.eval("function f(x) { debugger; }");

g.eval("var arr = [], j; for (j = 0; j < N; j++) arr[j] = {};");

g.eval("for (j = 0; j < N; j++) f(arr[j]);");

assertEq(i, N);

gc(); gc();

i = 0;

dbg.onDebuggerStatement = function (frame) {

    assertEq(cache.get(frame.arguments[0]), i++)

};

g.eval("for (j = 0; j < N; j++) f(arr[j]);");

assertEq(i, N);