Bug 150295 – [ES6] Typical Promise chain easily exhaust memory

• Component: JavaScriptCore
• Status: NEW

[Yusuke Suzuki]

This is originally reported in Chromium/Blink context[1].

In the following example,
```js

"use strict";
var p = null;
(function () {
    var N = 1000 * 1000;
    var counter = 0;
    var resolve;

    function read() {
        return Promise.resolve({done: ++counter >= N});
    }

    function pump() {
        return read().then(function(r) {
            if (counter % 10000 == 0)
                gc();
            if (r.done) {
                return;
            }
            return pump();
        });
    }

    p = pump();
}());
```

Since it chains promises like `a => b => c => ... too much promises => final`, if there are too much promises, it exhausts memory.

This behavior is well-specified correct behavior, but in practice, we would like to collect / reduce these promises.

[1]: https://github.com/domenic/streams-demo/issues/4