utask.h

/*
 * Sketch of the API surface we would need to expose
 * in order to shift the Promise implementation from dom to js/src.
 */

namespace JS {

    /*
     * Microtask API.
     *
     * SpiderMonkey does not have its own event queue implementation.  If an
     * embedding supports Promises, it must provide an event queue
     * implementation by calling SetEnqueueMicrotaskCallback. Promise objects
     * will then use that callback to put Microtask pointers into the queue,
     * and the embedding is responsibile for calling RunMicrotask on each of
     * those pointers eventually.
     */
    struct Microtask;

    /*
     * The embedding provides a callback for registering a microtask.
     */
    typedef bool (*EnqueueMicrotaskCallback)(JSContext *cx, Microtask *utask);

    JS_PUBLIC_API(bool)
    SetEnqueueMicrotaskCallback(JSRuntime *rt, EnqueueMicrotaskCallback cb);

    /*
     * Execute a microtask. The event loop calls this. Call it only once per
     * Microtask; on success or failure the microtask object is freed.
     */
    JS_PUBLIC_API(bool)
    RunMicrotask(JSContext *cx, Microtask *utask);

    /*
     * Drop a microtask without running it.
     */
    JS_PUBLIC_API(bool)
    DestroyMicrotask(JSContext *cx, Microtask *utask);

}