writer-starvation.htm

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This WPT test may be referenced by the following Test IDs:
- /IndexedDB/writer-starvation.htm - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<meta charset=utf-8>

<title>Writer starvation</title>

<link rel="author" href="mailto:odinho@opera.com" title="Odin Hørthe Omdal">

<meta name=timeout content=long>

<script src=/resources/testharness.js></script>

<script src=/resources/testharnessreport.js></script>

<script src=resources/support.js></script>

<script>

    var db, read_request_count = 0, read_success_count = 0;

    var write_request_count = 0, write_success_count = 0;

    var RQ_COUNT = 25;

    var open_rq = createdb(async_test(undefined));

    open_rq.onupgradeneeded = function(e) {

        db = e.target.result;

        db.createObjectStore("s")

          .add("1", 1);

    open_rq.onsuccess = function(e) {

        var i = 0, continue_reading = true;

        /* Pre-fill some read requests */

        for (i = 0; i < RQ_COUNT; i++)

            read_request_count++;

            db.transaction("s", "readonly", {durability: 'relaxed'})

              .objectStore("s")

              .get(1)

              .onsuccess = this.step_func(function(e) {

                    read_success_count++;

                    assert_equals(e.target.transaction.mode, "readonly");

});

        this.step(loop);

        function loop() {

            read_request_count++;

            db.transaction("s", "readonly", {durability: 'relaxed'})

              .objectStore("s")

              .get(1)

              .onsuccess = this.step_func(function(e)

                read_success_count++;

                assert_equals(e.target.transaction.mode, "readonly");

                if (read_success_count >= RQ_COUNT && write_request_count == 0)

                    write_request_count++;

                    db.transaction("s", "readwrite", {durability: 'relaxed'})

                      .objectStore("s")

                      .add("written", read_request_count)

                      .onsuccess = this.step_func(function(e)

                        write_success_count++;

                        assert_equals(e.target.transaction.mode, "readwrite");

                        assert_equals(e.target.result, read_success_count,

                                       "write cb came before later read cb's")

});

                    /* Reads done after the write */

                    for (i = 0; i < 5; i++)

                        read_request_count++;

                        db.transaction("s", "readonly", {durability: 'relaxed'})

                          .objectStore("s")

                          .get(1)

                          .onsuccess = this.step_func(function(e)

                            read_success_count++;

});

});

            if (read_success_count < RQ_COUNT + 5)

                step_timeout(this.step_func(loop), write_request_count ? 1000 : 100);

            else

                // This is merely a "nice" hack to run finish after the last request is done

                db.transaction("s", "readonly", {durability: 'relaxed'})

                  .objectStore("s")

                  .count()

                  .onsuccess = this.step_func(function()

                    step_timeout(this.step_func(finish), 100);

});

function finish() {

    assert_equals(read_request_count, read_success_count, "read counts");

    assert_equals(write_request_count, write_success_count, "write counts");

    this.done();

</script>

<div id=log></div>