ensure no race condition in swoole coroutines

are_threre_race_conditions_in_swoole_coroutines.php

<?php

# Swoole\Coroutine::enableScheduler();

Co\run(function () {
    $flag = 1;

    go(function() use(&$flag) {
        assert($flag == 1);
        $flag += 1;
        assert($flag == 2);
    });

    go(function() use(&$flag) {
        # let co#1 run first
        Co::sleep(0.3);

        assert($flag == 2);

        $flag += 1;
        assert($flag == 3);
    });

});

arguments passing to syscall.php

<?php

function syscall(int $arg) {
    # simulate overhead for invoking syscall
    Co::sleep(0.3);

    return $arg + 1;
}

function debug(int $id) {
    return function (string $format, ... $args) use ($id) {
        # TODO@haoliang ensure printf which writes to stdout/stderr will not yield
        printf("[co#%d] {$format}\n", $id, ...$args);
    };
}


Co\run(function () {
    $flag = 1;

    go(function() use (&$flag) {
        $debug = debug(1);

        $debug("entered");

        assert($flag == 1);
        $flag += 1;
        assert($flag == 2);

        $debug("invoking a syscall");
        $result = syscall($flag);
        $debug("got syscall result");
        assert($result == 3);
        $debug("exiting");
    });

    go(function() use(&$flag) {
        $debug = debug(2);

        $debug("entered");
        Co::sleep(0.1);
        $debug("re-entered");

        assert($flag == 2);

        $flag += 1;
        assert($flag == 3);
        $debug("exiting");
    });

});