KQueue and Fibers

[Jacob Carlborg]

On 2021-04-09 11:00, rashir wrote:
> Goodmorning everyone,
> I'm trying to understand both Kqueue and Fiber's operation on Mac. Why 
> don't I get the correct data as long as I read from the socket?
> It seems to be reading too early, but Kquue tells me that the socket is 
> readable.
> 
> ```D
>         const bytesRead = recv(fd, b.ptr, readableAmount < b.length ? 
> readableAmount : b.length, 0);
>         writeln("read bytesRead: ", bytesRead, "readableAmount:",
>                 readableAmount, " errno:", errno);
>         assert(bytesRead != EAGAIN && bytesRead != EWOULDBLOCK);
> ```

`recv` returns the number of bytes received or `-1` if an error 
occurred. `EAGAIN` and `EWOULDBLOCK` are error codes. You should not 
compare the value returned by `recv` with error codes. The error code 
will be placed in `errno`.

> ```D
>         assert(eventList[0].filter & EVFILT_READ);
> ```

The `filter` field of an event is not a flag/bit field. It's just a 
plain value, you should use `==` to check if it's a read event.

I'm not sure if fixing these things will solve your issue. But at least 
some problems I noticed.

-- 
/Jacob Carlborg