socket

fn socket(
    ev: *Evented,
    cancel_region: *CancelRegion,
    family: linux.sa_family_t,
    options: net.IpAddress.BindOptions,
) error{
    AddressFamilyUnsupported,
    ProtocolUnsupportedBySystem,
    ProcessFdQuotaExceeded,
    SystemFdQuotaExceeded,
    SystemResources,
    ProtocolUnsupportedByAddressFamily,
    SocketModeUnsupported,
    OptionUnsupported,
    Unexpected,
    Canceled,
}!fd_t {
    const mode, const protocol = try posixSocketModeProtocol(family, options.mode, options.protocol);
    const socket_fd = while (true) {
        const thread = try cancel_region.awaitIoUring();
        thread.enqueue().* = .{
            .opcode = .SOCKET,
            .flags = 0,
            .ioprio = 0,
            .fd = family,
            .off = mode | linux.SOCK.CLOEXEC,
            .addr = 0,
            .len = protocol,
            .rw_flags = 0,
            .user_data = @intFromPtr(cancel_region.fiber),
            .buf_index = 0,
            .personality = 0,
            .splice_fd_in = 0,
            .addr3 = 0,
            .resv = 0,
        };
        ev.yield(null, .nothing);
        const completion = cancel_region.completion();
        switch (completion.errno()) {
            .SUCCESS => break completion.result,
            .INTR, .CANCELED => {},
            .AFNOSUPPORT => return error.AddressFamilyUnsupported,
            .INVAL => return error.ProtocolUnsupportedBySystem,
            .MFILE => return error.ProcessFdQuotaExceeded,
            .NFILE => return error.SystemFdQuotaExceeded,
            .NOBUFS => return error.SystemResources,
            .NOMEM => return error.SystemResources,
            .PROTONOSUPPORT => return error.ProtocolUnsupportedByAddressFamily,
            .PROTOTYPE => return error.SocketModeUnsupported,
            else => |err| return unexpectedErrno(err),
        }
    };
    errdefer ev.closeAsync(socket_fd);

    if (options.ip6_only) |ip6_only| {
        if (linux.IPV6 == void) return error.OptionUnsupported;
        try ev.setsockopt(cancel_region, socket_fd, linux.IPPROTO.IPV6, linux.IPV6.V6ONLY, @intFromBool(ip6_only));
    }

    return socket_fd;
}