ziglings/unblock/src/main.zig

const std = @import("std");
const client = @import("client.zig");

fn handle_connections(clients: *client.Clients) !void {
    while (true) {
        for (clients.clients.items) |c| {
            clients.lock.lock();

            var buf = [_]u8{0} ** 1024;
            const sock = c.sock;
            const r = std.posix.recv(sock, &buf, 0) catch |err| switch (err) {
                error.WouldBlock => {
                    clients.lock.unlock();
                    continue;
                },
                else => {
                    std.debug.print("ERROR : {any}", .{err});
                    clients.lock.unlock();

                    continue;
                },
            };

            if (r > 0) {
                std.debug.print("Got {} bytes\n", .{r});
            }

            clients.lock.unlock();
        }

        std.time.sleep(7 * std.time.ns_per_ms);
    }
}

pub fn main() !void {
    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
    defer _ = gpa.deinit();

    const allocator = gpa.allocator();

    const sock = try std.posix.socket(std.posix.AF.INET, std.posix.SOCK.STREAM, 0);
    const parsed_address = try std.net.Address.parseIp4("127.0.0.1", 8080);
    var sock_flags = try std.posix.fcntl(sock, std.c.F.GETFD, 0);
    if (sock_flags < 0) {
        std.debug.print("got incorrect flags");
        return;
    }

    const enable = [_]u8{ 1, 1, 1, 1, 1, 1, 1, 1 };

    try std.posix.setsockopt(sock, std.posix.SOL.SOCKET, std.posix.SO.REUSEPORT | std.posix.SO.REUSEADDR, &enable);

    sock_flags = sock_flags | std.c.SOCK.NONBLOCK;
    const res = try std.posix.fcntl(sock, std.c.F.SETFD, sock_flags);
    if (res < 0) {
        std.debug.panic("could not fcntl\n");
    }

    // Only allow ipv4. select parsed_address.any to allow ipv4 and ipv6 or in6 for only ipv6
    try std.posix.bind(sock, @ptrCast(&parsed_address.in), parsed_address.getOsSockLen());
    try std.posix.listen(sock, 5);

    var addr: std.c.sockaddr.in = .{ .addr = 0, .port = 0 };
    var addr_size: std.posix.socklen_t = @sizeOf(std.c.sockaddr.in);

    var clients = client.Clients.init(allocator);
    defer clients.deinit();

    const t = try std.Thread.spawn(.{}, handle_connections, .{&clients});

    while (true) {
        // TODO: loop over this to accept more than one client
        const sock2 = try std.posix.accept(sock, @ptrCast(&addr), &addr_size, std.posix.SOCK.NONBLOCK);

        try clients.add(.{ .sock = sock2, .address = addr });

        std.debug.print("Got client {any}\n", .{addr});

        std.time.sleep(16 * std.time.ns_per_ms);
    }

    t.join();
}