Is http_listen blocking further call execution in my ccall program

Given the C Code

#include "http.h"

void on_request(http_s *request);


int main(void) {
  HTTP_HEADER_X_DATA = fiobj_str_new("X-Data", 6);
  http_listen("3000", NULL, .on_request = on_request, .log = 1);
  fio_start(.threads = 1);

void on_request(http_s *request) {
  http_set_cookie(request, .name = "my_cookie", .name_len = 9, .value = "data",
                  .value_len = 4);
  http_set_header(request, HTTP_HEADER_CONTENT_TYPE,
                  http_mimetype_find("txt", 3));
  http_set_header(request, HTTP_HEADER_X_DATA, fiobj_str_new("my data", 7));
  http_send_body(request, "Hello World!\r\n", 14);

I wrote it’s Julia’s ccall counterpart

# First, define the path to the shared library
const httplib = "./"

struct http_settings_s
    # Add other fields as needed

function on_request(request::Ptr{Cvoid})
    ccall((:http_send_body, httplib), Cvoid, (Ptr{Cvoid}, Cstring, Csize_t), request, "Hello World!\r\n", 14)

# Convert the Julia function to a C function pointer
const on_request_c = @cfunction(on_request, Cvoid, (Ptr{Cvoid},))

# Define the C struct
const settings = http_settings_s(on_request_c, 1)

println("before listen")

# Start listening on the specified port
ccall((:http_listen, httplib), Cintmax_t, (Cstring, Cstring, Ref{http_settings_s}), "3000", C_NULL, settings)

println("after listen")

# Start the server
ccall((:fio_start, httplib), Cvoid, (Cint,), 1)

println("after start")

and I get the output

julia http.jl
before listen
FATAL: No supported SSL/TLS library available.

the output of

# Start the server
ccall((:fio_start, httplib), Cvoid, (Cint,), 1)

looks like

❯ julia http.jl 
INFO: Server is running 1 worker X 1 thread with server 0.7.6 (kqueue)
* Detected capacity: 131056 open file limit
* Root pid: 72503
* Press ^C to stop

signature of various methods

intptr_t http_listen(const char *port, const char *binding,
                     struct http_settings_s);
/** Listens to HTTP connections at the specified `port` and `binding`. */

http_settings_s struct

struct http_settings_s {
  void (*on_request)(http_s *request);
  void (*on_upgrade)(http_s *request, char *requested_protocol, size_t len);
  void (*on_response)(http_s *response);
  void (*on_finish)(struct http_settings_s *settings);
  void *udata;
  const char *public_folder;
  size_t public_folder_length;
  size_t max_header_size;
  size_t max_body_size;
  intptr_t max_clients;
  void *tls;
  intptr_t reserved1;
  intptr_t reserved2;
  intptr_t reserved3;
  size_t ws_max_msg_size;
  uint8_t timeout;
  uint8_t ws_timeout;
  uint8_t log;
  uint8_t is_client;
int http_send_body(http_s *h, void *data, uintptr_t length);

this is resolved had to just use @async in front of http_listen