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wired guide

App timers

wired_srvrun_opt.on_step runs once per event-loop step, whether or not any connection is live – a clock tick, a periodic flush, anything the app needs to drive on its own schedule rather than a peer’s.

Code

main.c
#define WIRED_MAIN
#include "wired.h"


/* An app timer, independent of any connection: wired_srvrun_opt.on_step
 * fires at least every SRVRUN_PTO_MS (25ms) once registered, whether or
 * not any connection is live. Logged only for the first few ticks so the
 * golden output stays a fixed length regardless of how long the server
 * actually ran. */
#define TICKS_SHOWN 3
static int g_ticks = 0;


static void on_step(void* ctx, u64 now_ms) {
  static const char* const lines[TICKS_SHOWN] = {
      "tick 1\n", "tick 2\n", "tick 3\n"};
  (void)ctx;
  (void)now_ms;
  if (g_ticks >= TICKS_SHOWN) return;
  wired_log_str(lines[g_ticks]);
  g_ticks++;
}


static int on_request(
    void*                       ctx,
    const wired_h3reqdrive_req* req,
    u64                         offset,
    wired_obuf*                 body_out,
    const char**                content_type,
    int*                        more,
    u64*                        total_size) {
  (void)ctx;
  (void)req;
  (void)offset;
  (void)more;
  (void)total_size;
  *content_type = "text/plain";
  wired_obuf_printf(body_out, "ok");
  return 1;
}


int wired_main(int argc, char** argv) {
  /* The same fixed demo identity as the HTTP/3 hello page. */
  static wired_srvboot_demo_keys keys;
  wired_srvboot_id               id;
  wired_srvboot_demo(&id, &keys, 0x50, "guide-h3");


  wired_srvrun_opt opt = {0};
  opt.incoming_cpu     = -1;
  opt.on_step          = on_step;


  u16 port                 = (u16)wired_cliargs_int(argc, argv, "--port", 4433);
  wired_srvrun_handler h   = {.cb = on_request};
  wired_srvrun_obs     obs = {0};
  return wired_server_run_opt(port, &id, h, obs, &opt) ? 0 : 1;
}

Output

Terminal window
$ ./ops-timers --port 4433
tick 1
tick 2
tick 3
conn closed by peer (CONNECTION_CLOSE)
Terminal window
$ probe h3get 127.0.0.1:4433 /
GET / status=200 content-type=text/plain body="ok"

How it works

Section titled “How it works”
  • opt.on_step = on_step registers the hook; while one is registered the loop never blocks without a timeout, so it keeps firing at least every SRVRUN_PTO_MS (25ms) even with no traffic at all.
  • The hook receives the loop’s own monotonic clock (now_ms); this page logs a fixed count instead of the clock itself, so the golden output stays the same length regardless of how long the server actually ran before the client connected.
  • Every wired_server_wt_* send API may be called from inside this hook, same as from a request or datagram callback – it runs inside the loop.