CST-agent/tests/test_replay_starvation.c

#include "ctl.h"
#include "cst_agent.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/*
 * Starvation replay: same logical tool call, cut at several prefixes.
 * CTL+CST should never execute on incomplete prefixes; JSON-buffer fails to
 * parse (cannot execute). When the full stream is present, both succeed.
 */

typedef struct {
  int n_ready;
  size_t peak;
} ctl_stats_t;

static void on_ev(const ctl_event_t *ev, void *ud) {
  ctl_stats_t *s = ud;
  if (ev->type == CTL_EV_CALL_READY)
    s->n_ready++;
}

static int ctl_ready_on_prefix(const char *full, size_t ncut, size_t *peak) {
  ctl_stats_t st = {0};
  ctl_parser_t *p = ctl_parser_create(on_ev, &st);
  ctl_parser_feed(p, full, ncut);
  /* do not finish — simulate stream stall / truncation mid-turn */
  *peak = ctl_parser_pending_peak(p);
  int ready = st.n_ready;
  ctl_parser_destroy(p);
  return ready;
}

int main(void) {
  const char *ctl =
      "call x1 read_file\n"
      "arg path 5\n"
      "a.txt"
      "end\n";
  const char *json =
      "{\"name\":\"read_file\",\"arguments\":{\"path\":\"a.txt\"}}";

  size_t ctl_len = strlen(ctl);
  size_t json_len = strlen(json);

  int ctl_premature = 0, json_ok_full = 0, ctl_ok_full = 0;
  int json_fail_trunc = 0, ctl_safe_trunc = 0;

  /* full streams */
  {
    size_t peak = 0;
    ctl_stats_t st = {0};
    ctl_parser_t *p = ctl_parser_create(on_ev, &st);
    ctl_parser_feed(p, ctl, ctl_len);
    ctl_parser_finish(p);
    peak = ctl_parser_pending_peak(p);
    ctl_ok_full = (st.n_ready == 1);
    printf("CTL full: ready=%d peak=%zu\n", st.n_ready, peak);
    ctl_parser_destroy(p);
  }
  {
    cst_json_tool_t t;
    json_ok_full = cst_json_try_parse_tool(json, json_len, &t);
    printf("JSON full: ok=%d name=%s\n", json_ok_full, t.name);
  }

  /* truncate at 50% and 80% */
  size_t cuts[] = {ctl_len / 2, (ctl_len * 4) / 5, ctl_len - 2};
  for (size_t i = 0; i < sizeof(cuts) / sizeof(cuts[0]); i++) {
    size_t peak = 0;
    int ready = ctl_ready_on_prefix(ctl, cuts[i], &peak);
    printf("CTL cut %zu/%zu: ready=%d peak=%zu\n", cuts[i], ctl_len, ready,
           peak);
    if (ready)
      ctl_premature++;
    else
      ctl_safe_trunc++;
  }

  size_t jcuts[] = {json_len / 2, (json_len * 4) / 5, json_len - 2};
  for (size_t i = 0; i < sizeof(jcuts) / sizeof(jcuts[0]); i++) {
    cst_json_tool_t t;
    int ok = cst_json_try_parse_tool(json, jcuts[i], &t);
    printf("JSON cut %zu/%zu: ok=%d\n", jcuts[i], json_len, ok);
    if (!ok)
      json_fail_trunc++;
  }

  printf("\n=== summary ===\n");
  printf("CTL full success: %s\n", ctl_ok_full ? "yes" : "no");
  printf("JSON full success: %s\n", json_ok_full ? "yes" : "no");
  printf("CTL premature executes on trunc: %d (want 0)\n", ctl_premature);
  printf("CTL safe truncations: %d\n", ctl_safe_trunc);
  printf("JSON trunc failures: %d\n", json_fail_trunc);

  if (!ctl_ok_full || !json_ok_full || ctl_premature != 0)
    return 1;
  printf("replay_starvation: OK\n");
  return 0;
}