fuzz: progress dumps for long campaigns

fuzz/harness.c

@@ -7,6 +7,7 @@
 
 #include <inttypes.h>
 #include <limits.h>
+#include <signal.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -123,31 +124,66 @@ static double now_secs(void) {
     return (double)ts.tv_sec + (double)ts.tv_nsec / 1e9;
 }
 
+static volatile sig_atomic_t stop_requested = 0;
+static void on_signal(int sig) {
+    (void)sig;
+    stop_requested = 1;
+}
+
+static void write_progress(const char *path, const struct stats *stats, double elapsed,
+                           uint64_t seed, int final_flag) {
+    FILE *fp;
+    if (!path || !path[0]) return;
+    fp = fopen(path, "w");
+    if (!fp) return;
+    fprintf(fp,
+            "{\"executions\":%" PRIu64 ",\"divergences\":%" PRIu64
+            ",\"first_token_reject\":%" PRIu64
+            ",\"seconds\":%.6f,\"exec_per_sec\":%.2f,\"seed\":%" PRIu64
+            ",\"final\":%s}\n",
+            stats->executions, stats->divergences, stats->first_token_reject, elapsed,
+            stats->executions / (elapsed > 0 ? elapsed : 1.0), seed,
+            final_flag ? "true" : "false");
+    fflush(fp);
+    fclose(fp);
+}
+
 int main(int argc, char **argv) {
     double duration = 60.0;
     const char *seed_path = NULL;
+    const char *progress_path = NULL;
     uint64_t seed = (uint64_t)time(NULL) ^ (uint64_t)getpid();
     struct stats stats = { 0 };
     char buffer[256];
     double start;
     double end;
+    double last_progress = 0.0;
     int index;
 
+    signal(SIGTERM, on_signal);
+    signal(SIGINT, on_signal);
+
     for (index = 1; index < argc; ++index) {
         if (strcmp(argv[index], "--seconds") == 0 && index + 1 < argc) {
             duration = strtod(argv[++index], NULL);
         } else if (strcmp(argv[index], "--seed") == 0 && index + 1 < argc) {
             seed = strtoull(argv[++index], NULL, 10);
         } else if (strcmp(argv[index], "--seed-corpus") == 0 && index + 1 < argc) {
             seed_path = argv[++index];
+        } else if (strcmp(argv[index], "--progress-file") == 0 && index + 1 < argc) {
+            progress_path = argv[++index];
         } else {
-            fprintf(stderr, "usage: %s [--seconds N] [--seed N] [--seed-corpus PATH]\n", argv[0]);
+            fprintf(stderr,
+                    "usage: %s [--seconds N] [--seed N] [--seed-corpus PATH] "
+                    "[--progress-file PATH]\n",
+                    argv[0]);
             return 2;
         }
     }
 
     start = now_secs();
     end = start + duration;
+    last_progress = start;
 
     /* Seed corpus first (once each). */
     if (seed_path) {
@@ -168,24 +204,32 @@ int main(int argc, char **argv) {
         }
     }
 
-    while (now_secs() < end) {
+    while (!stop_requested && now_secs() < end) {
+        double now;
         generate(buffer, sizeof(buffer), seed + stats.executions);
         ++stats.executions;
         if (is_first_token_reject(buffer)) ++stats.first_token_reject;
         if (compare_one(buffer) != 0) {
             ++stats.divergences;
             fprintf(stderr, "DIVERGENCE: %s\n", buffer);
-            /* keep going; count all */
+        }
+        now = now_secs();
+        if (progress_path && (now - last_progress) >= 30.0) {
+            write_progress(progress_path, &stats, now - start, seed, 0);
+            last_progress = now;
         }
     }
 
     {
         double elapsed = now_secs() - start;
+        write_progress(progress_path, &stats, elapsed, seed, 1);
         printf("{\"executions\":%" PRIu64 ",\"divergences\":%" PRIu64
                ",\"first_token_reject\":%" PRIu64
-               ",\"seconds\":%.6f,\"exec_per_sec\":%.2f,\"seed\":%" PRIu64 "}\n",
-               stats.executions, stats.divergences, stats.first_token_reject,
-               elapsed, stats.executions / (elapsed > 0 ? elapsed : 1.0), seed);
+               ",\"seconds\":%.6f,\"exec_per_sec\":%.2f,\"seed\":%" PRIu64
+               ",\"stopped_early\":%s}\n",
+               stats.executions, stats.divergences, stats.first_token_reject, elapsed,
+               stats.executions / (elapsed > 0 ? elapsed : 1.0), seed,
+               stop_requested ? "true" : "false");
         return stats.divergences == 0 ? 0 : 1;
     }
 }

scripts/run-fuzz.sh

@@ -51,8 +51,10 @@ print(len(lines))
 PY
 
 RESULT="$WORK/result-$MODE.json"
+PROGRESS="$WORK/progress-$MODE.json"
 set +e
-"$WORK/harness" --seconds "$SECONDS_ARG" --seed-corpus "$SEED" >"$RESULT"
+"$WORK/harness" --seconds "$SECONDS_ARG" --seed-corpus "$SEED" \
+  --progress-file "$PROGRESS" >"$RESULT"
 STATUS=$?
 set -e
 END_UTC="$(date -u +%Y-%m-%dT%H:%M:%SZ)"