centipede: fix average_exec_per_sec stat (#4603)

Author: paulsemel

src/clusterfuzz/_internal/bot/fuzzers/centipede/engine.py

@@ -313,6 +313,11 @@ def fuzz(self, target_path, options, reproducers_dir, max_time):  # pylint: disa
         'actual_duration': actual_duration,
         'fuzzing_time_percent': fuzzing_time_percent,
     })
+    fuzz_time_secs_avg = stats.get('FuzzTimeSec_Avg', 1.0)
+    if fuzz_time_secs_avg == 0.0:
+      fuzz_time_secs_avg = 1.0
+    num_execs_avg = stats.get('NumExecs_Avg', 0.0)
+    stats['average_exec_per_sec'] = num_execs_avg / fuzz_time_secs_avg
     stats.update(_parse_centipede_logs(log_lines))
     return engine.FuzzResult(fuzz_result.output, fuzz_result.command, crashes,
                              stats, fuzz_result.time_executed)

src/clusterfuzz/_internal/metrics/fuzzer_stats_schema.py

@@ -851,6 +851,10 @@
     'mode': 'NULLABLE',
     'name': 'fuzzing_time_percent',
     'type': 'FLOAT'
+}, {
+    'mode': 'NULLABLE',
+    'name': 'average_exec_per_sec',
+    'type': 'FLOAT'
 }] + _COMMON_COLUMNS
 
 _SCHEMA = {

src/local/butler/scripts/setup.py

@@ -300,12 +300,12 @@ def __init__(self):
 logs: "Link to fuzzing logs"
 corpus_backup: "Backup copy of the minimized corpus generated based on code coverage"'''
 
-    self.stats_columns = """sum(t.number_of_executed_units) as tests_executed,
+    self.stats_columns = """sum(t.NumExecs_Max) as tests_executed,
 custom(j.new_crashes) as new_crashes,
 _EDGE_COV as edge_coverage,
 _COV_REPORT as cov_report,
 _CORPUS_SIZE as corpus_size,
-avg(t.FuzzTimeSec_Avg / t.NumExecs_Avg) as avg_exec_per_sec,
+avg(t.average_exec_per_sec) as avg_exec_per_sec,
 avg(t.fuzzing_time_percent) as fuzzing_time_percent,
 avg(t.crash_count*100) as regular_crash_percent,
 avg(t.oom_count*100) as oom_percent,