(self)
| 1227 | self.addCleanup(signal.signal, signum, old_handler) |
| 1228 | |
| 1229 | def measure_itimer_resolution(self): |
| 1230 | N = 20 |
| 1231 | times = [] |
| 1232 | |
| 1233 | def handler(signum=None, frame=None): |
| 1234 | if len(times) < N: |
| 1235 | times.append(time.perf_counter()) |
| 1236 | # 1 µs is the smallest possible timer interval, |
| 1237 | # we want to measure what the concrete duration |
| 1238 | # will be on this platform |
| 1239 | signal.setitimer(signal.ITIMER_REAL, 1e-6) |
| 1240 | |
| 1241 | self.addCleanup(signal.setitimer, signal.ITIMER_REAL, 0) |
| 1242 | self.setsig(signal.SIGALRM, handler) |
| 1243 | handler() |
| 1244 | while len(times) < N: |
| 1245 | time.sleep(1e-3) |
| 1246 | |
| 1247 | durations = [times[i+1] - times[i] for i in range(len(times) - 1)] |
| 1248 | med = statistics.median(durations) |
| 1249 | if support.verbose: |
| 1250 | print("detected median itimer() resolution: %.6f s." % (med,)) |
| 1251 | return med |
| 1252 | |
| 1253 | def decide_itimer_count(self): |
| 1254 | # Some systems have poor setitimer() resolution (for example |
no test coverage detected