[silx.util.retry] fix resetting the timeout timer when iterating

Author: woutdenolf

src/silx/utils/retry.py

@@ -85,12 +85,12 @@ def _retry_loop(retry_timeout=None, retry_period=None, retry_on_error=None):
     retry_state = {"t0": t0, "exception": None, "retry_on_error": retry_on_error}
     while True:
         yield retry_state
-        if retry_period is not None:
-            time.sleep(retry_period)
-        if has_timeout and (time.time() - t0) > retry_timeout:
+        if has_timeout and (time.time() - retry_state["t0"]) > retry_timeout:
             err_msg = "%s seconds" % retry_timeout
             cause = retry_state.get("exception")
             raise RetryTimeoutError(err_msg) from cause
+        if retry_period is not None:
+            time.sleep(retry_period)
 
 
 def retry(

src/silx/utils/test/test_retry.py

@@ -210,3 +210,28 @@ def test_retry_wrong_generator(self):
             @retry.retry()
             def method():
                 yield from range(3)
+
+    def test_retry_iter_reset(self):
+        failure_count = 0
+        retry_period = 0.2
+        failure_duration = 0.6
+
+        nfailures = int(failure_duration/retry_period + 0.5)
+        retry_timeout = failure_duration + retry_period
+
+        @retry.retry(retry_period=retry_period, retry_timeout=retry_timeout)
+        def iter_silx(start_index=0):
+            nonlocal failure_count
+
+            # This takes `10 * retry_period` seconds
+            if start_index == 0:
+                for i in range(10):
+                    time.sleep(retry_period)
+                    yield i
+
+            # This will fail for slightly longer than `failure_duration` seconds
+            if failure_count <= nfailures:
+                failure_count += 1
+                raise retry.RetryError()
+
+        assert list(iter_silx()) == list(range(10))