Use support.sleeping_retry() and support.busy_retry() (#93848)

* Replace time.sleep(0.010) with sleeping_retry() to
  use an exponential sleep.
* support.wait_process(): reuse sleeping_retry().
* _test_eintr: remove unused variables.

1 files changed, 8 insertions, 10 deletions

diff --git a/Lib/test/support/threading_helper.py b/Lib/test/support/threading_helper.py
index 26cbc6f..b9973c8 100644
--- a/Lib/test/support/threading_helper.py
+++ b/Lib/test/support/threading_helper.py
@@ -88,19 +88,17 @@ def wait_threads_exit(timeout=None):
         yield
     finally:
         start_time = time.monotonic()
-        deadline = start_time + timeout
-        while True:
+        for _ in support.sleeping_retry(timeout, error=False):
+            support.gc_collect()
             count = _thread._count()
             if count <= old_count:
                 break
-            if time.monotonic() > deadline:
-                dt = time.monotonic() - start_time
-                msg = (f"wait_threads() failed to cleanup {count - old_count} "
-                       f"threads after {dt:.1f} seconds "
-                       f"(count: {count}, old count: {old_count})")
-                raise AssertionError(msg)
-            time.sleep(0.010)
-            support.gc_collect()
+        else:
+            dt = time.monotonic() - start_time
+            msg = (f"wait_threads() failed to cleanup {count - old_count} "
+                   f"threads after {dt:.1f} seconds "
+                   f"(count: {count}, old count: {old_count})")
+            raise AssertionError(msg)
 
 
 def join_thread(thread, timeout=None):