Begin work of monkey-patching EPollSelector

1 files changed, 41 insertions, 0 deletions

diff --git a/replacement_poll_selector.py b/replacement_poll_selector.py
new file mode 100644
index 0000000..0813a66
--- /dev/null
+++ b/replacement_poll_selector.py
@@ -0,0 +1,41 @@
+import selectors
+import sys
+import threading
+import time
+from typing import List, Optional, Tuple
+
+from mini_scalene import MiniScalene
+
+
+@MiniScalene.shim
+def replacement_poll_selector(mini_scalene: MiniScalene) -> None:
+    """
+    A replacement for selectors.PollSelector that
+    periodically wakes up to accept signals
+    """
+
+    class ReplacementPollSelector(selectors.PollSelector):
+        def select(
+            self, timeout: Optional[float] = -1
+        ) -> List[Tuple[selectors.SelectorKey, int]]:
+            tident = threading.get_ident()
+            start_time = time.perf_counter()
+            if not timeout or timeout < 0:
+                interval = sys.getswitchinterval()
+            else:
+                interval = min(timeout, sys.getswitchinterval())
+            while True:
+                scalene.set_thread_sleeping(tident)
+                selected = super().select(interval)
+                scalene.reset_thread_sleeping(tident)
+                if selected or timeout == 0:
+                    return selected
+                end_time = time.perf_counter()
+                if timeout and timeout != -1:
+                    if end_time - start_time >= timeout:
+                        return []  # None
+
+    ReplacementPollSelector.__qualname__ = (
+        "replacement_poll_selector.ReplacementPollSelector"
+    )
+    selectors.PollSelector = ReplacementPollSelector  # type: ignore