From d02e39ec1023675b4b747e7af276b82532668342 Mon Sep 17 00:00:00 2001
From: Caleb Hattingh <caleb.hattingh@gmail.com>
Date: Fri, 31 Jan 2025 16:52:05 +0100
Subject: [PATCH 1/2] Treat min_workers=0 as "scale to zero", None to
 deactivate

---
 deadpool.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/deadpool.py b/deadpool.py
index 22b1633..7d446e2 100644
--- a/deadpool.py
+++ b/deadpool.py
@@ -265,7 +265,11 @@ def __init__(
         self.finitializer = finalizer
         self.finitargs = finalargs
         self.pool_size = max_workers or len(os.sched_getaffinity(0))
-        self.min_workers = min_workers or self.pool_size
+        if min_workers is None:
+            self.min_workers = self.pool_size
+        else:
+            self.min_workers = min_workers
+
         self.max_tasks_per_child = max_tasks_per_child
         self.max_worker_memory_bytes = max_worker_memory_bytes
         self.submitted_jobs: PriorityQueue[PrioritizedItem] = PriorityQueue(

From db3cfc32b95fea64c4201076d047e03808fbe653 Mon Sep 17 00:00:00 2001
From: Caleb Hattingh <caleb.hattingh@gmail.com>
Date: Sat, 1 Feb 2025 14:17:25 +0100
Subject: [PATCH 2/2] Tweak coverage

---
 deadpool.py            | 10 +++++-----
 tests/test_deadpool.py |  9 +++++++--
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/deadpool.py b/deadpool.py
index 7d446e2..b3ead44 100644
--- a/deadpool.py
+++ b/deadpool.py
@@ -147,10 +147,10 @@ def shutdown(self, wait=True):
 
         self.connection_receive_msgs_from_process.close()
 
-        if self.connection_send_msgs_to_process.writable:
+        if self.connection_send_msgs_to_process.writable:  # pragma: no branch
             try:
                 self.connection_send_msgs_to_process.send(None)
-            except BrokenPipeError:
+            except BrokenPipeError:  # pragma: no cover
                 pass
             else:
                 self.connection_send_msgs_to_process.close()
@@ -608,7 +608,7 @@ def shutdown(self, wait: bool = True, *, cancel_futures: bool = False) -> None:
             try:
                 worker = self.workers.get_nowait()
                 worker.shutdown()
-            except Empty:
+            except Empty:  # pragma: no cover
                 break
 
         # There may be a few processes left in the
@@ -677,7 +677,7 @@ def kill_proc_tree(
     for p in children:
         try:
             p.send_signal(sig)
-        except psutil.NoSuchProcess:
+        except psutil.NoSuchProcess:  # pragma: no cover
             pass
 
     gone, alive = psutil.wait_procs(children, timeout=timeout, callback=on_terminate)
@@ -730,7 +730,7 @@ def conn_send_safe(obj):
             conn.send(obj)
         except BrokenPipeError:  # pragma: no cover
             logger.debug("Pipe not usable")
-        except BaseException:
+        except BaseException:  # pragma: no cover
             logger.exception("Unexpected pipe error")
 
     def timed_out():
diff --git a/tests/test_deadpool.py b/tests/test_deadpool.py
index 7622a6f..2a32fa9 100644
--- a/tests/test_deadpool.py
+++ b/tests/test_deadpool.py
@@ -53,9 +53,14 @@ def test_cancel_all_futures():
 
 
 @pytest.mark.parametrize("malloc_threshold", [None, 0, 1_000_000])
-def test_simple(malloc_threshold):
+@pytest.mark.parametrize("daemon", [True, False])
+@pytest.mark.parametrize("min_workers", [None, 0])
+def test_simple(malloc_threshold, daemon, min_workers):
     with deadpool.Deadpool(
-        malloc_trim_rss_memory_threshold_bytes=malloc_threshold
+        malloc_trim_rss_memory_threshold_bytes=malloc_threshold,
+        daemon=daemon,
+        min_workers=min_workers,
+        max_workers=10,
     ) as exe:
         fut = exe.submit(t, 0.05)
         result = fut.result()