From b966ff7a3d6c4384f226e8e2bb9c9eb00582680a Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Sat, 27 May 2023 18:58:02 -0500
Subject: [PATCH] Await in sequence when we know we will be blocked by the
 entity platform semaphore (#93649)

* Defer creating tasks we know are going to wait on the entity platform semaphore

When looking at whats going on with aiomonitor-ng, I noticed
we end up creating a lot of tasks that block waiting for the
executor because of the entity platform parallel_updates semaphore.

When we know the tasks are going to block we now await them
in sequence to avoid feeding the loop a herd of tasks that
will block on the semaphore

* change during iteration fix

* change during iteration fix

* cleanup

* cleanup

* fix vizio test
---
 homeassistant/helpers/entity_platform.py    | 21 +++++++++++++++------
 tests/components/vizio/test_media_player.py |  2 ++
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/homeassistant/helpers/entity_platform.py b/homeassistant/helpers/entity_platform.py
index 4adb0f212b3..be335c7a40f 100644
--- a/homeassistant/helpers/entity_platform.py
+++ b/homeassistant/helpers/entity_platform.py
@@ -136,6 +136,7 @@ class EntityPlatform:
         self._process_updates: asyncio.Lock | None = None
 
         self.parallel_updates: asyncio.Semaphore | None = None
+        self._update_in_parallel: bool = True
 
         # Platform is None for the EntityComponent "catch-all" EntityPlatform
         # which powers entity_component.add_entities
@@ -186,6 +187,7 @@ class EntityPlatform:
 
         if parallel_updates is not None:
             self.parallel_updates = asyncio.Semaphore(parallel_updates)
+            self._update_in_parallel = parallel_updates != 1
 
         return self.parallel_updates
 
@@ -844,13 +846,20 @@ class EntityPlatform:
             return
 
         async with self._process_updates:
-            tasks: list[Coroutine[Any, Any, None]] = []
-            for entity in self.entities.values():
-                if not entity.should_poll:
-                    continue
-                tasks.append(entity.async_update_ha_state(True))
+            if self._update_in_parallel or len(self.entities) <= 1:
+                # If we know are going to update sequentially, we want to update
+                # to avoid scheduling the coroutines as tasks that will we know
+                # are going to wait on the semaphore lock.
+                for entity in list(self.entities.values()):
+                    if entity.should_poll and entity.hass:
+                        await entity.async_update_ha_state(True)
+                return
 
-            if tasks:
+            if tasks := [
+                entity.async_update_ha_state(True)
+                for entity in self.entities.values()
+                if entity.should_poll
+            ]:
                 await asyncio.gather(*tasks)
 
 
diff --git a/tests/components/vizio/test_media_player.py b/tests/components/vizio/test_media_player.py
index 69e4e4d5b04..86733d83f15 100644
--- a/tests/components/vizio/test_media_player.py
+++ b/tests/components/vizio/test_media_player.py
@@ -746,6 +746,8 @@ async def test_apps_update(
                 "homeassistant.components.vizio.gen_apps_list_from_url",
                 return_value=APP_LIST,
             ):
+                async_fire_time_changed(hass, dt_util.now() + timedelta(days=2))
+                await hass.async_block_till_done()
                 async_fire_time_changed(hass, dt_util.now() + timedelta(days=2))
                 await hass.async_block_till_done()
                 # Check source list, remove TV inputs, and verify that the integration is