Merge pull request #2365 from pguyot/w29/receive-lost-wake

esp32: return from receive_events once drained

These changes are made under both the "Apache 2.0" and the "GNU Lesser General
Public License 2.1 or later" license terms (dual license).

SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later

Author: bettio

CHANGELOG.md

@@ -83,6 +83,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fixed ESP32 socket driver holding the global socket-list lock across blocking TCP connects, leaking the port on connect failure, losing concurrent `accept` waiters, leaking `netbuf` on receive error paths, and a recycled-`netconn` race between socket close and the event handler
 - Fixed generic_unix TCP server sockets performing an abortive close that could truncate replies awaiting ack
 - Fixed a JIT crash (`EXC_BAD_ACCESS`/SIGBUS) on Apple Silicon
+- Fixed the ESP32 event poller re-blocking after running a listener, which could delay a process
+  readied by a driver (e.g. an active-mode socket message) until the next event or timer tick
 
 ## [0.7.0-alpha.1] - 2026-04-06
 

src/platforms/esp32/components/avm_sys/sys.c

@@ -132,6 +132,9 @@ static void receive_events(GlobalContext *glb, TickType_t wait_ticks)
     void *sender = NULL;
     QueueSetMemberHandle_t event_source;
     while ((event_source = xQueueSelectFromSet(event_set, wait_ticks))) {
+        // Drain without re-blocking after the first event, then return so the
+        // scheduler loop can run any process a listener just made ready
+        wait_ticks = 0;
         // Listener used shared event_queue.
         if (event_source == event_queue) {
             if (UNLIKELY(xQueueReceive(event_queue, &sender, 0) == pdFALSE)) {