[BLE Client] Deadlock if connection loss while readValue

[Rotzbua]

Board

heltec_wifi_kit_32

Device Description

nothing else connected

Hardware Configuration

nothing else connected

Version

v2.0.5

IDE Name

PlatformIO 6.1.4

Operating System

win10

Flash frequency

default

PSRAM enabled

no

Upload speed

default

Description

General

• ESP32 connects to target BLE device
• ESP32 hangs after some time

What happens

• Target BLE device has bad radio and often losses connection
• ESP32 stuck if BLE characteristics are read and connection is lost

Found issue

• BLE client uses semaphores to manage state
• Semaphore is not cleaned up if BLE device disconnects
• Seems similar to [BLE Client] Deadlock when calling writeValue after registerForNotify #4952

Sketch

use ble client example

Debug Message

[ 31021][V][BLEClient.cpp:412] getService(): >> getService: uuid: XXXXX
[ 31024][V][BLEClient.cpp:425] getService(): << getService: found the service with uuid: XXXXX
 - Found our service
 - Found our characteristic
[ 31246][V][BLERemoteCharacteristic.cpp:423] readValue(): >> readValue(): uuid: XXXXX, handle: 11 0x0b   
[ 31249][V][FreeRTOS.cpp:189] take(): Semaphore taking: name: ReadCharEvt (0x3ffdefa0), owner: <N/A> for readValue
[ 31259][V][FreeRTOS.cpp:198] take(): Semaphore taken:  name: ReadCharEvt (0x3ffdefa0), owner: readValue
[ 31268][V][FreeRTOS.cpp:63] wait(): >> wait: Semaphore waiting: name: ReadCharEvt (0x3ffdefa0), owner: readValue for readValue
[ 32426][D][BLEDevice.cpp:148] gattClientEventHandler(): gattClientEventHandler [esp_gatt_if: 4] ... ESP_GATTC_DISCONNECT_EVT
[ 32427][V][BLEUtils.cpp:1283] dumpGattClientEvent(): GATT Event: ESP_GATTC_DISCONNECT_EVT
[ 32434][V][BLEUtils.cpp:1326] dumpGattClientEvent(): [reason: ESP_GATT_CONN_TERMINATE_PEER_USER, conn_id: 0, remote_bda: XXXXX]
[ 32447][D][BLEClient.cpp:178] gattClientEventHandler(): gattClientEventHandler [esp_gatt_if: 4] ... ESP_GATTC_DISCONNECT_EVT
[ 32458][V][FreeRTOS.cpp:143] give(): Semaphore giving: name: OpenEvt (0x3ffdc248), owner: <N/A>
[ 32466][V][FreeRTOS.cpp:143] give(): Semaphore giving: name: RssiCmplEvt (0x3ffdc310), owner: <N/A>
[ 32475][V][FreeRTOS.cpp:143] give(): Semaphore giving: name: SearchCmplEvt (0x3ffdc2ac), owner: <N/A>
[ 32484][I][BLEDevice.cpp:633] removePeerDevice(): remove: 1, GATT role client
[ 32491][V][FreeRTOS.cpp:143] give(): Semaphore giving: name: WriteCharEvt (0x3ffdf390), owner: <N/A>
[ 32500][V][FreeRTOS.cpp:143] give(): Semaphore giving: name: WriteCharEvt (0x3ffdf868), owner: <N/A>
[ 32509][V][FreeRTOS.cpp:143] give(): Semaphore giving: name: WriteCharEvt (0x3ffdfd40), owner: <N/A>
[ 32518][V][FreeRTOS.cpp:143] give(): Semaphore giving: name: WriteCharEvt (0x3ffe1160), owner: <N/A>
[ 32527][V][FreeRTOS.cpp:143] give(): Semaphore giving: name: WriteCharEvt (0x3ffe1670), owner: <N/A>
[ 32536][V][FreeRTOS.cpp:143] give(): Semaphore giving: name: WriteCharEvt (0x3ffe1b80), owner: <N/A>
[ 32545][V][FreeRTOS.cpp:143] give(): Semaphore giving: name: WriteCharEvt (0x3ffe2090), owner: <N/A>
[ 32554][V][FreeRTOS.cpp:143] give(): Semaphore giving: name: WriteCharEvt (0x3ffe25a0), owner: <N/A>
[ 32563][V][FreeRTOS.cpp:143] give(): Semaphore giving: name: WriteCharEvt (0x3ffe2ab0), owner: <N/A>
[ 32572][V][FreeRTOS.cpp:143] give(): Semaphore giving: name: WriteCharEvt (0x3ffe2fc0), owner: <N/A>
[ 32580][V][FreeRTOS.cpp:143] give(): Semaphore giving: name: WriteCharEvt (0x3ffe34d0), owner: <N/A>
[ 32589][V][FreeRTOS.cpp:143] give(): Semaphore giving: name: WriteCharEvt (0x3ffe39e0), owner: <N/A>
[ 32598][V][FreeRTOS.cpp:143] give(): Semaphore giving: name: WriteCharEvt (0x3ffe4bc4), owner: <N/A>
[ 32607][V][FreeRTOS.cpp:143] give(): Semaphore giving: name: WriteCharEvt (0x3ffe509c), owner: <N/A>
[ 32616][D][BLEDevice.cpp:148] gattClientEventHandler(): gattClientEventHandler [esp_gatt_if: 4] ... ESP_GATTC_CLOSE_EVT
[ 32627][V][BLEUtils.cpp:1283] dumpGattClientEvent(): GATT Event: ESP_GATTC_CLOSE_EVT
[ 32634][V][BLEUtils.cpp:1297] dumpGattClientEvent(): [status: ESP_GATT_OK, reason:ESP_GATT_CONN_TERMINATE_PEER_USER, conn_id: 0]       
[ 32646][D][BLEDevice.cpp:148] gattClientEventHandler(): gattClientEventHandler [esp_gatt_if: 4] ... ESP_GATTC_UNREG_EVT
[ 32656][V][BLEUtils.cpp:1283] dumpGattClientEvent(): GATT Event: ESP_GATTC_UNREG_EVT

ESP32 stuck, no new output.

Other Steps to Reproduce

No response

I have checked existing issues, online documentation and the Troubleshooting Guide

• I confirm I have checked existing issues, online documentation and Troubleshooting guide.

[VojtechBartoska]

Hello @Rotzbua, thanks for opening an issue and as well proposing a solution. We will review your PR as soon as possible.