Crash on BLEDevice::deleteClient(pClient)

[Jeroen88]

I am trying to reuse the client, so I call BLEDevice::deleteClient(pClient). This causes a crash:

Decoding stack results
0x4008e320: invoke_abort at /home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/esp32/panic.c line 156
0x4008e59d: abort at /home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/esp32/panic.c line 171
0x400efb6b: __assert_func at ../../../.././newlib/libc/stdlib/assert.c line 63
0x400837cf: heap_caps_free at /home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/heap/heap_caps.c line 267
0x4008307d: _free_r at /home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/newlib/syscalls.c line 42
0x4017de81: operator delete(void*) at /builds/idf/crosstool-NG/.build/src/gcc-5.2.0/libstdc++-v3/libsupc++/del_op.cc line 46
0x400d6465: NimBLEClientCallbacks::~NimBLEClientCallbacks() at /home/jeroen/Arduino/libraries/NimBLE-Arduino-master/src/NimBLEClient.h line 101
0x400d6be5: NimBLEClient::~NimBLEClient() at /home/jeroen/Arduino/libraries/NimBLE-Arduino-master/src/NimBLEClient.cpp line 78
0x400d73e6: NimBLEDevice::deleteClient(NimBLEClient*) at /home/jeroen/Arduino/libraries/NimBLE-Arduino-master/src/NimBLEDevice.cpp line 160
0x400d2bf1: readBLEClients() at /home/jeroen/Arduino/test_BLE_02/test_BLE02/test_BLE02.ino line 781
0x400d2c4e: loop() at /home/jeroen/Arduino/test_BLE_02/test_BLE02/test_BLE02.ino line 788
0x400ed9c5: loopTask(void*) at /home/jeroen/Downloads/arduino-1.8.10-linux64/arduino-1.8.10/hardware/espressif/esp32/cores/esp32/main.cpp line 19
0x40093555: vPortTaskWrapper at /home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/freertos/port.c line 143

This is because BLEClient::m_deleteCallbacks is default true and BLEClient::BLEClient() sets the pointer m_pClientCallbacks to &defaultCallbacks. So before deleting this pointer, it should be checked that it does not point to &defaultCallbacks:

NimBLEClient::~NimBLEClient() { 
    // We may have allocated service references associated with this client.  
    // Before we are finished with the client, we must release resources.
    clearServices();
    
    if(m_deleteCallbacks && m_pClientCallbacks != &defaultCallbacks) {
        delete m_pClientCallbacks;
    }

} // ~NimBLEClient

[h2zero]

Thanks! I totally forgot about this when I added the default callbacks. Will fix asap.

One comment, if you are just wanting to connect the client instance to a different device you don't need to delete the client, just call connect with refreshServices = true.

[Jeroen88]

Thnx for the comment, I can use it! Still I need to clean up everything, to use the ESP for other tasks after reading the BLE peripherals.

[h2zero]

Fixed in commit 846d690

Thanks!

[Jeroen88]

Fixed by commit