After first connection to a device, when there is no bluez cache for it, trying to use service.find() to look for a characteristic causes SIGSEGV

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x61c1e5e0, pid=1113, tid=1624364128
#
# JRE version: Java(TM) SE Runtime Environment (8.0_65-b17) (build 1.8.0_65-b17)
# Java VM: Java HotSpot(TM) Client VM (25.65-b01 mixed mode linux-arm )
# Problematic frame:
# C  [libtinyb.so.0+0x6f5e0]  tinyb::BluetoothEvent::get_type() const+0x14
#

I think this is caused by a race condition where an event is received from the d_bus and handled in BluetoothEventManager::on_interface_added which in turn calls BluetoothManager::handle_event
The following code iterates on the event list on one thread