SmartThings Edge Driver to exhibit problem discussed here.
From the Devices tab in the SmartThings App, click +, Add device and Scan for nearby devices. The log will show
DEBUG Bug discovery 0
DEBUG Bug create? a455007a-daf1-51d4-b36c-1b5e6dc9ac5f parent Bug
DEBUG Bug create! a455007a-daf1-51d4-b36c-1b5e6dc9ac5f parent Bug
The first line reflects that there are 0 devices for this driver. Devices will only be “discovered” when this is 0. Later, discovery can be reattempted to see how many devices were actually created.
create? reflects the code’s attempt to acquire a counting try_create_device_semaphore that limits access to the try_create_device “resource” to 100 acquisitions.
create! reflects the code’s acquisition of such and the impending try_create_device call.
After each is the device_network_id (namespace UUID a455007a-daf1-51d4-b36c-1b5e6dc9ac5f), device model/type/sub_driver (parent) and label (Bug).
Give the system time to exhibit this bug. It will try to create one “Bug” parent device with 100 “Bug #” children. For each # (from 1 to 100), the log will show …
DEBUG Bug create? a455007a-daf1-51d4-b36c-1b5e6dc9ac5f # child Bug # 74510a53-72bc-4b05-9ea0-551379ff92cd
DEBUG Bug create! a455007a-daf1-51d4-b36c-1b5e6dc9ac5f # child Bug # 74510a53-72bc-4b05-9ea0-551379ff92cd
… where
the device_network_id matches that of the parent with a # suffix, the device model/type/sub_driver is “child”, the label is “Bug #” and the parent is specified by its UUID.
On subsequent discovery attempts, the log will show how many devices were created. If not for this bug, one would/should expect …
DEBUG Bug discovery 101
… but that is not what I see (more like 15).
My workaround is to change try_create_device_semaphore to a binary semaphore so that only one try_create_device can be done before the semaphore is released (which is done after init).
local try_create_device_semaphore = Semaphore()
To affect this change, remove the “Bug” parent device (this will remove it and all its children), uninstall, upload, assign and install this driver. The first discovery will create all 101 devices. As of this writing, this takes around 144 seconds (about 7 seconds per device).