# Try\_create\_device: though device may be "added", not always "init"ed

**URL:** <https://community.smartthings.com/t/try-create-device-though-device-may-be-added-not-always-init-ed/237794>\
**Category:** Writing Edge Drivers\
**Created:** [January 12, 2022, 8:47pm UTC](https://community.smartthings.com/t/try-create-device-though-device-may-be-added-not-always-init-ed/237794 "2022-01-12T20:47:26Z")\
**Posts on this page:** 1\
**Showing post:** 23

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**Author:** ![nayelyz](https://avatars.discourse-cdn.com/v4/letter/n/59ef9b/32.png) [@nayelyz](https://community.smartthings.com/u/nayelyz)\
**Post date:** [March 7, 2022, 3:10pm UTC](https://community.smartthings.com/t/try-create-device-though-device-may-be-added-not-always-init-ed/237794/23 "2022-03-07T15:10:43Z")

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Hi, @rossetyler. Sorry for the delay, the engineering team mentioned the following about your sample:

- In the driver you aren’t using any sockets at all, so there are no calls to `receive` but you use both `cosock.socket.sleep` and `cosock.socket.select`
- [In this file](https://github.com/rtyle/st-edge/blob/master/driver/legrand-rflc/package/src/lc7001/init.lua#L621) it is not clear if one of those functions is getting called in the `added` lifecycle and that is blocking `init`.
- You should check if the creation of the devices was successful using `assert(driver.try_create_device(...))` or `local success, err = driver.try_create_device(...)`. This way, you can see if there were immediate errors.
  - Especially because, in your sample, you’re calling `try_create_device` in a hot loop `100` times and this might be reaching the rate limit of devices created in a given timespan.

_In this case, this number of devices was an example, or do you actually have drivers that create `100` devices? If so, could you share the details of that use case?_

- Any time something could block the current thread, you can avoid that entirely by calling `cosock.spawn`. So, something like `cosock.spawn(function() local value, err = socket:receive() end)` would allow the use of the device thread for any other device events. For example:

_This sample shows how the device thread can be blocked_

```auto

-- This driver will lock up any device thread by
-- yielding the thread into a deadlock because
-- init cannot be processed until added is complete
-- but added is relying on init to complete

local tx, rx = cosock.channel.new()
local function added(driver, device)
  -- wait for init
  local init, err = rx:receive()
end

local function init(driver, device)
  -- send init
  tx:send(device.id)
end

local driver = Driver("...", {
  lifecycle_handlers = {
    added = added,
    init = init,
  }
})

```

_Considering the previous implementation, this is how we can avoid the blockage using `cosock.spawn`_

```auto
local tx, rx = cosock.channel.new()
local function added(driver, device)
  cosock.spawn(function()
    local init, err = rx:receive()
    
  end)
  -- wait for init
end

local function init(driver, device)
  -- send init
  tx:send(device.id)
end

local driver = Driver("...", {
  lifecycle_handlers = {
    added = added,
    init = init,
  }
})

```

cc @blueyetisoftware

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_[View the full topic](https://community.smartthings.com/t/try-create-device-though-device-may-be-added-not-always-init-ed/237794)._