Platform information: Hardware: Raspberry Pi 3 Model B Rev 1.2 OS: Raspbian GNU/Linux 8 (jessie) Java Runtime Environment: don’t know openHAB version: openHAB 2.3.0-1 (Release Build) Issue of the topic: How to setup a FIFO queue to send commands I am hoping to get some suggestions on how to sol…

After playing around with the referenced DP and realizing that the FIFO can not be a string item, I think I got it… By using a global string var to hold the FIFO items I came up with this test rule which seems to work nicely (I omitted the items definitions): import java.util.concurrent.locks.Reen…

[image] Design Pattern: Gate Keeper Tutorials & Examples Edit: Updated for OH 4, removed Nashorn JS and Python examples as those libraries are no longer maintained. Please see Design Pattern: What is a Design Pattern and How Do I Use Them for a desciption of D…

I read through the DP you referenced, but don’t understand the depth of OpenHab to see if multiple triggers to the proxy command are queued up and will execute in the order they were triggered?

[image] sl92656: It is interesting to note, that the secondary rule that is triggered within the first rule does not execute until the first one is finished… This is because of the lock Well done Please mark the thread as solved

I just want to add that even with your variable, there is nothing at all to guarantee the order of processing of events, particularly if they occur really really close together. OH isn’t a real time system and there are no checks in place to enforce the order. Usually this doesn’t matter because eve…

Thanks @rlkoshak for the input! I realize that OH is far from realtime. With multiple parallel processes running there is no guarantee at all, that some other process is also accessing the global FIFO variable and potentially destroying values that have been added by a first process. In general t…

[image] sl92656: With respect to errors within the lock/unlock, I’ll find that out immediately, since my OH TV remote won’t respond anymore :wink: It’s worse than that. No OH rules will at all until you restart OH.

Does that mean a lock is global, i.e. no other OH functions execute?

[image] (OH 1.x and OH 2.x Rules DSL only] Why have my Rules stopped running? Why Thread::sleep is a bad idea Scripts & Rules EDIT: While the general advice in this article still applies (i.e. it’s always worth while to make short running rules), the problem de…

Again thanks for the info. I need to study this a bit to see how I can utilize your “implement a while loop using Timers” suggestion, which has a lot of merits!

Ok, I thought about it and used the “Timer based while loop” to get rid of the Thread::sleep entries in the original while loop. I do realize, that adding items to the FIFO asynchronous to the “FIFO execution” rule is dangerous and does result in crashes of the rule if timed right, which in combina…

How to setup a FIFO queue to send commands

Setup, Configuration and Use Scripts & Rules

rlkoshak (Rich Koshak) October 9, 2018, 3:47am 10

The title talks about Thread::sleep because they are the most common problem. But locks can pose the same problem.