Hello All, I’m working on a command parsing and IO module based on freeRTOS. My command parsing task receives a formatted hex string and converts it to a packet with address fields, etc. From there the parser needs to forward the packets on to the appropriate IO task. I’m wondering what the best a…

I’d recommend using a separate (input) queue or message buffer per task. Both mechanisms support sending/pushing multiple items to have them pending in the queue or message buffer and to get processed later by the I/O tasks. Better don’t mess around with a single queue and extra mutex protection. …

I agree with Hartmut here. My normal design methodology is to assign each task to have some resource it is waiting on (A Queue, Buffer, Direct-to-Task notification, or a semaphore, but the last can normally be replaced with the notification). Also, each Queue or Buffer will normally have a sink defi…

My only concern with multiple queues was resource usage. Do empty queues use up much memory? If not then it sounds like the simplest option. Thanks for the input!

Queue space is pre-allocated on creation. Therefore their filling level doesn’t matter concerning memory/resource usage when queuing items by value/copy. You could also queue items by reference/pointer and manage the memory needed for the items yourself. But this is a bit more complicated (you need…

Ok, I have a few more questions. Is the memory allocation for the queue static or dynamic? If I have 20 queues say with the ability to hold 5 messages each and the maximum message length is 255 bytes is that 25kb that is constantly tied up? If I have multiple tasks all sending packets back to a se…

[image] Andys: Is the memory allocation for the queue static or dynamic? If I have 20 queues say with the ability to hold 5 messages each and the maximum message length is 255 bytes is that 25kb that is constantly tied up? A queue can be created either statically or dynamically . I have linke…

[image] rtel: A queue can be created either statically or dynamically . I have linked to the documentation so you can read how rather than repeat it here. The memory is constantly tied up if you allocated statically. If you allocated dynamically then you have the option to free the memory when t…

Dynamic with QueueDelete. The queue, while it exists, ALWAYS uses the same amount of memory. It allocates space for its maximum when created, so you can never get an ‘Out of Memory’ error in operation, only a Queue Full.

Inter task Communication Architecture

Kernel

Andys (Andrew Strachan) February 24, 2021, 2:26am 10

Thank you all, that’s cleared up a lot of things for me!

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Inter task Communication Architecture

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