Here's a general question... There are quite a few "default" NB task priorities declared for tasks which provide basic system utilities that I like to use as essential system resources: TCP, FTP, HTTP, Ethernet, etc. However, their default prios don't leave too much room for user-related tasks above them, and so I find I often wind up moving the NB default tasks below MAIN_PRIO down by an offset of 30 which then moves the default prios between FTP and ENC_TASK (48 to 36) respectively to (18 and 6) respectively. This then frees up a much bigger user task priority area (from 19 to 49). The default prio setup leaves prios from 0 to 35 unoccupied. But is there good reason to have tasks running at prios below the system TCP, Ethernet, FTP defaults? If so, I'm interested in what they might be. If not, why wouldn't the defaults be moved much lower to free up this middle block of task prio space for user tasks?
FYI, I often define my user task prios in a file called Tasks.h which includes commented indicators of the system defaults to see where everything sits in one consolidated place.
//TASKS listed in order of priority where LOWER NUMBER = HIGHER priority:
//----------------------------------------------------------------------_-
//IDLE task is set at lowest priority (63) // NB System
////LOWER priority than main above this line------------------------------
// #define MAIN_PRIO (50) // NB System
// #define FTP_PRIO (48) // NB System
// #define HTTP_PRIO (45) // NB System
// #define PPP_PRIO (44) // NB System
// #define TCP_PRIO (40) // NB System
// #define IP_PRIO (39) // NB System
// #define ETHER_SEND_PRIO (38) // NB System
// #define WIFI_TASK_PRIO (37) // NB System
// #define ENC_TASK_PRIORITY (36) // NB System
This must be quite a task-intensive app you are building!
I'm sure you know the lower the number the higher the priority. I have never even thought about messing with the NB default priorities, as I typically only add maybe 10 tasks maximum. The low priority tasks I build go above NB and the hotter tasks go before (lower than) NB tasks.
How many tasks are you instantiating?
Chris
Real Programmers don't comment their code. If it was hard to write, it should be hard to understand
I've got ~ 16 tasks that want to live between Main_PRIO and the NB regulars. Most of my tasks need the resources of the NB regulars for stuff like FTP, EFFS, etc. One reason for the number of tasks is that we're actively parsing (and often logging to SD or TCP socket) from 7 serial ports (5234 eTPU).
Each raw serial input task (one for each serial port) timestamps incoming data and stuffs it into FIFOs. These raw-input tasks have lower prio numbers (more importantance) than their corresponding parsers and loggers. They are designed to ensure capture (as opposed to interpreption) of incoming data, one task per port.
A corresponding set of parsing tasks eventually parses and acts on data in the fifos, logging to SD or TCP socket if needed. These parsing tasks can happen with less critical timing since the data is captured (and can stack up) in the fifos if things get busy.
Finally, a few tasks are talking over i2c.
All serial tasks do similar stuff, but much easier to think about in separate tasks.... Despite all that action, I want FTP and TCP stuff to take prio when access is needed so those tasks live below (higher prio than) my serial and i2c tasks. I guess I could gain task-number space by pushing MAIN to a higher prio number, but somehow i keep thinking about it being at 50...
I'm curious about your "hot tasks": Do they depend on the NB resources (FTP, TCP, etc)? It sounds like they don't since they are below (higher prio)?
