Details of old bug fix for change of priority

bennertz wrote on Wednesday, November 03, 2010:

I’m stuck with version 3.2.0 of FreeRTOS in some ancient code and updating to a newer version is not really an option, unfortunately. My platform is an ARM7 controller (STR710). The compiler tool chain I use is YAGARTO.

I would like to use the feature vTaskPrioritySet() when evolving the code but found a notice in the for the change from version 4.0.4 to version 4.0.5:

Bug fix:  The ‘value’ of the event list item is updated when the priority of a task is changed.  Previously only the priority of the TCB itself was changed.

Can anyone help me with the following questions:

  1. Does this fix affect a bug that was present in version 3.2.0 already?

  2. If so, are there any details on this issue still available (old ticket or such)? What would the effect of that bug be?

Thank you for all and any help,

rtel wrote on Wednesday, November 03, 2010:

Wow, that is going back a long way.  From the sound of the description the problem would have been that after calling vTaskPrioritySet( task_id, new_priority ) the task associated with task_id would only have changed to new_priority the next time it executed.  In other words, when the scheduler was making a decision as to which task to execute next the decision would have been made as if task_id had its original priority, but once it had been selected from that point on the decision would be made as if it had its new priority.


bennertz wrote on Monday, November 08, 2010:

Thank you very much for the help.