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[More about co-routines...]

Co-Routine States

Co-routines are only intended for use on very small processors that have severe RAM constraints, and would not normally be used on 32-bit microcontrollers.

A co-routine can exist in one of the following states:

  • Running

    When a co-routine is actually executing it is said to be in the Running state. It is currently utilising the processor.

  • Ready

    Ready co-routines are those that are able to execute (they are not blocked) but are not currently executing. A co-routine may be in the Ready state because:

    1. Another co-routine of equal or higher priority is already in the Running state, or
    2. A task is in the Running state - this can only be the case if the application uses both tasks and co-routines.

  • Blocked

    A co-routine is said to be in the Blocked state if it is currently waiting for either a temporal or external event. For example, if a co-routine calls crDELAY() it will block (be placed into the Blocked state) until the delay period has expired - a temporal event. Blocked co-routines are not available for scheduling.

There is currently no co-routine equivalent to a tasks Suspended state.

Valid co-routine state transitions

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