I have used a state machine based co-operative multitasking approach in man=
y systems. The main code is a loop calling each task state machine, which i=
s a large switch statement, usually. Finding the right size of block and un=
rolling loops can get tedious and it can look messy but it does work well. =
I have had such systems deal with timers and comms, the interrupt handles j=
ust raise flags and the code in the state machines handles things.=20

On 2013-04-18, at 11:20 PM, veegee <veegee@veegee.org> wrote:

> On 2013-04-18 10:59 AM, Joe Wronski wrote:
>> Having never worked with any RTOS due to ROM and RAM limitations, I find=
=20
>> Protothreads fascinating.    Where my cow-orkers and I had hand crafted=
=20
>> state machines which closely resembled the Protothreads expanded macros,=
=20
>> using PT would have made the code more readable and maintainable.  I had=
=20
>> never considered using the __LINE__ macro for anything other than=20
>> compiler error and warning info.  And I never realized that you could=20
>> put the case : argument of a switch within a while loop (Duff's Device).
>=20
> Yup, C switches behave somewhat like labels. The cases are valid
> anywhere within the switch.
>=20
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