[Tinyos-help] async/sync events preemption

[Frigging]

Hi,

by the way I'm interesting about tinyos 2.x

you've had wrote:
"Interrupts, however, can preempt tasks. All code that an interrupt handler
calls must be async. The hardware takes care of pushing some context on the
stack, and the compiler takes care of spilling registers to memory. The
question of when interrupts can be handled or not (interrupt preemption,
etc.) depends on 2 things: the chip architecture and whether the code has
disabled interrupts or adjusted the interrupt priority level."

but this means that asyc function could preempt an other async function?
However if an interrupt handler can call only async function, maybe it's
possible (if the chip architecture and whether the code has not disabled
interrupts or adjusted the interrupt priority level) preempt an other async
function. I think so, because I read your paper "TinyOS Programming" at page
39, and I understand that since "In this example, c can (theoretically)
preempt a ...", for me this means that async function can preempt task and
async function. While sync function is running (no-blocking), are interrupts
disabled? or is there a interrupts queue?

In tinyos 2.x where is interrupt priority level handled ? 

I'm very stubborn .. ehm sorry :-)

Thanks in adavance