Task switching and state information
Wrapping task_yield() in order to perform a library-wide context switch is
a thing to do. However, this can lead to
performing a task switch when it isis not needed, as the new active task may
not use the library at all, or may not use any state information in it.
Hence some iverhead.
Another solution is for each routine which uses state information to check
whether the state information iss relative to the current task, and perform
the switch whenever they are different. This is probably good
performance-wise, but requires all the programmer's attention, as s/he
should put this code on entry to every routine which uses state information.
Perhaps a simpler way would be to define a new keyword, sat "task", used as
a prefix when declaring variables. A task variable would be local, and any
change to it would be reflected in the task's context.
For instance:
<eucide>
task integer fontSize
</eucode>
{{{
defines a local integer variable whose value depends on the active task. As
it is possible to tell at interpretation time which tasks will use which
libraries, the interpreter can optimise things so as to perform a context
switch for state information only when there's a chance for it to be
relevant.
Any thoughts?
CChris
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