[ECOS] C++ exceptions and multithreading

[Øyvind Harboe <oyvind dot harboe at zylin dot com>]

Having looked at the code, I've pieced together the following:

unwind-sjlj.c (for which I can't find the source in eCos, I presume
this is part of GCC) uses a fc_static global variable to track the
current
frame context(verified in a debug session) => eCos is limited to 
supporting exception handling for a single thread.

http://savannah.gnu.org/cgi-bin/viewcvs/gcc/gcc/gcc/unwind-sjlj.c?rev=HE
AD&content-type=text/vnd.viewcvs-markup


There is one idea that immediately strikes me w.r.t. adding
multithreaded
C++ exceptions to eCos:

1. change definition of fc_static in unwind-sjlj.c to be a globally
visible
variable.
2. add a fc_static entry to the thread structure
3. for every thread context switch, save off the global fc_static
into the thread structure and restore the global fc_static from the
next running thread. 


*If* the above scheme works, I could make the changes easily enough.

Comments?


Øyvind


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