🚀 go-pugleaf

The standard says (my caps):

#  However, if the longjmp function is invoked from a nested 
#  signal handler (that is, from a function invoked as a result 
#  of A SIGNAL RAISED during the handling of another signal), 
#  the behavior is undefined.

Consider a signal handlers, sig_hand, set up using - 

 signal(SIGONE, sig_hand);

There is a SIGONE exception and sig_hand is now executing.  Two 
possibilities (of interest) are:

1. sig_hand calls raise(SIGSOMETHING);
2. another (async) exception is raised.

Since the standard makes no restriction on how the second signal is 
raised (as in caps), I assume both actions result in undefined behaviour.  
Since there is no way of disabling external interrupts, this would seem 
to make it impossible to guarantee defined behaviour.

Is 'nested' intended to only refer to 'nested function calls' as in 
case 1?  That is how I think it _should_ read, but not how I think 
it _does_ read.

-- 
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 Ian Cargill  CEng MIEE  | Find out about the Association of C and C++ Users
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