Re: [Boost-users] [coroutine] Bus error on Mac OS X 10.5

Subject: Re: [Boost-users] [coroutine] Bus error on Mac OS X 10.5
From: Nat Goodspeed (nat_at_[hidden])
Date: 2009-04-08 23:47:38

Nat Goodspeed wrote:

> banana.cpp now runs on my Mac!

Mine -- but not all target Macs, sigh! We have to support OS X 10.4 as 
well. To my distress, 10.4 does not have swapcontext() et al.

The #else clause in boost/coroutine/detail/context_posix.hpp contains 
the following comment (along with an #error):

/**
  * This is just a temporary placeholder. Context swapping can
  * be implemented on all most posix systems lacking *context using the
  * sigaltstack+longjmp trick.
  * Eventually it will be implemented, but for now just throw an error.
  * Most posix systems are at least SuSv2 compliant anyway.
  */

After a couple hours of searching, I have not yet turned up either an 
article or an example of the "sigaltstack + longjmp trick." Can anyone 
steer me to a reference implementation? I can't just hack something 
together on my own: my boss wants me to forget about coroutines in C++, 
and that would be a shame indeed. If I could adapt an implementation 
that already works, though, I might still pull this off.

Many thanks!