Originally posted by: bluecoder

hi,

how would I determine whether cplex already found a feasible primal solution to a MIP - while it is still solving (so IloCplex::solve is still running) - from a signal handler? The reason is, that I want to abort the solving from within the signal handler only if a primal solution is already found.
From my tests I concluded that IloCplex::isPrimalFeasible only returns true after IloCplex::solve terminated.

Best Regards,
Jörg
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Originally posted by: SystemAdmin

To make sure I got you right: You are talking about a signal handler, like something that is set via sigaction() or signal() in Linux?
In general there is no way to get the information you want directly from the CPLEX object.
What you can do is the following:

• Register a MIPInfoCallback with the IloCplex instance that performs the solve.
• Create a flag variable that is shared between the callback and the signal handler.
• The callback is invoked periodically by CPLEX. Every time it is invoked you can check whether a feasible solution exists. If so then set the flag to true.
• In the signal handler check the shared flag.

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Originally posted by: bluecoder

> dju358 wrote:
> You are talking about a signal handler, like something that is set via sigaction() or signal() in Linux?
yep, exactly.

And thanks for the reply, what you described worked out well.
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