The routine CPXgetlpcallbackfunc accesses the user-written callback routine to be called after each iteration during the optimization of a continuous problem (LP, QP, or QCP), and also periodically during the CPLEX presolve algorithm.

Callback description

 int callback (CPXCENVptr env,
               void       *cbdata,
               int        wherefrom,
               void       *cbhandle);
 

This is the user-written callback routine.

Callback return value

A nonzero terminates the optimization.

Callback arguments

env

A pointer to the CPLEX environment that was passed into the associated optimization routine.

cbdata

A pointer passed from the optimization routine to the user-written callback function that identifies the LP problem being optimized. The only purpose for the cbdata pointer is to pass it to the routine CPXgetcallbackinfo.

wherefrom

An integer value indicating which optimization algorithm the user-written callback function was called from. Possible values and their meaning appear in the table.

cbhandle

Pointer to user private data, as passed to CPXsetlpcallbackfunc.

Parameters

env

A pointer to the CPLEX environment as returned by CPXopenCPLEX.

callback_p

The address of the pointer to the current user-written callback function. If no callback function has been set, the pointer evaluates to NULL.

cbhandle_p

The address of a variable to hold the user's private pointer.

Example

 status = CPXgetlpcallbackfunc (env, mycallback, NULL);