`CPXCALLBACKINFO`


typedef enum {
   CPXCALLBACKINFO_THREADID,
   CPXCALLBACKINFO_NODECOUNT,
   CPXCALLBACKINFO_ITCOUNT,
   CPXCALLBACKINFO_BEST_SOL,
   CPXCALLBACKINFO_BEST_BND,
   CPXCALLBACKINFO_THREADS,
   CPXCALLBACKINFO_FEASIBLE,
   CPXCALLBACKINFO_TIME,
   CPXCALLBACKINFO_DETTIME,
   CPXCALLBACKINFO_NODEUID,
   CPXCALLBACKINFO_NODEDEPTH,
   CPXCALLBACKINFO_CANDIDATE_SOURCE,
   CPXCALLBACKINFO_RESTARTS,
   CPXCALLBACKINFO_AFTERCUTLOOP,
   CPXCALLBACKINFO_NODESLEFT
} CPXCALLBACKINFO;

Description

The CPXCALLBACKINFO enumeration specifies the information that can be queried from an invocation of the generic callback by means of these routines:

value	type	description
`CPXCALLBACKINFO_THREADID`	`CPXINT` or `CPXLONG`	A unique identifier for the calling thread. The identifiers range from 0 (zero) through N-1, where N is the maximum number of threads CPLEX is allowed to allocate for the solve. The thread on which the user started the solve always has identifier 0 (zero).
`CPXCALLBACKINFO_NODECOUNT`	`CPXINT` or `CPXLONG`	Number of nodes processed so far
`CPXCALLBACKINFO_ITCOUNT`	`CPXINT` or `CPXLONG`	Simplex iterations executed so far
`CPXCALLBACKINFO_BEST_SOL`	`double`	Objective value of the best known feasible solution. May be infinite if no feasible solution is known. Warning: This best known solution is global only if the callback is invoked in context CPX_CALLBACKCONTEXT_GLOBAL_PROGRESS. In all other cases, this is a thread-local value which may be different from the best known globally valid value.
`CPXCALLBACKINFO_BEST_BND`	`double`	The best known bound on the optimal objective function value. For MIP, this bound is usually the objective value of the best open node. The value may be infinite if no better information is currently available. Important: This bound may be infinite (`-CPX_INFBOUND` or `CPX_INFBOUND`, depending on the objective sense) if no bound has been computed yet, or if no bound is available for the calling thread. Warning: Note that the best bound may exceed the value of the best feasible solution when optimality is proven.
`CPXCALLBACKINFO_FEASIBLE`	`CPXINT` or `CPXLONG`	Returns a true value (nonzero)if a feasible solution is known, false (zero) otherwise.
`CPXCALLBACKINFO_THREADS`	`CPXINT` or `CPXLONG`	Number of threads allocated by CPLEX for the current solve.
`CPXCALLBACKINFO_TIME`	`double`	Returns a timestamp. Depending on clock type for computation time, this timeis either wallclock or CPU time. This value is the equivalent of CPXXgettime and CPXgettime.
`CPXCALLBACKINFO_DETTIME`	`double`	Returns a deterministic timestamp. This value is equivalent to CPXXgetdettime and CPXgetdettime. Warning: In threads that execute speculative code, this function may return infinity (a number for which `isinf()` returns true and `fpclassify()` returns `FP_INFINITE`) when invoked in the context CPX_CALLBACKCONTEXT_THREAD_DOWN.
`CPXCALLBACKINFO_NODEUID`	`long`	Returns a unique identifier for the current MIP search tree node. If the callback is invoked in a situation where there is no current node, then the query produces an error. Therefore, this information can only be queried in the contexts: CPX_CALLBACKCONTEXT_RELAXATION, CPX_CALLBACKCONTEXT_BRANCHING, CPX_CALLBACKCONTEXT_CANDIDATE, but only if the candidate solution comes from an integer feasible node (see the description of `CPXCALLBACKINFO_CANDIDATE_SOURCE` below). Note: The very first node processed during tree search has unique id 0. For any other node, no assumption about the unique id should be made other than that the value is unique.
`CPXCALLBACKINFO_NODEDEPTH`	`long`	Returns the depth of the current node in the MIP search tree. If the callback is invoked in a situation where there is no current node, then the query produces an error. Therefore, this information can only be queried in the contexts: CPX_CALLBACKCONTEXT_RELAXATION, CPX_CALLBACKCONTEXT_BRANCHING, CPX_CALLBACKCONTEXT_CANDIDATE, but only if the candidate solution comes from an integer feasible node (see the description of `CPXCALLBACKINFO_CANDIDATE_SOURCE` below).
`CPXCALLBACKINFO_CANDIDATE_SOURCE`	`int`	Returns the source of the current candidate solution. This information can only be queried in the CPX_CALLBACKCONTEXT_CANDIDATE context. In all other contexts, querying this information will return an error. The source of the current candidate solution is one of the following: CPX_LAZYCONSTRAINTCALLBACK_MIPSTART, if the solution comes from a MIP start. CPX_LAZYCONSTRAINTCALLBACK_HEUR, if the solution comes from a heuristic. CPX_LAZYCONSTRAINTCALLBACK_USER, if the solution is provided by the user (via CPXXcallbackpostheursoln and CPXcallbackpostheursoln). CPX_LAZYCONSTRAINTCALLBACK_NODE, if the solution comes from an integer feasible node.
`CPXCALLBACKINFO_RESTARTS`	`int`	Returns the number of restarts performed so far. This information cannot be queried from the CPX_CALLBACKCONTEXT_THREAD_UP or CPX_CALLBACKCONTEXT_THREAD_DOWN context.
`CPXCALLBACKINFO_AFTERCUTLOOP`	`int`	Returns true if the callback is invoked after CPLEX has completed its cut loop and false otherwise. This information can only be queried from the CPX_CALLBACKCONTEXT_RELAXATION context.
`CPXCALLBACKINFO_NODESLEFT`	`long`	Returns the number of open nodes left. Note that this number can only be an estimate for the real number of open nodes since the calling thread cannot inspect the actual number of open nodes in other threads. This information can not be queried in all contexts (most notably not in CPX_CALLBACKCONTEXT_THREAD_UP or CPX_CALLBACKCONTEXT_THREAD_DOWN).

CPXCALLBACKINFO

Description

See also

`CPXCALLBACKINFO`