feat(handle-termination-condition): Checks for non optimal barrier

- Added for Barrier solve with no cross solve which may terminate in a result that is not optimal but still a valid result

pyomo/contrib/appsi/base.py

@@ -67,6 +67,9 @@ class TerminationCondition(enum.Enum):
     licensingProblems = 13
     """The solver exited due to licensing problems"""
 
+    barrierNonOptimal = 14
+    """Barrier Non-optimal"""
+
 
 class SolverConfig(ConfigDict):
     """

pyomo/contrib/appsi/solvers/cplex.py

@@ -280,6 +280,8 @@ def _postsolve(self, timer: HierarchicalTimer, solve_time):
             results.termination_condition = TerminationCondition.maxIterations
         elif status in [11, 25, 107, 131]:
             results.termination_condition = TerminationCondition.maxTimeLimit
+        elif status in {6}:
+            results.termination_condition = TerminationCondition.barrierNonOptimal
         else:
             results.termination_condition = TerminationCondition.unknown
 

pyomo/opt/results/solver.py

@@ -74,6 +74,8 @@ class TerminationCondition(str, enum.Enum):
                                                     #    optimizer
     licensingProblems='licensingProblems'           # Problem accessing solver license
 
+    barrierNonOptimal='barrierNonOptimal'           # Barrier - Non-optimal
+
     # Overloading __str__ is needed to match the behavior of the old
     # pyutilib.enum class (removed June 2020). There are spots in the
     # code base that expect the string representation for items in the

pyomo/solvers/plugins/solvers/CPLEX.py

@@ -549,6 +549,7 @@ def process_logfile(self):
                         TerminationCondition.maxTimeLimit,
                         TerminationCondition.noSolution,
                         TerminationCondition.unbounded,
+                        TerminationCondition.barrierNonOptimal
                     }
                 ):
                     # If we have already determined the termination condition, reduce it to a warning.
@@ -606,6 +607,9 @@ def process_logfile(self):
             elif len(tokens) >= 4 and tokens[0] == "Barrier" and tokens[2] == "Optimal:":
                 results.solver.termination_condition = TerminationCondition.optimal
                 results.solver.termination_message = ' '.join(tokens)
+            elif len(tokens) >= 4 and tokens[0] == "Barrier" and tokens[2] == "Non-optimal:":
+                results.solver.termination_condition = TerminationCondition.barrierNonOptimal
+                results.solver.termination_message = ' '.join(tokens)
             elif len(tokens) >= 4 and tokens[0] == "Dual" and tokens[3] == "Infeasible:":
                 results.solver.termination_condition = TerminationCondition.infeasible
                 results.solver.termination_message = ' '.join(tokens)