fix concurrent solve test

src/pyscipopt/scip.pxd

@@ -1681,6 +1681,9 @@ cdef extern from "scip/scip_tree.h":
 cdef extern from "scip/scip_var.h":
     SCIP_RETCODE SCIPchgVarBranchPriority(SCIP* scip, SCIP_VAR* var, int branchpriority)
 
+cdef extern from "tpi/tpi.h":
+    int SCIPtpiGetNumThreads()
+
 cdef class Expr:
     cdef public terms
 

src/pyscipopt/scip.pyx

@@ -3096,8 +3096,12 @@ cdef class Model:
     def solveConcurrent(self):
         """Transforms, presolves, and solves problem using additional solvers which emphasize on
         finding solutions."""
-        PY_SCIP_CALL(SCIPsolveConcurrent(self._scip))
-        self._bestSol = Solution.create(self._scip, SCIPgetBestSol(self._scip))
+        if SCIPtpiGetNumThreads() == 1:
+            warnings.warn("SCIP was compiled without task processing interface. Parallel solve not possible - using optimize() instead of solveConcurrent()") 
+            self.optimize()
+        else:
+            PY_SCIP_CALL(SCIPsolveConcurrent(self._scip))
+            self._bestSol = Solution.create(self._scip, SCIPgetBestSol(self._scip))
 
     def presolve(self):
         """Presolve the problem."""

tests/test_model.py

@@ -78,6 +78,15 @@ def test_model():
 
     assert s.getStatus() == 'unbounded'
 
+def test_solve_concurrent():
+    s = Model()
+    x = s.addVar("x", vtype = 'C', obj = 1.0)
+    y = s.addVar("y", vtype = 'C', obj = 2.0)
+    c = s.addCons(x + y <= 10.0)
+    s.setMaximize()
+    s.solveConcurrent()
+    assert s.getStatus() == 'optimal'
+    assert s.getObjVal() == 20.0
 
 def test_multiple_cons_simple():
     def assert_conss_eq(a, b):
@@ -177,4 +186,8 @@ def test_model_ptr():
 
 if __name__ == "__main__":
     test_model()
+    test_solve_concurrent()
+    test_multiple_cons_simple()
+    test_multiple_cons_names()
+    test_multiple_cons_params()
     test_model_ptr()