Fix #150, wrong infinite max_time

processscheduler/solver.py

@@ -140,7 +140,7 @@ def __init__(self, **data) -> None:
             z3.set_option("smt.arith.random_initial_value", False)
 
         # set timeout
-        if self.max_time != "inf":
+        if self.max_time != float("inf"):
             z3.set_option("timeout", int(self.max_time * 1000))  # in milliseconds
 
         # some flags that will be used after
@@ -784,7 +784,7 @@ def _solve_optimize_incremental(
             print(
                 f"\tFound value: {current_variable_value} elapsed time:{total_time:.3f}s"
             )
-            if self.max_time != "inf" and total_time > self.max_time:
+            if self.max_time != float("inf") and total_time > self.max_time:
                 print("Max time exceeded. Stop incremental solver.")
                 break
 
@@ -807,7 +807,7 @@ def _solve_optimize_incremental(
                 # Compute the expected value
                 a, b, c = calc_parabola_from_three_points([0, 1, 2], three_last_times)
                 expected_next_time = a * 9 + 3 * b + c
-                if self.max_time != "inf" and expected_next_time > self.max_time:
+                if self.max_time != float("inf") and expected_next_time > self.max_time:
                     print(
                         "Max time expected on the next iteration. Stop incremental solver."
                     )

test/test_solver.py

@@ -283,6 +283,16 @@ def test_solve_max_time():
     assert not solution
 
 
+def test_solve_inf_max_time():
+    """just to test that setting max_time to 'inf' works"""
+    problem = build_complex_problem("SolveInfMaxTime", 10)
+    ps.ObjectiveMinimizeMakespan()
+    # 1s is not enough to solve this problem
+    max_time_solver = ps.SchedulingSolver(problem=problem, max_time=float("inf"))
+    solution = max_time_solver.solve()
+    assert solution
+
+
 def test_solve_non_integer_max_time():
     """a stress test which"""
     problem = build_complex_problem(name="SolveMaxTime", n=1000)