return MOI.TIME_LIMIT when time_limit_sec is set

src/optimize.jl

@@ -236,6 +236,10 @@ function MOI.get(model::Optimizer, ::MOI.TerminationStatus)
         else
             return MOI.OPTIMAL
         end
+    elseif model.solver_status == "UNKNOWN" &&
+           model.time_limit_sec !== nothing &&
+           abs(model.solve_time_sec - model.time_limit_sec) < 1
+        return MOI.TIME_LIMIT   # The solver timed out
     else
         return MOI.OTHER_ERROR
     end

test/examples/nqueens_time_limit.jl

@@ -0,0 +1,35 @@
+# Copyright (c) 2022 MiniZinc.jl contributors
+#
+# Use of this source code is governed by an MIT-style license that can be found
+# in the LICENSE.md file or at https://opensource.org/licenses/MIT.
+
+# N-queens example
+# based on MiniZinc example nqueens.mzn
+# queen in column i is in row q[i]
+
+# Test solver time out 
+function test_nqueens_timeout()
+    n = 100 # can't finish in 1s
+    model = MOI.instantiate(
+        () -> MiniZinc.Optimizer{Int}("chuffed");
+        with_cache_type = Int,
+        with_bridge_type = Int,
+    )
+    MOI.set(model, MOI.RawOptimizerAttribute("model_filename"), "test.mzn")
+    q = MOI.add_variables(model, n)
+    MOI.add_constraint.(model, q, MOI.Interval(1, n))
+    MOI.add_constraint(model, MOI.VectorOfVariables(q), MOI.AllDifferent(n))
+    for op in (+, -)
+        f = MOI.Utilities.vectorize([op(q[i], i) for i in eachindex(q)])
+        MOI.add_constraint(model, f, MOI.AllDifferent(n))
+    end
+
+    # test timeout in 1s
+    MOI.set(model, MOI.TimeLimitSec(), 1.0)
+    # solve
+    MOI.optimize!(model)
+    @test MOI.get(model, MOI.TerminationStatus()) === MOI.TIME_LIMIT
+    @test MOI.get(model, MOI.ResultCount()) == 0
+    rm("test.mzn")
+    return
+end