Improve handling of SIGINT interrupts (#621)

Author: odow

src/MOI_wrapper/MOI_callbacks.jl

@@ -32,12 +32,15 @@ function _gurobi_callback_wrapper(
     cb_where::Cint,
     p_user_data::Ptr{Cvoid},
 )
-    user_data = unsafe_pointer_to_objref(p_user_data)::_CallbackUserData
     try
-        user_data.callback(
-            CallbackData(user_data.model, cb_data, cb_where),
-            cb_where,
-        )
+        reenable_sigint() do
+            user_data = unsafe_pointer_to_objref(p_user_data)::_CallbackUserData
+            user_data.callback(
+                CallbackData(user_data.model, cb_data, cb_where),
+                cb_where,
+            )
+            return
+        end
     catch ex
         GRBterminate(p_model)
         if !(ex isa InterruptException)

src/MOI_wrapper/MOI_wrapper.jl

@@ -2791,13 +2791,14 @@ function MOI.optimize!(model::Optimizer)
     # Catch [CTRL+C], even when Julia is run from a script not in interactive
     # mode. If `true`, then a script would call `atexit` without throwing the
     # `InterruptException`. `false` is the default in interactive mode.
-    #
-    # TODO(odow): Julia 1.5 exposes `Base.exit_on_sigint(::Bool)`.
-    ccall(:jl_exit_on_sigint, Cvoid, (Cint,), false)
-    model.ret_GRBoptimize = GRBoptimize(model)
+    Base.exit_on_sigint(false)
+    disable_sigint() do
+        model.ret_GRBoptimize = GRBoptimize(model)
+        return
+    end
     _check_ret_GRBoptimize(model)
     if !isinteractive()
-        ccall(:jl_exit_on_sigint, Cvoid, (Cint,), true)
+        Base.exit_on_sigint(true)
     end
 
     # Post-optimize caching to speed up the checks in VariablePrimal and