Allow Monitor#interests to be nil

ext/nio4r/monitor.c

@@ -163,7 +163,11 @@ static VALUE NIO_Monitor_interests(VALUE self)
 
 static VALUE NIO_Monitor_set_interests(VALUE self, VALUE interests)
 {
-    NIO_Monitor_update_interests(self, NIO_Monitor_symbol2interest(interests));
+    if(NIL_P(interests)) {
+        NIO_Monitor_update_interests(self, 0);
+    } else {
+        NIO_Monitor_update_interests(self, NIO_Monitor_symbol2interest(interests));
+    }
 
     return rb_ivar_get(self, rb_intern("interests"));
 }
@@ -292,9 +296,11 @@ static void NIO_Monitor_update_interests(VALUE self, int interests)
         rb_ivar_set(self, rb_intern("interests"), Qnil);
     }
 
-    monitor->interests = interests;
+    if(monitor->interests != interests) {
+        monitor->interests = interests;
 
-    ev_io_stop(monitor->selector->ev_loop, &monitor->ev_io);
-    ev_io_set(&monitor->ev_io, monitor->ev_io.fd, monitor->interests);
-    ev_io_start(monitor->selector->ev_loop, &monitor->ev_io);
+        ev_io_stop(monitor->selector->ev_loop, &monitor->ev_io);
+        ev_io_set(&monitor->ev_io, monitor->ev_io.fd, monitor->interests);
+        ev_io_start(monitor->selector->ev_loop, &monitor->ev_io);
+    }
 }

ext/nio4r/org/nio4r/Monitor.java

@@ -62,7 +62,12 @@ public IRubyObject setInterests(ThreadContext context, IRubyObject interests) {
         Ruby ruby = context.getRuntime();
         SelectableChannel channel = (SelectableChannel)io.getChannel();
 
-        key.interestOps(Nio4r.symbolToInterestOps(ruby, channel, interests));
+        if(interests != context.nil) {
+            key.interestOps(Nio4r.symbolToInterestOps(ruby, channel, interests));
+        } else {
+            key.interestOps(0);
+        }
+
         this.interests = interests;
 
         return this.interests;

lib/nio/monitor.rb

@@ -26,12 +26,12 @@ def initialize(io, interests, selector)
 
     # Replace the existing interest set with a new one
     #
-    # @param interests [:r, :w, :rw] I/O readiness we're interested in (read/write/readwrite)
+    # @param interests [:r, :w, :rw, nil] I/O readiness we're interested in (read/write/readwrite)
     #
     # @return [Symbol] new interests
     def interests=(interests)
       raise EOFError, "monitor is closed" if closed?
-      raise ArgumentError, "bad interests: #{interests}" unless %i[r w rw].include?(interests)
+      raise ArgumentError, "bad interests: #{interests}" unless [:r, :w, :rw, nil].include?(interests)
 
       @interests = interests
     end

spec/nio/monitor_spec.rb

@@ -29,6 +29,12 @@
   end
 
   describe "#interests=" do
+    it "can set interests to nil" do
+      expect(monitor.interests).not_to eq(nil)
+      monitor.interests = nil
+      expect(monitor.interests).to eq(nil)
+    end
+
     it "changes the interest set" do
       expect(monitor.interests).not_to eq(:w)
       monitor.interests = :w