-#define EV_READ 0x01
-#define EV_WRITE 0x02
-#define EV_TIMEOUT 0x000100
-#define EV_PERIODIC 0x000200
-#define EV_SIGNAL 0x000400
-#define EV_IDLE 0x000800
-#define EV_CHECK 0x001000
-#define EV_PREPARE 0x002000
-#define EV_CHILD 0x004000
+#define EV_READ 0x01 /* io only */
+#define EV_WRITE 0x02 /* io only */
+#define EV_TIMEOUT 0x000100 /* timer only */
+#define EV_PERIODIC 0x000200 /* periodic timer only */
+#define EV_SIGNAL 0x000400 /* signal only */
+#define EV_IDLE 0x000800 /* idle only */
+#define EV_CHECK 0x001000 /* check only */
+#define EV_PREPARE 0x002000 /* prepare only */
+#define EV_CHILD 0x004000 /* child/pid only */