Add notice about MPMC implementation

jserv · jserv · commit ca042ce91681 · 2021-04-21T00:31:05.000+08:00
diff --git a/mpmc/mpmc.c b/mpmc/mpmc.c
@@ -1,3 +1,7 @@
+/* A multiple-producer/multiple-consumer queue
+ * NOTE: dequeue operation would block if there is no element.
+ */
+
 #ifndef _GNU_SOURCE
 #define _GNU_SOURCE
 #endif
