4 files changed, 35 insertions, 15 deletions
diff --git a/benchmark/dgram/array-vs-concat.js b/benchmark/dgram/array-vs-concat.js
index 669cf47df4..d260a48063 100644
--- a/benchmark/dgram/array-vs-concat.js
+++ b/benchmark/dgram/array-vs-concat.js
@@ -29,17 +29,25 @@ function main({ dur, len, num, type, chunks }) {
 
   function onsendConcat() {
     if (sent++ % num === 0) {
-      for (var i = 0; i < num; i++) {
-        socket.send(Buffer.concat(chunk), PORT, '127.0.0.1', onsend);
-      }
+      // The setImmediate() is necessary to have event loop progress on OSes
+      // that only perform synchronous I/O on nonblocking UDP sockets.
+      setImmediate(() => {
+        for (var i = 0; i < num; i++) {
+          socket.send(Buffer.concat(chunk), PORT, '127.0.0.1', onsend);
+        }
+      });
     }
   }
 
   function onsendMulti() {
     if (sent++ % num === 0) {
-      for (var i = 0; i < num; i++) {
-        socket.send(chunk, PORT, '127.0.0.1', onsend);
-      }
+      // The setImmediate() is necessary to have event loop progress on OSes
+      // that only perform synchronous I/O on nonblocking UDP sockets.
+      setImmediate(() => {
+        for (var i = 0; i < num; i++) {
+          socket.send(chunk, PORT, '127.0.0.1', onsend);
+        }
+      });
     }
   }
 
diff --git a/benchmark/dgram/multi-buffer.js b/benchmark/dgram/multi-buffer.js
index a1c50551b8..7b69a82255 100644
--- a/benchmark/dgram/multi-buffer.js
+++ b/benchmark/dgram/multi-buffer.js
@@ -27,9 +27,13 @@ function main({ dur, len, num, type, chunks }) {
 
   function onsend() {
     if (sent++ % num === 0) {
-      for (var i = 0; i < num; i++) {
-        socket.send(chunk, PORT, '127.0.0.1', onsend);
-      }
+      // The setImmediate() is necessary to have event loop progress on OSes
+      // that only perform synchronous I/O on nonblocking UDP sockets.
+      setImmediate(() => {
+        for (var i = 0; i < num; i++) {
+          socket.send(chunk, PORT, '127.0.0.1', onsend);
+        }
+      });
     }
   }
 
diff --git a/benchmark/dgram/offset-length.js b/benchmark/dgram/offset-length.js
index 7c672acae2..696fa6a7a0 100644
--- a/benchmark/dgram/offset-length.js
+++ b/benchmark/dgram/offset-length.js
@@ -23,9 +23,13 @@ function main({ dur, len, num, type }) {
 
   function onsend() {
     if (sent++ % num === 0) {
-      for (var i = 0; i < num; i++) {
-        socket.send(chunk, 0, chunk.length, PORT, '127.0.0.1', onsend);
-      }
+      // The setImmediate() is necessary to have event loop progress on OSes
+      // that only perform synchronous I/O on nonblocking UDP sockets.
+      setImmediate(() => {
+        for (var i = 0; i < num; i++) {
+          socket.send(chunk, 0, chunk.length, PORT, '127.0.0.1', onsend);
+        }
+      });
     }
   }
 
diff --git a/benchmark/dgram/single-buffer.js b/benchmark/dgram/single-buffer.js
index d183b9cd1d..5c95b17887 100644
--- a/benchmark/dgram/single-buffer.js
+++ b/benchmark/dgram/single-buffer.js
@@ -23,9 +23,13 @@ function main({ dur, len, num, type }) {
 
   function onsend() {
     if (sent++ % num === 0) {
-      for (var i = 0; i < num; i++) {
-        socket.send(chunk, PORT, '127.0.0.1', onsend);
-      }
+      // The setImmediate() is necessary to have event loop progress on OSes
+      // that only perform synchronous I/O on nonblocking UDP sockets.
+      setImmediate(() => {
+        for (var i = 0; i < num; i++) {
+          socket.send(chunk, PORT, '127.0.0.1', onsend);
+        }
+      });
     }
   }