only call cargo.drain once each time it's drained

1 files changed, 4 insertions, 1 deletions

diff --git a/lib/async.js b/lib/async.js
index 1eebb15..dcbc511 100755
--- a/lib/async.js
+++ b/lib/async.js
@@ -751,6 +751,7 @@
             saturated: null,
             empty: null,
             drain: null,
+            drained: true,
             push: function (data, callback) {
                 if(data.constructor !== Array) {
                     data = [data];
@@ -760,6 +761,7 @@
                         data: task,
                         callback: typeof callback === 'function' ? callback : null
                     });
+                    cargo.drained = false;
                     if (cargo.saturated && tasks.length === payload) {
                         cargo.saturated();
                     }
@@ -769,7 +771,8 @@
             process: function process() {
                 if (working) return;
                 if (tasks.length === 0) {
-                    if(cargo.drain) cargo.drain();
+                    if(cargo.drain && !cargo.drained) cargo.drain();
+                    cargo.drained = true;
                     return;
                 }