Merge pull request #21 from dtex/issue-19

Allow tasks to be enqueued out of order

.travis.yml

@@ -1,9 +1,9 @@
 language: node_js
 sudo: false
 node_js:
-  - 4
   - 6
   - 8
+  - 10
 before_script:
   - npm install -g grunt-cli
 compiler: clang

lib/temporal.js

@@ -11,6 +11,9 @@ var exportable = new Emitter();
 // Object containing callback queues, keys are time in MS
 var queue = {};
 
+// Store the last event time
+var gLast = Date.now();
+
 // Actively processing queue
 var isProcessing = false;
 
@@ -50,6 +53,10 @@ function Task(entry) {
   this.type = entry.type;
   this.time = entry.time;
 
+  if (this.later > gLast) {
+    gLast = this.later;
+  }
+
   if (!queue[this.later]) {
     queue[this.later] = [];
   }
@@ -157,15 +164,13 @@ function processQueue() {
     exportable.emit("busy");
   }
 
-  var scheduled = Object.keys(queue);
-  var last = scheduled.length && +scheduled[scheduled.length - 1];
   var now = getTime();
   var entries = [];
   var callProcessQueue = true;
   var entry, i;
 
   // Nothing scheduled, don't call processQueue again
-  if (last <= now) {
+  if (gLast <= now) {
     callProcessQueue = false;
   }
 
@@ -199,6 +204,12 @@ function processQueue() {
         // Calculate the next execution time
         entry.later = now + entry.time;
 
+        // With sub-millisecond wait times, it's conceivable that the clock
+        // may have passed our next task time so make sure it runs
+        if (entry.later > gLast) {
+          gLast = entry.later;
+        }
+
         // Create a queue entry if none exists
         if (!queue[entry.later]) {
           queue[entry.later] = [];