From 40af3285f4d4e31e798a0e63943348dccad746e3 Mon Sep 17 00:00:00 2001
From: Andreas Fankhauser <23085769+hiddenalpha@users.noreply.github.com>
Date: Tue, 7 May 2024 12:36:22 +0200
Subject: [PATCH] [SDCISA-15833, #170] Reduce risk of 'onDone()' from being
 called too many times.

---
 .../redisques/scheduling/PeriodicSkipScheduler.java       | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/main/java/org/swisspush/redisques/scheduling/PeriodicSkipScheduler.java b/src/main/java/org/swisspush/redisques/scheduling/PeriodicSkipScheduler.java
index 03f2a7d..3bcc27b 100644
--- a/src/main/java/org/swisspush/redisques/scheduling/PeriodicSkipScheduler.java
+++ b/src/main/java/org/swisspush/redisques/scheduling/PeriodicSkipScheduler.java
@@ -4,6 +4,7 @@
 import io.vertx.core.Vertx;
 import org.slf4j.Logger;
 
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Consumer;
 
 import static java.lang.System.currentTimeMillis;
@@ -47,10 +48,16 @@ private void onTrigger(Timer timer) {
             return;
         }
         timer.begEpochMs = currentTimeMillis();
+        boolean oldValue = timer.isPending.getAndSet(true);
+        assert !oldValue : "Why is this already pending?";
         timer.task.accept(timer::onTaskDone_);
     }
 
     private void onTaskDone(Timer timer) {
+        boolean oldVal = timer.isPending.getAndSet(false);
+        if (!oldVal) {
+            throw new IllegalStateException("MUST NOT be called multiple times!");
+        }
         timer.endEpochMs = currentTimeMillis();
     }
 
@@ -64,6 +71,7 @@ public class Timer {
         private long id;
         // When the last run has begun and end.
         private long begEpochMs, endEpochMs;
+        private final AtomicBoolean isPending = new AtomicBoolean();
 
         private Timer(Consumer<Runnable> task) {
             this.task = task;