From a24a8d1d818176e9e17e14d9c1aa76ded84b9246 Mon Sep 17 00:00:00 2001
From: waschndolos <killear@gmx.de>
Date: Thu, 28 Mar 2024 18:43:17 +0100
Subject: [PATCH] Revert "Fix initilization potential deadlock (#637)"

This reverts commit d79999a08e65d4d972cbf8935c544bec8871ecce.
---
 .../service/DefaultPrometheusMetrics.java     | 59 ++++++-------------
 1 file changed, 19 insertions(+), 40 deletions(-)

diff --git a/src/main/java/org/jenkinsci/plugins/prometheus/service/DefaultPrometheusMetrics.java b/src/main/java/org/jenkinsci/plugins/prometheus/service/DefaultPrometheusMetrics.java
index 71210e13a..9024c9c3d 100644
--- a/src/main/java/org/jenkinsci/plugins/prometheus/service/DefaultPrometheusMetrics.java
+++ b/src/main/java/org/jenkinsci/plugins/prometheus/service/DefaultPrometheusMetrics.java
@@ -1,62 +1,45 @@
 package org.jenkinsci.plugins.prometheus.service;
 
 import hudson.ExtensionList;
-import hudson.init.InitMilestone;
-import hudson.init.Initializer;
 import io.prometheus.client.Collector;
 import io.prometheus.client.CollectorRegistry;
 import io.prometheus.client.dropwizard.DropwizardExports;
 import io.prometheus.client.exporter.common.TextFormat;
 import io.prometheus.client.hotspot.DefaultExports;
-import java.io.IOException;
-import java.io.StringWriter;
-import java.util.concurrent.atomic.AtomicReference;
 import jenkins.metrics.api.Metrics;
-import org.jenkinsci.plugins.prometheus.CodeCoverageCollector;
-import org.jenkinsci.plugins.prometheus.DiskUsageCollector;
-import org.jenkinsci.plugins.prometheus.ExecutorCollector;
-import org.jenkinsci.plugins.prometheus.JenkinsStatusCollector;
-import org.jenkinsci.plugins.prometheus.JobCollector;
+import org.jenkinsci.plugins.prometheus.*;
 import org.jenkinsci.plugins.prometheus.config.disabledmetrics.FilteredMetricEnumeration;
 import org.jenkinsci.plugins.prometheus.util.JenkinsNodeBuildsSampleBuilder;
-import org.kohsuke.accmod.Restricted;
-import org.kohsuke.accmod.restrictions.NoExternalUse;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-@Restricted(NoExternalUse.class)
+import java.io.IOException;
+import java.io.StringWriter;
+import java.util.concurrent.atomic.AtomicReference;
+
 public class DefaultPrometheusMetrics implements PrometheusMetrics {
 
     private static final Logger logger = LoggerFactory.getLogger(DefaultPrometheusMetrics.class);
 
-    private volatile boolean initialized = false;
-    private volatile boolean initializing = false;
     private final CollectorRegistry collectorRegistry;
     private final AtomicReference<String> cachedMetrics;
 
     public DefaultPrometheusMetrics() {
-        this.collectorRegistry = CollectorRegistry.defaultRegistry;
-        this.cachedMetrics = new AtomicReference<>("");
-    }
+        CollectorRegistry collectorRegistry = CollectorRegistry.defaultRegistry;
+        collectorRegistry.register(new JobCollector());
+        collectorRegistry.register(new JenkinsStatusCollector());
+        collectorRegistry.register(new DropwizardExports(Metrics.metricRegistry(), new JenkinsNodeBuildsSampleBuilder()));
+        collectorRegistry.register(new DiskUsageCollector());
+        collectorRegistry.register(new ExecutorCollector());
+        collectorRegistry.register(new CodeCoverageCollector());
 
-    @Initializer(after = InitMilestone.JOB_LOADED)
-    public void init() {
-        if (!initialized && !initializing) {
-            initializing = true;
-            logger.debug("Initializing...");
-            collectorRegistry.register(new JobCollector());
-            collectorRegistry.register(new JenkinsStatusCollector());
-            collectorRegistry.register(
-                    new DropwizardExports(Metrics.metricRegistry(), new JenkinsNodeBuildsSampleBuilder()));
-            collectorRegistry.register(new DiskUsageCollector());
-            collectorRegistry.register(new ExecutorCollector());
-            collectorRegistry.register(new CodeCoverageCollector());
-            // other collectors from other plugins
-            ExtensionList.lookup(Collector.class).forEach(collectorRegistry::register);
-            DefaultExports.initialize();
-            initialized = true;
-            initializing = false;
-        }
+        // other collectors from other plugins
+        ExtensionList.lookup(Collector.class).forEach(collectorRegistry::register);
+
+        DefaultExports.initialize();
+
+        this.collectorRegistry = collectorRegistry;
+        this.cachedMetrics = new AtomicReference<>("");
     }
 
     @Override
@@ -66,10 +49,6 @@ public String getMetrics() {
 
     @Override
     public void collectMetrics() {
-        if(!initialized) {
-            logger.debug("Not initialized");
-            return;
-        }
         try (StringWriter buffer = new StringWriter()) {
             TextFormat.write004(buffer, new FilteredMetricEnumeration(collectorRegistry.metricFamilySamples().asIterator()));
             cachedMetrics.set(buffer.toString());