Reload TrackerList when hosts are automatically updated

[Copilot]

When tracker hosts are automatically updated via HostsDownloadWorker, the ServiceSinkhole.mapHostsBlocked map is reloaded but the TrackerList singleton's internal data structures (hostnameToTracker and trackingIps) remain stale. This causes incorrect tracker identification after automatic updates.

Changes

TrackerList.java

• Added reloadTrackerData() static method to clear and reload tracker data atomically
• Changed trackingIps from HashSet to ConcurrentHashMap.newKeySet() for thread safety
• Added reloadLock to synchronize clear-and-reload operations

ServiceSinkhole.java

• Call TrackerList.reloadTrackerData() in prepareHostsBlocked() after reloading hosts

ActivitySettings.java

• Use reloadTrackerData() instead of loadTrackers() when domain_based_blocked changes to properly clear old data

Example

When hosts are updated:

// Before: TrackerList singleton retains stale data
prepareHostsBlocked(c);  // Only reloads mapHostsBlocked

// After: TrackerList reloads in sync
prepareHostsBlocked(c);  // Reloads both mapHostsBlocked and TrackerList

Thread safety is maintained through synchronized reload and concurrent collections.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• dl.google.com
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.lang.invoke=ALL-UNNAMED --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.prefs/java.util.prefs=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.prefs/java.util.prefs=ALL-UNNAMED --add-opens=java.base/java.nio.charset=ALL-UNNAMED --add-opens=java.base/java.net=ALL-UNNAMED --add-opens=java.base/java.util.concurrent.atomic=ALL-UNNAMED --add-opens=java.xml/javax.xml.namespace=ALL-UNNAMED -Xmx4608m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -cp /home/REDACTED/.gradle/wrapper/dists/gradle-8.13-bin/5xuhj0ry160q40clulazy9h7d/gradle-8.13/lib/gradle-daemon-main-8.13.jar (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

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This section details on the original issue you should resolve

<issue_title>Updating tracker hosts automatically</issue_title>
<issue_description>The latest updates update some of the tracker hosts automatically. Does the TrackerList actually reload properly after this, since this is used for checking traffic in ServiceSinkhole?</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Updating tracker hosts automatically #501

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