if (jvmArgs.size > 1) {
            throw GradleException("gradle.properties and build-logic/gradle.properties have different org.gradle.jvmargs " +
                "which may cause two daemons to be spawned on CI and in IDEA. " +
                "Use the same org.gradle.jvmargs for both builds.")
        }
    }
}

fun readProperties(propertiesFile: File) = java.util.Properties().apply {

      if: ${{ matrix.language == 'java' && github.repository_owner != 'gradle' }}
      run: ./gradlew --init-script .github/workflows/codeql-analysis.init.gradle -S testClasses

    - name: Cleanup Gradle Daemons
      run: ./gradlew --stop
      if: ${{ matrix.language == 'java' }}

    # ℹ️ Command-line programs to run using the OS shell.
    # 📚 https://git.io/JvXDl

    private
    val daemonPids = ConcurrentHashMap.newKeySet<String>()

    private
    val logger = Logging.getLogger(DaemonTracker::class.java)

    override fun close() {
        logger.lifecycle("Cleaning up daemons...")
        cleanUpDaemons()
    }

    fun newDaemonListener() =
        object : TestListener {
            override fun beforeTest(test: TestDescriptor) = Unit

that can send requests to a Gradle daemon.
Each daemon runs one request at a time. Generally speaking, the daemons only act in response to a request from a client and do not take any action on their own.
There are some background actions that the daemon takes, for example monitoring system memory, watching for file changes or cleaning up caches.