Concurrency problems with multiple starts of the plugin system causes JIRA not to start when 'atlassian.plugins.enable.wait' system property specified.

During system startup the DefaultPluginTransformer clears the plugin cache if the system property 'atlassian.plugins.enable.wait' is specified or changed. This occurs midway through the startup and after a number of plugins have already been started.

Why a change of timeout necessitates a plugin cache clear is a mystery, but in JIRA this timing is wrong and can cause

"Caused by: java.io.IOException: Unable to delete file: E:\data\jira\plugins\.osgi-plugins\felix\felix-cache\bundle9\version0.0\bundle.jar"

which causes

"com.atlassian.plugin.osgi.container.OsgiContainerException: Unable to clear OSGi caches
at com.atlassian.plugin.osgi.container.impl.DefaultOsgiPersistentCache.clear(DefaultOsgiPersistentCache.java:75)"

Which causes the spring.timeout never to be written to .properties and so not be set.