private SubServicesBundle doGetSubServiceBundle(String routerID) {
/* Ensure we have a PathServiceBundle, even an empty one, to synchronize on. */
SubServicesBundle ssb = null;
synchronized (subServices) {
ssb = subServices.get(routerID);
if (ssb == null) {
ssb = new SubServicesBundle();
ssb.pathService = null;
ssb.timestampLoaded = System.currentTimeMillis();
ssb.reloadInProgress = false;
subServices.put(routerID, ssb);
}
}
/*
* Synchronize access to the bundle only, to prevent blocking requests to other graphs.
* Check for first-time loading, no background reload is possible since no older version is
* available.
*/
synchronized (ssb) {
if (ssb.pathService == null) {
SubServicesBundle newSsb = loadSubServices(routerID);
ssb.pathService = newSsb.pathService;
ssb.patchService = newSsb.patchService;
ssb.context = newSsb.context;
ssb.timestampLoaded = System.currentTimeMillis();
return ssb;
}
}
/* Here background reload becomes possible. */
boolean reload = false;
synchronized (ssb) {
if (checkReload(routerID, ssb.timestampLoaded) && !ssb.reloadInProgress) {
if (!asyncReload) {
LOG.info("Reloading modified graph '" + routerID + "'");
// Sync reload: remove old version before loading new one, in synchronized
// block.
ssb.pathService = null;
ssb.patchService = null;
ssb.context.close();
ssb.context = null;
SubServicesBundle newSsb = loadSubServices(routerID);
ssb.pathService = newSsb.pathService;
ssb.patchService = newSsb.patchService;
ssb.context = newSsb.context;
ssb.timestampLoaded = System.currentTimeMillis();
} else {
reload = true;
ssb.reloadInProgress = true;
}
}
}
if (reload) {
// Async reload: load new version but keep old one while not ready for other
// requests.
SubServicesBundle newSsb = loadSubServices(routerID);
synchronized (ssb) {
LOG.info("Async reloading modified graph '" + routerID + "'");
ssb.pathService = newSsb.pathService;
ssb.patchService = newSsb.patchService;
ssb.context.close();
ssb.context = newSsb.context;
ssb.reloadInProgress = false;
ssb.timestampLoaded = System.currentTimeMillis();
}
}
return ssb;
}
