private FileSystemWatcher EnsureWatcher(string channelName)
{
FileSystemWatcher watcher;
if (watcherList.TryGetValue(channelName, out watcher))
{
return(watcher);
}
lock (lockObj)
{
if (watcherList.TryGetValue(channelName, out watcher))
{
return(watcher);
}
var folder = XDIOStreamBroadcaster.GetChannelDirectory(channelName);
watcher = new FileSystemWatcher(folder, "*.msg")
{
NotifyFilter = NotifyFilters.CreationTime | NotifyFilters.LastWrite
};
watcher.Changed += OnMessageReceived;
watcherList.Add(channelName, watcher);
}
return(watcher);
}
/// <summary>
/// Provides a thread safe method to lookup/create a instance of FileSystemWatcher for a particular channel.
/// </summary>
/// <param name = "channelName"></param>
/// <returns></returns>
private FileSystemWatcher EnsureWatcher(string channelName)
{
FileSystemWatcher watcher;
// try to get a reference to the watcher used for the current watcher
if (!watcherList.TryGetValue(channelName, out watcher))
{
// if no watcher then lock the list
lock (lockObj)
{
// whilst locked double check if the item has been added since the lock was applied
if (!watcherList.TryGetValue(channelName, out watcher))
{
// create a new watcher for the given channel, by default this is not enabled.
string folder = XDIOStreamBroadcaster.GetChannelDirectory(channelName);
watcher = new FileSystemWatcher(folder, "*.msg")
{
NotifyFilter = NotifyFilters.CreationTime | NotifyFilters.LastWrite
};
watcher.Changed += OnMessageReceived;
watcherList.Add(channelName, watcher);
}
}
}
return(watcher);
}