c# - send SignalR client message from background thread -

i'm trying track progress of hangfire background jobs guided article http://docs.hangfire.io/en/latest/background-processing/tracking-progress.html

unfortunately example given in article not working. downloaded , run sample web application (https://github.com/hangfireio/hangfire.highlighter) locally. it's ok when client subscribes after job complete. in case message sent directly hub , has been received client. otherwise message call invoked hangfire job , nothing happens. no exceptions, no result. causing behavior? in case: hangfire jobs not work asynchronously...

code sample:

hangfire job (see highlight method)

using system; using system.collections.generic; using system.net.http; using system.threading.tasks; using hangfire.highlighter.hubs; using hangfire.highlighter.models; using microsoft.aspnet.signalr;  namespace hangfire.highlighter.jobs {     public class snippethighlighter : idisposable     {         private readonly ihubcontext _hubcontext;         private readonly highlighterdbcontext _dbcontext;          public snippethighlighter()             : this(globalhost.connectionmanager.gethubcontext<snippethub>(), new highlighterdbcontext())         {         }          internal snippethighlighter(ihubcontext hubcontext, highlighterdbcontext dbcontext)         {             if (hubcontext == null) throw new argumentnullexception("hubcontext");             if (dbcontext == null) throw new argumentnullexception("dbcontext");              _hubcontext = hubcontext;             _dbcontext = dbcontext;         }          public void highlight(int snippetid)         {             var snippet = _dbcontext.codesnippets.find(snippetid);             if (snippet == null) return;              snippet.highlightedcode = highlightsource(snippet.sourcecode);             snippet.highlightedat = datetime.utcnow;              _dbcontext.savechanges();              _hubcontext.clients.group(snippethub.getgroup(snippet.id))                 .highlight(snippet.highlightedcode);         }          public void dispose()         {             _dbcontext.dispose();         }          private static async task<string> highlightsourceasync(string source)         {             using (var client = new httpclient())             {                 var response = await client.postasync(                     @"http://hilite.me/api",                     new formurlencodedcontent(new dictionary<string, string>                 {                     { "lexer", "c#" },                     { "style", "vs" },                     { "code", source }                 }));                  response.ensuresuccessstatuscode();                  return await response.content.readasstringasync();             }         }          private static string highlightsource(string source)         {             // microsoft.net.http not provide synchronous api,             // using wrapper perform sync call.             return runsync(() => highlightsourceasync(source));         }          private static tresult runsync<tresult>(func<task<tresult>> func)         {             return task.run<task<tresult>>(func).unwrap().getawaiter().getresult();         }     } } 

hub

using system.data.entity; using system.linq; using system.threading.tasks; using hangfire.highlighter.models; using microsoft.aspnet.signalr;  namespace hangfire.highlighter.hubs {     public class snippethub : hub     {         public async task subscribe(int snippetid)         {             await groups.add(context.connectionid, getgroup(snippetid));              // when user subscribes snippet              // highlighted, need send immediately, because             // otherwise listen infinitely.             using (var db = new highlighterdbcontext())             {                 var snippet = await db.codesnippets                     .where(x => x.id == snippetid && x.highlightedcode != null)                     .singleordefaultasync();                  if (snippet != null)                 {                     clients.client(context.connectionid)                         .highlight(snippet.id, snippet.highlightedcode);                 }             }         }          public static string getgroup(int snippetid)         {             return "snippet:" + snippetid;         }     } } 

singnalr configured using owin startup class.