I'm trying to talk to a USB device using libusb, but I feel like I'm tripping up on the first leg of the race. I know precisely what endpoints I need to talk to, etc., but I can't even get that far. I have, in essence:
usb_device *dev = ...; // opened from get_busses()
usb_set_configuration(dev, dev->config[0].bConfigurationValue); // bConfigVal = 1
Now, I can look at the device information in debug mode and I know that the current configuration is 0 (uninitialized / just after restart), and there's exactly 1 valid configuration, which has a configuration number of 1. But when I set the config to 1, I get a return value of -22, which (passed through the stringifier) translates to "windows api error: bad parameter.
I haven't been able to find other people having a similar problem, and it seems like such a simple thing to do -- I can't even claim the interface, or set the alt-interface, or anything like that, because I have to set the configuration first. What am I missing? (if it matters: this is on WinXP)
Looking at libusb-win32\src\driver\set_configuration.c, there seem to be a bunch of different reasons for returning STATUS_INVALID_PARAMETER.
Use libusb_set_debug (from your user mode application) to set verbose debug level, then run Sysinternals DebugView to see the driver's error messages. Hopefully you'd see a clue as to why your set_configuration call fails.
Related
Looking at the MDN documentation IOS/Safari fully supports ServiceWorkerGlobalScope.onfetch but when you look at the FetchEvent specification it says it is not supported at all by Safari.
In particular, I would like to store some state for each client and was hoping to use the fetchEvent.clientId property of the event to index it. Of course I presume I also have access to the fetchEvent.request object otherwise I can't see how a service worker can do anything useful and I could simulate clientID from a passed in parameter in the url. But the docs don't really tell me what IOS/Safari supports and doesn't so I don't know which way to go.
Can someone please tell me precisely what does IOS/Safari pass when it calls the defined onfetch function.
I found the answer to my question by using https://jakearchibald.github.io/isserviceworkerready/demos/fetchevent/
connecting my iPad to my Macbook and debugging my iPad. I was eventually able to open the web inspector for the Service worker for that page, and the console.log showed the event passed in.
FetchEvent.clientID is present but a zero length string. As it happens I did the same thing on my (linux) Desktop using Chrome and its also a zero length string, BUT it has another parameter resultingClientId with what looks like a UUID in it. That parameter is not there in Safari.
The FetchEvent.request is there, and in particular the URL. So I can generate my own client id in the client (I am using Date.now().toString() as that is good enough for my purposes) for use in the service worker. In fact my site without a service worker was using the in the URLs I need to intercept already, so I am happy that I have a solution.
Is it possible to write a plugin for Glimpse's existing SQL tab?
I'm trying to log my SQL queries and the currently available extensions don't support our in-house SQL libary. I have written a custom plugin which logs what I want, but it has limited functionality and it doesn't integrate with the existing SQL tab.
Currently, I'm logging to my custom plugin using a single helper method inside my DAL's base class. This function looks takes the SqlCommand and Duration in order to show data on my custom tab:
// simplified example:
Stopwatch sw = Stopwatch.StartNew();
sqlCommand.Connection = sqlConnection;
sqlConnection.Open();
object result = sqlCommand.ExecuteScalar();
sqlConnection.Close();
sw.Stop();
long duration = sw.ElapsedMilliseconds;
LogSqlActivity(sqlCommand, null, duration);
This works well on my 'custom' tab but unfortunately means I don't get metrics shown on Glimpse's HUD:
Is there a way I can provide Glimpse directly with the info it needs (in terms of method names, and parameters) so it displays natively on the SQL tab?
The following advise is based on the fact that you can't use DbProviderFactory and you can't use a proxied SqlCommand, etc.
The data that appears in the "out-of-the-box" SQL tab is based on messages of given types been published through our internal Message Broker (see below on information on this). Because of the above limitations in your case, to get things lighting up correctly (i.e. your data showing up in HUD and the SQL tab), you will need to simulate the work that we do under the covers when we publish these messages. This shouldn't be that difficult and once done, should just work moving forward.
If you have a look at the various proxies we have here you will be above to see what messages we publish in what circumstances. Here are some highlights:
DbCommand
Log command start - here
Log command error - here
Log command end - here
DbConnection:
Log connection open - here
Log connection closed - here
DbTransaction
Log Started - here
Log committed - here
Log rollback - here
Other
Command row count here - Glimpses calculates this at the DbDataReader level but you could do it elsewhere as well
Now that you have an idea of what messages we are expecting and how we generate them, as long as you pass in the right data when you publish those messages, everything should just light up - if you are interested here is the code that looks for the messages that you will be publishing.
Message Broker: If you at the GlimpseConfiguration here you will see how to access the Broker. This can be done statically if needed (as we do here). From here you can publish the messages you need.
Helpers: For generating some of the above messages, you can use the helpers inside the Support class here. I would have shifted all the code for publishing the actual messages to this class, but I didn't think there would be too many people doing what you are doing.
Update 1
Starting point: With the above approach you shouldn't need to write your own plugin. You should just be able to access the broker GlimpseConfiguration.GetConfiguredMessageBroker() (make sure you check if its null, which it is if Glimpse is turned off, etc) and publish your messages.
I would imagine that you would put the inspection that leverages the broker and published the messages, where ever you have knowledge of the information that needs to be collected (i.e. inside your custom lib). Normally this would require references inside your lib to glimpse (which you may not want), so to protect against this, from your lib, you would call a proxy (which could be another VS proj) that has the glimpse dependency. Hence your ado lib only has references to your own code.
To get your toes wet, try just publishing a couple of fake connection and command messages. Assuming the broker you get from GlimpseConfiguration.GetConfiguredMessageBroker() isn't null, these should just show up. Then you can work towards getting real data into it from your lib.
Update 2
Obsolete Broker Access
Its marked as obsolete because its going to change in v2. You will still be able to do what you need to do, but the way of accessing the broker has changed. For what you currently need to do this is ok.
Sometimes null
As you have found this is really dependent on where in the page lifecycle you are currently at. To get around this, I would probably change my original recommendation a little.
In the code where you are currently creating messages and pushing them to the message bus, try putting them into HttpContext.Current.Items. If you haven't used it before, this is a store which asp.net provides out of the box which lasts the lifetime of a given request. You could have a list that you put in there, still create the message objects that you are doing, but put them into that list instead of pushing them through the broker.
Then, create a HttpModule (its really simple to do) which taps into the PostLogRequest event. Within this handler, you would pull the list out of the context, iterate through it and push the message into the message broker (accessing the same way you have been).
I'm creating an application that uses NSNetService to publish a server, and I've come across the NSNetServiceListenForConnections option that can be used in OS X 10.9 with the publishWithOptions: method. This new options is highlighted in the "What's New in OS X 10.9" page provided by Apple. It states If you send the NSNetServiceListenForConnections option flag in the options value passed to publishWithOptions:, OS X automatically handles all of the connection management for you, however, I don't see how this a new behavior? I currently just call the publish method and wait for the ServerAcceptCallBack, which is set by the CFSocketCreate method. I doesn't seem to make this any easier?
I'm following some of Apple's code from the CocoaEcho example, which gets a port and opens a CFSocket. I know you can pass 0 as the port parameter for the initWithDomain: name: port: method, but that chooses a "random" port, and I'm guessing that that's not a 100% safe thing to do. I thought that NSNetServiceListenForConnections might have something to do with that, but going by the description, it doesn't.
So to my actual question, after all the rambling:
What does the NSNetServiceListenForConnections option actually do, and (why) should I use it?
Side question: If I should use it, how do I check for availability? I've been told to use if (&NSNetServiceListenForConnections != NULL), but NSNetServiceListenForConnections is an NSUInteger so I can't get the address (via &)
With this option, you don't have to open or manage the sockets at all (i.e. no calling CFSocketCreate). It creates the socket for you. Although I'm finding in 10.9.2 it isn't closing the socket properly if you call stop on the netService, but I'm still investigating. (It did seem to be closing them in 10.9.0 and 10.9.1). The socket seems to stay open until you quit the app.
In my winrt app, I am trying to update the live tile based on polled URIs. There is currently no update happening and I can't figure out how to troubleshoot. There are numerous scenarios that could be breaking things but i can't seem to find anyway to get insight into potential errors.
The TileUpdateManager seems to be a bit of a black hole that absorbs information but never lets it out.
Does anyone know of how to view errors from the TileUpdateManager?
If it interests anyone, here is my update code:
TileUpdateManager.CreateTileUpdaterForApplication().EnableNotificationQueue(true);
PeriodicUpdateRecurrence recurrence = PeriodicUpdateRecurrence.HalfHour;
List<Uri> urisToPoll = new List<Uri>();
urisToPoll.Add(new Uri(#"http://livetileservice2012.azurewebsites.net/api/liveupdate/1"));
urisToPoll.Add(new Uri(#"http://livetileservice2012.azurewebsites.net/api/liveupdate/2"));
TileUpdateManager.CreateTileUpdaterForApplication().StartPeriodicUpdateBatch(urisToPoll, recurrence);
To expand on Nathan's comment, here are two steps you can take to troubleshoot:
Enter your URI straight into a browser to see the results that are returned, and inspect them for being proper XML. As Nathan points out, your URIs are returning JSON which will be ignored by the tile update manager. As a working example (that I use in Chapter 13 of my HTML/JS book), try http://programmingwin8-js-ch13-hellotiles.azurewebsites.net/Default.cshtml.
If you feel that your URI is returning proper XML, try it in the Push and Periodic Notifications Sample (Scenarios 4 and 5 for tiles and badges). If this works, then the error would be in your app code and not in the service.
Do note that StartPeriodicUpdate[Batch] will send a request to the service right away, rather than waiting for the first interval to pass.
Also, if you think that you might have a problem with the service, it's possible to step through its code using Visual Studio Express for Web running on the localhost, when the app is also running inside Visual Studio Express for Win8 (where localhost is enabled).
.Kraig
I thought this would be dead simple however....
Right, so all I'm simply trying to do is read a value from my registry. I have been through several examples but can't get any of them to work. I've also tried running my application in Admin mode and still nothing. Can someone please help?
From all my examples that I've tried, I'll use the simplest one.
This works:
Dim val As String
val = Registry.LocalMachine.OpenSubKey("Hardware\Description\System\CentralProcessor\0").GetValue("Identifier").ToString()
MsgBox(val)
This (the one I want) doesn't:
Dim val As String
val = Registry.LocalMachine.OpenSubKey("SOFTWARE\PTSClient").GetValue("ConfigDB").ToString()
MsgBox(val)
THe latter path and value is one that I've manually created in the registry. I've checked the permissions between the two and they are the exact same. I've also tried running the app as administrator. I get a runtime error on the val= line, it says: Use the "new" keyword to create an object instance.
Any ideas? All the various online examples have failed and for the life of me, I can't figure out why...
Cheers,
J
Well, I have tried your code with a sample application compiled for x86 and, as expected, it fails with a null value exception.
I assume you are building an application for x86 mode and running in a 64bit environment.
Of course, if this is not the case, let me know and I will delete this answer.
In the situation outlined above, the calls to read/write in the LocalMachine.Software registry path will be automatically changed by the Operating System to read/write in the Software\Wow6432Node subkey and thus, your code is unable to find your manually inserted key ("SOFTWARE\PTSClient").
This code will give a null value as return from Registry.LocalMachine.OpenSubKey("SOFTWARE\PTSClient") leading to the failure to get the ConfigDB value.
You need to add your keys/values to the Software\Wow6432Node path or compile your application for AnyCPU mode or let your code write the value to the register (it will be redirected to the Wow6432Node).