I call a DLL written in C++ (VS2012) from a software (LabView) and what it does is uploading a file on a server via FTP.
While the DLL is uploading the file (15MB) it does not let LabView continue with other tasks.
How could this problem be solved?
Regardless of what you have to do on the C++ side to make the call threadsafe, you will need to configure the call in LabVIEW not to run in the UI thread (which I believe is the default configuration, for safety reasons). Double click the node and select the run in any thread option.
Also, if you want to ensure running it in its own thread, you can put it in a separate VI and change the execution settings of that VI to run in a different execution system. LabVIEW doesn't give you direct control of threads, because it manages them on its own, but this should make the VI execute in a different thread.
Operations with FTP are long-term.
It is better to perform such operations in another thread.
Related
I have a C++ windows service running on system privileges and I need to make some changes in some of my DLLs that are loaded to several windows processes (explorer.exe, etc.).
The only time to do so is when these processes are down. I'm trying to make to impact to the UX minimal, so I don't wan't to force quit those or to popup any annoying message boxes and ask the user to do so.
I have tried to start this task on the startup of my service, the issue is several of these processes start before I finished it.
I'm trying to understand if there is a way to delay the start of processes on Windows startup, until I finish my task. Is there any event or anything familiar that I can set that will block those?
The other option is to do the needed task on shutdown. I did not find a way to do so yet, and all the related questions seem a bit old (how to delay shutdown and run a process in window service
), and regard to older version of windows.
This solution needs to be compatible with Windows versions greater than 7.
You can do this by using MoveFileEx and setting MOVEFILE_DELAY_UNTIL_REBOOT which will replace the file at the next reboot.
This should be well before any other processes have started, but without more details on your usecase its hard to tell if this'll work for you. Either way, searching for this flag should give you lots of information about this kind of issue.
According to the documentation, this has been supported since XP.
I want to make an application run slower, it that possible? I have created application which read file created by another process but that process create file and delete it so fast, so it is possible to make that application be slow so I can read file faster?
I tried
SetPriorityClass(GetProcessHandleByName("dd.exe"), IDLE_PRIORITY_CLASS);
and set my process to
SetPriorityClass(GetCurrentProcess(), REALTIME_PRIORITY_CLASS);
but yet the process run faster it is possible to slow it down? thanks.
Modifying the working directory permissions to allow processes to read/write data to new files, but not modify/delete existing files might be a different approach that would work.
See https://superuser.com/questions/745923/ntfs-permissions-create-files-and-folder-but-prevent-deletion-and-modification
See the answer SO : Suspend/Resume a process. Which gives information on the three choices for suspending an application.
They are basically stop each thread. Use the undocumented SuspendProcess and Debug the process.
These are the methods of substantially delaying the process.
I'm facing an issue with TerminateProcess() function.
The application I'm currently writing a JobScheduler app that schedules and launches job at a specific time.
For this purpose, I'm using CreateProcess() to execute my JobLauncher.
The JobLauncher process then launches a console program (using createprocess ) which effectively executes the job executable, waits for its termination and monitors the duration, user and kernel times elapsed etc.
In order to kill the job from the JobScheduler I firstly started using TerminateProcess() but it does not allow me to close the executable itself properly. I mean i found no way to hook any termination event.
Until I find a better way than a brutal TerminateProcess(), I wrote an intermediate solution using the GenerateConsoleCtrlEvent() in the calling program.
In the job application that launches the target job executable, I installed a handler using SetConsoleCtrlHandler().
And in the handler, I can terminate the process of the job and notifies my thirdparties properly.
This is the better solution I found for now.
Is there a better way to programmaticaly and properly close a process ?
Do you this solution is completly absurd ?
I'm not a "system-level" specialist developer though...
Z.
This well know Windows console problem and you can find some solutions here.
We used on internal console utility which has name "Kamikaze". It worked as described here and for me it's a best solution cause there is no problem with porting between Windows versions and Windows architectures (x86, x64).
In my app I have a plugin system that allow users to develop plugins (in C/C++ dylib) and execute them at runtime (using dlopen/dlsym).
Basically I have a main thread (which is drawing my GUI) and another thread (which is the plugin thread) that is loading/running the plugin.
What I would like to do is to allow the user to debug is plugin in Xcode and keep the main thread running.
I already know that in XCode you can create a dylib project and set in Info > Launch > Wait for ??? to launch (which work great), but the problem Im having with that is:
If the user stop the dylib debugging it close the main application launched (my app, which I don't want as I want to keep it running).
It stall the main application thread completely (the GUI stop refreshing until the user continue).
Is there any way to still allow the users to use XCode to develop/debug their plugins avoiding the 2 problems above?
Or I'll have to integrate a text editor and somehow interface clang++/lldb directly inside my app to let the users develop/debug (which sounds to me like alot of work, especially since XCode already have all the functionalities)?
TIA!
lldb has the ability to run all threads when you step or next, but when you interrupt the program (press Pause), all threads will be stopped. lldb doesn't currently have any UI to do what you want -- there's no technical limitation but I don't think I've seen a use case that called for this behavior. There was an obscure command added to gdb, thread dont-suspend-while-stepping which would designate a specific thread and tell gdb to allow that thread to run whenever the debugger was step/nexting, but even in that case when you interrupted the program all threads would be stopped..
I'm trying to find an easy way to execute a java vm in windows using a C++ wrapper. I can use CreateProcess() to launch java.exe directly with all of my parameters that I need to give it. The problem is this now shows up as two processes in process manager. So, if I kill the parent process, the java.exe instance still sticks around.
The reason I need to do this is that we have a few java programs, all of which will be running concurrently. I want to be able to give them distinguishable names in the process explorer, so that if a user has trouble with one of them, they don't have to guess which java.exe process that corresponds to.
You can replace java.exe with your own executable. This article from the Java Glossary discusses how java.exe works and where to find the source for it. It's possible that you could get by simply by copying and then renaming java.exe