I have a class which I wrote and one of its object is "SerialPort" .NET class. In my MainWindow I created instance of my class called "SerialPortComm", then I send through some functions of mine, commands to the Serial Port, and I receive answers through "DataReceived" event.
But when I trying to use Dispatcher.BeginInvoke to write my data I have received (successfully), nothing shows on the RichTextBox which I'm trying to write to.
What can caused that, and How I can make it works?
SerialPortComm.cs
public partial class SerialPortComm : UserControl { public SerialPort mySerialPort = new SerialPort(); public void Open_Port(string comNumber, int baudRate) { mySerialPort.PortName = comNumber; mySerialPort.BaudRate = baudRate;
I have a SDI application. I created a method OnClose to handle ON_WM_CLOSE of CMainFrm. This onclose() function calls a method in cmyview.cpp. Here, I created a thread that calls global function and from this function it calls another function in cmyview.cpp. At certain condition my application should close at here, I used postmessgae(WM_CLOSE (or) WM_DESTROY). I am having an error as object reference not set on postmessage(WM_CLOSE) it is going to afxwin2.inl page where exception occurs.
Below is code snippetHere, either j or k will only be true depneds on user input)
I need using CSemaphore class in MFC C++ application. I have an edit1 box with multil ine and each line has a string. I'm trying to loop through edit1 box and for each string to start a thread that is using the string for specific function. I'm trying to limit the run of only one thread at the same time with semaphores but all treads start at the same time.
So when i click button1 i loop through edit1 box and start threads:
Code: void CMFCApplication1Dlg::onButton1Click() { int i, nLineCount = edit1.GetLineCount(); CString strText, strLine, mesaj; for (i = 0; i < nLineCount; i++) {
[Code] ....
While looping through edit1 box multi line and starting the threads:
Code: UINT CMFCApplication1Dlg::StartThread(LPVOID param) { WaitForSingleObject(semafor, INFINITE); // wait for semafor to signal THREADSTRUCT* ts = (THREADSTRUCT*)param; // here i'm doing some operations with the string from edit1 box ReleaseSemaphore(semafor, 1, NULL); //release the semaphore for next thread to begin }
Instead of running only one thread at a time all threads start. What am i doing wrong ?
How can I implement the paradigm demonstrated by the code below to run on WinXP?
I want to fork a process or create a thread that shares global variables with the parent process/thread.
The child process/thread monitors the progress of the parent process/thread.
I cannot find documentation for a fork function per se, a Unix term. It might be called something different for WinXP.
I would be happy to use threads instead. But I'm rusty even with Unix application threads; and I know nothing of WinXP application threads.
So any turnkey implementation that demonstrates the simplest use of process or thread functions for my purpose demonstrated below.
In either case, do "forked" processes and threads share global address space in WinXP, as they do in Unix?
I would prefer to avoid the overhead of IPC mechanisms. The "overhead" includes my own relearning curve.
The GUI screwed up my indentation. I would try to correct it. But the proper indentation appears when I edit the posting. I suppose I need to insert real tabs. Haven't figured out how (yet).
Not even real tabs work; and I cannot get the "paste as text" button to behave as I expect. What is the trick for posting indented text in this GUI?
#include "stdafx.h" #include <stdlib.h> #include <Windows.h> long curCount; int isRunning; int _tmain(int argc, char* argv[]) { curCount = 0; isRunning = 1;
I am having a strange problem trying to display a dialog from a UI thread. The dialog simply fails to display. I have a function DisplayFlashBox(), which creates the UI thread:
CUIThread* CIMUIHelper:: DisplayFlashBox(const CString &sMessage, const int nInstrumentUID) { CUIThread *pThread = new CUIThread(); pThread->SetString(sMessage); pThread->SetInstrumentUID(nInstrumentUID); pThread->CreateThread();
[Code] .....
The dialog doesn't display. When I tried debugging, I found the OnInitDialog() method of CIMFlashBox class doesn't actually return. Very strange. I tried calling the DoModal() method instead of Create, but doesn't display the dialog either.
I have main thread that creates an WebBrowser2 COM object. and i want to invoke JScript functions on it from another thread. i try to use GIT but still doesn't work for me.. there is a problem with marshal WebBrowser2 for JScript?
Can local variable be passed as the parameter for a new created thread procedure? Here is the example code:
Code: void CDLG::some_function() { CString strFileName="abc.doc"; //local variable, can it be valid for being passed into the following new thread??? //Can strFileName still be accessed from within the stack of thread procedure? ::AfxBeginThread(ProcessContentThread,(LPVOID)&strFileName); }
[Code]...
There is another method using variable on the heap,
I test these code, both methods work as expected, but I doubt whether the first method is a good way. OR if only the second method is the correct way to pass a parameter to a thread.
I have a thread with a while(1) loop in it. When the user push the stop button I would like that thread to end.
I thought about creating a bool and checking its value periodically in the thread and when I push the stop button I change the value of the bool for that the thread breaks out of the loop and finishes.
I'm the author of a realtime MIDI software called ChordEase which makes use of the MIDI aspects of the multimedia API, specifically MIDI input callbacks. In XP and before, these callbacks originated in the kernel and therefore had realtime priority by definition, but from Vista on, they originate in thread pool threads, and have a priority of zero. This is a problem because at priority zero they can be blocked by the GUI thread, causing serious latency, and I have proved that such blocking occurs.
I have experimented with raising the callback thread priority, using either of the following methods: 1) calling SetThreadPriority within the MIDI input callback function, and then setting a flag so that it isn't done repeatedly, or 2) creating a DLL that catches thread creation via DLL_ATTACH_THREAD in DllMain, and calling SetThreadPriority there. The first method is slightly wasteful since the flag has to be tested for every MIDI input event, but it also has the advantage of only affecting the MIDI input threads, whereas the second method affects all threads in the pool regardless of what they're used for. Neither method appears to cause any harmful effects but they make me nervous*. Other possible methods would include 3) using the thread pool API to raise the priority of the pool (assuming I could gain access to the pool handle somehow), or 4) permanently lowering the priority of the GUI thread, which I'm very reluctant to do because of the risk of unintended consequences.
I'm assuming the MIDI input callbacks are using threads in the default thread pool though I haven't actually proved this. Assuming that's so, are these threads private to my application, or is my application sharing them with other applications? Is there a safer way to achieve the result of increasing the priority of MIDI input callbacks? It's incredibly frustrating that MS would change the behavior of MIDI input callbacks so drastically without even telling anyone, but that's how it goes!
[URL] ....
*See for example theses warnings about changing thread pool priorities : [URL] ....
error C3867: 'WordParsor::Form1::PutUpfrmIO': function call missing argument list; use '&WordParsor::Form1::PutUpfrmIO' to create a pointer to memberc:userskingc++wordparsorwordparsorForm1.h... and the suggestion fix generate another error.
One person suggested the gcroot<> object wrapper... but I do not know how to modify/declair the function or its argument type.
I have been trying to make a very simply programme that checks if the inputted information is an integer or not (i.e: that it contains no other characters).
I have tried using the isdigit function (but this only works for single characters). I have tried cin.clear, cin.ignore (1000) but this doesn't work either..
Any effective way to check if x in the following programme has been entered correctly
#include <iostream> using namespace std; int main() { cout << "Please enter an integer (positive or negative)" << endl; int x; cin >> x; HERE I WOULD LIKE CODE TO CHECK IF THE USERS INPUT IS VALID }
I have two third party DLL files that I wanted to check if they are 32bit or 64. I searched the web and some suggested corflags, I found it under "C:Program Files (x86)Microsoft SDKsWindowsv7.0ABin" (my machine is 64bit but I didn't find the utility under "Program Files" folder), it came out with the message:
corflags : error CF007 : The specified file does not have a valid NT file header
Under visual studio, this is a typical run time error,
Code: void func(int x){ x = 3; } int main() { int x; func(x); }
When x is passed to the function func, it is not initialized. But my question is that why it should be an error? On the other hand, if I change the definition of func a little bit like this,
Code: void func(int& x) { *x = 3; } int main() { int x; func(&x); }
Now in main, x is still not initialized, but this time there isn't a run time error like "the variable is being used without being initialized. Why?
run-time check failure #0 - the value of ESP was not properly saved across a function call. This is usually a result of calling a function declared with one calling convention with a function pointer declared with a different calling convention
when i try to run my code. It has compiled fine on another computer, but it simply will not work on this one. This is the part of code where it is receiving the error. it has to do with the stoi
Code: #include <string> // for use of string #include <fstream> //for file handling #include <iostream> // for file handling #include <cstdlib> #include <iomanip> //for the setprecision used further below using namespace std; struct MasterData //struct created named 'MasterData' to hold one line from master file
Just wonder is it possible that if the file exist, this function below will fail by returning non-zero value?
_access( INIFilename, 00 ) 00 - check for Existence only
I noticed that sometimes if even the file exist, the function will fail or return non-zero value. So trying to find out and duplicate this error. It tends to happen intermittently. How can I find out what causing this error?
I have the following code below. I am getting a memory access violation when accessing cmd->query_string in the loop function. The loop() function is running in another thread. The cmd object appears to be destroyed after calling the send_command function. How do I create an object on the heap and access the query_string.
I was working on a problem that was best solved with chaining threads together using a blocking thread-safe queue. Eg threads A and B pass data to each other using a queue ... a simple producer consumer design A -> B. This has two benefits: 1) being that there is a buffer between the two threads to cache for a slow consumer and 2) allows for better throughput when loads of data are high because the two can run in parallel. Most of the time the design works well under load. but I found when pushing data through the threads intermittently, i.e. once about 0.5 seconds it ran poorly, mostly from what seemed to be latency introduced during the OS waking up of the consumer thread B.
What i have come up with to solve this issue is what i call an .... Its a wrapper around a basic thread safe queue and adds one extra function called .... The idea here is that if you have a simple case (or perhaps a slightly more complicated case) of two threads in a prod cons design and you know the producer will create or received the data, process it, and then push onto the queue, why not give the consumer thread a heads up to let it know the data is about to arrive. In this case call .... In this way you can have the consumer thread in a polling state anticipating the arrival of data and avoid the time to schedule it back to a running state.
Anyway, i have some code below and I was looking to get some feedback. I have tested it somewhat and it does improve the responsiveness quite substantially.
