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can't you just copy the file and rename it ?
This signature was proudly tested on animals.
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Hi everyone,
Here is a problem of mine....
I have a function (threadfunction). And i am creating a thread using Createthread() Function from a buttonClick....I have a local integer value in the threadFunction
Each time I click the button,new thread should create,...Its creting new threads , but its overwriting the local integer value ie it is shared by all the created threads....
Please help me out...
Within the threadfunction, I am decrementing the value after each 200 ms,
DWORD WINAPI personal_recv_fnc_thread( LPVOID lpParam)
{
int i=10;
do
{
Sleep(200);
--i;
}while(i>=0);
return 0;
}
I want to run each thread and decrement the value in all thread separately.....ie each thread should decrement its own local value
modified on Thursday, January 22, 2009 6:05 AM
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Member 4250705 wrote: Its creting new threads , but its overwriting the parameter value ie it is shared by all the created threads....
Well, yes, that's the standard behavior. When you start a new thread, you only create the thread, not duplicate any global value. You will need to make the variable local to your thread function in order to have multiple different variables.
Wait, I misunderstood your question. What are you passing to your thread function ? Could you post the code where you call CreateThread ?
modified on Thursday, January 22, 2009 6:08 AM
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but that will again overwrite by all thread...
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Shouldn't you be casting lpParam to an int pointer rather than an int?
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Indeed it should. Are you sure you are not mistaking? Try the following: use TRACE to display your i variable once before the do and every loop inside the do, then run 3 threads, each with let's say- a 300 ms delay and then check out your output window. You should see that when a new thread is started your already running ones are not affected.
So something like this:
DWORD WINAPI personal_recv_fnc_thread( LPVOID lpParam)
{
int i=10;
TRACE("%X: RUNNING THREAD, starting from %d =====================\n", GetCurrewntThreadId(), i);
do
{
Sleep(200);
--i;
TRACE("%X: %d\n", GetCurrewntThreadId(), i);
}while(i>=0);
return 0;
}
...
CreateThread(...personal_recv_fnc_thread...);
Sleep(300);
CreateThread(...personal_recv_fnc_thread...);
Sleep(300);
CreateThread(...personal_recv_fnc_thread...);
...
To be absolutely sure, i tried this. It works as it should.
p.s: next time you post code, use <pre> and </pre> tags please, makes things easier to read.
> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <
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Member 4250705 wrote: Its creting new threads , but its overwriting the local integer value ie it is shared by all the created threads....
That's not true, according to documentation [^]:
All threads of a process share its virtual address space. The local variables of a function are unique to each thread that runs the function.
You may verify with the following simple test program
Please note: fixed to avoid *disaster* [^] 
DWORD WINAPI ThreadProc(
LPVOID lpParameter
)
{
int i=10;
const int BUFSIZE = 0x100;
TCHAR szBuf[BUFSIZE];
HRESULT hr;
do
{
Sleep(200);
--i;
printf("%x %d\n", (INT_PTR)lpParameter, i);
hr = StringCchPrintf(szBuf, BUFSIZE, _T("%x %d\n"), (INT_PTR)lpParameter, i);
if ( SUCCEEDED(hr)) OutputDebugString(szBuf);
} while (i>=0) ;
return 0;
}
bool main()
{
for (int i=0; i<10; i++)
{
DWORD dwId;
CreateThread(NULL, 0, ThreadProc, (LPVOID)i, 0, &dwId);
}
Sleep (4000);
return true;
}
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
modified on Thursday, January 22, 2009 8:07 AM
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Using C-runtime functions in a thread created by a method other than calling _beginthread, _beginthreadex[^] is bad form and a recipe for disaster. The reason the CRT has these functions is that some features of the CRT require thread specific initialisation, which your code is bypassing. The following is quoted from the documentation on CreateThread[^]:
A thread in an executable that calls the C run-time library (CRT) should use the _beginthreadex and _endthreadex functions for thread management rather than CreateThread and ExitThread; this requires the use of the multi-threaded version of the CRT. If a thread created using CreateThread calls the CRT, the CRT may terminate the process in low-memory conditions.
Steve
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You're right, thanks for pointing out.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
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Hi,
I want to call a templated function with template parameters chosen at runtime.
for example something like this
func(int x)
{
if( x == 0)
templatedFunction <<int>> y = new templatedFunc<<int>>();
else
templatedFunction <<double>> y = new templatedFunc<<double>>();
}
is this possible in C++?
thx in advance
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You answered your own question i believe. It is possible with switch cases or using if-else.
> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <
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I tried the code below
switch (pType)
{
case itk::ImageIOBase::IOComponentType::CHAR:
otb::VectorImage<char, 2>::Pointer p = otb::VectorImage<char, 2>::New();
break;
case itk::ImageIOBase::IOComponentType::UCHAR:
otb::VectorImage<unsigned char, 2>::Pointer p = otb::VectorImage<unsigned char, 2>::New();
break;
}
when this code compiles it gives errors
Error 4 error C2360: initialization of 'p' is skipped by 'case' label d:\otb\imageeditorapp\imagetoolbox\imageio.h 44
Error 5 error C2371: 'p' : redefinition; different basic types d:\otb\imageeditorapp\imagetoolbox\imageio.h 45
Error 9 error C2360: initialization of 'p' is skipped by 'case' label d:\otb\imageeditorapp\imagetoolbox\imageio.h 44
Error 10 error C2371: 'p' : redefinition; different basic types d:\otb\imageeditorapp\imagetoolbox\imageio.h 45
I did not understand the mistake, if this is possible :/
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Read this[^], and when you get errors, you can click on them in your output window, on the part after the error word, for example C2360 and press F1 to see what that error means, assuming you are using VS.
> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <
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I tried with the code below and it compied without errors
if(pType == itk::ImageIOBase::IOComponentType::CHAR)
otb::VectorImage<char,2>::Pointer p = otb::VectorImage<char,2>::New();
else if(pType == itk::ImageIOBase::IOComponentType::UCHAR)
otb::VectorImage<unsigned>::Pointer p = otb::VectorImage<unsigned>::New();
</unsigned></unsigned>
bu I could not understand why, is there a problem with my switch statement code in the previous message 
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You need to define a scope for the memory allocation in the switch statement.
Put the object creation code with parenthesis.
switch (pType)
{
case itk::ImageIOBase::IOComponentType::CHAR:
{
otb::VectorImage<char, 2>::Pointer p = otb::VectorImage<char, 2>::New();
}
break;
case itk::ImageIOBase::IOComponentType::UCHAR:
{
otb::VectorImage<unsigned char, 2>::Pointer p = otb::VectorImage<unsigned char, 2>::New();
}
break;
}
This also means you can use the object only within the parenthesis.
The new lambda functions available in the new C++ standards is what you need.
But unfortunately it is not currently available.
It will be available in VS 2010.
«_Superman_»
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So you mean I can not use this new variable after the switch or if statement
if (x==0)
double y;
else
int y;
y = 0; ERROR // 'y' undeclared identifier 
So any of you have a solution for this kind of problem?
What I want to do is this.
I have a parameter, and I want to declare a templated variable according to this parameter(if parameter is 1, it is char, if 2, int etc). and I will use it till the end of the scope of the program.
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Why don't do all processing there itself.
switch (pType)
{
case itk::ImageIOBase::IOComponentType::CHAR:
{
otb::VectorImage<char, 2>::Pointer p = otb::VectorImage<char, 2>::New();
DoAllProcessing(p);
}
break;
case itk::ImageIOBase::IOComponentType::UCHAR:
{
otb::VectorImage<unsigned char, 2>::Pointer p = otb::VectorImage<unsigned char, 2>::New();
DoAllProcessing(p);
}
break;
}
OR
otb::VectorImage&lt;char, 2>::Pointer p1;
otb::VectorImage&lt;unsigned char, 2>::Pointer p2;
int flag = 0;
switch (pType)
{
case itk::ImageIOBase::IOComponentType::CHAR:
{
p1 = otb::VectorImage<char, 2>::New();
flag = 1;
}
break;
case itk::ImageIOBase::IOComponentType::UCHAR:
{
p2 = otb::VectorImage<unsigned char, 2>::New();
flag = 2;
}
break;
}
if (1 == flag)
DoAllProcessing(p1);
else if (2 == flag)
DoAllProcessing(p2);
«_Superman_»
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I'll continue with one of the possibilities, thx for your help, but it is a disappointment not being able to code in a straight manner
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Write a wrapper class (maybe a template) that can hold whatever type of value you wish to use. OR maybe use template methods, am not completely sure what you want to do exactly. You can't declare a variable without explicitly stating a type, so this doesn't work:
if (whatever_condition_is_true) make Y an int;
else make Y a double;
return Y;
BUT you could make a wrapper, something like this, for example:
class CWrapperBase
{
...
};
template <typename typename="">
class CWrapper: public CWrapperBase
{
public:
TypeName m_value;
CWrapper(const TypeName &value)
{
m_value = value;
}
operator =(const TypeName &other)
{
m_value = other;
}
operator TypeName &()
{
return m_value;
}
};
CWrapperBase GetValue(int x)
{
if (x == 0) return CWrapper<double>(1.0);
else return CWrapper<int>(2);
}
</int></double></typename>
This above is far from complete, just a starting point...
> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <
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hhhakan wrote: bu I could not understand why, is there a problem with my switch statement code in the previous message Confused
Quote Selected Text
Yes and no, I believe.
The following code fails to compile:
1. void func1(int input)
2. {
3. switch(input)
4. {
5. case 0:
6. int g = 0;
7. break;
8. case 1:
9. int h = 0;
10 break;
11 }
12 }
With the following error:
line 8 error: jump to case label
line 6 error: crosses initialization of 'int g'
(MinGW gcc)
This code on the other hand works fine:
void func1(int input)
{
switch(input)
{
case 0:
int g;
g = 0;
break;
case 1:
int h;
h = 0;
break;
}
}
I'm far too lazy right now to look it up, but I guess you can't declare and initialize a variable inside a switch statement.
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Hi All
I have a dialog based application(MFC) and application is running in background(through startup).But at the time of system boot my application has blocked by windows defender.I have attached application.exe.manifest.How can i remove the Windows defender is blocking application?Plz help me
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Hello everyone,
I have a problem with adding event handlers to my dynamically created RichEdit Controls.
Depending on the user between 1 and 4 controls are created.
My intention is that the user can right click somewhere in one of the controls, then i try to figure out what the content is at that place. In the menu, that should pop up at that place, there should be an entry like 'more information' and by clicking on it a new dialog opens with the detailed description of whatever the user clicked on.
But I really don't know how to set the WM_RButtonDown for the individual number of Controls.
Any help would be appreciated...
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How would you achieve this if you were using only one rich edit? Would you create your own class inheriting from CRichEditCtrl and define your own handler code for WM_RBUTTONDOWN? If so, where's the problem? If you have 4 instances of that class then your WM_RBUTTONDOWN will be handled in the instance that belongs to the control that was right-clicked. Am i missing your point here?
> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <
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Hi Code-o-mat,
no, you are not missing the point. I didn't think about deriving my own class, I really had no clue how to solve this problem. Currently I'm using CRichEditCtrl and I if i only had one control to create I would do this statically and would use the Wizard to add an EventHandler.
Could you perhaps give me another hint how to write my handler code?
Thanks for your help.
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Okay, I figured it out in the meantime.
Thanks again for pointing me the way.
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