C / C++ / MFC

Re: How to redirect WriteFile func writes to console

20-Feb-18 6:18

Yes because you didn't put it in a worker thread Smile | :)

You need runCommand() to be in a worker thread .. it has to execute in the background so you can keep the WPF framework running in the foreground.

Look back at the windows code I had to do the same thing the CreateProcess(...) is inside a function which is spawned into it's own thread via CreateThread.

Unfortunately I don't use C# enough to know the code for making a worker thread off the top of my head.
I actually don't have the WPF framework installed on my VisualStudio at the moment to work it out.

Basically however we can describe it
1.) everything in runCommand() needs to go inside the worker thread start function .. when the thread starts it runs the app
2.) When the app finishes or your WPF app finishes you need to close the worker thread (LOOK at WM_DESTROY on the windows code)

So basically this worker thread will be chugging along in the background running the app but your program comes back to you to continue on to run the WPF framework.

So you job is to work out how to make a WPF worker thread and incorporate the code Smile | :)

In vino veritas

leon de boer20-Feb-18 6:33

Re: How to redirect WriteFile func writes to console

20-Feb-18 6:33

If you want a total guess looking at the MSDN reference and your code but ignoring the exit problem Wink | ;-)

using System.Threading;
new Thread(() => 
{
    Thread.CurrentThread.IsBackground = true; 
    runCommand();
}).Start();

Łukasz Gęsieniec20-Feb-18 23:32

Łukasz Gęsieniec

20-Feb-18 23:32

Running runCommand() from new Thread didn't help. I can read all outputs after console app quits.
It is harder to build GUI using WinAPI than using WPF but WinAPI code works.

Re: How to redirect WriteFile func writes to console

leon de boer21-Feb-18 7:12

Re: How to redirect WriteFile func writes to console

21-Feb-18 7:12

Okay the problem is console.writeline is blocking

C# test.net » Using Process.Start to capture console output[^]

.net - Does Console.WriteLine block? - Stack Overflow[^]

You can use one of the methods or Console.Out.WriteLineAsync("..."); if available.

For us old timers it's actually faster to build a GUI with the API than with the WPF framework Smile | :)

In vino veritas

modified 21-Feb-18 20:03pm.

Łukasz Gęsieniec21-Feb-18 19:57

Łukasz Gęsieniec

21-Feb-18 19:57

OK, I know what you mean Smile | :)

For me, it is easier to use WPF because I am embedded system engineer.
I am from embedded world and I do not know Windows internals.
That is why I am asking a lot of (stupid) questions. After reading several articles I supposed that redirect output and develop GUI app should be easier Smile | :)

Now I know that my strange console app does not use standard printf function Cry | :((

Re: How to redirect WriteFile func writes to console

leon de boer22-Feb-18 14:19

Re: How to redirect WriteFile func writes to console

22-Feb-18 14:19

The obvious question is can you not simply replace the program communicating with a proper windows code or is it a private format they won't disclose. Just saying it would be faster, cleaner and less code than what you are doing now Smile | :)

In vino veritas

Łukasz Gęsieniec22-Feb-18 19:50

Łukasz Gęsieniec

22-Feb-18 19:50

Yes, it is a private closed format.
Another way to communicate with the console app is passing command line arguments:

MyApp.exe -Iinput.txt -Ooutput.txt

where in the input.txt file in each line is a key command (e - exits the program, other keys do some actions):
l
f
m
c
o
e
in the output.txt file, the program saves its output. Even something like this works:
MyApp.exe -OCON - prints output to console twice.
But problem is the same. If I monitor the output file, the content appears after app quits (e command in input file)

Re: How to redirect WriteFile func writes to console

Peter_in_278022-Feb-18 20:21

Peter_in_2780

22-Feb-18 20:21

This smells to me of buffering. I'm guessing your app doesn't call flush() or equivalent on its output file, so the output is buffered until the explicit or implicit close() call at termination.
If you can make your app output lots of data, you will probably see it appear in chunks, which will be whatever buffer size is used.
The reason it works on the console is that console drivers do not buffer.
I have no idea if you can suppress buffering in your redirection, but if you could, my 2c says that would solve your problem.

Good luck!
Peter

Software rusts. Simon Stephenson, ca 1994. So does this signature. me, 2012

Re: How to redirect WriteFile func writes to console

leon de boer22-Feb-18 21:06

problem defining a function inside a structure in c

22-Feb-18 21:06

Yes standard console output is always buffered.
You can actually easily remove it

setvbuf(stdout, NULL, _IONBF, 0);
setvbuf(stderr, NULL, _IONBF, 0);

The problem is it will slow the console program down like a dog as each character invokes a full call.

I sometimes do it when I have a embedded target with UART debugger like on the Raspberry Pi.

In vino veritas

Member 1367832014-Feb-18 5:40

Member 13678320

14-Feb-18 5:40

my code is:
#include<stdio.h>
#include<conio.h>

struct point
{
int x,y;
void getdis()
{
printf("%d",x+y);
}
};

int main()
{
struct point p;
int a=5,b=10;
p.getdis(a,b);
getch();
return 0;

}

problem is:8 2 F:\software\Dev-Cpp\bin\point.c [Error] expected ':', ',', ';', '}' or '__attribute__' before '{' token
I cannot understand what to write before the getdis function to avoid this error

suman chandra modak

Re: problem defining a function inside a structure in c

David Crow14-Feb-18 6:09

David Crow

14-Feb-18 6:09

void getdis()
...
p.getdis(a,b);

These two do not match. Hint: they should.

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles

Re: problem defining a function inside a structure in c

CPallini14-Feb-18 10:44

CPallini

14-Feb-18 10:44

methods are a C++ feature you can only mimic in C, suing function pointers and the like. For instance

#include<stdio.h>
struct point
{
  int x,y;
  void (*pfun)(struct point *pp);
};

void getdis(struct point *pp)
{
  printf("%d\n", (pp->x + pp->y));
}

int main()
{
  struct point p;
  p.x = 5; p.y = 10;
  p.pfun = getdis;

  p.pfun(&p);

  getchar();
  return 0;
}

setting Boundary condition X^2-Y^2 for solving Laplace equation for NxN grid.

Member 1362564310-Feb-18 17:23

Member 13625643

10-Feb-18 17:23

i am trying to write a code to solve Laplace equation using Successive

Python

Over relaxation(SOR)on a NXN matrix
boundary condition is X^2-y^2
i dont know how to set this boundary condition on the Mesh created by me

here is the code

import numpy as np
from pylab import *
import sys
import copy
import matplotlib.pyplot as plt
import matplotlib.ticker as ticker
L =[[]for i in range(2)]
N=int(input("Enter a number N for N x N grid: "))
h=1/N
def clear_list1():
    L[1].clear()
    L[0].clear()
iterat=0
error=0.75
clear_list1()
xx=np.arange(0,N,h)
yy=np.arange(0,N,h)
x,y = np.meshgrid(xx,yy)
phi= copy.deepcopy((x**2-y**2))
phi[1:-1,1:-1]=0
phi_new = copy.deepcopy(phi)
resid=np.zeros((N,N))


while True:
    if iterat<21:

       for w in np.linspace(1,2,11):
           for i in range(1,N-1):
               for j in range(1,N-1):
                   phi1=(phi[i+1,j]+phi[i-1,j]+phi[i,j+1]+phi[i,j-1])/4
                   phi[i,j]=w*phi1+(1-w)*phi1
                   
       Sumresidual=0
       for i in range(1,N-1):
           for j in range(1,N-1):
               resid[i,j]= -4*phi[i,j]+phi[i+1,j]+phi[i-1,j]+phi[i,j+1]+phi[i,j-1]
               Sumresidual=Sumresidual+(resid[i,j])**2
    else:
        break
    iterat=iterat+1
    p=np.sqrt(Sumresidual)
    L[0].append(p)
    L[1].append(w)

ax = plt.axes()
ax.xaxis.set_major_locator(ticker.MaxNLocator(5))

plt.plot(L[0],L[1])
plt.yscale('log')
plt.xlabel('w')
plt.ylabel('|| residual ||')
plt.title('effect of w on residual')
plt.show()

Re: setting Boundary condition X^2-Y^2 for solving Laplace equation for NxN grid.

Victor Nijegorodov10-Feb-18 23:07

Victor Nijegorodov

10-Feb-18 23:07

And what does your code have to do with the C / C++ / MFC Forum?

Default Stack Size

ForNow10-Feb-18 17:02

10-Feb-18 17:02

hi
I was getting storage overlays in my local variable when I noticed that the SP register was 0X4652E25F0 and my BP registers was 0X4C652E2A60 does that mean that my stack size is 144 bytes

I have a table in the function itself that is 256 bytes to translate ASCII to EBCDIC

beginthread stack size is 0

Richard MacCutchan10-Feb-18 21:23

Richard MacCutchan

10-Feb-18 21:23

Quote:
In addition, the stack_size argument can be 0, in which case the operating system uses the same value as the stack that's specified for the main thread.

Don't try to guess what the situation may be just by looking at registers. In most code BP is set as a base register from an offset of SP, but that does not imply any particular stack size.

ForNow11-Feb-18 3:55

11-Feb-18 3:55

I guess it could be set /F compiler option thanks

Richard MacCutchan11-Feb-18 6:32

Richard MacCutchan

11-Feb-18 6:32

ForNow wrote:
I guess it could be ...

... anything. Guessing is not generally a good strategy for fixing problems. You need to be sure what the problem is first. Maybe if you show the code where the problem occurs, and a few more details, we could make some useful suggestions.

ForNow11-Feb-18 6:48

11-Feb-18 6:48

if stepped thru the code in Assembler after the function prologue by subtracting BP - SP = stack size right ?

I added code to a source file in Hercules cpu.c thing is its a makefile build which very confusing I was wondering if there isn't -F or /F flag for the stack size I guess it would default to some number my local variables and parameters would make the stack a little over 300 bytes, which is not too big

I am trying to figure to determine where in the makefile is the compile for CPU.C

Thanks

Richard MacCutchan11-Feb-18 7:10

Richard MacCutchan

11-Feb-18 7:10

I think we are talking at cross-purposes. What you are referring to is a function's frame size, which is a portion of the thread's stack. The frame will be created large enough for all the locally declared variables in that function, so you need to look at the source code to see why it is not large enough, or why it is being overwritten.

The makefile may be using an inference rule for cpu.c, so you cannot always find a specific line which references it. But you should be able to find a reference to it somewhere in the Makefile (or any of its included subfiles). However, as I mentioned, you still need to diagnose the actual problem, and changing the stack size for the final application is unlikely to make any difference.

ForNow11-Feb-18 7:13