Re: Using SetConsoleCtrlHandler

Tech-Archive recommends: Repair Windows Errors & Optimize Windows Performance

From "Windows Internals, 4th Edition" (p. 108)

"The POSIX subsystem uses kernel-mode APCs to emulate the delivery of POSIX
signals to POSIX processes".

Also from the same page:

"Kernel mode APCs interrupt a thread and execute a procedure without the
thread's intervention or consent".

That tells me they would behave like a UNIX developer would expect.

Marc

"Tony Proctor" <tony_proctor@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:eEO3XfOqHHA.3296@xxxxxxxxxxxxxxxxxxxxxxx
...actually, I don't suppose anyone knows how things like SIGINT are
implemented in the POSIX sub-system under Windows. Do they even work like
a
UNIX developer would expect?

Tony Proctor

"Gary Chanson" <gchanson@xxxxxxxxxxxxxxxx> wrote in message
news:O$s$jsDqHHA.4132@xxxxxxxxxxxxxxxxxxxxxxx
My solution for a similar situation was to redirect the exception to
the
appropriate thread using a User APC. In my case, I can be reasonably
certain that the task will enter an alertable state within a reasonable
time, so this works very nicely and is a lot cleaner they your
alternative.

--

- Gary Chanson (Windows SDK MVP)
- Abolish Public Schools



"Tony Proctor" <tony_proctor@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote in
message
news:eFnX5$BqHHA.1148@xxxxxxxxxxxxxxxxxxxxxxx
Windows is not very good at handling this sort of asynchronous
interrupt
on
a single thread Emmanuel (i.e. similar to UNIX signals, or even VMS
ASTs)

The question has been asked before:


http://groups.google.ie/group/microsoft.public.win32.programmer.kernel/browse_frm/thread/608ad10204f76515/1e175f06dca6106f?hl=en#1e175f06dca6106f

I've even found myself in the same boat in trying to port a language,
and
its framework, to the Windows O/S. In the end, I suspended the thread,
read
its context, redirected it to a point that would generate the required
exception, and then released it. Surprisingly, it worked OK in practice
(although not on Alpha AXP H/W) but there were a few issues with win32
api
calls that had to be addressed (mentioned in that old thread)

Tony Proctor

"Emmanuel Stapf [ES]" <manus@xxxxxxxxxxxxxxxxx> wrote in message
news:uQhAUi9pHHA.1144@xxxxxxxxxxxxxxxxxxxxxxx
Hi,

I've a console single threaded application and I'm trying to catch a
Ctrl+C. No
matter if I use SetConsoleCtrlHandler or a signal handler, my code to
handle
this gets called in another thread. Is there a way to have the
handler
called
from the main thread?

In the code below, simply comment the call to `signal' or to
`SetConsoleCtrlHandler' to observe the similar behavior. On Unix,
using
`signal', it is called from the same thread.

Thanks for any highlight,
Manu

PS: this is shown by the code:

#include <windows.h>
#include <stdio.h>
#include <signal.h>

BOOL CtrlHandler( DWORD fdwCtrlType )
{
switch( fdwCtrlType ) {
case CTRL_C_EVENT:
printf( "Ctrl-C event\n\n" );
return TRUE;
default:
return FALSE;
}
}

void handler (int sig) {
printf ("From Signal\n");
signal (SIGINT, handler);
}

void main( void )
{
signal (SIGINT, handler);
//SetConsoleCtrlHandler( (PHANDLER_ROUTINE) CtrlHandler, TRUE );

printf("Use Ctrl+C to see what is going on.\n" );
while( 1 ){ }
}








.

Relevant Pages

  • Re: Using SetConsoleCtrlHandler
    ... "bare minimum" principal should work even in multithreaded POSIX apps, ... you rely on recursive lock acqusition in your "signal handler" - hard to ... POSIX signals to POSIX processes". ... "Kernel mode APCs interrupt a thread and execute a procedure without ...
    (microsoft.public.win32.programmer.kernel)
  • Re: Using SetConsoleCtrlHandler
    ... POSIX signals to POSIX processes". ... void handler { ...
    (microsoft.public.win32.programmer.kernel)
  • Re: Using SetConsoleCtrlHandler
    ... Assuming the signal handler does the minimum (ie. set a global, ... Only a single-threaded POSIX ... POSIX signals to POSIX processes". ... "Kernel mode APCs interrupt a thread and execute a procedure without the ...
    (microsoft.public.win32.programmer.kernel)
  • Re: Using SetConsoleCtrlHandler
    ... you rely on recursive lock acqusition in your "signal handler" - hard to ... POSIX signals to POSIX processes". ... "Kernel mode APCs interrupt a thread and execute a procedure without ...
    (microsoft.public.win32.programmer.kernel)
  • Re: Using SetConsoleCtrlHandler
    ... Tony Proctor ... "The POSIX subsystem uses kernel-mode APCs to emulate the delivery of ... "Kernel mode APCs interrupt a thread and execute a procedure without the ... void handler { ...
    (microsoft.public.win32.programmer.kernel)