1. C_func problems...
Can anybody tell me why the following code has a machine-level
exception error when run?
The relevant msdn entry is here:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc/base/createmutex.asp
Very frustrating...
constant NULL = -1
include dll.e
include machine.e
constant kernel32 = open_dll("kernel32")
--HANDLE CreateMutex(
-- LPSECURITY_ATTRIBUTES lpMutexAttributes,
-- BOOL bInitialOwner,
-- LPCTSTR lpName
--);
constant xCreateMutex = define_c_func(kernel32, "CreateMutexA",
{C_POINTER, C_CHAR, C_POINTER}, C_INT )
function createMutex(sequence name)
atom ret, str
str = allocate_string(name)
ret = c_func(xCreateMutex, {NULL, 0, str})
free(str)
return ret
end function
? createMutex("testing")
--
MrTrick
2. Re: C_func problems...
NULL should be 0, not -1
-1 is sent to a C function as #FFFFFFFF and it thinks that's a memory
address (pointer) of a the structure LPSECURITY_ATTRIBUTES. 0, on the
other hand, is an empty memory address.
On Thu, 25 Nov 2004 17:04:10 +1100, Patrick Barnes <mrtrick at gmail.com> wrote:
>
> Can anybody tell me why the following code has a machine-level
> exception error when run?
>
> The relevant msdn entry is here:
>
> http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc/base/createmutex.asp
>
> Very frustrating...
>
> }}}
<eucode>
> constant NULL = -1
> include dll.e
> include machine.e
> constant kernel32 = open_dll("kernel32")
> --HANDLE CreateMutex(
> -- LPSECURITY_ATTRIBUTES lpMutexAttributes,
> -- BOOL bInitialOwner,
> -- LPCTSTR lpName
> --);
> constant xCreateMutex = define_c_func(kernel32, "CreateMutexA",
> {C_POINTER, C_CHAR, C_POINTER}, C_INT )
>
> function createMutex(sequence name)
> atom ret, str
> str = allocate_string(name)
> ret = c_func(xCreateMutex, {NULL, 0, str})
> free(str)
> return ret
> end function
>
> ? createMutex("testing")
> </eucode>
{{{
>
> --
> MrTrick
>
>
3. Re: C_func problems...
BOOL bInitialOwner
BOOL should be C_INT
Bernie
My files in archive:
w32engin.ew mixedlib.e eu_engin.e win32eru.ew
Can be downloaded here:
http://www.rapideuphoria.com/cgi-bin/asearch.exu?dos=on&win=on&lnx=on&gen=on&keywords=bernie+ryan
4. Re: C_func problems...
- Posted by Patrick Barnes <mrtrick at gmail.com>
Nov 25, 2004
-
Last edited Nov 26, 2004
On Thu, 25 Nov 2004 09:22:23 -0800, Bernie Ryan <guest at rapideuphoria.com>
wrote:
> BOOL bInitialOwner
>
> BOOL should be C_INT
Why C_INT? What's wrong with C_CHAR?
--
MrTrick
-------------------------------------------------------------------------------------
magnae clunes mihi placent, nec possum de hac re mentiri.
5. Re: C_func problems...
- Posted by Bernie Ryan <xotron at bluefrog.com>
Nov 25, 2004
-
Last edited Nov 26, 2004
Patrick Barnes wrote:
>
> On Thu, 25 Nov 2004 09:22:23 -0800, Bernie Ryan <guest at rapideuphoria.com>
> wrote:
> > BOOL bInitialOwner
> >
> > BOOL should be C_INT
>
> Why C_INT? What's wrong with C_CHAR?
>
> --
> MrTrick
>
> -------------------------------------------------------------------------------------
> magnae clunes mihi placent, nec possum de hac re mentiri.
>
>
Because if you ever use it in a structure as C_CHAR windows
will be passed the wrong size structure, so I suggest that
you always use C_INT, it is not absolutely necessasry in this case.
Bernie
My files in archive:
w32engin.ew mixedlib.e eu_engin.e win32eru.ew
Can be downloaded here:
http://www.rapideuphoria.com/cgi-bin/asearch.exu?dos=on&win=on&lnx=on&gen=on&keywords=bernie+ryan
6. Re: C_func problems...
- Posted by Patrick Barnes <mrtrick at gmail.com>
Nov 25, 2004
-
Last edited Nov 26, 2004
On Thu, 25 Nov 2004 14:38:11 -0800, Bernie Ryan <guest at rapideuphoria.com>
wrote:
> Patrick Barnes wrote:
> >
> > On Thu, 25 Nov 2004 09:22:23 -0800, Bernie Ryan <guest at rapideuphoria.com>
> > wrote:
> > > BOOL bInitialOwner
> > >
> > > BOOL should be C_INT
> >
> > Why C_INT? What's wrong with C_CHAR?
>
> Because if you ever use it in a structure as C_CHAR windows
> will be passed the wrong size structure, so I suggest that
> you always use C_INT, it is not absolutely necessasry in this case.
>
Okay, thanks. It did turn out that the NULL being defined improperly
was the issue.
--
MrTrick
