Hi,
I have an unmanaged pointer to a class that I want to hold in a managed
class. I pass the pointer (from unmanaged code) in the constructor of the
managed class, and at that point it has value. It is stored in a member
variable in my managed class declared as MyObj __nogc* pMyObj. When I try to
retrieve it later, using a function declared as MyObj __nogc* GetObj, the
pointer has been corrupted and shows up as <undefined value> when inspecting
it from the debugger. How do I prevent that?
Thanks,
Lev
7  1847 
Does the object definitely still exist? If the object the pointer points to
has ceased to be, then the pointer you're looking at will be invalid.
Posting a bit more code might help - a cut-down test case or something. I
don't pass in unmanaged pointers to functions - wherever I've had to mix
managed/unmanaged, it's always been possible for the managed class to own
the unmanaged. Let me know if you figure out what the problem is.
Steve
"Lev" <bo*****@hotmail.com> wrote in message
news:ON**************@tk2msftngp13.phx.gbl... Hi,
I have an unmanaged pointer to a class that I want to hold in a managed
class. I pass the pointer (from unmanaged code) in the constructor of the
managed class, and at that point it has value. It is stored in a member
variable in my managed class declared as MyObj __nogc* pMyObj. When I try
to retrieve it later, using a function declared as MyObj __nogc* GetObj, the
pointer has been corrupted and shows up as <undefined value> when
inspecting it from the debugger. How do I prevent that?
Thanks,
Lev
Hi Steve,
Yes, I am positive that the object pointed to still exists. The object
pointed to is created even before the managed class is created and deleted
long after the managed class has ceased to exist. I am now trying further
investigations into the modification of the pointer... Any ideas are much
appreciated :-)
"Steve McLellan" <sjm.NOSPAM AT fixerlabs DOT com> wrote in message
news:eD*************@tk2msftngp13.phx.gbl... Does the object definitely still exist? If the object the pointer points
to has ceased to be, then the pointer you're looking at will be invalid.
Posting a bit more code might help - a cut-down test case or something. I
don't pass in unmanaged pointers to functions - wherever I've had to mix
managed/unmanaged, it's always been possible for the managed class to own
the unmanaged. Let me know if you figure out what the problem is.
Steve
"Lev" <bo*****@hotmail.com> wrote in message
news:ON**************@tk2msftngp13.phx.gbl... Hi,
I have an unmanaged pointer to a class that I want to hold in a managed
class. I pass the pointer (from unmanaged code) in the constructor of
the managed class, and at that point it has value. It is stored in a member
variable in my managed class declared as MyObj __nogc* pMyObj. When I
try to retrieve it later, using a function declared as MyObj __nogc* GetObj,
the pointer has been corrupted and shows up as <undefined value> when
inspecting it from the debugger. How do I prevent that?
Thanks,
Lev
Thought I'd check :-)
When are you looking at it in the debugger? Are you sure the constructor's
been entered when you're viewing it? None of the stuff passed in to a
function is defined immediately when the function is entered; the first
debugger 'step' takes it into the function. If you try and use the pointer
inside the managed class, do you get an error?
Steve Hi Steve,
Yes, I am positive that the object pointed to still exists. The object
pointed to is created even before the managed class is created and deleted
long after the managed class has ceased to exist. I am now trying further
investigations into the modification of the pointer... Any ideas are much
appreciated :-)
"Steve McLellan" <sjm.NOSPAM AT fixerlabs DOT com> wrote in message
news:eD*************@tk2msftngp13.phx.gbl... Does the object definitely still exist? If the object the pointer points
to has ceased to be, then the pointer you're looking at will be invalid.
Posting a bit more code might help - a cut-down test case or something.
I don't pass in unmanaged pointers to functions - wherever I've had to mix
managed/unmanaged, it's always been possible for the managed class to
own the unmanaged. Let me know if you figure out what the problem is.
Steve
"Lev" <bo*****@hotmail.com> wrote in message
news:ON**************@tk2msftngp13.phx.gbl... Hi,
I have an unmanaged pointer to a class that I want to hold in a
managed class. I pass the pointer (from unmanaged code) in the constructor of
the managed class, and at that point it has value. It is stored in a
member variable in my managed class declared as MyObj __nogc* pMyObj. When I try to retrieve it later, using a function declared as MyObj __nogc* GetObj,
the pointer has been corrupted and shows up as <undefined value> when
inspecting it from the debugger. How do I prevent that?
Thanks,
Lev
Yes, I am quite confident that the constructor has been entered. I assign
the pointer to a member variable as the last step in the constructor.
However, when I tried to execute a method on the pointer (it is an interface
pointer), I got a System.OutOfMemoryException... That leaves me at a loss...
"Steve McLellan" <sjm.NOSPAM AT fixerlabs DOT com> wrote in message
news:%2****************@tk2msftngp13.phx.gbl... Thought I'd check :-)
When are you looking at it in the debugger? Are you sure the constructor's
been entered when you're viewing it? None of the stuff passed in to a
function is defined immediately when the function is entered; the first
debugger 'step' takes it into the function. If you try and use the pointer
inside the managed class, do you get an error?
Steve
Hi Steve,
Yes, I am positive that the object pointed to still exists. The object
pointed to is created even before the managed class is created and
deleted long after the managed class has ceased to exist. I am now trying
further investigations into the modification of the pointer... Any ideas are
much appreciated :-)
"Steve McLellan" <sjm.NOSPAM AT fixerlabs DOT com> wrote in message
news:eD*************@tk2msftngp13.phx.gbl... Does the object definitely still exist? If the object the pointer
points to has ceased to be, then the pointer you're looking at will be invalid.
Posting a bit more code might help - a cut-down test case or
something. I don't pass in unmanaged pointers to functions - wherever I've had to
mix managed/unmanaged, it's always been possible for the managed class to
own the unmanaged. Let me know if you figure out what the problem is.
Steve
"Lev" <bo*****@hotmail.com> wrote in message
news:ON**************@tk2msftngp13.phx.gbl...
> Hi,
>
> I have an unmanaged pointer to a class that I want to hold in a managed > class. I pass the pointer (from unmanaged code) in the constructor
of the > managed class, and at that point it has value. It is stored in a member > variable in my managed class declared as MyObj __nogc* pMyObj. When
I try to
> retrieve it later, using a function declared as MyObj __nogc*
GetObj, the > pointer has been corrupted and shows up as <undefined value> when
inspecting
> it from the debugger. How do I prevent that?
>
> Thanks,
>
> Lev
>
>
Ok, did some further investigations. If I call a method on the passed
interface pointer from the constructor, all is well. This leads me to
believe that the pointer stored internally in the managed class gets
corrupted or gc'ed eventhough it is declared as __nogc...
"Lev" <boazlev NOSPAM at h0tmail dot com> wrote in message
news:%2***************@TK2MSFTNGP11.phx.gbl... Yes, I am quite confident that the constructor has been entered. I assign
the pointer to a member variable as the last step in the constructor.
However, when I tried to execute a method on the pointer (it is an
interface pointer), I got a System.OutOfMemoryException... That leaves me at a
loss...
"Steve McLellan" <sjm.NOSPAM AT fixerlabs DOT com> wrote in message
news:%2****************@tk2msftngp13.phx.gbl... Thought I'd check :-)
When are you looking at it in the debugger? Are you sure the
constructor's been entered when you're viewing it? None of the stuff passed in to a
function is defined immediately when the function is entered; the first
debugger 'step' takes it into the function. If you try and use the
pointer inside the managed class, do you get an error?
Steve
Hi Steve,
Yes, I am positive that the object pointed to still exists. The
object pointed to is created even before the managed class is created and deleted long after the managed class has ceased to exist. I am now trying further investigations into the modification of the pointer... Any ideas are much appreciated :-)
"Steve McLellan" <sjm.NOSPAM AT fixerlabs DOT com> wrote in message
news:eD*************@tk2msftngp13.phx.gbl...
> Does the object definitely still exist? If the object the pointer points to
> has ceased to be, then the pointer you're looking at will be
invalid. > Posting a bit more code might help - a cut-down test case or something. I > don't pass in unmanaged pointers to functions - wherever I've had to mix > managed/unmanaged, it's always been possible for the managed class
to own > the unmanaged. Let me know if you figure out what the problem is.
>
> Steve
>
> "Lev" <bo*****@hotmail.com> wrote in message
> news:ON**************@tk2msftngp13.phx.gbl...
> > Hi,
> >
> > I have an unmanaged pointer to a class that I want to hold in a
managed > > class. I pass the pointer (from unmanaged code) in the constructor
of the
> > managed class, and at that point it has value. It is stored in a
member > > variable in my managed class declared as MyObj __nogc* pMyObj.
When I try
> to
> > retrieve it later, using a function declared as MyObj __nogc* GetObj, the
> > pointer has been corrupted and shows up as <undefined value> when
> inspecting
> > it from the debugger. How do I prevent that?
> >
> > Thanks,
> >
> > Lev
> >
> >
>
>
Yes, although I'm sure it shouldn't. Try removing the __nogc bit, see if
that makes a difference, and try writing a managed wrapper for it - store it
in a simple managed class and store that in your existing managed class. It
really shouldn't be affected by the garbage collector. What's the
constructor argument? Is it exactly the same as the stored pointer def (ie
not a base class or anything)?
Steve
"Lev" <boazlev NOSPAM at h0tmail dot com> wrote in message
news:e$**************@TK2MSFTNGP10.phx.gbl... Ok, did some further investigations. If I call a method on the passed
interface pointer from the constructor, all is well. This leads me to
believe that the pointer stored internally in the managed class gets
corrupted or gc'ed eventhough it is declared as __nogc...
"Lev" <boazlev NOSPAM at h0tmail dot com> wrote in message
news:%2***************@TK2MSFTNGP11.phx.gbl... Yes, I am quite confident that the constructor has been entered. I
assign the pointer to a member variable as the last step in the constructor.
However, when I tried to execute a method on the pointer (it is an
interface pointer), I got a System.OutOfMemoryException... That leaves me at a
loss...
"Steve McLellan" <sjm.NOSPAM AT fixerlabs DOT com> wrote in message
news:%2****************@tk2msftngp13.phx.gbl... Thought I'd check :-)
When are you looking at it in the debugger? Are you sure the constructor's been entered when you're viewing it? None of the stuff passed in to a
function is defined immediately when the function is entered; the
first debugger 'step' takes it into the function. If you try and use the pointer inside the managed class, do you get an error?
Steve
> Hi Steve,
>
> Yes, I am positive that the object pointed to still exists. The object > pointed to is created even before the managed class is created and
deleted > long after the managed class has ceased to exist. I am now trying
further > investigations into the modification of the pointer... Any ideas are
much > appreciated :-)
>
> "Steve McLellan" <sjm.NOSPAM AT fixerlabs DOT com> wrote in message
> news:eD*************@tk2msftngp13.phx.gbl...
> > Does the object definitely still exist? If the object the pointer
points > to
> > has ceased to be, then the pointer you're looking at will be invalid. > > Posting a bit more code might help - a cut-down test case or
something. I
> > don't pass in unmanaged pointers to functions - wherever I've had
to mix > > managed/unmanaged, it's always been possible for the managed class to own
> > the unmanaged. Let me know if you figure out what the problem is.
> >
> > Steve
> >
> > "Lev" <bo*****@hotmail.com> wrote in message
> > news:ON**************@tk2msftngp13.phx.gbl...
> > > Hi,
> > >
> > > I have an unmanaged pointer to a class that I want to hold in a
managed
> > > class. I pass the pointer (from unmanaged code) in the
constructor of > the
> > > managed class, and at that point it has value. It is stored in a
member
> > > variable in my managed class declared as MyObj __nogc* pMyObj.
When I > try
> > to
> > > retrieve it later, using a function declared as MyObj __nogc*
GetObj, > the
> > > pointer has been corrupted and shows up as <undefined value>
when > > inspecting
> > > it from the debugger. How do I prevent that?
> > >
> > > Thanks,
> > >
> > > Lev
> > >
> > >
> >
> >
>
>
Putting the pointer in a wrapper does not seem to help at all. Still getting
the NullReferenceException due to the pointer going into the undefined
state...
"Steve McLellan" <sjm.NOSPAM AT fixerlabs DOT com> wrote in message
news:uz*************@TK2MSFTNGP10.phx.gbl... Yes, although I'm sure it shouldn't. Try removing the __nogc bit, see if
that makes a difference, and try writing a managed wrapper for it - store
it in a simple managed class and store that in your existing managed class.
It really shouldn't be affected by the garbage collector. What's the
constructor argument? Is it exactly the same as the stored pointer def (ie
not a base class or anything)?
Steve
"Lev" <boazlev NOSPAM at h0tmail dot com> wrote in message
news:e$**************@TK2MSFTNGP10.phx.gbl... Ok, did some further investigations. If I call a method on the passed
interface pointer from the constructor, all is well. This leads me to
believe that the pointer stored internally in the managed class gets
corrupted or gc'ed eventhough it is declared as __nogc...
"Lev" <boazlev NOSPAM at h0tmail dot com> wrote in message
news:%2***************@TK2MSFTNGP11.phx.gbl... Yes, I am quite confident that the constructor has been entered. I assign the pointer to a member variable as the last step in the constructor.
However, when I tried to execute a method on the pointer (it is an interface pointer), I got a System.OutOfMemoryException... That leaves me at a
loss...
"Steve McLellan" <sjm.NOSPAM AT fixerlabs DOT com> wrote in message
news:%2****************@tk2msftngp13.phx.gbl...
> Thought I'd check :-)
>
> When are you looking at it in the debugger? Are you sure the
constructor's > been entered when you're viewing it? None of the stuff passed in to
a > function is defined immediately when the function is entered; the first > debugger 'step' takes it into the function. If you try and use the
pointer > inside the managed class, do you get an error?
>
> Steve
>
> > Hi Steve,
> >
> > Yes, I am positive that the object pointed to still exists. The
object > > pointed to is created even before the managed class is created and
deleted
> > long after the managed class has ceased to exist. I am now trying
further
> > investigations into the modification of the pointer... Any ideas
are much
> > appreciated :-)
> >
> > "Steve McLellan" <sjm.NOSPAM AT fixerlabs DOT com> wrote in
message > > news:eD*************@tk2msftngp13.phx.gbl...
> > > Does the object definitely still exist? If the object the
pointer points
> > to
> > > has ceased to be, then the pointer you're looking at will be
invalid. > > > Posting a bit more code might help - a cut-down test case or
something.
> I
> > > don't pass in unmanaged pointers to functions - wherever I've
had to mix
> > > managed/unmanaged, it's always been possible for the managed
class to > own
> > > the unmanaged. Let me know if you figure out what the problem
is. > > >
> > > Steve
> > >
> > > "Lev" <bo*****@hotmail.com> wrote in message
> > > news:ON**************@tk2msftngp13.phx.gbl...
> > > > Hi,
> > > >
> > > > I have an unmanaged pointer to a class that I want to hold in
a > managed
> > > > class. I pass the pointer (from unmanaged code) in the
constructor of
> > the
> > > > managed class, and at that point it has value. It is stored in
a > member
> > > > variable in my managed class declared as MyObj __nogc* pMyObj.
When I
> > try
> > > to
> > > > retrieve it later, using a function declared as MyObj __nogc*
GetObj,
> > the
> > > > pointer has been corrupted and shows up as <undefined value> when > > > inspecting
> > > > it from the debugger. How do I prevent that?
> > > >
> > > > Thanks,
> > > >
> > > > Lev
> > > >
> > > >
> > >
> > >
> >
> >
>
>
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