I cannot figure out how to get H5Ewalk() to work. I get a good
looking H5E_error2_t struct on the first entrance to my callback function
but after I call H5Eget_msg() the strings are gone. The subsequent calls to
the callback all have bad strings too. I'm guessing they are getting freed
from the heap and overwritten with debug mode "deleted" values but is that
what's supposed to happen?
I'm using hdf5-1.8.15-patch1 and MSVS10.
Thanks,
David
#include <hdf5/hdf5.h> #include <stdio.h>
herr_t callback(unsigned n, const H5E_error2_t *err_desc, void* client_data)
{
printf(err_desc->func_name); // prints the function name
H5Eget_msg(err_desc->maj_num, NULL, NULL, 0);
printf(err_desc->func_name); // prints garbage
return 0;
}
Hi David,
I also encountered this issue. My understanding is that *any *call to an H5
function resets the error stack because in principle that call could
produce its own error [see, e.g. H5E.c:871]. Since H5get_msg succeeds, it
wipes the error stack, so error_desc becomes invalid.
The solution I used was to store the error code and translate to messages
after traversing the stack. If there are better solutions I'd love to hear
them!
Cheers,
Martijn
···
On 30 October 2015 at 01:26, David <list@aue.org> wrote:
Hi,
I cannot figure out how to get H5Ewalk() to work. I get a good
looking H5E_error2_t struct on the first entrance to my callback function
but after I call H5Eget_msg() the strings are gone. The subsequent calls to
the callback all have bad strings too. I'm guessing they are getting
freed from the heap and overwritten with debug mode "deleted" values but is
that what's supposed to happen?
I'm using hdf5-1.8.15-patch1 and MSVS10.
Thanks,
David
#include <hdf5/hdf5.h> #include <stdio.h>
herr_t callback(unsigned n, const H5E_error2_t *err_desc, void*
client_data)
{
printf(err_desc->func_name); // prints the function name
H5Eget_msg(err_desc->maj_num, NULL, NULL, 0);
printf(err_desc->func_name); // prints garbage
return 0;
}
Martijn is correct about the error stack being reset, which is why you need to
save the stack and restore it on calls that will reset the stack.
Allen
···
On Friday, October 30, 2015 02:35:04 PM Martijn Jasperse wrote:
Hi David,
I also encountered this issue. My understanding is that *any *call to an H5
function resets the error stack because in principle that call could
produce its own error [see, e.g. H5E.c:871]. Since H5get_msg succeeds, it
wipes the error stack, so error_desc becomes invalid.
The solution I used was to store the error code and translate to messages
after traversing the stack. If there are better solutions I'd love to hear
them!
Cheers,
Martijn
On 30 October 2015 at 01:26, David <list@aue.org> wrote:
> Hi,
>
> I cannot figure out how to get H5Ewalk() to work. I get a good
> looking H5E_error2_t struct on the first entrance to my callback function
> but after I call H5Eget_msg() the strings are gone. The subsequent calls
> to
> the callback all have bad strings too. I'm guessing they are getting
> freed from the heap and overwritten with debug mode "deleted" values but
> is
> that what's supposed to happen?
>
> I'm using hdf5-1.8.15-patch1 and MSVS10.
>
> Thanks,
> David
>
> #include <hdf5/hdf5.h>
> #include <stdio.h>
>
> herr_t callback(unsigned n, const H5E_error2_t *err_desc, void*
> client_data)
> {
>
> printf(err_desc->func_name); // prints the function name
>
> H5Eget_msg(err_desc->maj_num, NULL, NULL, 0);
>
> printf(err_desc->func_name); // prints garbage
> return 0;
>
> }
>
> int main(int argc, char* argv[])
> {
>
> H5Fopen("missingfile", H5F_ACC_RDWR, H5P_DEFAULT);
> H5Ewalk(H5E_DEFAULT, H5E_WALK_UPWARD, callback, NULL);
> return 0;
>
> }
>
>
> _______________________________________________
> Hdf-forum is for HDF software users discussion.
> Hdf-forum@lists.hdfgroup.org
> http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org
> Twitter: https://twitter.com/hdf5
H5Eget_msg() uses the FUNC_ENTER_API(FAIL) macro on entrance which clears
the error stack.
Interestingly the deprecated functions H5Eget_major() and H5Eget_minor()
uses FUNC_ENTER_API_NOCLEAR(NULL) instead which preserves the error stack.
In the manual Section 9.4.7, "Traverse an Error Stack with a Callback
Function" the example code uses H5Eget_msg() as though the stack is not
cleared which of course fails under the current implementation. Might it be
that at one point the intention was to have H5Eget_msg() not clear the
error stack so that using it in the callback for H5Ewalk() is possible? I
don't see any reasonable way to implement a walk callback without using the
deprecated functions instead.
David
···
On Fri, Oct 30, 2015 at 7:04 AM, Allen Byrne <byrn@hdfgroup.org> wrote:
Martijn is correct about the error stack being reset, which is why you
need to
save the stack and restore it on calls that will reset the stack.
Allen
On Friday, October 30, 2015 02:35:04 PM Martijn Jasperse wrote:
> Hi David,
> I also encountered this issue. My understanding is that *any *call to an
H5
> function resets the error stack because in principle that call could
> produce its own error [see, e.g. H5E.c:871]. Since H5get_msg succeeds, it
> wipes the error stack, so error_desc becomes invalid.
>
> The solution I used was to store the error code and translate to messages
> after traversing the stack. If there are better solutions I'd love to
hear
> them!
>
> Cheers,
> Martijn
>
> On 30 October 2015 at 01:26, David <list@aue.org> wrote:
> > Hi,
> >
> > I cannot figure out how to get H5Ewalk() to work. I get a good
> > looking H5E_error2_t struct on the first entrance to my callback
function
> > but after I call H5Eget_msg() the strings are gone. The subsequent
calls
> > to
> > the callback all have bad strings too. I'm guessing they are getting
> > freed from the heap and overwritten with debug mode "deleted" values
but
> > is
> > that what's supposed to happen?
> >
> > I'm using hdf5-1.8.15-patch1 and MSVS10.
> >
> > Thanks,
> > David
> >
> > #include <hdf5/hdf5.h>
> > #include <stdio.h>
> >
> > herr_t callback(unsigned n, const H5E_error2_t *err_desc, void*
> > client_data)
> > {
> >
> > printf(err_desc->func_name); // prints the function name
> >
> > H5Eget_msg(err_desc->maj_num, NULL, NULL, 0);
> >
> > printf(err_desc->func_name); // prints garbage
> > return 0;
> >
> > }
> >
> > int main(int argc, char* argv[])
> > {
> >
> > H5Fopen("missingfile", H5F_ACC_RDWR, H5P_DEFAULT);
> > H5Ewalk(H5E_DEFAULT, H5E_WALK_UPWARD, callback, NULL);
> > return 0;
> >
> > }
> >
> >
> > _______________________________________________
> > Hdf-forum is for HDF software users discussion.
> > Hdf-forum@lists.hdfgroup.org
> > http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org
> > Twitter: https://twitter.com/hdf5
H5Eget_msg sounds like it should not clear the stack or have any side
effect whatsoever. Is there a technical reason why it calls the
FUNC_ENTER_API macro?
-Jason
···
On Fri, Oct 30, 2015 at 6:32 PM, David <list@aue.org> wrote:
H5Eget_msg() uses the FUNC_ENTER_API(FAIL) macro on entrance which clears
the error stack.
Interestingly the deprecated functions H5Eget_major() and H5Eget_minor()
uses FUNC_ENTER_API_NOCLEAR(NULL) instead which preserves the error stack.
In the manual Section 9.4.7, "Traverse an Error Stack with a Callback
Function" the example code uses H5Eget_msg() as though the stack is not
cleared which of course fails under the current implementation. Might it be
that at one point the intention was to have H5Eget_msg() not clear the
error stack so that using it in the callback for H5Ewalk() is possible? I
don't see any reasonable way to implement a walk callback without using the
deprecated functions instead.
David
On Fri, Oct 30, 2015 at 7:04 AM, Allen Byrne <byrn@hdfgroup.org> wrote:
Martijn is correct about the error stack being reset, which is why you
need to
save the stack and restore it on calls that will reset the stack.
Allen
On Friday, October 30, 2015 02:35:04 PM Martijn Jasperse wrote:
> Hi David,
> I also encountered this issue. My understanding is that *any *call to
an H5
> function resets the error stack because in principle that call could
> produce its own error [see, e.g. H5E.c:871]. Since H5get_msg succeeds,
it
> wipes the error stack, so error_desc becomes invalid.
>
> The solution I used was to store the error code and translate to
messages
> after traversing the stack. If there are better solutions I'd love to
hear
> them!
>
> Cheers,
> Martijn
>
> On 30 October 2015 at 01:26, David <list@aue.org> wrote:
> > Hi,
> >
> > I cannot figure out how to get H5Ewalk() to work. I get a good
> > looking H5E_error2_t struct on the first entrance to my callback
function
> > but after I call H5Eget_msg() the strings are gone. The subsequent
calls
> > to
> > the callback all have bad strings too. I'm guessing they are getting
> > freed from the heap and overwritten with debug mode "deleted" values
but
> > is
> > that what's supposed to happen?
> >
> > I'm using hdf5-1.8.15-patch1 and MSVS10.
> >
> > Thanks,
> > David
> >
> > #include <hdf5/hdf5.h>
> > #include <stdio.h>
> >
> > herr_t callback(unsigned n, const H5E_error2_t *err_desc, void*
> > client_data)
> > {
> >
> > printf(err_desc->func_name); // prints the function name
> >
> > H5Eget_msg(err_desc->maj_num, NULL, NULL, 0);
> >
> > printf(err_desc->func_name); // prints garbage
> > return 0;
> >
> > }
> >
> > int main(int argc, char* argv[])
> > {
> >
> > H5Fopen("missingfile", H5F_ACC_RDWR, H5P_DEFAULT);
> > H5Ewalk(H5E_DEFAULT, H5E_WALK_UPWARD, callback, NULL);
> > return 0;
> >
> > }
> >
> >
> > _______________________________________________
> > Hdf-forum is for HDF software users discussion.
> > Hdf-forum@lists.hdfgroup.org
> > http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org
> > Twitter: https://twitter.com/hdf5
Any thoughts from the HDF5 team about if H5Eget_msg() and
H5Eget_class_name() should work as illustrated in User's Guide Section
9.4.7? Meaning calling them would not reset the error stack.
···
On Fri, Oct 30, 2015 at 3:40 PM, Jason Newton <nevion@gmail.com> wrote:
H5Eget_msg sounds like it should not clear the stack or have any side
effect whatsoever. Is there a technical reason why it calls the
FUNC_ENTER_API macro?
-Jason
On Fri, Oct 30, 2015 at 6:32 PM, David <list@aue.org> wrote:
H5Eget_msg() uses the FUNC_ENTER_API(FAIL) macro on entrance which clears
the error stack.
Interestingly the deprecated functions H5Eget_major() and H5Eget_minor()
uses FUNC_ENTER_API_NOCLEAR(NULL) instead which preserves the error stack.
In the manual Section 9.4.7, "Traverse an Error Stack with a Callback
Function" the example code uses H5Eget_msg() as though the stack is not
cleared which of course fails under the current implementation. Might it be
that at one point the intention was to have H5Eget_msg() not clear the
error stack so that using it in the callback for H5Ewalk() is possible? I
don't see any reasonable way to implement a walk callback without using the
deprecated functions instead.
David
On Fri, Oct 30, 2015 at 7:04 AM, Allen Byrne <byrn@hdfgroup.org> wrote:
Martijn is correct about the error stack being reset, which is why you
need to
save the stack and restore it on calls that will reset the stack.
Allen
On Friday, October 30, 2015 02:35:04 PM Martijn Jasperse wrote:
> Hi David,
> I also encountered this issue. My understanding is that *any *call to
an H5
> function resets the error stack because in principle that call could
> produce its own error [see, e.g. H5E.c:871]. Since H5get_msg succeeds,
it
> wipes the error stack, so error_desc becomes invalid.
>
> The solution I used was to store the error code and translate to
messages
> after traversing the stack. If there are better solutions I'd love to
hear
> them!
>
> Cheers,
> Martijn
>
> On 30 October 2015 at 01:26, David <list@aue.org> wrote:
> > Hi,
> >
> > I cannot figure out how to get H5Ewalk() to work. I get a good
> > looking H5E_error2_t struct on the first entrance to my callback
function
> > but after I call H5Eget_msg() the strings are gone. The subsequent
calls
> > to
> > the callback all have bad strings too. I'm guessing they are getting
> > freed from the heap and overwritten with debug mode "deleted" values
but
> > is
> > that what's supposed to happen?
> >
> > I'm using hdf5-1.8.15-patch1 and MSVS10.
> >
> > Thanks,
> > David
> >
> > #include <hdf5/hdf5.h>
> > #include <stdio.h>
> >
> > herr_t callback(unsigned n, const H5E_error2_t *err_desc, void*
> > client_data)
> > {
> >
> > printf(err_desc->func_name); // prints the function name
> >
> > H5Eget_msg(err_desc->maj_num, NULL, NULL, 0);
> >
> > printf(err_desc->func_name); // prints garbage
> > return 0;
> >
> > }
> >
> > int main(int argc, char* argv[])
> > {
> >
> > H5Fopen("missingfile", H5F_ACC_RDWR, H5P_DEFAULT);
> > H5Ewalk(H5E_DEFAULT, H5E_WALK_UPWARD, callback, NULL);
> > return 0;
> >
> > }
> >
> >
> > _______________________________________________
> > Hdf-forum is for HDF software users discussion.
> > Hdf-forum@lists.hdfgroup.org
> > http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org
> > Twitter: https://twitter.com/hdf5
