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Try running the case in the debugger. When the error occurs, you
should be able to look up the call stack and see which routine is
calling return_memory with what return_memory has determined to be
an invalid pointer. If it is one of your routines, perhaps it will
then be clear what is going on.<br>
<br>
Another place to look for help is the routine<br>
<a class="moz-txt-link-freetext" href="http://www.coin-or.org/CppAD/Doc/ta_inuse.xml">http://www.coin-or.org/CppAD/Doc/ta_inuse.xml</a><br>
Perhaps at some point in your program you think you have deleted all
your CppAD objects, but you have not yet done so. Note that since
you are only using one thread, its thread number is zero.<br>
<br>
As a last resort, in<br>
cppad/thread_alloc.hpp
<br>
you can set CPPAD_TRACE_THREAD to 0 and CPPAD_TRACE_CAPACITY
to 972. Then redirect the trace output to a file. Perhaps you can
see where the memory has already been freed.<br>
<br>
On 03/01/2012 08:17 AM, Michael Braun wrote:
<blockquote cite="mid:651AF3E4-618E-4646-B119-39623178DC24@mit.edu"
type="cite">
<pre wrap="">Hi.
I have a rather complex use case for CppAD that is generating an error. Unfortunately, I cannot construct a simple, reproducible case, but I am hoping someone can point me in the right direction to diagnose the problem.
I have written a class that includes an ADFun<double> as a member. I am then exposing my C++ class in R, and then calling the C++ member functions using the Rcpp modules functionality.
If I launch R, run my R script, construct an object from the C++ class, everything works fine. But then, after I delete the C++ object, unload the dynamic library, and start over again, I get the following error after trying to load in completely unrelated data:
cppad-20120227 error from a known source:
return_memory: attempt to return memory not in use
v_ptr = 0x7fa4739037b8
thread = 0
capacity = 972
See CPPAD_TRACE_THREAD & CPPAD_TRACE_CAPACITY in
# include <cppad/thread_alloc.hpp>
Error detected by false result for
false
at line 982 in the file
/opt/cppad/include/cppad/thread_alloc.hpp
Assertion failed: (false), function CppAD::ErrorHandler::Default, file /opt/cppad/include/cppad/error_handler.hpp, line 217.
What's interesting is that when I get this error message, the object of the class that uses CppAD should have already been deleted. And this error pops up long before I call the constructor. It is only after I restart R that I can run my program again. So this makes me think that something is going on with how CppAD re-allocates memory.
I am not doing anything special to de-allocate the ADFun or AD objects at all? Should I? Also, I am not running any multi-threaded code, so I am not invoking "parallel mode." I was not able to find an example of using CppAD in parallel mode, even if the application itself is sequential.
Can you offer some suggestions on what to look for, or explain what might might cause CppAD to want to return memory that is not in use?
Thanks,
Michael
Michael Braun
MIT Sloan School of Management
<a class="moz-txt-link-abbreviated" href="mailto:braunm@mit.edu">braunm@mit.edu</a>
--------------------------------------------------
View my research at
<a class="moz-txt-link-freetext" href="http://braunm.scripts.mit.edu/">http://braunm.scripts.mit.edu/</a>
</pre>
<br>
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<pre wrap="">_______________________________________________
CppAD mailing list
<a class="moz-txt-link-abbreviated" href="mailto:CppAD@list.coin-or.org">CppAD@list.coin-or.org</a>
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</pre>
</blockquote>
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