On Mon, 23 Sep 2013, potato_research wrote:
Hello,
I'm using BGL in my project and, with some input data, I get - sooner or later, as I run r_c_shortest_paths many times - a segfault.
This behaviour is apparently quite random, as I can see by implementing a custom visitor that the last label evaluated before the crash changes all the time. I must also say that the graph I use, while always having the same topological structure, has different properties that affect labelling each time I run the algorithm and these vary quite randomly from one run to the other, as they are generated by a random heuristics.
Anyway, with one particular set of input data, I manage to have the program segfault (as I said, sooner or later) 100% of the times. This is far from being an MWE, but it's the best I could produce.
Could you please try the version that is in the trunk now? I added a bunch of assertions to try to diagnose this issue.
I tried to debug the memory leak with valgrind and it turns out that r_c_shortest_paths_dispatch is trying to access memory in a block previously freed by:
l_alloc.deallocate( cur_outer_splabel.get(), 1 );
in r_c_shortest_paths.hpp:314. After some debugging I started to believe that the problem doesn't rely with my code, but it might be a bug in r_c_shortest_paths.hpp. If this is actually the case and where the problem lies, though, I haven't been able to figure out with certainty.
The output from valgrind can be found here: http://pastebin.com/raw.php?i=WWafwFv3 (output cleaned up and with templates substituted) http://pastebin.com/raw.php?i=cb3p6jzM (raw output intended to facilitate reading and with templates substituted) http://pastebin.com/raw.php?i=qeauBQTm (raw output indented to facilitate reading) http://pastebin.com/raw.php?i=hpppf49c (raw output)
My code (the whole project) can be found here: https://github.com/alberto-santini/maritime-vrp
In order to run it, one must have a licensed copy of CPLEX and change the include and library paths in the Makefile's accordingly. Unfortunately, without putting the labelling part inside a price-and-branch procedure (that uses CPLEX as a solver for the master problem) I wasn't able to produce input data by hand that would lead me to obtain the segfault.
Can you dump each set of input data before it goes into r_c_shortest_paths, then send whichever version causes it to fail? -- Jeremiah Willcock