Thanks for the message Joaquin!
I am running the boost invariant checks for multi-index and something which took a minute is now taking a full day to run. Any how, I haven't had any of the assertions fail in 5 iterations which completed so far and I have moved to version 1.57.0
Will get back if I see any issues with this again.
On Thursday, 13 November 2014 10:30 PM, "boost-users-request@lists.boost.org" wrote:
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Today's Topics:
1. Re: [Mutli-Index, InterProcess] Multi-index stability issue
with interprocess? (Joaquin M Lopez Munoz)
2. [Graph] A* with heterogeneous heuristics (Sensei)
3. 1.57.0 link errors (missing ctor/dtor for
boost::archive::detail::shared_ptr_helper) (David Abdurachmanov)
4. [BGL] Shortest-Path subject to length constraint (Yun Liu)
----------------------------------------------------------------------
Message: 1
Date: Thu, 13 Nov 2014 10:41:08 +0000 (UTC)
From: Joaquin M Lopez Munoz
To: boost-users@lists.boost.org
Subject: Re: [Boost-users] [Mutli-Index, InterProcess] Multi-index
stability issue with interprocess?
Message-ID:
Content-Type: text/plain; charset=utf-8
vibhor aggarwal writes:
I am creating a multi-index [...] and storing that in a managed
memory mapped file (boos::interprocess) [...]
All the data is first inserted into the multi-index once and then it
is read from the muti-index with a query [...]
boost::tie(l, u) = m_p_mi_ts->get<0>().
equal_range(boost::make_tuple(i, j));
We are testing this whole process over and over again (each iteration
is a new run of the process), and once in every 50 or so iterations
we get a segment fault inside boost on firing the query. Here is the
boost part of the stack from the core dump:
With so little information, I can only guess: the crash is hapenning
at a very superficial level into equal_range, namely when dereferencing
the container's header node (the top of the rb-tree ordered indices are
based on). This suggests that the container layout is seriously screwed;
possible reasons:
* Memory overwrites from some adjacent structure
* File corruption (?)
* m_p_mi has been changed somewhere
* Some sort of overrun within the memory-mapped file
It'd be best if you could provide a testing case for this or some more
context. If this is not an option, you can activate Boost.MultiIndex
invariant-checking mode:
http://www.boost.org/libs/multi_index/doc/tutorial
/debug.html#invariant_check
which will assert as soon as some internal corruption is detected
(caveat: this mode will reduce performance drastically).
Joaqu?n M L?pez Mu?oz
Telef?nica
------------------------------
Message: 2
Date: Thu, 13 Nov 2014 12:41:32 +0100
From: Sensei
To: boost-users@lists.boost.org
Subject: [Boost-users] [Graph] A* with heterogeneous heuristics
Message-ID: <546498EC.6070204@gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Dear all,
I haven't given up in trying to implement an A* algorithm with BGL. My
problem is theoretically simple, as in some previous posts.
Given a graph of letters, and a word, find the path in the
graph that minimizes the distance between the letters of
the word and the nodes in the graph.
It's best to show an example:
/*
* B H
* / \ /
* A---D---F---G---I
* \ /\
* C E
*
* input: A E I O U
* result: A D F G I
*/
With that graph, my heuristic should take into account not just the
letter in the graph per se, but the *corresponding* one in the input
word. So, starting with "AEIOU" the search will:
- expand A (A in **A**EIOU)
- find B, C, D
- expand D (closest to E in A**E**IOU)
- find D, F
- expand F (closest to I in AE**I**OU)
- find G
- expand G (only one, closest to O in AEI**O**U)
- find H, I
- expand U (closest to U in AEIO**U**)
This settings could also be more complicated, adding weights to edges,
but for now I am happy with this problem.
What I've done now? Implementing my own A* algorithm, by hand. Of course
this might work, but I'd prefer using BGL's facilities.
I must say that I am quite confused about BGL's data structures, as for
instance in the A* cities example (1), we need to create a weight map,
so what if I don't need weights? Moreover, predecessors and distances
are instantiated with a std::vector, but what happens if I need to
operate on a very large graph, for instance 200M nodes? Moreover, what
will happen when I will distribute the graph over a cluster with Boost
Parallel Graph? ... Ok maybe this is too ahead of the time! :)
Basically, I'd need to replicate my A* ugly by-hand implementation with
custom visitors and custom heuristics.
Below you may find my failed attempt. I need some help with this,
because I find the documentation a little bit hard to understand,
especially when some newbie like me approaches Boost :)
Failures in my code: I can't get to define a non-weighted graph, and the
call to the A* search is cryptic: I don't have weights. Should I define
fake ones for instance all equal to 1?
I really hope you guys can help me in this, my code works, but using BGL
would be best!
Thanks!
(1) http://www.boost.org/doc/libs/1_57_0/libs/graph/example/astar-cities.cpp
#include <iostream>
#include
#include <vector>
#include <string>
#include <utility>
#include
#include
#include
#include
typedef boost::adjacency_list graph;
typedef boost::graph_traits<graph>::edge_iterator edge_iterator;
// Custom A* heuristic
template
class bestmatch_heuristic : public boost::astar_heuristic
{
public:
typedef typename boost::graph_traits<Graph>::vertex_descriptor Vertex;
bestmatch_heuristic() { };
CostType operator()(Vertex u)
{
std::cout << ">>>> h(" << u << ") = " << 1 << std::endl;
return 1;
}
private:
};
// Used to end the A* search algorithm
struct end_astar { };
// Custom A* visitor
template <class Vertex>
class bestmatch_visitor : public boost::default_astar_visitor
{
public:
bestmatch_visitor(Vertex goal) : destination_(goal) { };
template<class Graph>
void discover_vertex(Vertex u, const Graph &g)
{
std::cout << "discover " << u << std::endl;
}
template <class Graph>
void examine_vertex(Vertex u, Graph& g)
{
std::cout << "examine " << u << std::endl;
if (u == destination_) throw end_astar();
}
private:
Vertex destination_;
};
int main()
{
/*
* B H
* / \ /
* A---D---F---G---I
* \ /\
* C E
*
* input: A E I O U
* result: A D F G I
*/
std::unordered_map letters;
auto getletter = [](std::size_t i) -> char { return 'A' + i; };
for (int i = 'A'; i <= 'I'; i++) letters[i] = i - 'A';
graph g;
boost::add_edge(letters['A'], letters['B'], g);
boost::add_edge(letters['A'], letters['C'], g);
boost::add_edge(letters['A'], letters['D'], g);
boost::add_edge(letters['B'], letters['D'], g);
boost::add_edge(letters['C'], letters['D'], g);
boost::add_edge(letters['D'], letters['E'], g);
boost::add_edge(letters['D'], letters['F'], g);
boost::add_edge(letters['F'], letters['G'], g);
boost::add_edge(letters['G'], letters['H'], g);
boost::add_edge(letters['G'], letters['I'], g);
edge_iterator ei, ee;
for (boost::tie(ei, ee) = boost::edges(g); ei != ee; ei++)
{
std::cout << getletter(boost::source(*ei, g)) << " -> " <<
getletter(boost::target(*ei, g)) << std::endl;
}
// Heuristics
bestmatch_heuristic h;
// Predecessors
std::vectorgraph::vertex_descriptor p(boost::num_vertices(g));
try
{
#if 0
boost::astar_search_tree(// Graph
g,
// Start node
letters['A'],
// Heuristics
bestmatch_heuristic(),
// Predecessor map
boost::predecessor_map(boost::make_iterator_property_map(p.begin(),
boost::get(boost::vertex_index, g))));
#endif
}
catch (end_astar e)
{
}
}
------------------------------
Message: 3
Date: Thu, 13 Nov 2014 10:07:07 +0100
From: David Abdurachmanov
To: boost-users@lists.boost.org
Cc: amey@rrsd.com
Subject: [Boost-users] 1.57.0 link errors (missing ctor/dtor for
boost::archive::detail::shared_ptr_helper)
Message-ID:
Content-Type: text/plain; charset="us-ascii"
Hi,
I am moving to Boost 1.57.0 and having issues with some code related to serialization.
https://github.com/cms-sw/cmssw/blob/CMSSW_7_3_X/CondFormats/Serialization/i...
https://github.com/cms-sw/cmssw/blob/CMSSW_7_3_X/CondFormats/Serialization/i...
In both cases the problem is here:
#if BOOST_VERSION >= 103500
#include
#endif
[snip]
#if BOOST_VERSION >= 103500
// mix-in helper class for serializing shared_ptr
, public boost::archive::detail::shared_ptr_helper
#endif
A similar (or the same) problem is reported here: http://boost.2283326.n4.nabble.com/Serialization-link-error-in-1-56-td466683...
It seems that ctor/dtor are not exported anymore:
/testSerializationDQMObjects.o: In function `eos::portable_oarchive::portable_oarchive(std::ostream&
, unsigned int)':
testSerializationDQMObjects.cpp:(.text._ZN3eos17portable_oarchiveC2ERSoj[_ZN3eos17portable_oarchiveC5ERSoj]+0x54): undefined reference to `boost::archive::detail::shared_ptr_helper:
:shared_ptr_helper()'
testSerializationDQMObjects.cpp:(.text._ZN3eos17portable_oarchiveC2ERSoj[_ZN3eos17portable_oarchiveC5ERSoj]+0x1c1): undefined reference to `boost::archive::detail::shared_ptr_helper
::~shared_ptr_helper()'
boost::serialization::shared_ptr_helper does not seem to be a drop-in replacement at first look.
There is also 'shared_ptr_helper_base', but is only available in the implementation file.
Is such mix-in class still available in a new Boost version?
Thanks,
david
