Version: 0.2.7
Last-Modified: Wed, 16 Dec 2009 15:37:06 +0100
Authors:
Pietro Abate,
Ralf Treinen,
Stefano Zacchiroli
Each participating solver must be bundled as a single directory (from now on called "the solver directory").
The directory name identifies the solver in the competition, hence the directory name should resemble the legacy solver name as closely as possible.
The directory name must be matched by the regular expression
[a-z][a-zA-Z0-9-]*
, that is it must consist of Latin letters,
arabic numerals, and dashes only, and it must start with a lower
case letter.
Each solver directory must contain an executable of the same name of the solver (from now on called "the solver").
The solver directory can contain support files and/or sub-directories.
The solver will be executed on a GNU/Linux host, architecture x86, 32 bit.
The solver will be executed in a constrained chroot environment containing:
A standard POSIX environment. In particular a POSIX-compatible shell,
which may be invoked by /bin/sh
, will be available, as well as a GNU
Bourne-Again SHell (invoked as /bin/bash
).
A Java Runtime Environment (JRE) 6; the Java application launcher can be
invoked as /usr/bin/java
.
A Python 2.5 environment; the main Python interpreter can be invoked as
/usr/bin/python
.
No other libraries, for any programming language, can a priori be assumed to be available in the chroot environment. That means:
Solvers prepared using compilers supporting compilation to ELF must be
submitted as statically linked ELF binaries. No assumptions can be made
on available shared libraries (*.so
) in the chroot environment.
Solvers written in some (supported) interpreted language must use the usual
shebang lines (#!/path/to/interpreter
) to invoke their interpreter.
Solvers written in Java must be wrapped by shell scripts invoking the Java application launcher as needed.
Solvers needing other kind of support in the chroot must make specific arrangements with the competition organizers before the final submission.
The solver execution will be additionally constrained by the following limits
(as implemented by ulimit
):
The solver will be executed from within the solver directory.
The solver will be called with 2 command line arguments: cudfin
and
cudfout
, in this order. Both arguments are absolute file systems paths.
cudfin
points to a complete CUDF 2.0 document, describing an upgrade
scenario. The CUDF document will be encoded as ASCII plain text, not
compressed.
CUDF 2.0 specifications are available at http://www.mancoosi.org/deliverables/.
According to the specifications, the document will consist of an optional preamble stanza, followed by several package stanzas, and ended by a request stanza.
cudfout
points to a non-existent file that should be created by the
solver to store its result.
Solver's standard output can be used to emit informative message about what the solver is doing.
If the solver is able to find a solution, then it must:
write to cudfout
the solution encoded in CUDF syntax as described in
Appendix B of the CUDF 2.0 specification;
exit with an exit code of 0.
If the solver is unable to find a solution, then it must:
write to cudfout
the string "FAIL" (without quotes), possibly followed
by an explanation in subsequent lines (lines are separated by newline
characters, ASCII 0x0A);
exit with an exit code of 0.
All exit codes other than 0 will be considered as indications of unexpected and exceptional failures not related to the inability to find a solution.
Your solver tool is called Super Solver. It consists of a statically linked
executable solver
which will need for its execution files aux1
and
aux2
. The program solver
reads the file passed as its only command line
argument, writes to standard output, and produces exit codes as required, but
has to be called with options -foo
and -bar
.
You create a directory called super-solver/
containing the following files:
./super-solver$ ls -1 -F
aux1
aux2
solver*
super-solver*
The file super-solver
, which according to the above rules is the main entry
point to Super Solver, consists of the following two lines:
#/bin/bash
./solver -foo -bar "$@"
You submit the above directory in form of an archive file.
We will extract that archive somewhere in the file hierarchy of the chroot, say
at /some/path
. This yields a directory /some/path/super-solver
containing
the above 4 files. In order to run your tool on a CUDF document which is placed
at /some/other/path/problem.cudf
we will run something like:
cd /some/path/super-solver && \
./super-solver /some/other/path/problem.cudf \
/yet/another/path/output.cudf
and look at the resulting exit code.