Releasing FRODO version 2.18 (JaCoP catalog + performance)
Details
CHANGES IN VERSION 2.18 SINCE VERSION 2.17.1
Major changes
Added API support for JaCoP's full constraint catalog via the new JaCoPproblem class, using cloneable subclasses.
Fixed a major memory leak in the JaCoP interface, which resulted in constraint checks having a complexity that was not constant, but rather linear in the number of past constraint checks. This bugfix has resulted in dramatic speedups on large problems (see graphs below):
On meeting scheduling problems: up to 100x for ADOPT, ASO-DPOP and O-DPOP; 20x for MGM2; 10x for Max-Sum; 3x for DSA and MGM;
On MaxDisCSPs: up to 100x for ADOPT and O-DPOP; 20x for ASO-DPOP and Max-Sum; 2x for SynchBB;
On graph coloring: up to 20x for ASO-DPOP and O-DPOP, 2x for DSA, MGM and MGM2; 20% for SynchBB;
XCSP parsers no longer implement DCOPProblemInterfaces; instead their new parse() method returns one that uses more efficient datastructures than XCSP. This has also resulted in speedups on small problems, on which the parsing overhead used to be significant (see graphs below):
On meeting scheduling problems: up to 2.5x for DSA, MGM, DPOP and MB-DPOP; 2x for ADOPT, ASO-DPOP, O-DPOP and SynchBB; 1.5x for MGM2;
On MaxDisCSPs: up to 4x for Max-Sum; 2x for AFB and SynchBB;
On graph coloring: up to 2x for DPOP;
Fixed missing re-encryptions in P2-DPOP. This bugfix has resulted in slowdowns on small problems for P2-DPOP (see graphs below):
On meeting scheduling problems: up to 2x slowdown;
On graph coloring: up to 35% slowdown;
Fixed a conceptual bug in P3/2-DPOP, following which a DFS rerooting could be triggered while the DFS was still needed for SecureCircularRouting. This was fixed by having SecureCircularRouting keep using the initial DFS. No empirically measured performance impact.
Scatter plots can now display different markers for different problem size parameter values.
Fixed a bug in the XCSP parser when encountering infeasible constraints, which were incorrectly treated as feasible.
Fixed a bug following which the communication performance metrics were not correctly summed up by message type.
Fixed bugs in the counting of NCCCs (some constraint checks were skipped).
Minor changes
Fixed a bug in AbstractDCOPsolver, which used to override message types in the constructor rather than in the solve() method, resulting in interferences between solvers. Also added missing message type overrides that could result in interferences between solvers.
Fixed bugs following which the SingleQueueAgent and the CentralLinearOrdering module would incorrectly make changes to the list of agents in the problem.
Solved an inf-inf bug in MGM and MGM2.
Fixed a bug when attempting to plot infinite values.
Fixed a bug in the JaCoPutilSpace.iterator() methods, which could result in an "inf - inf" error on spaces with infeasible default utilities.
Fixed a synchronization bug in the visualizer control panel that could make message types appear multiple times.
Caught rare misleading "division by zero" exceptions that were due to integer overflows when attempting to create too large arrays.
Fixed the (benign) NullPointerExceptions that used to be thrown when showing message exchanges along edges.
Added constructors to the solvers that set the shift for the ProblemRescaler.
Scatter plots can now display different markers for different problem size parameter values, to help identify and investigate corner cases.
