faudes::SccFilter Class Reference
[General Purpose Functions]

Filter for strictly connected components (SCC) search/compute routines. More...

#include <cfl_graphfncts.h>

List of all members.

Public Types

enum  FMode {
  FmNoFilter = 0x00, FmFindFirst = 0x01, FmIgnoreTrivial = 0x02, FmStatesAvoid = 0x10,
  FmStatesRequire = 0x20, FmEventsAvoid = 0x40, FmIgnoreLiveLocks = 0x1000, FmLiveLocksOnly = 0x2000,
  FmIgnoreUnaccessible = 0x4000
}
 

Typedef for filter modes.

More...

Public Member Functions

 SccFilter (void)
 Constructor (no filter).
 SccFilter (const SccFilter &rSrc)
 Constructor (copy constructor).
 SccFilter (int mode, const Generator &rGen)
 Constructor (from flags w.r.t.
 SccFilter (int mode, const StateSet &rStatesAvoidRequire)
 Constructor (from flags and state set, either avoid or require).
 SccFilter (int mode, const StateSet &rStatesAvoid, const StateSet &rStatesRequire)
 Constructor (from flags and state sets).
 SccFilter (int mode, const EventSet &rEventsAvoid)
 Constructor (from flags and event sets).
 SccFilter (int mode, const StateSet &rStatesAvoid, const StateSet &rStatesRequire, const EventSet &rEventsAvoid)
 Constructor (from flags and sets).
 ~SccFilter (void)
 Destructor.
int Mode (void) const
 Member access.
const StateSetStatesAvoid (void) const
 Member access.
const StateSetStatesRequire (void) const
 Member access.
void Clear (void)
 Edit filter (RTI): no filter.
void StatesAvoid (const StateSet &rStatesAvoid)
 Edit filter (RTI): set avoid states.
void StatesRequire (const StateSet &rStatesRequire)
 Edit filter (RTI): set required states.
void EventsAvoid (const EventSet &rEventsAvoid)
 Edit filter (RTI): set avoid events.
void IgnoreTrivial (bool flag)
 Edit filter (RTI): ignore trivial.
void FindFirst (bool flag)
 Edit filter (RTI): find first.

Protected Member Functions

void MergeStatesAvoid (const StateSet &rStatesAvoid)
 Edit filter (RTI): avoid states.

Protected Attributes

int mMode
 Flag, combining bit masks from Mode.
const StateSetpStatesAvoid
 States to avoid (if flag StatesAvoid is set).
const StateSetpStatesRequire
 States to require (if flag StatesRequire is set).
const EventSetpEventsAvoid
 Events to avoid (if flag EventssAvoid is set).
StateSetmpStatesAvoid
 Local sets (optional).
StateSetmpStatesRequire
EventSetmpEventsAvoid

Static Protected Attributes

static const StateSet msEmptyStates = StateSet()
 Static emptysets.
static const EventSet msEmptyEvents = EventSet()

Friends

void SearchScc (const Idx vState, int &vRcount, const Generator &rGen, const SccFilter &rFilter, StateSet &rTodo, std::stack< Idx > &rStack, StateSet &rStackStates, std::map< const Idx, int > &rDfn, std::map< const Idx, int > &rLowLnk, std::list< StateSet > &rSccList, StateSet &rRoots)
 Search for strongly connected components (SCC).
bool ComputeNextScc (const Generator &rGen, SccFilter &rFilter, StateSet &rScc)
 Compute next SCC.

Detailed Description

Filter for strictly connected components (SCC) search/compute routines.

When ComputeScc()/HasScc()/NextScc() traverse a specified transition sytem in their search, a SccFilter parameter can mute certain transitions. The respective filter conditions are set by the constructor and consist of a flag word (mMode) and additional parameters (depending on the flags). The Flags can be combined from the following:

  • NoFilter: std textbook beheviour;
  • FindFirst: stop the search after one SCC has been found;
  • IgnoreTrivial: dont report singleton SCCs without selfloop;
  • StatesAvoid: mute specified states from trasition structure;
  • StatesRequire: dont report SCCs that fail to contain at least one state from the specified set;
  • EventsAvoid: mute any transitions with an event label from the specified set.

Convenience modes set up the state related filter conditions from the set of marked states:

  • IgnoreLiveLocks: set StatesRequire to the marked states of a specified Generator;
  • LiveLocksOnly: set StatesAvoid to the marked states of a specified Generator;
  • IgnoreUnaccessible: initialise todo list with accessible states only.

Technical note: SccFilters interally use references to condition parameters that are required to exist during the life time of the filter object.

Technical note: currently, there is no EventsRequire filter because the implementation interprets the transition relation primarily from a directed graph perspective; while StatesRequire makes sense for marked states semantics, we are not aware of any applications for a corresponding version of EventsRequire; please let us know if you require such an extension.

Definition at line 64 of file cfl_graphfncts.h.


Member Enumeration Documentation

Typedef for filter modes.

Enumerator:
FmNoFilter 
FmFindFirst 
FmIgnoreTrivial 
FmStatesAvoid 
FmStatesRequire 
FmEventsAvoid 
FmIgnoreLiveLocks 
FmLiveLocksOnly 
FmIgnoreUnaccessible 

Definition at line 88 of file cfl_graphfncts.h.


Constructor & Destructor Documentation

faudes::SccFilter::SccFilter ( void   ) 

Constructor (no filter).

Definition at line 50 of file cfl_graphfncts.cpp.

faudes::SccFilter::SccFilter ( const SccFilter rSrc  ) 

Constructor (copy constructor).

Definition at line 62 of file cfl_graphfncts.cpp.

faudes::SccFilter::SccFilter ( int  mode,
const Generator rGen 
)

Constructor (from flags w.r.t.

Generator)

Definition at line 134 of file cfl_graphfncts.cpp.

faudes::SccFilter::SccFilter ( int  mode,
const StateSet rStatesAvoidRequire 
)

Constructor (from flags and state set, either avoid or require).

Definition at line 93 of file cfl_graphfncts.cpp.

faudes::SccFilter::SccFilter ( int  mode,
const StateSet rStatesAvoid,
const StateSet rStatesRequire 
)

Constructor (from flags and state sets).

Definition at line 113 of file cfl_graphfncts.cpp.

faudes::SccFilter::SccFilter ( int  mode,
const EventSet rEventsAvoid 
)

Constructor (from flags and event sets).

Definition at line 74 of file cfl_graphfncts.cpp.

faudes::SccFilter::SccFilter ( int  mode,
const StateSet rStatesAvoid,
const StateSet rStatesRequire,
const EventSet rEventsAvoid 
)

Constructor (from flags and sets).

faudes::SccFilter::~SccFilter ( void   ) 

Destructor.

Definition at line 43 of file cfl_graphfncts.cpp.


Member Function Documentation

void faudes::SccFilter::Clear ( void   ) 

Edit filter (RTI): no filter.

Definition at line 163 of file cfl_graphfncts.cpp.

void faudes::SccFilter::EventsAvoid ( const EventSet rEventsAvoid  ) 

Edit filter (RTI): set avoid events.

Definition at line 201 of file cfl_graphfncts.cpp.

void faudes::SccFilter::FindFirst ( bool  flag  ) 

Edit filter (RTI): find first.

Definition at line 215 of file cfl_graphfncts.cpp.

void faudes::SccFilter::IgnoreTrivial ( bool  flag  ) 

Edit filter (RTI): ignore trivial.

Definition at line 209 of file cfl_graphfncts.cpp.

void faudes::SccFilter::MergeStatesAvoid ( const StateSet rStatesAvoid  )  [protected]

Edit filter (RTI): avoid states.

Definition at line 193 of file cfl_graphfncts.cpp.

int faudes::SccFilter::Mode ( void   )  const [inline]

Member access.

Definition at line 126 of file cfl_graphfncts.h.

void faudes::SccFilter::StatesAvoid ( const StateSet rStatesAvoid  ) 

Edit filter (RTI): set avoid states.

Definition at line 177 of file cfl_graphfncts.cpp.

const StateSet& faudes::SccFilter::StatesAvoid ( void   )  const [inline]

Member access.

Definition at line 129 of file cfl_graphfncts.h.

void faudes::SccFilter::StatesRequire ( const StateSet rStatesRequire  ) 

Edit filter (RTI): set required states.

Definition at line 185 of file cfl_graphfncts.cpp.

const StateSet& faudes::SccFilter::StatesRequire ( void   )  const [inline]

Member access.

Definition at line 132 of file cfl_graphfncts.h.


Friends And Related Function Documentation

bool ComputeNextScc ( const Generator rGen,
SccFilter rFilter,
StateSet rScc 
) [friend]

Compute next SCC.

This function provides an API for the iterative computation of SCCs. It invokes SearchScc() to find the next SCC and then adds the SCC to the StatesAvoid Filter. This approach is not computationally efficient but it allows for simple Lua wrappers.

Parameters:
rGen Generator under investigation
rFilter Filter out specified transitions
rScc First SCC that has been found, empty if no such.
Returns:
True if an SCC has been found, false if not.
void SearchScc ( const Idx  vState,
int &  vRcount,
const Generator rGen,
const SccFilter rFilter,
StateSet rTodo,
std::stack< Idx > &  rStack,
StateSet rStackStates,
std::map< const Idx, int > &  rDfn,
std::map< const Idx, int > &  rLowLnk,
std::list< StateSet > &  rSccList,
StateSet rRoots 
) [friend]

Search for strongly connected components (SCC).

This function partitions the stateset of a generator into equivalent classes such that states x1 and x2 are equivalent iff there is a path from x1 to x2 AND a path from x2 to x1.

This function implements the algorithm based on a recursive depth first search presented in:

-- Aho, Hopcroft, Ullman: The Design and Analysis of Computer Algorithms --

While the original algorithm works on a directed graph, this implementation adds some features that refer to transition systems and allow to filter SCCs on the run. The filter condition is specified by the SccFilter parameter rFilter.

Note: this version is derived from earlier implementations used in various plug-ins; in due course, this version will replace earlier versions.

Note: Due to the recursive implementation, this function requires a stack size proportional to the largest SCC. We have experienced typical default configurations to be good for a depth of about 80000 (Mac OSX 10.6, Debian 7.4). For SCCs exceeding the default stack size, you may adjust the operating system parameters accordingly. On Unix/Linux/MacOsX this is done by the shell command "ulimit -s hard". A future revision of SearchSCC() may be re-designed to circumvent this inconvenient issue.

Note: for a convenience API see also ComputeScc()

Parameters:
vState State, from which the current recursion is started.
vRcount Denotes the current depth of the recursion.
rGen Transition system to investigate
rFilter Filter out specified transitions
rTodo Set of states that up to now were not found by the depth first search.
rStack Stack of states to represent current path.
rStackStates Set of states that are in rStack
rDfn Map assigning to each state idx its Depth-First Number.
rLowLnk Map assigning to each state its LOWLINK Number.
rSccList Set SCCs (accumulative result).
rRoots Set of states that each are root of some SCC (accumulative result).

Member Data Documentation

int faudes::SccFilter::mMode [protected]

Flag, combining bit masks from Mode.

Definition at line 159 of file cfl_graphfncts.h.

Definition at line 170 of file cfl_graphfncts.h.

Local sets (optional).

Definition at line 168 of file cfl_graphfncts.h.

Definition at line 169 of file cfl_graphfncts.h.

const EventSet faudes::SccFilter::msEmptyEvents = EventSet() [static, protected]

Definition at line 174 of file cfl_graphfncts.h.

const StateSet faudes::SccFilter::msEmptyStates = StateSet() [static, protected]

Static emptysets.

Definition at line 173 of file cfl_graphfncts.h.

Events to avoid (if flag EventssAvoid is set).

Definition at line 165 of file cfl_graphfncts.h.

States to avoid (if flag StatesAvoid is set).

Definition at line 161 of file cfl_graphfncts.h.

States to require (if flag StatesRequire is set).

Definition at line 163 of file cfl_graphfncts.h.


The documentation for this class was generated from the following files:

libFAUDES 2.23h --- 2014.04.03 --- c++ api documentaion by doxygen