Detailed Description

A transition from one TESLA state to another.

Definition at line 69 of file Transition.h.

#include "Transition.h"

Inheritance diagram for tesla::Transition:

Collaboration diagram for tesla::Transition:

Public Types
enum	TransitionKind { Null, Now, Fn, FieldAssign, SubAutomaton }
	Information for LLVM's RTTI (isa<>, cast<>, etc.). More...

Public Member Functions
virtual	~Transition ()

const State &	Source () const

const State &	Destination () const

virtual bool	EquivalentTo (const Transition &T) const =0
	Does this transition consume and produce the same symbols as another? More...

bool	RequiresInit () const
	This transition triggers initialisation of its TESLA automata class. More...

bool	RequiresCleanup () const
	This transition triggers cleanup of its TESLA automata class. More...

virtual bool	IsStrict () const
	This transition can only occur as described in an automaton. More...

virtual const ReferenceVector	Arguments () const =0
	Arguments referenced by this transition. More...

llvm::SmallVector< const Argument *, 4 >	NewArguments () const
	Arguments newly referenced by this transition (unknown to previous state). More...

int	NewArgMask () const
	A bitmask representing the arguments newly referenced by this transition. More...

void	ReferencesThusFar (llvm::OwningArrayPtr< const Argument * > &Args, ReferenceVector &Ref) const
	The references known at the point this transition occurs. More...

virtual bool	IsRealisable () const =0
	Can this transition be captured by real instrumentation code? More...

virtual std::string	ShortLabel () const =0
	A short, human-readable label. More...

virtual std::string	DotLabel () const =0
	A label that can go in a .dot file (can use newline, Greek HTML codes...). More...

virtual std::string	String () const

bool	InScope () const

virtual TransitionKind	getKind () const =0

Static Public Member Functions
static void	Create (State &From, State &To, TransitionVector &Transitions, bool Init=false, bool Cleanup=false)
	Create an unconditional transition. More...

static void	Create (State &From, State &To, const FunctionEvent &Ev, TransitionVector &, bool Init, bool Cleanup, bool OutOfScope=false)
	Create a FunctionEvent transition. More...

static void	Create (State &From, State &To, const FieldAssignment &A, TransitionVector &, bool Init, bool Cleanup, bool OutOfScope=false)
	Create a FieldAssignment transition. More...

static void	Create (State &From, State &To, const NowEvent &, const AutomatonDescription &, TransitionVector &, bool Init, bool Cleanup)

static void	CreateSubAutomaton (State &From, State &To, const Identifier &, TransitionVector &)

static void	Copy (State &From, State &To, const Transition *Other, TransitionVector &, bool OutOfScope=false)
	Creates a transition between the specified states, with the same transition type as the copied transition. More...

static void	GroupClasses (const TransitionVector &, TransitionSets &)
	Group transitions into equivalence classes. More...

Protected Member Functions
	Transition (const State &From, const State &To, bool Init, bool Cleanup, bool OutOfScope)

Static Protected Member Functions
static void	Register (llvm::OwningPtr< Transition > &, State &From, State &To, TransitionVector &)

static void	Append (const llvm::OwningPtr< Transition > &, TransitionSets &)

Protected Attributes
const State &	From

const State &	To

bool	Init
	This transition triggers initialisation. More...

bool	Cleanup
	This transition triggers cleanup. More...

const bool	OutOfScope

Member Enumeration Documentation

enum tesla::Transition::TransitionKind

Information for LLVM's RTTI (isa<>, cast<>, etc.).

Enumerator
Null
Now
Fn
FieldAssign
SubAutomaton

Definition at line 186 of file Transition.h.

186 { Null, Now, Fn, FieldAssign, SubAutomaton };

Constructor & Destructor Documentation

virtual tesla::Transition::~Transition ( )

inlinevirtual

Definition at line 137 of file Transition.h.

137 {}

tesla::Transition::Transition	(	const State &	From,
		const State &	To,
		bool	Init,
		bool	Cleanup,
		bool	OutOfScope
	)

inlineprotected

Definition at line 195 of file Transition.h.

     : From(From), To(To), Init(Init), Cleanup(Cleanup),
       OutOfScope(OutOfScope)
   {
     // An out-of-scope event cannot cause initialisation.
     assert(!Init || !OutOfScope);
   }

Member Function Documentation

static void tesla::Transition::Append	(	const llvm::OwningPtr< Transition > &	,
		TransitionSets &
	)

staticprotected

virtual const ReferenceVector tesla::Transition::Arguments ( ) const

pure virtual

Arguments referenced by this transition.

Implemented in tesla::SubAutomatonTransition, tesla::FieldAssignTransition, tesla::FnTransition, tesla::NowTransition, and tesla::NullTransition.

void tesla::Transition::Copy	(	State &	From,
		State &	To,
		const Transition *	Other,
		TransitionVector &	Transitions,
		bool	OutOfScope = `false`
	)

static

Creates a transition between the specified states, with the same transition type as the copied transition.

This is used when constructing DFA transitions from NFA transitions.

Definition at line 94 of file Transition.cpp.

References getKind(), OutOfScope, RequiresCleanup(), and RequiresInit().

Referenced by tesla::internal::DFABuilder::ConstructDFA(), and tesla::internal::NFAParser::Parse().

                                                                       {
 
   OwningPtr<Transition> New;
   bool Init = Other->RequiresInit();
   bool Cleanup = Other->RequiresCleanup();
 
   OutOfScope |= Other->OutOfScope;
   assert(!Init || !OutOfScope);
 
   switch (Other->getKind()) {
   case Null:
     assert(!OutOfScope);
     return;
 
   case Now: {
     assert(!OutOfScope);
     auto O = cast<NowTransition>(Other);
     New.reset(new NowTransition(From, To, O->Ev, O->Refs, Init, Cleanup));
     break;
   }
 
   case Fn:
     New.reset(new FnTransition(From, To, cast<FnTransition>(Other)->Ev,
                                Init, Cleanup, OutOfScope));
     break;
 
   case FieldAssign:
     New.reset(new FieldAssignTransition(
                   From, To, cast<FieldAssignTransition>(Other)->Assign,
                   Init, Cleanup, OutOfScope));
     break;
 
   case SubAutomaton:
     assert(!OutOfScope);
     New.reset(new SubAutomatonTransition(From, To,
                   cast<SubAutomatonTransition>(Other)->ID));
     break;
   }
 
   assert(New);
   Register(New, From, To, Transitions);
 }

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void tesla::Transition::Create	(	State &	From,
		State &	To,
		TransitionVector &	Transitions,
		bool	Init = `false`,
		bool	Cleanup = `false`
	)

static

Create an unconditional transition.

An unconditional transition (ε in the automata literature) cannot be driven by instrumentation, so it should only appear in an NFA.

Parameters

[in,out]	From	The state to transition from; will be given ownership of the new transition.
[in]	To	The state to transition to.
[out]	Transitions	A place to record the new transition.
[in]	Init	Transition triggers class initialisation.
[in]	Cleanup	Transition triggers class cleanup.

Definition at line 49 of file Transition.cpp.

                                                  {
   OwningPtr<Transition> T(new NullTransition(From, To, Init, Cleanup));
   Register(T, From, To, Transitions);
 }

void tesla::Transition::Create	(	State &	From,
		State &	To,
		const FunctionEvent &	Ev,
		TransitionVector &	Transitions,
		bool	Init,
		bool	Cleanup,
		bool	OutOfScope = `false`
	)

static

Create a FunctionEvent transition.

Parameters

[in,out]	From	The state to transition from; will be given ownership of the new transition.
[in]	To	The state to transition to.
[in]	Ev	Protobuf representation of the event.
[out]	Transitions	A place to record the new transition.
[in]	Init	Transition triggers class initialisation.
[in]	Cleanup	Transition triggers class cleanup.
[in]	OutOfScope	The transition is out of a conditional automaton's scope.

Definition at line 66 of file Transition.cpp.

                                          {
 
   OwningPtr<Transition> T(
     new FnTransition(From, To, Ev, Init, Cleanup, OutOfScope));
 
   Register(T, From, To, Transitions);
 }

void tesla::Transition::Create	(	State &	From,
		State &	To,
		const FieldAssignment &	A,
		TransitionVector &	Transitions,
		bool	Init,
		bool	Cleanup,
		bool	OutOfScope = `false`
	)

static

Create a FieldAssignment transition.

Parameters

[in,out]	From	The state to transition from; will be given ownership of the new transition.
[in]	To	The state to transition to.
[in]	A	Protobuf representation of the event.
[out]	Transitions	A place to record the new transition.
[in]	Init	Transition triggers class initialisation.
[in]	Cleanup	Transition triggers class cleanup.
[in]	OutOfScope	The transition is out of a conditional automaton's scope.

Definition at line 76 of file Transition.cpp.

                                          {
 
   OwningPtr<Transition> T(
     new FieldAssignTransition(From, To, A, Init, Cleanup, OutOfScope));
 
   Register(T, From, To, Transitions);
 }

void tesla::Transition::Create	(	State &	From,
		State &	To,
		const NowEvent &	Ev,
		const AutomatonDescription &	Automaton,
		TransitionVector &	Transitions,
		bool	Init,
		bool	Cleanup
	)

static

Definition at line 55 of file Transition.cpp.

References tesla::AutomatonDescription::argument.

                                                                                 {
 
   ReferenceVector Refs(Automaton.argument().data(),
                                  Automaton.argument_size());
 
   OwningPtr<Transition> T(new NowTransition(From, To, Ev, Refs, Init, Cleanup));
   Register(T, From, To, Transitions);
 }

void tesla::Transition::CreateSubAutomaton	(	State &	From,
		State &	To,
		const Identifier &	ID,
		TransitionVector &	Transitions
	)

static

Definition at line 86 of file Transition.cpp.

                                                                    {
 
   OwningPtr<Transition> T(new SubAutomatonTransition(From, To, ID));
   Register(T, From, To, Transitions);
 }

const State& tesla::Transition::Destination ( ) const

inline

Definition at line 140 of file Transition.h.

References To.

Referenced by tesla::internal::DFABuilder::ConstructDFA().

140 { return To; }

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virtual std::string tesla::Transition::DotLabel ( ) const

pure virtual

A label that can go in a .dot file (can use newline, Greek HTML codes...).

Implemented in tesla::SubAutomatonTransition, tesla::FieldAssignTransition, tesla::FnTransition, tesla::NowTransition, and tesla::NullTransition.

virtual bool tesla::Transition::EquivalentTo ( const Transition & T ) const

pure virtual

Does this transition consume and produce the same symbols as another?

Implemented in tesla::SubAutomatonTransition, tesla::FieldAssignTransition, tesla::FnTransition, tesla::NowTransition, and tesla::NullTransition.

virtual TransitionKind tesla::Transition::getKind ( ) const

pure virtual

Implemented in tesla::SubAutomatonTransition, tesla::FieldAssignTransition, tesla::FnTransition, tesla::NowTransition, and tesla::NullTransition.

Referenced by tesla::NullTransition::classof(), tesla::NowTransition::classof(), tesla::FnTransition::classof(), tesla::FieldAssignTransition::classof(), tesla::SubAutomatonTransition::classof(), tesla::internal::DFABuilder::ConstructDFA(), Copy(), tesla::NullTransition::EquivalentTo(), tesla::NowTransition::EquivalentTo(), tesla::FnTransition::EquivalentTo(), tesla::FieldAssignTransition::EquivalentTo(), and tesla::SubAutomatonTransition::EquivalentTo().

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void tesla::Transition::GroupClasses	(	const TransitionVector &	Ungrouped,
		TransitionSets &	EquivalenceClasses
	)

static

Group transitions into equivalence classes.

Definition at line 153 of file Transition.cpp.

References tesla::debugs().

Referenced by tesla::internal::DFABuilder::ConstructDFA(), and tesla::internal::NFAParser::Parse().

                                                                   {
 
   auto& Out = debugs("tesla.automata.transitions.equivalence");
   Out << "grouping transitions:\n";
 
   for (auto *T : Ungrouped) {
     Out << "  " << T->String() << "\n";
 
     bool FoundEquivalent = false;
     for (auto& Set : EquivalenceClasses) {
       auto *Head = *Set.begin();
       if (T->EquivalentTo(*Head)) {
         assert(Head->EquivalentTo(*T));
         FoundEquivalent = true;
         Set.insert(T);
         break;
       }
     }
 
     if (!FoundEquivalent) {
       SmallPtrSet<const Transition*, 4> New;
       New.insert(T);
       EquivalenceClasses.push_back(New);
     }
   }
 
   Out << "equivalence classes:\n";
   for (auto& EquivClass : EquivalenceClasses) {
     bool Head = true;
     for (const Transition *T : EquivClass) {
       Out << (Head ? "  " : "   == ") << T->String() << "\n";
       Head = false;
     }
   }
 }

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bool tesla::Transition::InScope ( ) const

inline

Definition at line 183 of file Transition.h.

References OutOfScope.

Referenced by tesla::State::UpdateReferences().

183 { return !OutOfScope; }

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virtual bool tesla::Transition::IsRealisable ( ) const

pure virtual

Can this transition be captured by real instrumentation code?

Implemented in tesla::SubAutomatonTransition, tesla::FieldAssignTransition, tesla::FnTransition, tesla::NowTransition, and tesla::NullTransition.

Referenced by tesla::internal::DFABuilder::ConstructDFA().

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virtual bool tesla::Transition::IsStrict ( ) const

inlinevirtual

This transition can only occur as described in an automaton.

Reimplemented in tesla::FieldAssignTransition, and tesla::FnTransition.

Definition at line 152 of file Transition.h.

152 { return false; }

int tesla::Transition::NewArgMask ( ) const

A bitmask representing the arguments newly referenced by this transition.

Definition at line 239 of file Transition.cpp.

                                  {
   auto NewArgs(NewArguments());
   int Mask = 0;
 
   for (int i = 0; i < NewArgs.size(); i++)
     if ((NewArgs[i] != NULL) && (NewArgs[i]->type() == Argument::Variable))
       Mask += (1 << i);
 
   return Mask;
 }

SmallVector< const Argument *, 4 > tesla::Transition::NewArguments ( ) const

Arguments newly referenced by this transition (unknown to previous state).

Definition at line 226 of file Transition.cpp.

                                                               {
   auto OldArgs(From.References());
   auto TransArgs(Arguments());
 
   SmallVector<const Argument*,4> NewArgs(TransArgs.size());
   for (size_t i = 0; i < NewArgs.size(); i++)
     if ((OldArgs.size() <= i) || (OldArgs[i] == NULL))
       NewArgs[i] = TransArgs[i];
 
   return NewArgs;
 }

void tesla::Transition::ReferencesThusFar	(	llvm::OwningArrayPtr< const Argument * > &	Args,
		ReferenceVector &	Ref
	)		const

The references known at the point this transition occurs.

Parameters

[out]	Args	where to store the resulting array of arguments
[out]	Ref	a reference to the created arguments; includes length

Definition at line 191 of file Transition.cpp.

Referenced by tesla::State::UpdateReferences().

                                                                {
 
   // Put this transition's *variable* references in var-index order.
   SmallVector<const Argument*, 4> MyRefs;
   for (auto Arg : this->Arguments())
     if (Arg && Arg->type() == Argument::Variable) {
       size_t i = Arg->index();
 
       if (MyRefs.size() <= i)
         MyRefs.resize(i + 1);
 
       MyRefs[i] = Arg;
     }
 
   auto& FromRefs = From.References();
   const size_t Size = FromRefs.size();
 
   auto Arguments = new const Argument*[Size];
   for (size_t i = 0; i < Size; i++) {
     if ((MyRefs.size() > i) && MyRefs[i])
       Arguments[i] = MyRefs[i];
 
     else if ((FromRefs.size() > i) && FromRefs[i])
       Arguments[i] = FromRefs[i];
 
     else
       Arguments[i] = NULL;
   }
 
   Args.reset(Arguments);
   Ref = ReferenceVector(Arguments, Size);
 }

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void tesla::Transition::Register	(	llvm::OwningPtr< Transition > &	,
		State &	From,
		State &	To,
		TransitionVector &
	)

staticprotected

Definition at line 138 of file Transition.cpp.

References tesla::State::AddTransition(), tesla::debugs(), tesla::State::ID(), and tesla::State::UpdateReferences().

                                                          {
 
   Transitions.push_back(T.get());
   debugs("tesla.automata.transitions") << "registered " << T->String() << "\n";
 
   // We should never try to update the start state's references.
   assert(To.ID() != 0);
 
   // Update the state we're pointing to with the references it should
   // know about thus far in the execution of the automaton.
   To.UpdateReferences(*T.get());
   From.AddTransition(T);
 }

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bool tesla::Transition::RequiresCleanup ( ) const

inline

This transition triggers cleanup of its TESLA automata class.

Definition at line 149 of file Transition.h.

References Cleanup.

Referenced by Copy().

149 { return Cleanup; }

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bool tesla::Transition::RequiresInit ( ) const

inline

This transition triggers initialisation of its TESLA automata class.

Definition at line 146 of file Transition.h.

References Init.

Referenced by Copy().

146 { return Init; }

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virtual std::string tesla::Transition::ShortLabel ( ) const

pure virtual

A short, human-readable label.

Implemented in tesla::SubAutomatonTransition, tesla::FieldAssignTransition, tesla::FnTransition, tesla::NowTransition, and tesla::NullTransition.

const State& tesla::Transition::Source ( ) const

inline

Definition at line 139 of file Transition.h.

References From.

139 { return From; }

string tesla::Transition::String ( ) const

virtual

Definition at line 251 of file Transition.cpp.

References tesla::ShortName().

Referenced by tesla::State::String().

                                 {
   string NewArgs;
   for (auto A : NewArguments())
     if ((A != NULL) && (A->type() == Argument::Variable))
       NewArgs += " " + ShortName(A);
 
   string Special =
     string(RequiresInit() ? "<<init>>" : "")
     + (RequiresCleanup() ? "<<cleanup>>" : "")
     ;
 
   return (Twine()
     + "--("
     + ShortLabel()
     + (NewArgs.empty() ? "" : ":" + NewArgs)
     + (Special.empty() ? "" : " " + Special)
     + ")-->("
     + Twine(To.ID())
     + ")"
   ).str();
 }

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Member Data Documentation

bool tesla::Transition::Cleanup

protected

This transition triggers cleanup.

This transition is not named by the (conditional) TESLA automaton.

Definition at line 208 of file Transition.h.

Referenced by RequiresCleanup().

const State& tesla::Transition::From

protected

Definition at line 204 of file Transition.h.

Referenced by Source().

bool tesla::Transition::Init

protected

This transition triggers initialisation.

Definition at line 207 of file Transition.h.

Referenced by RequiresInit().

const bool tesla::Transition::OutOfScope

protected

Definition at line 211 of file Transition.h.

Referenced by Copy(), and InScope().

const State& tesla::Transition::To

protected

Definition at line 205 of file Transition.h.

Referenced by Destination().

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

tesla/common/Transition.h
tesla/common/Transition.cpp

Computer Laboratory

Detailed Description

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation