at.dms.kjc.rstream
Class FusionState

java.lang.Object
  at.dms.kjc.rstream.FusionState

Direct Known Subclasses:

FilterFusionState, JoinerFusionState, SplitterFusionState

public abstract class FusionState
extends Object

This abstract class represents the state necessary for each FlatNode in the application to be converted to imperative SIR code by GenerateCCode. Any state that can be shared over FilterFusionState, JoinerFusionState, and SplitterFusionState is here. Plus it defines a common interface (getWork(), initTasks()) for those nodes.

Author:

Michael Gordon

Field Summary

protected static String	BACKUPCOUNTER
static String	BUFFERNAME the variaible prefix of the incoming buffer
protected JVariableDefinition[]	bufferVar the size of the incoming buffers for each incoming edge
protected static HashMap<FlatNode,FusionState>	fusionState a hashmap of all fusionstates created so far, indexed by flatnode
protected int	myUniqueID the unique ID of this fusionstate
protected boolean	necessary true if this node *needs* to code generated for correctness false for some identity's and duplicate splitters
protected FlatNode	node the flatnode that this object represents
protected int[]	remaining the number of items remaining on the tape after the init stage has completed for each incoming channel of the node

Constructor Summary

protected

FusionState(FlatNode node) create a new FusionState object that represents *node*, note one should never create fusionstates, they are created using getFusionState().

Method Summary

abstract int	getBufferSize(FlatNode prev, boolean init) get the size of the buffer from *prev* to this node
abstract JVariableDefinition	getBufferVar(FlatNode prev, boolean init) Return the JVariableDefinition associated with the incoming buffer from *prev* to this node.
static FusionState	getFusionState(FlatNode node) Given FlatNode *node*, return the fusion state object representing it.
FlatNode	getNode() Return the FlatNode associated with this FusionState
abstract int	getRemaining(FlatNode prev, boolean init) get the number of items remaining after the init stage on the incoming buffer from *prev* to this node
abstract JStatement[]	getWork(JBlock enclosingBlock, boolean isInit) get the block that will perform the init stage (*isInit* = true) or the steady-state (*isInit* = false), add any var decls to *enclosingBlock*
abstract void	initTasks(Vector<JFieldDeclaration> fields, Vector<JMethodDeclaration> functions, JBlock initFunctionCalls, JBlock main) called by GenerateCCode so that this node can add any initialization code to the application
protected JStatement	intAssignStm(JVariableDefinition def, int value) Returnn a JAssignmentStatement that will assign *value* to def*.
boolean	isNecesary()
protected JVariableDefinition	makeBuffer(int bufferSize, CType elementType, String bufferName) create a JVarDef representing an array of type *elementType* (which itself can be an array, with *bufferSize* elements and name *bufferName*.
protected JStatement	remainingBackupLoop(JVariableDefinition buffer, JVariableDefinition loopCounterBackup, int offset, int remainingItems) Return SIR code to move *remainingItems* to the beginning of *buffer* starting at *offset*, using *loopCounterBackup* as the induction variable of the loop.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

necessary

protected boolean necessary

true if this node *needs* to code generated for correctness false for some identity's and duplicate splitters

node

protected FlatNode node

the flatnode that this object represents

remaining

protected int[] remaining

the number of items remaining on the tape after the init stage has completed for each incoming channel of the node

bufferVar

protected JVariableDefinition[] bufferVar

the size of the incoming buffers for each incoming edge

fusionState

protected static HashMap<FlatNode,FusionState> fusionState

a hashmap of all fusionstates created so far, indexed by flatnode

myUniqueID

protected int myUniqueID

the unique ID of this fusionstate

BUFFERNAME

public static String BUFFERNAME

the variaible prefix of the incoming buffer

BACKUPCOUNTER

protected static String BACKUPCOUNTER

Constructor Detail

FusionState

protected FusionState(FlatNode node)

create a new FusionState object that represents *node*, note one should never create fusionstates, they are created using getFusionState().

Method Detail

getBufferSize

public abstract int getBufferSize(FlatNode prev,
                                  boolean init)

get the size of the buffer from *prev* to this node

getRemaining

public abstract int getRemaining(FlatNode prev,
                                 boolean init)

get the number of items remaining after the init stage on the incoming buffer from *prev* to this node

isNecesary

public boolean isNecesary()

initTasks

public abstract void initTasks(Vector<JFieldDeclaration> fields,
                               Vector<JMethodDeclaration> functions,
                               JBlock initFunctionCalls,
                               JBlock main)

called by GenerateCCode so that this node can add any initialization code to the application

getWork

public abstract JStatement[] getWork(JBlock enclosingBlock,
                                     boolean isInit)

get the block that will perform the init stage (*isInit* = true) or the steady-state (*isInit* = false), add any var decls to *enclosingBlock*

getFusionState

public static FusionState getFusionState(FlatNode node)

Given FlatNode *node*, return the fusion state object representing it. This forces only one fusion state to be created for each node. Remember all fusionstates in a hashmap indexed by FlatNode.

getBufferVar

public abstract JVariableDefinition getBufferVar(FlatNode prev,
                                                 boolean init)

Return the JVariableDefinition associated with the incoming buffer from *prev* to this node.

getNode

public FlatNode getNode()

Return the FlatNode associated with this FusionState

intAssignStm

protected JStatement intAssignStm(JVariableDefinition def,
                                  int value)

Returnn a JAssignmentStatement that will assign *value* to def*.

remainingBackupLoop

protected JStatement remainingBackupLoop(JVariableDefinition buffer,
                                         JVariableDefinition loopCounterBackup,
                                         int offset,
                                         int remainingItems)

Return SIR code to move *remainingItems* to the beginning of *buffer* starting at *offset*, using *loopCounterBackup* as the induction variable of the loop.

makeBuffer

protected JVariableDefinition makeBuffer(int bufferSize,
                                         CType elementType,
                                         String bufferName)

create a JVarDef representing an array of type *elementType* (which itself can be an array, with *bufferSize* elements and name *bufferName*.