PendingAssignment.cc

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/*
    Copyright (c) 2002-2009 Tampere University.
 
    This file is part of TTA-Based Codesign Environment (TCE).
 
    Permission is hereby granted, free of charge, to any person obtaining a
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/**
 * @file PendingAssignment.cc
 *
 * Implementation of PendingAssignment class.
 *
 * @author Ari Mets�halme 2006 (ari.metsahalme-no.spam-tut.fi)
 * @note rating: red
 */
 
#include <string>
 
#include "ResourceBroker.hh"
#include "PendingAssignment.hh"
#include "MoveNode.hh"
 
using std::string;
 
/**
 * Constructor.
 */
PendingAssignment::PendingAssignment(ResourceBroker& broker):
    broker_(broker), cycle_(-1), node_(NULL), assignmentTried_(false),
    lastTriedAssignment_(-1) {
}
 
/**
 * Destructor.
 */
PendingAssignment::~PendingAssignment(){
}
 
/**
 * Return the broker of this pending assignment.
 *
 * @return The broker of this pending assignment.
 */
ResourceBroker&
PendingAssignment::broker() {
    return broker_;
}
 
/**
 * Record the input node to which resources have to be assigned or
 * allocated, and the cycle in which the node should be placed.
 *
 * @param cycle Cycle.
 * @param node Node.
 */
void
PendingAssignment::setRequest(int cycle, MoveNode& node,
                              const TTAMachine::Bus* bus,
                              const TTAMachine::FunctionUnit* srcFU,
                              const TTAMachine::FunctionUnit* dstFU,
                              int immWriteCycle,
                              const TTAMachine::ImmediateUnit* immu,
                              int immRegIndex) {
    cycle_ = cycle;
    node_ = &node;
    bus_ = bus;
    srcFU_ = srcFU;
    dstFU_ = dstFU;
    immWriteCycle_ = immWriteCycle;
    immu_ = immu;
    immRegIndex_ = immRegIndex;
    lastTriedAssignment_ = -1;
}
 
/**
 * Return true if, for the currently applied assignments, there exists
 * at least one tentative assignment which has not been tried yet.
 *
 * @return True if, for the currently applied assignments, there exists
 * at least one tentative assignment which has not been tried yet.
 */
bool
PendingAssignment::isAssignmentPossible() {
    if (lastTriedAssignment_ == -1) {
        availableResources_ = broker_.allAvailableResources(
        cycle_, *node_, bus_, srcFU_, dstFU_, immWriteCycle_, immu_,
        immRegIndex_);
        // Sorts candidate set of resources by their use count or name if
        // the use counts are identical
        availableResources_.sort();
    }
    return lastTriedAssignment_ < availableResources_.count() - 1;
}
 
/**
 * Try to assign the next possible assignment found by current
 * broker.
 *
 * @exception ModuleRunTimeError If this PendingAssignment has run out of
 * possible assignments.
 */
void
PendingAssignment::tryNext() {
 
    lastTriedAssignment_ += 1;
 
    if (availableResources_.count() == 0 ||
        lastTriedAssignment_ >= availableResources_.count()) {
        string msg = "Ran out of possible assignments!";
        throw ModuleRunTimeError(__FILE__, __LINE__, __func__, msg);
    }
 
    broker_.assign(
        cycle_, *node_, availableResources_.resource(lastTriedAssignment_),
        immWriteCycle_, immRegIndex_);
    assignmentTried_ = true;
}
 
/**
 * Unassign the resource of this pending assignment currently assigned
 * to the node.
 *
 * Last tried assignment is remembered.
 *
 * @exception ModuleRunTimeError If no resource in the set of
 * resources of this pending assignment is currently assigned to the
 * node.
 */
void
PendingAssignment::undoAssignment() {
    if (broker_.isAlreadyAssigned(cycle_, *node_, bus_)) {
        broker_.unassign(*node_);
    } else {
        string msg = "No resource in the set of resources of this pending"
            "assignment was assigned to the given node!";
        throw ModuleRunTimeError(__FILE__, __LINE__, __func__, msg);
    }
}
 
/**
 * Clear out the record of the possible resource assignments of the
 * current broker that have been already tried.
 *
 * If one of the possible resources is still assigned to the node,
 * unassign it.
 */
void
PendingAssignment::forget() {
    if (broker_.isAlreadyAssigned(cycle_, *node_, bus_)) {
        broker_.unassign(*node_);
    }
    lastTriedAssignment_ = -1;
}
 
/**
 * Clears the pending assignment. 
 *
 * Does not unassign anything.
 */
void
PendingAssignment::clear() {
    cycle_ = -1;
    node_ = NULL;
    immu_ = NULL;
    immWriteCycle_ = -1;
    immRegIndex_ = -1;
 
    assignmentTried_ = false;
    lastTriedAssignment_ = -1;
    availableResources_.clear();
    bus_ = NULL;
}