transact.cxx

eCos1.31版

}

const std::vector<CdlConflict>&
CdlTransactionBody::get_deleted_structural_conflicts() const
{
    CYG_REPORT_FUNCNAME("CdlTransaction::get_deleted_structural_conflicts");
    CYG_REPORT_FUNCARG1XV(this);
    CYG_PRECONDITION_THISC();

    CYG_REPORT_RETURN();
    return deleted_structural_conflicts;
}

const std::vector<CdlConflict>&
CdlTransactionBody::get_resolved_conflicts() const
{
    CYG_REPORT_FUNCNAME("CdlTransaction::get_resolved_conflicts");
    CYG_REPORT_FUNCARG1XV(this);
    CYG_PRECONDITION_THISC();

    CYG_REPORT_RETURN();
    return resolved_conflicts;
}

const std::list<CdlConflict>&
CdlTransactionBody::get_global_conflicts_with_solutions() const
{
    CYG_REPORT_FUNCNAME("CdlTransaction::get_global_conflicts_with_solutions");
    CYG_REPORT_FUNCARG1XV(this);
    CYG_PRECONDITION_THISC();

    CYG_REPORT_RETURN();
    return global_conflicts_with_solutions;
}

//}}}

//}}}
//{{{  Commit/cancel operations                 

// ----------------------------------------------------------------------------
void
CdlTransactionBody::add_commit_cancel_op(CdlTransactionCommitCancelOp* op)
{
    CYG_REPORT_FUNCNAME("CdlTransaction::add_commit_cancel_op");
    CYG_REPORT_FUNCARG2XV(this, op);
    CYG_PRECONDITION_THISC();
    CYG_PRECONDITIONC(0 != op);

    commit_cancel_ops.push_back(op);
    
    CYG_REPORT_RETURN();
}

void
CdlTransactionBody::cancel_last_commit_cancel_op()
{
    CYG_REPORT_FUNCNAME("CdlTransaction::cancel_last_commit_cancel_op");
    CYG_REPORT_FUNCARG1XV(this);
    CYG_PRECONDITION_THISC();

    CdlTransactionCommitCancelOp* op = *(commit_cancel_ops.rbegin());
    commit_cancel_ops.pop_back();
    op->cancel(this);
    delete op;
        
    CYG_REPORT_RETURN();
}

CdlTransactionCommitCancelOp*
CdlTransactionBody::get_last_commit_cancel_op() const
{
    CYG_REPORT_FUNCNAMETYPE("CdlTransaction::get_last_commit_cancel_op", "result %p");
    CYG_REPORT_FUNCARG1XV(this);
    CYG_PRECONDITION_THISC();

    CdlTransactionCommitCancelOp* op = *(commit_cancel_ops.rbegin());
    
    CYG_REPORT_RETVAL(op);
    return op;
}

const std::vector<CdlTransactionCommitCancelOp*>&
CdlTransactionBody::get_commit_cancel_ops() const
{
    CYG_REPORT_FUNCNAME("CdlTransaction::get_commit_cancel_ops");
    CYG_REPORT_FUNCARG1XV(this);
    CYG_PRECONDITION_THISC();

    CYG_REPORT_RETURN();
    return commit_cancel_ops;
}

//}}}
//{{{  Propagation                              

// ----------------------------------------------------------------------------
// Propagation should happen whenever one or more changes have been applied,
// so that the impact of these changes on other parts of the configuration
// can be fully assessed. The transaction keeps track of all the changes
// to date and invokes appropriate node and property update handlers.

void
CdlTransactionBody::propagate()
{
    CYG_REPORT_FUNCNAME("CdlTransaction::propagate");
    CYG_REPORT_FUNCARG1XV(this);
    CYG_INVARIANT_THISC(CdlTransactionBody);
    
    // Now it is time to worry about value and active changes.
    // Propagation may result in new entries, so only the
    // front item of one of the vectors is modified.
    while ((0 < value_changes.size()) || (0 < active_changes.size())) {
        
        if (0 != value_changes.size()) {
            
            CdlValuable valuable = value_changes.front();
            value_changes.pop_front();
            
            // A value change may invalidate one or more solutions.
            // This happens during propagation rather than at the time
            // that the value is actually changed, so that multiple
            // solutions can be applied in one go.
            std::list<CdlConflict>::iterator conf_i, conf_j;
            for (conf_i = new_conflicts.begin(); conf_i != new_conflicts.end(); conf_i++) {
                CYG_LOOP_INVARIANT_CLASSC(*conf_i);
                (*conf_i)->update_solution_validity(valuable);
            }
            for (conf_i = global_conflicts_with_solutions.begin();
                 conf_i != global_conflicts_with_solutions.end();
                 ) {
                
                CYG_LOOP_INVARIANT_CLASSC(*conf_i);
                conf_j = conf_i++;

                (*conf_j)->update_solution_validity(valuable);
                if (!(*conf_j)->has_known_solution()) {
                    global_conflicts_with_solutions.erase(conf_j);
                }
            }

            // If the valuable is no longer loaded then there is
            // no need to worry about propagation
            if (0 != valuable->get_toplevel()) {
                
                // Inform the valuable itself about the update, so that
                // e.g. the value can be checked against legal_values
                valuable->update(this, CdlUpdate_ValueChange);
            
                std::vector<CdlReferrer>& referrers = valuable->referrers;
                std::vector<CdlReferrer>::iterator ref_i;
                for (ref_i = referrers.begin(); ref_i != referrers.end(); ref_i++) {
                    ref_i->update(this, valuable, CdlUpdate_ValueChange);
                }
            }
                
        } else {
            
            CdlNode node = active_changes.front();
            active_changes.pop_front();

            if (0 != node->get_toplevel()) {
                node->update(this, CdlUpdate_ActiveChange);
            
                std::vector<CdlReferrer>& referrers = node->referrers;
                std::vector<CdlReferrer>::iterator ref_i;
                for (ref_i = referrers.begin(); ref_i != referrers.end(); ref_i++) {
                    ref_i->update(this, node, CdlUpdate_ActiveChange);
                }
            }
        }
    }

    CYG_REPORT_RETURN();
}

// ----------------------------------------------------------------------------
bool
CdlTransactionBody::is_propagation_required() const
{
    CYG_REPORT_FUNCNAMETYPE("CdlTransaction::is_propagation_required", "result %d");
    CYG_REPORT_FUNCARG1XV(this);
    CYG_PRECONDITION_THISC();

    bool result = false;

    if ((0 != value_changes.size()) || (0 != active_changes.size())) {
        result = true;
    }
    
    CYG_REPORT_RETVAL(result);
    return result;
}


// ----------------------------------------------------------------------------
void
CdlTransactionBody::add_legal_values_change(CdlValuable valuable)
{
    CYG_REPORT_FUNCNAME("CdlTransaction::add_legal_values_change");
    CYG_REPORT_FUNCARG2XV(this, valuable);
    CYG_PRECONDITION_THISC();
    CYG_PRECONDITION_CLASSC(valuable);

    legal_values_changes.insert(valuable);
    
    CYG_REPORT_RETURN();
}

const std::set<CdlValuable>&
CdlTransactionBody::get_legal_values_changes() const
{
    CYG_REPORT_FUNCNAME("CdlTransaction::get_legal_values_changes");
    CYG_REPORT_FUNCARG1XV(this);
    CYG_PRECONDITION_THISC();

    CYG_REPORT_RETURN();
    return legal_values_changes;
}

//}}}
//{{{  Cancel                                   

// ----------------------------------------------------------------------------
// Cancellation is straightforward, essentially it just involves clearing
// out all of the STL containers. The transaction object can then be-used,
// so fields like parent and toplevel must not change.
void
CdlTransactionBody::cancel()
{
    CYG_REPORT_FUNCNAME("CdlTransaction::cancel");
    CYG_REPORT_FUNCARG1XV(this);
    CYG_INVARIANT_THISC(CdlTransactionBody);

    // First take care of the cancel ops, if any, in case a cancel op
    // depends on some of the other transaction state.
    std::vector<CdlTransactionCommitCancelOp*>::reverse_iterator cancel_i;
    for (cancel_i = commit_cancel_ops.rbegin(); cancel_i != commit_cancel_ops.rend(); cancel_i++) {
        (*cancel_i)->cancel(this);
        delete *cancel_i;
        *cancel_i = 0;
    }
    commit_cancel_ops.clear();
    
    this->changes.clear();
    std::list<CdlConflict>::iterator conf_i;
    for (conf_i = this->new_conflicts.begin(); conf_i != this->new_conflicts.end(); conf_i++) {
        CYG_LOOP_INVARIANT_CLASSC(*conf_i);
        delete *conf_i;
    }
    this->new_conflicts.clear();
    for (conf_i = this->new_structural_conflicts.begin(); conf_i != this->new_structural_conflicts.end(); conf_i++) {
        CYG_LOOP_INVARIANT_CLASSC(*conf_i);
        delete *conf_i;
    }
    this->new_structural_conflicts.clear();
    
    this->deleted_structural_conflicts.clear();
    this->deleted_conflicts.clear();
    
    // Any conflicts created and resolved during this transaction will
    // still be present in resolved_conflicts. Some global conflicts
    // may be there as well.
    std::vector<CdlConflict>::iterator conf_i2;
    for (conf_i2 = this->resolved_conflicts.begin(); conf_i2 != this->resolved_conflicts.end(); conf_i2++) {
        if (this == (*conf_i2)->transaction) {
            delete (*conf_i2);
        }
    }
    this->resolved_conflicts.clear();

    // Any global conflicts which have been updated with a solution need
    // to have that solution cleared. Currently no attempt is made to
    // keep solutions valid for global conflicts.
    for (conf_i = this->global_conflicts_with_solutions.begin();
         conf_i != this->global_conflicts_with_solutions.end();
         conf_i++) {

        CYG_LOOP_INVARIANT_CLASSC(*conf_i);
        (*conf_i)->clear_solution();
    }
    this->global_conflicts_with_solutions.clear();
    
    this->activated.clear();
    this->deactivated.clear();
    this->legal_values_changes.clear();
    this->value_changes.clear();
    this->active_changes.clear();

    CYG_REPORT_RETURN();
}

//}}}
//{{{  Commit                                   

// ----------------------------------------------------------------------------
// The commit operation. There are two main branches for this code. The
// first branch deals with sub-transactions, and basically involves
// transferring changes from the sub-transaction to the parent. It is
// assumed that the sub-transaction has been fully propagated, so
// data can just be transferred from the child to the parent.
//
// The second branch involves committing changes from a transaction to
// the toplevel, invoking the transaction callback if necessary.

void
CdlTransactionBody::commit()
{
    CYG_REPORT_FUNCNAME("CdlTransaction::commit");
    CYG_REPORT_FUNCARG1XV(this);
    CYG_INVARIANT_THISC(CdlTransactionBody);

    std::map<CdlValuable, CdlValue>::iterator map_i;
    std::list<CdlConflict>::iterator conf_i, conf_j;
    std::vector<CdlConflict>::const_iterator conf_i2, conf_j2;
    std::set<CdlNode>::iterator set_i, set_j, set_k;
    std::set<CdlValuable>::iterator set_i2, set_j2;

    if (0 != parent) {
        // Any conflicts that were solved by the inference engine further
        // down are still resolved.
        // Great care has to be taken with conflict ownership. The following
        // cases have to be considered.
        // 1) the resolved conflict is global, its transaction is zero, this
        //    conflict must only be destroyed if the toplevel transaction
        //    is committed - at which time time the conflict should appear
        //    on the deleted_conflicts lists.
        // 2) the conflict belongs to a higher level transaction, we have
        //    recursed a certain amount trying to resolve it e.g. to explore
        //    OR branches of the tree. Again the resolved conflict can only
        //    be destroyed when the appropriate higher-level commit happens,
        //    and should appear on the deleted conflicts list.
        // 3) the conflict was created and resolved further down the tree.
        //    We are keeping it around for informational purposes only.
        //    Associating it with this transaction allows the code to
        //    distinguish this case from (1) and (2).
        for (conf_i2 = resolved_conflicts.begin(); conf_i2 != resolved_conflicts.end(); conf_i2++) {
            CdlConflict conf = *conf_i2;
            CYG_LOOP_INVARIANT_CLASSC(conf);
            CYG_LOOP_INVARIANTC(parent->resolved_conflicts.end() == \
                                std::find(parent->resolved_conflicts.begin(), \
                                          parent->resolved_conflicts.end(), conf));
            parent->resolved_conflicts.push_back(conf);
            parent->dirty = true;
            if (this == conf->transaction) {
                conf->transaction = parent;
            }
        }
        resolved_conflicts.clear();

        // Any global conflicts for which solutions were found in the
        // sub-transaction still have solutions in the parent.
        for (conf_i = global_conflicts_with_solutions.begin(); conf_i != global_conflicts_with_solutions.end(); conf_i++) {
            
            CdlConflict conf = *conf_i;
            CYG_LOOP_INVARIANT_CLASSC(conf);
            
            // It is not clear that this search is actually useful, especially
            // given that the solution is currently stored with the conflict
            // rather than with the transaction.
            conf_j = std::find(parent->global_conflicts_with_solutions.begin(),
                                parent->global_conflicts_with_solutions.end(),
                                conf);
            if (conf_j == parent->global_conflicts_with_solutions.end()) {
                parent->global_conflicts_with_solutions.push_back(conf);
                parent->dirty = true;
            }
        }
        global_conflicts_with_solutions.clear();
        
        // Now take care of deleted conflicts.
        for (conf_i2 = deleted_conflicts.begin(); conf_i2 != deleted_conflicts.end(); conf_i2++) {
            CdlConflict conf = *conf_i2;