#include "misc/util/util_hack.h"
#include "cuddInt.h"

Functions
void	Cudd_Ref (DdNode *n)

void	Cudd_RecursiveDeref (DdManager table, DdNode n)

void	Cudd_IterDerefBdd (DdManager table, DdNode n)

void	Cudd_DelayedDerefBdd (DdManager table, DdNode n)

void	Cudd_RecursiveDerefZdd (DdManager table, DdNode n)

void	Cudd_Deref (DdNode *node)

int	Cudd_CheckZeroRef (DdManager *manager)

void	cuddReclaim (DdManager table, DdNode n)

void	cuddReclaimZdd (DdManager table, DdNode n)

void	cuddShrinkDeathRow (DdManager *table)

void	cuddClearDeathRow (DdManager *table)

int	cuddIsInDeathRow (DdManager dd, DdNode f)

int	cuddTimesInDeathRow (DdManager dd, DdNode f)

Variables
static ABC_NAMESPACE_IMPL_START char rcsid[]	DD_UNUSED = "$Id: cuddRef.c,v 1.28 2004/08/13 18:04:50 fabio Exp $"

Function Documentation

int Cudd_CheckZeroRef ( DdManager * manager )

Function********************************************************************

Synopsis [Checks the unique table for nodes with non-zero reference counts.]

Description [Checks the unique table for nodes with non-zero reference counts. It is normally called before Cudd_Quit to make sure that there are no memory leaks due to missing Cudd_RecursiveDeref's. Takes into account that reference counts may saturate and that the basic constants and the projection functions are referenced by the manager. Returns the number of nodes with non-zero reference count. (Except for the cases mentioned above.)]

SideEffects [None]

SeeAlso []

Definition at line 466 of file cuddRef.c.

 {
     int size;
     int i, j;
     int remain; /* the expected number of remaining references to one */
     DdNodePtr *nodelist;
     DdNode *node;
     DdNode *sentinel = &(manager->sentinel);
     DdSubtable *subtable;
     int count = 0;
     int index;
 
 #ifndef DD_NO_DEATH_ROW
     cuddClearDeathRow(manager);
 #endif
 
     /* First look at the BDD/ADD subtables. */
     remain = 1; /* reference from the manager */
     size = manager->size;
     remain += 2 * size; /* reference from the BDD projection functions */
 
     for (i = 0; i < size; i++) {
         subtable = &(manager->subtables[i]);
         nodelist = subtable->nodelist;
         for (j = 0; (unsigned) j < subtable->slots; j++) {
             node = nodelist[j];
             while (node != sentinel) {
                 if (node->ref != 0 && node->ref != DD_MAXREF) {
                     index = (int) node->index;
                     if (node != manager->vars[index]) {
                         count++;
                     } else {
                         if (node->ref != 1) {
                             count++;
                         }
                     }
                 }
                 node = node->next;
             }
         }
     }
 
     /* Then look at the ZDD subtables. */
     size = manager->sizeZ;
     if (size) /* references from ZDD universe */
         remain += 2;
 
     for (i = 0; i < size; i++) {
         subtable = &(manager->subtableZ[i]);
         nodelist = subtable->nodelist;
         for (j = 0; (unsigned) j < subtable->slots; j++) {
             node = nodelist[j];
             while (node != NULL) {
                 if (node->ref != 0 && node->ref != DD_MAXREF) {
                     index = (int) node->index;
                     if (node == manager->univ[manager->permZ[index]]) {
                         if (node->ref > 2) {
                             count++;
                         }
                     } else {
                         count++;
                     }
                 }
                 node = node->next;
             }
         }
     }
 
     /* Now examine the constant table. Plusinfinity, minusinfinity, and
     ** zero are referenced by the manager. One is referenced by the
     ** manager, by the ZDD universe, and by all projection functions.
     ** All other nodes should have no references.
     */
     nodelist = manager->constants.nodelist;
     for (j = 0; (unsigned) j < manager->constants.slots; j++) {
         node = nodelist[j];
         while (node != NULL) {
             if (node->ref != 0 && node->ref != DD_MAXREF) {
                 if (node == manager->one) {
                     if ((int) node->ref != remain) {
                         count++;
                     }
                 } else if (node == manager->zero ||
                 node == manager->plusinfinity ||
                 node == manager->minusinfinity) {
                     if (node->ref != 1) {
                         count++;
                     }
                 } else {
                     count++;
                 }
             }
             node = node->next;
         }
     }
     return(count);
 
 } /* end of Cudd_CheckZeroRef */

void Cudd_DelayedDerefBdd	(	DdManager *	table,
		DdNode *	n
	)

Function********************************************************************

Synopsis [Decreases the reference count of BDD node n.]

Description [Enqueues node n for later dereferencing. If the queue is full decreases the reference count of the oldest node N to make room for n. If N dies, recursively decreases the reference counts of its children. It is used to dispose of a BDD that is currently not needed, but may be useful again in the near future. The dereferencing proper is done as in Cudd_IterDerefBdd.]

SideEffects [None]

SeeAlso [Cudd_RecursiveDeref Cudd_IterDerefBdd]

Definition at line 274 of file cuddRef.c.

 {
     DdNode *N;
     int ord;
     DdNodePtr *stack;
     int SP;
 
     unsigned int live = table->keys - table->dead;
     if (live > table->peakLiveNodes) {
         table->peakLiveNodes = live;
     }
 
     n = Cudd_Regular(n);
 #ifdef DD_DEBUG
     assert(n->ref != 0);
 #endif
 
 #ifdef DD_NO_DEATH_ROW
     N = n;
 #else
     if (cuddIsConstant(n) || n->ref > 1) {
 #ifdef DD_DEBUG
         assert(n->ref != 1 && (!cuddIsConstant(n) || n == DD_ONE(table)));
 #endif
         cuddSatDec(n->ref);
         return;
     }
 
     N = table->deathRow[table->nextDead];
 
     if (N != NULL) {
 #endif
 #ifdef DD_DEBUG
         assert(!Cudd_IsComplement(N));
 #endif
         stack = table->stack;
         SP = 1;
         do {
 #ifdef DD_DEBUG
             assert(N->ref != 0);
 #endif
             if (N->ref == 1) {
                 N->ref = 0;
                 table->dead++;
 #ifdef DD_STATS
                 table->nodesDropped++;
 #endif
                 ord = table->perm[N->index];
                 stack[SP++] = Cudd_Regular(cuddE(N));
                 table->subtables[ord].dead++;
                 N = cuddT(N);
             } else {
                 cuddSatDec(N->ref);
                 N = stack[--SP];
             }
         } while (SP != 0);
 #ifndef DD_NO_DEATH_ROW
     }
     table->deathRow[table->nextDead] = n;
 
     /* Udate insertion point. */
     table->nextDead++;
     table->nextDead &= table->deadMask;
 #if 0
     if (table->nextDead == table->deathRowDepth) {
         if (table->deathRowDepth < table->looseUpTo / 2) {
             extern void (*MMoutOfMemory)(long);
             void (*saveHandler)(long) = MMoutOfMemory;
             DdNodePtr *newRow;
             MMoutOfMemory = Cudd_OutOfMem;
             newRow = ABC_REALLOC(DdNodePtr,table->deathRow,2*table->deathRowDepth);
             MMoutOfMemory = saveHandler;
             if (newRow == NULL) {
                 table->nextDead = 0;
             } else {
                 int i;
                 table->memused += table->deathRowDepth;
                 i = table->deathRowDepth;
                 table->deathRowDepth <<= 1;
                 for (; i < table->deathRowDepth; i++) {
                     newRow[i] = NULL;
                 }
                 table->deadMask = table->deathRowDepth - 1;
                 table->deathRow = newRow;
             }
         } else {
             table->nextDead = 0;
         }
     }
 #endif
 #endif
 
 } /* end of Cudd_DelayedDerefBdd */

void Cudd_Deref ( DdNode * node )

Function********************************************************************

Synopsis [Decreases the reference count of node.]

Description [Decreases the reference count of node. It is primarily used in recursive procedures to decrease the ref count of a result node before returning it. This accomplishes the goal of removing the protection applied by a previous Cudd_Ref.]

SideEffects [None]

SeeAlso [Cudd_RecursiveDeref Cudd_RecursiveDerefZdd Cudd_Ref]

Definition at line 438 of file cuddRef.c.

 {
     node = Cudd_Regular(node);
     cuddSatDec(node->ref);
 
 } /* end of Cudd_Deref */

void Cudd_IterDerefBdd	(	DdManager *	table,
		DdNode *	n
	)

Function********************************************************************

Synopsis [Decreases the reference count of BDD node n.]

Description [Decreases the reference count of node n. If n dies, recursively decreases the reference counts of its children. It is used to dispose of a BDD that is no longer needed. It is more efficient than Cudd_RecursiveDeref, but it cannot be used on ADDs. The greater efficiency comes from being able to assume that no constant node will ever die as a result of a call to this procedure.]

SideEffects [None]

SeeAlso [Cudd_RecursiveDeref Cudd_DelayedDerefBdd]

Definition at line 217 of file cuddRef.c.

 {
     DdNode *N;
     int ord;
     DdNodePtr *stack = table->stack;
     int SP = 1;
 
     unsigned int live = table->keys - table->dead;
     if (live > table->peakLiveNodes) {
         table->peakLiveNodes = live;
     }
 
     N = Cudd_Regular(n);
 
     do {
 #ifdef DD_DEBUG
         assert(N->ref != 0);
 #endif
 
         if (N->ref == 1) {
             N->ref = 0;
             table->dead++;
 #ifdef DD_STATS
             table->nodesDropped++;
 #endif
             ord = table->perm[N->index];
             stack[SP++] = Cudd_Regular(cuddE(N));
             table->subtables[ord].dead++;
             N = cuddT(N);
         } else {
             cuddSatDec(N->ref);
             N = stack[--SP];
         }
     } while (SP != 0);
 
 } /* end of Cudd_IterDerefBdd */

void Cudd_RecursiveDeref	(	DdManager *	table,
		DdNode *	n
	)

Function********************************************************************

Synopsis [Decreases the reference count of node n.]

Description [Decreases the reference count of node n. If n dies, recursively decreases the reference counts of its children. It is used to dispose of a DD that is no longer needed.]

SideEffects [None]

SeeAlso [Cudd_Deref Cudd_Ref Cudd_RecursiveDerefZdd]

Definition at line 154 of file cuddRef.c.

 {
     DdNode *N;
     int ord;
     DdNodePtr *stack = table->stack;
     int SP = 1;
 
     unsigned int live = table->keys - table->dead;
     if (live > table->peakLiveNodes) {
         table->peakLiveNodes = live;
     }
 
     N = Cudd_Regular(n);
 
     do {
 #ifdef DD_DEBUG
         assert(N->ref != 0);
 #endif
 
         if (N->ref == 1) {
             N->ref = 0;
             table->dead++;
 #ifdef DD_STATS
             table->nodesDropped++;
 #endif
             if (cuddIsConstant(N)) {
                 table->constants.dead++;
                 N = stack[--SP];
             } else {
                 ord = table->perm[N->index];
                 stack[SP++] = Cudd_Regular(cuddE(N));
                 table->subtables[ord].dead++;
                 N = cuddT(N);
             }
         } else {
             cuddSatDec(N->ref);
             N = stack[--SP];
         }
     } while (SP != 0);
 
 } /* end of Cudd_RecursiveDeref */

void Cudd_RecursiveDerefZdd	(	DdManager *	table,
		DdNode *	n
	)

Function********************************************************************

Synopsis [Decreases the reference count of ZDD node n.]

Description [Decreases the reference count of ZDD node n. If n dies, recursively decreases the reference counts of its children. It is used to dispose of a ZDD that is no longer needed.]

SideEffects [None]

SeeAlso [Cudd_Deref Cudd_Ref Cudd_RecursiveDeref]

Definition at line 385 of file cuddRef.c.

 {
     DdNode *N;
     int ord;
     DdNodePtr *stack = table->stack;
     int SP = 1;
 
     N = n;
 
     do {
 #ifdef DD_DEBUG
         assert(N->ref != 0);
 #endif
 
         cuddSatDec(N->ref);
     
         if (N->ref == 0) {
             table->deadZ++;
 #ifdef DD_STATS
             table->nodesDropped++;
 #endif
 #ifdef DD_DEBUG
             assert(!cuddIsConstant(N));
 #endif
             ord = table->permZ[N->index];
             stack[SP++] = cuddE(N);
             table->subtableZ[ord].dead++;
             N = cuddT(N);
         } else {
             N = stack[--SP];
         }
     } while (SP != 0);
 
 } /* end of Cudd_RecursiveDerefZdd */

void Cudd_Ref ( DdNode * n )

AutomaticStart AutomaticEnd Function********************************************************************

Synopsis [Increases the reference count of a node, if it is not saturated.]

Description []

SideEffects [None]

SeeAlso [Cudd_RecursiveDeref Cudd_Deref]

Definition at line 129 of file cuddRef.c.

 {
 
     n = Cudd_Regular(n);
 
     cuddSatInc(n->ref);
 
 } /* end of Cudd_Ref */

void cuddClearDeathRow ( DdManager * table )

Function********************************************************************

Synopsis [Clears the death row.]

Description []

SideEffects [None]

SeeAlso [Cudd_DelayedDerefBdd Cudd_IterDerefBdd Cudd_CheckZeroRef cuddGarbageCollect]

Definition at line 726 of file cuddRef.c.

 {
 #ifndef DD_NO_DEATH_ROW
     int i;
 
     for (i = 0; i < table->deathRowDepth; i++) {
         if (table->deathRow[i] == NULL) break;
         Cudd_IterDerefBdd(table,table->deathRow[i]);
         table->deathRow[i] = NULL;
     }
 #ifdef DD_DEBUG
     for (; i < table->deathRowDepth; i++) {
         assert(table->deathRow[i] == NULL);
     }
 #endif
     table->nextDead = 0;
 #endif
 
 } /* end of cuddClearDeathRow */

int cuddIsInDeathRow	(	DdManager *	dd,
		DdNode *	f
	)

Function********************************************************************

Synopsis [Checks whether a node is in the death row.]

Description [Checks whether a node is in the death row. Returns the position of the first occurrence if the node is present; -1 otherwise.]

SideEffects [None]

SeeAlso [Cudd_DelayedDerefBdd cuddClearDeathRow]

Definition at line 762 of file cuddRef.c.

 {
 #ifndef DD_NO_DEATH_ROW
     int i;
 
     for (i = 0; i < dd->deathRowDepth; i++) {
         if (f == dd->deathRow[i]) {
             return(i);
         }
     }
 #endif
 
     return(-1);
 
 } /* end of cuddIsInDeathRow */

void cuddReclaim	(	DdManager *	table,
		DdNode *	n
	)

Function********************************************************************

Synopsis [Brings children of a dead node back.]

Description []

SideEffects [None]

SeeAlso [cuddReclaimZdd]

Definition at line 584 of file cuddRef.c.

 {
     DdNode *N;
     int ord;
     DdNodePtr *stack = table->stack;
     int SP = 1;
     double initialDead = table->dead;
 
     N = Cudd_Regular(n);
 
 #ifdef DD_DEBUG
     assert(N->ref == 0);
 #endif
 
     do {
         if (N->ref == 0) {
             N->ref = 1;
             table->dead--;
             if (cuddIsConstant(N)) {
                 table->constants.dead--;
                 N = stack[--SP];
             } else {
                 ord = table->perm[N->index];
                 stack[SP++] = Cudd_Regular(cuddE(N));
                 table->subtables[ord].dead--;
                 N = cuddT(N);
             }
         } else {
             cuddSatInc(N->ref);
             N = stack[--SP];
         }
     } while (SP != 0);
 
     N = Cudd_Regular(n);
     cuddSatDec(N->ref);
     table->reclaimed += initialDead - table->dead;
 
 } /* end of cuddReclaim */

void cuddReclaimZdd	(	DdManager *	table,
		DdNode *	n
	)

Function********************************************************************

Synopsis [Brings children of a dead ZDD node back.]

Description []

SideEffects [None]

SeeAlso [cuddReclaim]

Definition at line 638 of file cuddRef.c.

 {
     DdNode *N;
     int ord;
     DdNodePtr *stack = table->stack;
     int SP = 1;
 
     N = n;
 
 #ifdef DD_DEBUG
     assert(N->ref == 0);
 #endif
 
     do {
         cuddSatInc(N->ref);
 
         if (N->ref == 1) {
             table->deadZ--;
             table->reclaimed++;
 #ifdef DD_DEBUG
             assert(!cuddIsConstant(N));
 #endif
             ord = table->permZ[N->index];
             stack[SP++] = cuddE(N);
             table->subtableZ[ord].dead--;
             N = cuddT(N);
         } else {
             N = stack[--SP];
         }
     } while (SP != 0);
 
     cuddSatDec(n->ref);
 
 } /* end of cuddReclaimZdd */

void cuddShrinkDeathRow ( DdManager * table )

Function********************************************************************

Synopsis [Shrinks the death row.]

Description [Shrinks the death row by a factor of four.]

SideEffects [None]

SeeAlso [cuddClearDeathRow]

Definition at line 688 of file cuddRef.c.

 {
 #ifndef DD_NO_DEATH_ROW
     int i;
 
     if (table->deathRowDepth > 3) {
         for (i = table->deathRowDepth/4; i < table->deathRowDepth; i++) {
             if (table->deathRow[i] == NULL) break;
             Cudd_IterDerefBdd(table,table->deathRow[i]);
             table->deathRow[i] = NULL;
         }
         table->deathRowDepth /= 4;
         table->deadMask = table->deathRowDepth - 1;
         if ((unsigned) table->nextDead > table->deadMask) {
             table->nextDead = 0;
         }
         table->deathRow = ABC_REALLOC(DdNodePtr, table->deathRow,
                                    table->deathRowDepth);
     }
 #endif
 
 } /* end of cuddShrinkDeathRow */

int cuddTimesInDeathRow	(	DdManager *	dd,
		DdNode *	f
	)

Function********************************************************************

Synopsis [Counts how many times a node is in the death row.]

Description []

SideEffects [None]

SeeAlso [Cudd_DelayedDerefBdd cuddClearDeathRow cuddIsInDeathRow]

Definition at line 793 of file cuddRef.c.

 {
     int count = 0;
 #ifndef DD_NO_DEATH_ROW
     int i;
 
     for (i = 0; i < dd->deathRowDepth; i++) {
         count += f == dd->deathRow[i];
     }
 #endif
 
     return(count);
 
 } /* end of cuddTimesInDeathRow */

Variable Documentation

ABC_NAMESPACE_IMPL_START char rcsid [] DD_UNUSED = "$Id: cuddRef.c,v 1.28 2004/08/13 18:04:50 fabio Exp $"

static

CFile***********************************************************************

FileName [cuddRef.c]

PackageName [cudd]

Synopsis [Functions that manipulate the reference counts.]

Description [External procedures included in this module:

Internal procedures included in this module:

]

SeeAlso []

Author [Fabio Somenzi]

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

Neither the name of the University of Colorado nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.]

Definition at line 95 of file cuddRef.c.

Functions

Variables

Function Documentation

Variable Documentation