Ejemplo n.º 1
0
static
void share_private_nodes(int worker_q) {
  choiceptr sharing_node = B;

#ifdef DEBUG_OPTYAP
  OPTYAP_ERROR_CHECKING(share_private_nodes, YOUNGER_CP(LOCAL_top_cp, LOCAL_top_cp_on_stack));
  { choiceptr aux_cp = B;
    while (aux_cp != LOCAL_top_cp) {
      OPTYAP_ERROR_CHECKING(share_private_nodes, YOUNGER_CP(LOCAL_top_cp, aux_cp));
      OPTYAP_ERROR_CHECKING(share_private_nodes, EQUAL_OR_YOUNGER_CP(LOCAL_top_cp_on_stack, aux_cp));
      aux_cp = aux_cp->cp_b;
    }
  }
#endif /* DEBUG_OPTYAP */

#ifdef TABLING
  /* check if the branch is already shared */
  if (EQUAL_OR_YOUNGER_CP(LOCAL_top_cp_on_stack, sharing_node)) {
    or_fr_ptr or_frame;
    sg_fr_ptr sg_frame;
    dep_fr_ptr dep_frame;

#ifdef DEBUG_OPTYAP
    { or_fr_ptr aux_or_fr;
      aux_or_fr = LOCAL_top_or_fr;
      while (aux_or_fr != REMOTE_top_or_fr(worker_q)) {
	OPTYAP_ERROR_CHECKING(share_private_nodes, YOUNGER_CP(OrFr_node(REMOTE_top_or_fr(worker_q)), OrFr_node(aux_or_fr)));
        aux_or_fr = OrFr_next_on_stack(aux_or_fr);
      }
    }
#endif /* DEBUG_OPTYAP */

    /* update old shared nodes */
    or_frame = LOCAL_top_or_fr;
    while (or_frame != REMOTE_top_or_fr(worker_q)) {
      LOCK_OR_FRAME(or_frame);
      BRANCH(worker_q, OrFr_depth(or_frame)) = BRANCH(worker_id, OrFr_depth(or_frame));
      OrFr_owners(or_frame)++;
      if (BITMAP_member(OrFr_members(or_frame), worker_id))
        BITMAP_insert(OrFr_members(or_frame), worker_q);
      UNLOCK_OR_FRAME(or_frame);
      or_frame = OrFr_next_on_stack(or_frame);
    }

    /* update worker Q top subgoal frame */
    sg_frame = LOCAL_top_sg_fr;
    while (sg_frame && YOUNGER_CP(SgFr_gen_cp(sg_frame), sharing_node)) {
      sg_frame = SgFr_next(sg_frame);
    }
    REMOTE_top_sg_fr(worker_q) = sg_frame;

    /* update worker Q top dependency frame */
    dep_frame = LOCAL_top_dep_fr;
    while (YOUNGER_CP(DepFr_cons_cp(dep_frame), sharing_node)) {
      dep_frame = DepFr_next(dep_frame);
    }
    REMOTE_top_dep_fr(worker_q) = dep_frame;

    /* update worker Q top shared nodes */
    REMOTE_top_cp_on_stack(worker_q) = REMOTE_top_cp(worker_q) = LOCAL_top_cp;
    REMOTE_top_or_fr(worker_q) = LOCAL_top_or_fr;
  } else
#endif /* TABLING */
  {
    int depth;
    bitmap bm_workers;
    or_fr_ptr or_frame, previous_or_frame;
#ifdef TABLING
    choiceptr consumer_cp, next_node_on_branch;
    dep_fr_ptr dep_frame;
    sg_fr_ptr sg_frame;
    CELL *stack, *stack_limit;

    /* find top dependency frame above current choice point */
    dep_frame = LOCAL_top_dep_fr;
    while (EQUAL_OR_YOUNGER_CP(DepFr_cons_cp(dep_frame), sharing_node)) {
      dep_frame = DepFr_next(dep_frame);
    }
    /* initialize tabling auxiliary variables */ 
    consumer_cp = DepFr_cons_cp(dep_frame);
    next_node_on_branch = NULL;
    stack_limit = (CELL *)TR;
    stack = (CELL *)LOCAL_TrailTop;
#endif /* TABLING */

    /* initialize auxiliary variables */
    BITMAP_clear(bm_workers);
    BITMAP_insert(bm_workers, worker_id);
    BITMAP_insert(bm_workers, worker_q);
    previous_or_frame = NULL;
    depth = OrFr_depth(LOCAL_top_or_fr);

    /* sharing loop */
#ifdef TABLING
    while (YOUNGER_CP(sharing_node, LOCAL_top_cp_on_stack)) {
#else
    while (sharing_node != LOCAL_top_cp) {
#endif /* TABLING */

#ifdef DEBUG_OPTYAP
      if (next_node_on_branch) {
        choiceptr aux_cp = B;
        while (aux_cp != next_node_on_branch) {
	  OPTYAP_ERROR_CHECKING(share_private_nodes, sharing_node == aux_cp);
	  OPTYAP_ERROR_CHECKING(share_private_nodes, YOUNGER_CP(next_node_on_branch, aux_cp));
          aux_cp = aux_cp->cp_b;
        }
      } else {
        choiceptr aux_cp = B;
        while (aux_cp != sharing_node) {
	  OPTYAP_ERROR_CHECKING(share_private_nodes, YOUNGER_CP(sharing_node, aux_cp));
          aux_cp = aux_cp->cp_b;
        }
      }
#endif /* DEBUG_OPTYAP */

      ALLOC_OR_FRAME(or_frame);
      if (previous_or_frame) {
#ifdef TABLING
        OrFr_next_on_stack(previous_or_frame) =
#endif /* TABLING */
        OrFr_nearest_livenode(previous_or_frame) = OrFr_next(previous_or_frame) = or_frame;
      }
      previous_or_frame = or_frame;
      depth++;
      INIT_LOCK(OrFr_lock(or_frame));
      OrFr_node(or_frame) = sharing_node;
      OrFr_alternative(or_frame) = sharing_node->cp_ap;
      OrFr_pend_prune_cp(or_frame) = NULL;
      OrFr_nearest_leftnode(or_frame) = LOCAL_top_or_fr;
      OrFr_qg_solutions(or_frame) = NULL;
#ifdef TABLING_INNER_CUTS
      OrFr_tg_solutions(or_frame) = NULL;
#endif /* TABLING_INNER_CUTS */
#ifdef TABLING
      OrFr_suspensions(or_frame) = NULL;
      OrFr_nearest_suspnode(or_frame) = or_frame;
      OrFr_owners(or_frame) = 2;
      if (next_node_on_branch)
        BITMAP_clear(OrFr_members(or_frame));
      else
#endif /* TABLING */
        OrFr_members(or_frame) = bm_workers;

      YAPOR_ERROR_CHECKING(share_private_nodes, sharing_node->cp_ap == GETWORK || sharing_node->cp_ap == GETWORK_SEQ);
      if (sharing_node->cp_ap && YAMOP_SEQ(sharing_node->cp_ap)) {
        sharing_node->cp_ap = GETWORK_SEQ;
      } else {
        sharing_node->cp_ap = GETWORK;
      }
      sharing_node->cp_or_fr = or_frame;
      sharing_node = sharing_node->cp_b;

#ifdef TABLING
      /* when next_node_on_branch is not NULL the **
      ** sharing_node belongs to a frozen branch. */   
      if (YOUNGER_CP(consumer_cp, sharing_node)) {
        /* frozen stack segment */
        if (! next_node_on_branch)
          next_node_on_branch = sharing_node;
        STACK_PUSH_UP(or_frame, stack);
        STACK_CHECK_EXPAND(stack, stack_limit);
        STACK_PUSH_UP(sharing_node, stack);
        STACK_CHECK_EXPAND(stack, stack_limit);
        sharing_node = consumer_cp;
        dep_frame = DepFr_next(dep_frame);
        consumer_cp = DepFr_cons_cp(dep_frame);
      } else if (consumer_cp == sharing_node) {
        dep_frame = DepFr_next(dep_frame);
        consumer_cp = DepFr_cons_cp(dep_frame);
      }
      if (next_node_on_branch == sharing_node)
        next_node_on_branch = NULL;
#endif /* TABLING */
      OPTYAP_ERROR_CHECKING(share_private_nodes, next_node_on_branch && YOUNGER_CP(next_node_on_branch, sharing_node));
    }

    /* initialize last or-frame pointer */
    or_frame = sharing_node->cp_or_fr;
    if (previous_or_frame) {
#ifdef TABLING
      OrFr_next_on_stack(previous_or_frame) =
#endif /* TABLING */
      OrFr_nearest_livenode(previous_or_frame) = OrFr_next(previous_or_frame) = or_frame;
    }

#ifdef TABLING
    /* update or-frames stored in auxiliary stack */
    while (STACK_NOT_EMPTY(stack, (CELL *)LOCAL_TrailTop)) {
      next_node_on_branch = (choiceptr) STACK_POP_DOWN(stack);
      or_frame = (or_fr_ptr) STACK_POP_DOWN(stack);
      OrFr_nearest_livenode(or_frame) = OrFr_next(or_frame) = next_node_on_branch->cp_or_fr;
    }
#endif /* TABLING */

    /* update depth */
    if (depth >= MAX_BRANCH_DEPTH)
      Yap_Error(SYSTEM_ERROR_INTERNAL, TermNil, "maximum depth exceded (share_private_nodes)");
    or_frame = B->cp_or_fr;
#ifdef TABLING
    previous_or_frame = LOCAL_top_cp_on_stack->cp_or_fr;
    while (or_frame != previous_or_frame) {
#else
    while (or_frame != LOCAL_top_or_fr) {
#endif /* TABLING */
      unsigned int branch;
      if (OrFr_alternative(or_frame)) {
        branch = YAMOP_OR_ARG(OrFr_alternative(or_frame)) + 1;
      } else {
        branch = 1;
      }
      branch |= YAMOP_CUT_FLAG;  /* in doubt, assume cut */
      BRANCH(worker_id, depth) = BRANCH(worker_q, depth) = branch;
      OrFr_depth(or_frame) = depth--;
      or_frame = OrFr_next_on_stack(or_frame);
    }

    YAPOR_ERROR_CHECKING(share_private_nodes, depth != OrFr_depth(LOCAL_top_or_fr));

#ifdef DEBUG_OPTYAP
    { or_fr_ptr aux_or_fr = B->cp_or_fr;
      choiceptr aux_cp;
      while (aux_or_fr != LOCAL_top_cp_on_stack->cp_or_fr) {
        aux_cp = OrFr_node(aux_or_fr);
	OPTYAP_ERROR_CHECKING(share_private_nodes, OrFr_next(aux_or_fr) != aux_cp->cp_b->cp_or_fr);
	OPTYAP_ERROR_CHECKING(share_private_nodes, OrFr_nearest_livenode(aux_or_fr) != aux_cp->cp_b->cp_or_fr);
        aux_or_fr = OrFr_next_on_stack(aux_or_fr);
      }
      aux_or_fr = B->cp_or_fr;
      while (aux_or_fr != LOCAL_top_cp_on_stack->cp_or_fr) {
        or_fr_ptr nearest_leftnode = OrFr_nearest_leftnode(aux_or_fr);
        aux_cp = OrFr_node(aux_or_fr);
        while (OrFr_node(nearest_leftnode) != aux_cp) {
	  OPTYAP_ERROR_CHECKING(share_private_nodes, YOUNGER_CP(OrFr_node(nearest_leftnode), aux_cp));
          aux_cp = aux_cp->cp_b;
        }
        aux_or_fr = OrFr_next_on_stack(aux_or_fr);
      }
    }
#endif /* DEBUG_OPTYAP */

    /* update old shared nodes */
    while (or_frame != REMOTE_top_or_fr(worker_q)) {
      LOCK_OR_FRAME(or_frame);
      BRANCH(worker_q, OrFr_depth(or_frame)) = BRANCH(worker_id, OrFr_depth(or_frame));
#ifdef TABLING
      OrFr_owners(or_frame)++;
      if (BITMAP_member(OrFr_members(or_frame), worker_id))
#endif /* TABLING */
        BITMAP_insert(OrFr_members(or_frame), worker_q);
      UNLOCK_OR_FRAME(or_frame);
      or_frame = OrFr_next_on_stack(or_frame);
    }

    LOCK_OR_FRAME(REMOTE_top_or_fr(worker_q));
    or_fr_ptr old_top = REMOTE_top_or_fr(worker_q);
    Set_REMOTE_top_cp(worker_q,B);
    Set_LOCAL_top_cp(B);
    REMOTE_top_or_fr(worker_q) = LOCAL_top_or_fr = Get_LOCAL_top_cp()->cp_or_fr;
    UNLOCK_OR_FRAME(old_top);  

#ifdef TABLING
    /* update subgoal frames in the maintained private branches */
    sg_frame = LOCAL_top_sg_fr;
    while (sg_frame && YOUNGER_CP(SgFr_gen_cp(sg_frame), B)) {
      choiceptr top_cp_on_branch;
      top_cp_on_branch = SgFr_gen_cp(sg_frame);
      while (YOUNGER_CP(top_cp_on_branch, B)) {
        top_cp_on_branch = top_cp_on_branch->cp_b;
      }
      SgFr_gen_top_or_fr(sg_frame) = top_cp_on_branch->cp_or_fr;
      sg_frame = SgFr_next(sg_frame);
    }
    /* update worker Q top subgoal frame */
    REMOTE_top_sg_fr(worker_q) = sg_frame;
    /* update subgoal frames in the recently shared branches */
    while (sg_frame && YOUNGER_CP(SgFr_gen_cp(sg_frame), LOCAL_top_cp_on_stack)) {
      SgFr_gen_worker(sg_frame) = MAX_WORKERS;
      SgFr_gen_top_or_fr(sg_frame) = SgFr_gen_cp(sg_frame)->cp_or_fr;
      sg_frame = SgFr_next(sg_frame);
    }

    /* update dependency frames in the maintained private branches */
    dep_frame = LOCAL_top_dep_fr;
    while (YOUNGER_CP(DepFr_cons_cp(dep_frame), B)) {
      choiceptr top_cp_on_branch;
      top_cp_on_branch = DepFr_cons_cp(dep_frame);
      while (YOUNGER_CP(top_cp_on_branch, B)) {
        top_cp_on_branch = top_cp_on_branch->cp_b;
      }
      DepFr_top_or_fr(dep_frame) = top_cp_on_branch->cp_or_fr;
      dep_frame = DepFr_next(dep_frame);
    }
    /* update worker Q top dependency frame */
    REMOTE_top_dep_fr(worker_q) = dep_frame;
    /* update dependency frames in the recently shared branches */
    while (YOUNGER_CP(DepFr_cons_cp(dep_frame), LOCAL_top_cp_on_stack)) {
      DepFr_top_or_fr(dep_frame) = DepFr_cons_cp(dep_frame)->cp_or_fr;
      dep_frame = DepFr_next(dep_frame);
    }
#endif /* TABLING */

#ifdef DEBUG_OPTYAP
    { dep_fr_ptr aux_dep_fr = LOCAL_top_dep_fr;
      while(aux_dep_fr != GLOBAL_root_dep_fr) {
        choiceptr top_cp_on_branch;
        top_cp_on_branch = DepFr_cons_cp(aux_dep_fr);
        while (YOUNGER_CP(top_cp_on_branch, B)) {
          top_cp_on_branch = top_cp_on_branch->cp_b;
        }
	OPTYAP_ERROR_CHECKING(share_private_nodes, top_cp_on_branch->cp_or_fr != DepFr_top_or_fr(aux_dep_fr));
        aux_dep_fr = DepFr_next(aux_dep_fr);
      }
    }
#endif /* DEBUG_OPTYAP */

    /* update top shared nodes */
#ifdef TABLING
    REMOTE_top_cp_on_stack(worker_q) = LOCAL_top_cp_on_stack = 
#endif /* TABLING */
    REMOTE_top_cp(worker_q) = LOCAL_top_cp = B;
    REMOTE_top_or_fr(worker_q) = LOCAL_top_or_fr = LOCAL_top_cp->cp_or_fr;
  }

#ifdef TABLING_INNER_CUTS
  /* update worker Q pruning scope */
  if (LOCAL_pruning_scope && EQUAL_OR_YOUNGER_CP(LOCAL_top_cp, LOCAL_pruning_scope)) {
    REMOTE_pruning_scope(worker_q) = LOCAL_pruning_scope;
    PUT_IN_PRUNING(worker_q);
  } else {
    PUT_OUT_PRUNING(worker_q);
    REMOTE_pruning_scope(worker_q) = NULL;
  }
#endif /* TABLING_INNER_CUTS */

  /* update worker Q prune request */
  if (LOCAL_prune_request) {
    CUT_send_prune_request(worker_q, LOCAL_prune_request);
  }

  /* update load and return */
  REMOTE_load(worker_q) = LOCAL_load = 0;
  return;
}
Ejemplo n.º 2
0
static
void share_private_nodes(int worker_q) {
  int depth;
  choiceptr AuxB;
  or_fr_ptr or_frame, previous_or_frame;

  /* initialize auxiliary variables */
  AuxB = B;
  previous_or_frame = NULL;
  depth = OrFr_depth(LOCAL_top_or_fr);
  /* sharing loop */
  while (AuxB != LOCAL_top_cp) {
    depth++;
    ALLOC_OR_FRAME(or_frame);
    INIT_LOCK(OrFr_lock(or_frame));
    SetOrFr_node(or_frame, AuxB);
    OrFr_alternative(or_frame) = AuxB->cp_ap;
    OrFr_pend_prune_cp(or_frame) = NULL;
    OrFr_nearest_leftnode(or_frame) = LOCAL_top_or_fr;
    OrFr_qg_solutions(or_frame) = NULL;
    BITMAP_clear(OrFr_members(or_frame));
    BITMAP_insert(OrFr_members(or_frame), worker_id);
    BITMAP_insert(OrFr_members(or_frame), worker_q);
    if (AuxB->cp_ap && YAMOP_SEQ(AuxB->cp_ap)) {
      AuxB->cp_ap = GETWORK_SEQ;
    } else {
      AuxB->cp_ap = GETWORK;
    }
    AuxB->cp_or_fr = or_frame;
    AuxB = AuxB->cp_b;
    if (previous_or_frame) {
      OrFr_nearest_livenode(previous_or_frame) = OrFr_next(previous_or_frame) = or_frame;
    }
    previous_or_frame = or_frame;
  }
  /* initialize last or-frame pointer */
  or_frame = AuxB->cp_or_fr;
  if (previous_or_frame) {
    OrFr_nearest_livenode(previous_or_frame) = OrFr_next(previous_or_frame) = or_frame;
  }
  /* update depth */
  if (depth >= MAX_BRANCH_DEPTH)
    Yap_Error(INTERNAL_ERROR, TermNil, "maximum depth exceded (share_private_nodes)");
  or_frame = B->cp_or_fr;
  while (or_frame != LOCAL_top_or_fr) {
    unsigned int branch;
    if (OrFr_alternative(or_frame)) {
      branch = YAMOP_OR_ARG(OrFr_alternative(or_frame)) + 1;
    } else {
      branch = 1;
    }
    branch |= YAMOP_CUT_FLAG;  /* in doubt, assume cut */
    BRANCH(worker_id, depth) = BRANCH(worker_q, depth) = branch;
    OrFr_depth(or_frame) = depth--;
    or_frame = OrFr_next_on_stack(or_frame);
  }
  /* update old shared nodes */
  while (or_frame != REMOTE_top_or_fr(worker_q)) {
    LOCK_OR_FRAME(or_frame);
    BRANCH(worker_q, OrFr_depth(or_frame)) = BRANCH(worker_id, OrFr_depth(or_frame));
    BITMAP_insert(OrFr_members(or_frame), worker_q);
    UNLOCK_OR_FRAME(or_frame);
    or_frame = OrFr_next_on_stack(or_frame);
  }
  /* update top shared nodes */
  REMOTE_top_cp(worker_q) = LOCAL_top_cp = B;
  REMOTE_top_or_fr(worker_q) = LOCAL_top_or_fr = LOCAL_top_cp->cp_or_fr;
  /* update prune request */
  if (LOCAL_prune_request) {
    CUT_send_prune_request(worker_q, LOCAL_prune_request);
  }
  /* update load and return */
  REMOTE_load(worker_q) = LOCAL_load = 0;
  return;
}
Ejemplo n.º 3
0
int p_share_work(void) {
  int worker_q = LOCAL_share_request;

  if (! BITMAP_member(OrFr_members(REMOTE_top_or_fr(worker_q)), worker_id) ||
      B == REMOTE_top_cp(worker_q) ||
      (LOCAL_load <= GLOBAL_delayed_release_load  && OrFr_nearest_livenode(LOCAL_top_or_fr) == NULL)) {
    /* refuse sharing request */
    REMOTE_reply_signal(LOCAL_share_request) = no_sharing;
    LOCAL_share_request = MAX_WORKERS;
    PUT_OUT_REQUESTABLE(worker_id);
    return 0;
  }
  /* sharing request accepted */
  COMPUTE_SEGMENTS_TO_COPY_TO(worker_q);
  REMOTE_q_fase_signal(worker_q) = Q_idle;
  REMOTE_p_fase_signal(worker_q) = P_idle;
#ifndef TABLING
  /* wait for incomplete installations */
  while (LOCAL_reply_signal != worker_ready);
#endif /* TABLING */
  LOCAL_reply_signal = sharing;
  REMOTE_reply_signal(worker_q) = sharing;
  share_private_nodes(worker_q);
  if(Get_LOCAL_prune_request())
    CUT_send_prune_request(worker_q, Get_LOCAL_prune_request()); 
  REMOTE_reply_signal(worker_q) = nodes_shared;
  /* copy local stack ? */
  LOCK(REMOTE_lock_signals(worker_q));
  if (REMOTE_q_fase_signal(worker_q) < local) {
    REMOTE_p_fase_signal(worker_q) = local;              
    UNLOCK(REMOTE_lock_signals(worker_q));
    P_COPY_LOCAL_TO(worker_q);
  } else {
    UNLOCK(REMOTE_lock_signals(worker_q));
    goto sync_with_q;
  }
  /* copy global stack ? */
  LOCK(REMOTE_lock_signals(worker_q));
  if (REMOTE_q_fase_signal(worker_q) < global) {
    REMOTE_p_fase_signal(worker_q) = global;
    UNLOCK(REMOTE_lock_signals(worker_q));
    P_COPY_GLOBAL_TO(worker_q);
  } else {
    UNLOCK(REMOTE_lock_signals(worker_q));
    goto sync_with_q;
  }
  /* copy trail stack ? */
  LOCK(REMOTE_lock_signals(worker_q));
  if (REMOTE_q_fase_signal(worker_q) < trail) {
    REMOTE_p_fase_signal(worker_q) = trail;
    UNLOCK(REMOTE_lock_signals(worker_q));
    P_COPY_TRAIL_TO(worker_q);
  } else UNLOCK(REMOTE_lock_signals(worker_q));

sync_with_q:
  REMOTE_reply_signal(worker_q) = copy_done;
  while (LOCAL_reply_signal == sharing);
  while (REMOTE_reply_signal(worker_q) != worker_ready);
  LOCAL_share_request = MAX_WORKERS;
  PUT_IN_REQUESTABLE(worker_id);

  return 1;
}
Ejemplo n.º 4
0
static
void share_private_nodes(int worker_q) {
  int depth;
  choiceptr AuxB;
  or_fr_ptr or_frame, previous_or_frame;

  /* initialize auxiliary variables */
  AuxB = B;
  previous_or_frame = NULL;
  depth = OrFr_depth(LOCAL_top_or_fr);
  /* sharing loop */
  while (AuxB != LOCAL_top_cp) {
    depth++;
    ALLOC_OR_FRAME(or_frame);
    INIT_LOCK(OrFr_lock(or_frame));
    OrFr_node(or_frame) = AuxB;
    OrFr_alternative(or_frame) = AuxB->cp_ap;
    OrFr_pend_prune_cp(or_frame) = NULL;
    OrFr_nearest_leftnode(or_frame) = LOCAL_top_or_fr;
    OrFr_qg_solutions(or_frame) = NULL;
    BITMAP_clear(OrFr_members(or_frame));
    BITMAP_insert(OrFr_members(or_frame), worker_id);
    BITMAP_insert(OrFr_members(or_frame), worker_q);
    if (AuxB->cp_ap && YAMOP_SEQ(AuxB->cp_ap)) {
      AuxB->cp_ap = GETWORK_SEQ;
    } else {
      AuxB->cp_ap = GETWORK;
    }
    AuxB->cp_or_fr = or_frame;
    AuxB = AuxB->cp_b;
    if (previous_or_frame) {
      OrFr_nearest_livenode(previous_or_frame) = OrFr_next(previous_or_frame) = or_frame;
    }
    previous_or_frame = or_frame;
  }
  /* initialize last or-frame pointer */
  or_frame = AuxB->cp_or_fr;
  if (previous_or_frame) {
    OrFr_nearest_livenode(previous_or_frame) = OrFr_next(previous_or_frame) = or_frame;
  }
  /* update depth */
  if (depth >= MAX_BRANCH_DEPTH)
    Yap_Error(INTERNAL_ERROR, TermNil, "maximum depth exceded (share_private_nodes)");
  or_frame = B->cp_or_fr;

  while (or_frame != LOCAL_top_or_fr) {
    unsigned int branch;
    if (OrFr_alternative(or_frame)) {
      branch = YAMOP_OR_ARG(OrFr_alternative(or_frame)) + 1;
    } else {
      branch = 1;
    }
    branch |= YAMOP_CUT_FLAG;  /* in doubt, assume cut */
    BRANCH(worker_id, depth) = BRANCH(worker_q, depth) = branch;
    OrFr_depth(or_frame) = depth--;
    or_frame = OrFr_next_on_stack(or_frame);
  }
  /* update old shared nodes */
  while (or_frame != REMOTE_top_or_fr(worker_q)) {
    LOCK_OR_FRAME(or_frame);
    BRANCH(worker_q, OrFr_depth(or_frame)) = BRANCH(worker_id, OrFr_depth(or_frame));
    BITMAP_insert(OrFr_members(or_frame), worker_q);
    UNLOCK_OR_FRAME(or_frame);
    or_frame = OrFr_next_on_stack(or_frame);
  }
  /* move conditional bindings to BA */
  {
    tr_fr_ptr top, tr_ptr;
    top = LOCAL_top_cp->cp_tr;
    tr_ptr = TR;
    while (tr_ptr != top) {
      CELL aux_cell = TrailTerm(--tr_ptr);
      if (IsVarTerm(aux_cell) && 
          ((CELL *)aux_cell < B->cp_h || (choiceptr)aux_cell > B) &&
          !((CELL *)aux_cell < H_FZ || (choiceptr)aux_cell > B_FZ)) {
	CELL *ptr = STACK_TO_SBA(aux_cell);
	*ptr = TrailVal(tr_ptr);
        *(CELL *)aux_cell = (CELL)ptr;
      } else if (IsPairTerm(aux_cell) && (ADDR) RepPair(aux_cell) > HeapTop) {
        /* avoid frozen segments */
        aux_cell = (CELL) RepPair(aux_cell);
        tr_ptr = (tr_fr_ptr) aux_cell;
#ifdef MULTI_ASSIGNMENT_VARIABLES
     } else {
       CELL *cell_ptr = RepAppl(aux_cell);
       /* first do as a for a standard cell */
       if ((cell_ptr < B->cp_h || cell_ptr > (CELL *)B) && !(cell_ptr < H_FZ || (choiceptr)cell_ptr > B_FZ)) {
	 CELL *ptr = STACK_TO_SBA(cell_ptr);
	 /* we may have several bindings in the trail */
	 if ((CELL)ptr != *cell_ptr) {
	   *ptr = TrailVal(tr_ptr);
	   *cell_ptr = (CELL)ptr;
	 }
       }
       /* but we also need to skip the old value */
       tr_ptr--;
#endif /* MULTI_ASSIGNMENT_VARIABLES */
     }
    }
  }
  /* update frozen registers */
  B_FZ  = B;
  H_FZ  = B->cp_h;
  TR_FZ = B->cp_tr;
  /* update top shared nodes */
  REMOTE_top_cp(worker_q) = LOCAL_top_cp = B;
  REMOTE_top_or_fr(worker_q) = LOCAL_top_or_fr = LOCAL_top_cp->cp_or_fr;
  /* update prune request */
  if (LOCAL_prune_request) {
    CUT_send_prune_request(worker_q, LOCAL_prune_request);
  }
  /* update load and return */
  REMOTE_load(worker_q) = LOCAL_load = 0;
}