event_globalbnd.c

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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
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/*                  This file is part of the program and library             */
/*         SCIP --- Solving Constraint Integer Programs                      */
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/*  Copyright (c) 2002-2025 Zuse Institute Berlin (ZIB)                      */
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/**@file   event_globalbnd.c
 * @ingroup DEFPLUGINS_EVENT
 * @brief  eventhandler for storing all global bound changes
 * @author Leona Gottwald
 *
 * the bound changes are stored so that they can be shared with other threads
 * in a concurrent solve.
 */
 
/*--+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
 
#include "blockmemshell/memory.h"
#include "scip/boundstore.h"
#include "scip/concurrent.h"
#include "scip/event_globalbnd.h"
#include "scip/pub_event.h"
#include "scip/pub_lp.h"
#include "scip/pub_message.h"
#include "scip/pub_var.h"
#include "scip/scip_concurrent.h"
#include "scip/scip_copy.h"
#include "scip/scip_event.h"
#include "scip/scip_mem.h"
#include "scip/scip_message.h"
#include "scip/scip_prob.h"
#include "scip/syncstore.h"
#include <string.h>
 
#define EVENTHDLR_NAME         "globalbnd"
#define EVENTHDLR_DESC         "event handler for globalbnd event"
 
 
/*
 * Data structures
 */
 
/** event handler data */
struct SCIP_EventhdlrData
{
   int                    filterpos;
   SCIP_Bool              storebounds;
   SCIP_BOUNDSTORE*       boundstore;
};
 
/*
 * Local methods
 */
 
/*
 * Callback methods of event handler
 */
 
/** destructor of event handler to free user data (called when SCIP is exiting) */
static
SCIP_DECL_EVENTFREE(eventFreeGlobalbnd)
{  /*lint --e{715}*/
   SCIP_EVENTHDLRDATA* eventhdlrdata;
 
   assert(scip != NULL);
   assert(eventhdlr != NULL);
   assert(strcmp(SCIPeventhdlrGetName(eventhdlr), EVENTHDLR_NAME) == 0);
 
   eventhdlrdata = SCIPeventhdlrGetData(eventhdlr);
   assert(eventhdlrdata != NULL);
 
   SCIPfreeMemory(scip, &eventhdlrdata);
   SCIPeventhdlrSetData(eventhdlr, NULL);
 
   return SCIP_OKAY;
}
 
/** initialization method of event handler (called after problem was transformed) */
static
SCIP_DECL_EVENTINIT(eventInitGlobalbnd)
{  /*lint --e{715}*/
   SCIP_EVENTHDLRDATA* eventhdlrdata;
 
   assert(scip != NULL);
   assert(eventhdlr != NULL);
   assert(strcmp(SCIPeventhdlrGetName(eventhdlr), EVENTHDLR_NAME) == 0);
 
   eventhdlrdata = SCIPeventhdlrGetData(eventhdlr);
   assert(eventhdlrdata != NULL);
 
   if( eventhdlrdata->filterpos < 0 && SCIPgetSubscipDepth(scip) == 0 && SCIPsyncstoreIsInitialized(SCIPgetSyncstore(scip)) )
   {
      SCIP_VAR** vars;
      int nvars;
      int i;
 
      SCIPdebugMsg(scip, "catching events in " EVENTHDLR_NAME " eventhdlr\n");
 
      /* notify SCIP that this event handler wants to react on global bound change events */
      nvars = SCIPgetNVars(scip);
      vars = SCIPgetVars(scip);
      eventhdlrdata->storebounds = TRUE;
      SCIP_CALL( SCIPboundstoreCreate(scip, &eventhdlrdata->boundstore, SCIPgetNOrigVars(scip)) );
 
      SCIP_CALL( SCIPcatchEvent(scip, SCIP_EVENTTYPE_VARADDED, eventhdlr, NULL, &eventhdlrdata->filterpos) );
      for( i = 0; i < nvars ; ++i )
      {
         SCIP_CALL( SCIPcatchVarEvent(scip, vars[i], SCIP_EVENTTYPE_GBDCHANGED, eventhdlr, NULL, NULL) );
      }
   }
 
   return SCIP_OKAY;
}
 
/** deinitialization method of event handler (called before transformed problem is freed) */
static
SCIP_DECL_EVENTEXIT(eventExitGlobalbnd)
{  /*lint --e{715}*/
   SCIP_EVENTHDLRDATA* eventhdlrdata;
 
   assert(scip != NULL);
   assert(eventhdlr != NULL);
   assert(strcmp(SCIPeventhdlrGetName(eventhdlr), EVENTHDLR_NAME) == 0);
 
   eventhdlrdata = SCIPeventhdlrGetData(eventhdlr);
   assert(eventhdlrdata != NULL);
 
   /* notify SCIP that your event handler wants to drop the event type var added */
   if( eventhdlrdata->filterpos >= 0 )
   {
      SCIP_CALL( SCIPdropEvent(scip, SCIP_EVENTTYPE_VARADDED, eventhdlr, NULL, eventhdlrdata->filterpos) );
      eventhdlrdata->filterpos = -1;
      SCIPboundstoreFree(scip, &eventhdlrdata->boundstore);
   }
 
   return SCIP_OKAY;
}
 
/** execution method of event handler */
static
SCIP_DECL_EVENTEXEC(eventExecGlobalbnd)
{  /*lint --e{715}*/
   SCIP_EVENTHDLRDATA* eventhdlrdata;
   SCIP_VAR*           var;
   SCIP_Real           newbound;
   SCIP_BOUNDTYPE      boundtype;
   SCIP_Real           constant;
   SCIP_Real           scalar;
 
   SCIPdebugMsg(scip, "exec method of eventhdlr " EVENTHDLR_NAME "\n");
 
   assert(eventhdlr != NULL);
   assert(strcmp(SCIPeventhdlrGetName(eventhdlr), EVENTHDLR_NAME) == 0);
   assert(event != NULL);
   assert(scip != NULL);
 
   eventhdlrdata = SCIPeventhdlrGetData(eventhdlr);
   assert(eventhdlrdata != NULL);
 
   var = SCIPeventGetVar(event);
   switch( SCIPeventGetType(event) )
   {
   case SCIP_EVENTTYPE_VARADDED:
      SCIP_CALL( SCIPcatchVarEvent(scip, var, SCIP_EVENTTYPE_GBDCHANGED, eventhdlr, NULL, NULL) );
      return SCIP_OKAY;
   case SCIP_EVENTTYPE_GLBCHANGED:
      boundtype = SCIP_BOUNDTYPE_LOWER;
      break;
   case SCIP_EVENTTYPE_GUBCHANGED:
      boundtype = SCIP_BOUNDTYPE_UPPER;
      break;
   default:
      SCIPABORT();
      return SCIP_ERROR; /*lint !e527*/
   }
 
   if( !eventhdlrdata->storebounds )
      return SCIP_OKAY;
 
   newbound = SCIPeventGetNewbound(event);
   constant = 0.0;
   scalar = 1.0;
   SCIP_CALL( SCIPvarGetOrigvarSum(&var, &scalar, &constant) );
   if( var != NULL )
   {
      int varidx;
 
      varidx = SCIPgetConcurrentVaridx(scip, var);
      if( varidx >= 0 )
      {
         boundtype = scalar < 0.0 ? SCIPboundtypeOpposite(boundtype) : boundtype;
         newbound = (newbound - constant) / scalar;
 
         SCIP_CALL( SCIPboundstoreAdd(scip, eventhdlrdata->boundstore, varidx, newbound, boundtype) );
      }
   }
   return SCIP_OKAY;
}
 
/** creates event handler for globalbnd event */
SCIP_RETCODE SCIPincludeEventHdlrGlobalbnd(
   SCIP*                 scip                /**< SCIP data structure */
   )
{
   SCIP_EVENTHDLRDATA* eventhdlrdata = NULL;
   SCIP_EVENTHDLR* eventhdlr = NULL;
 
   /* create globalbnd event handler data */
   SCIP_CALL( SCIPallocMemory(scip, &eventhdlrdata) );
   eventhdlrdata->filterpos = -1;
 
   /* include event handler into SCIP */
 
   /* use SCIPincludeEventhdlrBasic() plus setter functions if you want to set callbacks one-by-one and your code should
    * compile independent of new callbacks being added in future SCIP versions
    */
   SCIP_CALL( SCIPincludeEventhdlrBasic(scip, &eventhdlr, EVENTHDLR_NAME, EVENTHDLR_DESC,
         eventExecGlobalbnd, eventhdlrdata) );
   assert(eventhdlr != NULL);
 
   /* set non fundamental callbacks via setter functions */
   SCIP_CALL( SCIPsetEventhdlrFree(scip, eventhdlr, eventFreeGlobalbnd) );
   SCIP_CALL( SCIPsetEventhdlrInit(scip, eventhdlr, eventInitGlobalbnd) );
   SCIP_CALL( SCIPsetEventhdlrExit(scip, eventhdlr, eventExitGlobalbnd) );
 
   return SCIP_OKAY;
}
 
 
/** gets the global bound changes stored in the eventhandler */
SCIP_BOUNDSTORE* SCIPeventGlobalbndGetBoundChanges(
   SCIP_EVENTHDLR*       eventhdlr           /**< the globalbound eventhandler */
   )
{
   SCIP_EVENTHDLRDATA* eventhdlrdata;
   assert(eventhdlr != NULL);
   assert(strcmp(EVENTHDLR_NAME, SCIPeventhdlrGetName(eventhdlr)) == 0);
 
   eventhdlrdata = SCIPeventhdlrGetData(eventhdlr);
   assert(eventhdlrdata != NULL);
 
   return eventhdlrdata->boundstore;
}
 
/** enables storing of bound changes */
void SCIPeventGlobalbndEnableBoundStorage(
   SCIP_EVENTHDLR*       eventhdlr           /**< the globalbound eventhandler */
   )
{
   SCIP_EVENTHDLRDATA* eventhdlrdata;
 
   assert(eventhdlr != NULL);
   assert(strcmp(EVENTHDLR_NAME, SCIPeventhdlrGetName(eventhdlr)) == 0);
 
   eventhdlrdata = SCIPeventhdlrGetData(eventhdlr);
   assert(eventhdlrdata != NULL);
 
   eventhdlrdata->storebounds = TRUE;
}
 
/** disables storing of bound changes */
void SCIPeventGlobalbndDisableBoundStorage(
   SCIP_EVENTHDLR*       eventhdlr           /**< the globalbound eventhandler */
   )
{
   SCIP_EVENTHDLRDATA* eventhdlrdata;
 
   assert(eventhdlr != NULL);
   assert(strcmp(EVENTHDLR_NAME, SCIPeventhdlrGetName(eventhdlr)) == 0);
 
   eventhdlrdata = SCIPeventhdlrGetData(eventhdlr);
   assert(eventhdlrdata != NULL);
 
   eventhdlrdata->storebounds = FALSE;
}
 
/** clears all bound changes stored in the eventhandler */
void SCIPeventGlobalbndClearBoundChanges(
   SCIP_EVENTHDLR*       eventhdlr           /**< the globalbound eventhandler */
   )
{
   SCIP_EVENTHDLRDATA* eventhdlrdata;
 
   assert(eventhdlr != NULL);
   assert(strcmp(EVENTHDLR_NAME, SCIPeventhdlrGetName(eventhdlr)) == 0);
 
   eventhdlrdata = SCIPeventhdlrGetData(eventhdlr);
   assert(eventhdlrdata != NULL);
 
   SCIPboundstoreClear(eventhdlrdata->boundstore);
}