Add IF clauses to schedule items

Schedule items in Cactus can already have WHILE clauses, which means
that they are executed while a certain condition are true.  This patch
adds IF clauses, which means that they are executed only if a certain
condition is true.  The syntax is equivalent to WHILE clauses.

These if clauses is different from the existing C-syntax if
statements, which are only evaluated at startup and determine how the
schedule is constructed.  These if clauses are evaluated every time
the schedule is traversed, and can skip certain schedule items.


git-svn-id: http://svn.cactuscode.org/flesh/trunk@4478 17b73243-c579-4c4c-a9d2-2d5706c11dac

7 files changed, 394 insertions, 35 deletions

diff --git a/src/include/cctk_Schedule.h b/src/include/cctk_Schedule.h
index e8f70dc1..ed6bcb2a 100644
--- a/src/include/cctk_Schedule.h
+++ b/src/include/cctk_Schedule.h
@@ -86,6 +86,7 @@ int CCTK_ScheduleFunction(void *function,
                           int n_before,
                           int n_after,
                           int n_while,
+                          int n_if,
                           ...);
 
 int CCTK_ScheduleGroup(const char *name,
@@ -99,6 +100,7 @@ int CCTK_ScheduleGroup(const char *name,
                        int n_before,
                        int n_after,
                        int n_while,
+                       int n_if,
                        ...);
 
 int CCTK_ScheduleGroupStorage(const char *group);
diff --git a/src/include/cctki_Schedule.h b/src/include/cctki_Schedule.h
index 2b77b826..9361053d 100644
--- a/src/include/cctki_Schedule.h
+++ b/src/include/cctki_Schedule.h
@@ -14,7 +14,11 @@
 
 /* Types needed by other routines. */
 
-typedef enum {sched_mod_none, sched_before, sched_after, sched_while} t_sched_modifier_type;
+typedef enum {
+  sched_mod_none,
+  sched_before, sched_after,
+  sched_while, sched_if
+} t_sched_modifier_type;
 
 typedef struct T_SCHED_MODIFIER
 {
@@ -58,7 +62,8 @@ int CCTKi_DoScheduleSortAllGroups(void);
 int CCTKi_DoScheduleTraverse(const char *group_name,
                              int (*item_entry)(void *, void *),
                              int (*item_exit)(void *, void *),
-                             int  (*while_check)(int, char **, void *, void *, int),
+                             int (*while_check)(int, char **, void *, void *, int),
+                             int (*if_check)(int, char **, void *, void *),
                              int (*function_process)(void *, void *, void *),
                              void *data);
 
diff --git a/src/include/cctki_ScheduleBindings.h b/src/include/cctki_ScheduleBindings.h
index c318effd..a87fb301 100644
--- a/src/include/cctki_ScheduleBindings.h
+++ b/src/include/cctki_ScheduleBindings.h
@@ -33,6 +33,7 @@ int CCTKi_ScheduleFunction(void *function,
                            int n_before,
                            int n_after,
                            int n_while,
+                           int n_if,
                            const int *timelevels, 
                            ...);
 
@@ -50,6 +51,7 @@ int CCTKi_ScheduleGroup(const char *realname,
                         int n_before,
                         int n_after,
                         int n_while,
+                        int n_if,
                         const int *timelevels,
                         ...
                         );
diff --git a/src/main/ScheduleInterface.c b/src/main/ScheduleInterface.c
index 46650121..b9ea8402 100644
--- a/src/main/ScheduleInterface.c
+++ b/src/main/ScheduleInterface.c
@@ -129,6 +129,7 @@ static int ParseOption(t_attribute *attribute,
 static t_sched_modifier *CreateModifiers(int n_before,
                                          int n_after,
                                          int n_while,
+                                         int n_if,
                                          va_list *ap);
 
 int ValidateModifiers(t_sched_modifier *modifier);
@@ -149,6 +150,11 @@ static int CCTKi_SchedulePrintWhile(int n_whiles,
                                     t_attribute *attribute,
                                     t_sched_data *data,
                                     int first);
+static int CCTKi_SchedulePrintIf(int n_if,
+                                 char **ifs,
+                                 t_attribute *attribute,
+                                 t_sched_data *data,
+                                 int first);
 static int CCTKi_SchedulePrintFunction(void *function, t_attribute *attribute, t_sched_data *data);
 
 static int CCTKi_ScheduleCallEntry(t_attribute *attribute, t_sched_data *data);
@@ -158,6 +164,10 @@ static int CCTKi_ScheduleCallWhile(int n_whiles,
                                    t_attribute *attribute,
                                    t_sched_data *data,
                                    int first);
+static int CCTKi_ScheduleCallIf(int n_ifs,
+                                char **ifs,
+                                t_attribute *attribute,
+                                t_sched_data *data);
 static int CCTKi_ScheduleCallFunction(void *function,
                                       t_attribute *attribute,
                                       t_sched_data *data);
@@ -369,6 +379,11 @@ int CCTK_CallFunction(void *function,
    @vtype   int
    @vio     in
    @endvar
+   @var     n_if
+   @vdesc   Number of vars to schedule if
+   @vtype   int
+   @vio     in
+   @endvar
    @var     timelevels
    @vdesc   The number of timelevels of the storage groups to enable.
    @vtype   const int *
@@ -400,6 +415,7 @@ int CCTKi_ScheduleFunction(void *function,
                            int n_before,
                            int n_after,
                            int n_while,
+                           int n_if,
                            const int *timelevels,
                            ...
                            )
@@ -414,13 +430,14 @@ int CCTKi_ScheduleFunction(void *function,
   attribute = CreateAttribute(where,name,description, language, thorn, implementation,
                               n_mem_groups, n_comm_groups, n_trigger_groups,
                               n_sync_groups, n_options, timelevels, &ap);
-  modifier  = CreateModifiers(n_before, n_after, n_while, &ap);
+  modifier  = CreateModifiers(n_before, n_after, n_while, n_if, &ap);
 
   va_end(ap);
 
   ValidateModifiers(modifier);
 
-  if(attribute && (modifier || (n_before == 0 && n_after == 0 && n_while == 0)))
+  if(attribute && (modifier || (n_before == 0 && n_after == 0 &&
+                                n_while == 0 && n_if == 0)))
   {
     attribute->FunctionData.type = TranslateFunctionType(where);
 
@@ -525,6 +542,11 @@ int CCTKi_ScheduleFunction(void *function,
    @vtype   int
    @vio     in
    @endvar
+   @var     n_if
+   @vdesc   Number of vars to schedule if
+   @vtype   int
+   @vio     in
+   @endvar
    @var     timelevels
    @vdesc   The number of timelevels of the storage groups to enable.
    @vtype   const int *
@@ -554,6 +576,7 @@ int CCTKi_ScheduleGroup(const char *realname,
                         int n_before,
                         int n_after,
                         int n_while,
+                        int n_if,
                         const int *timelevels,
                         ...
                         )
@@ -568,13 +591,14 @@ int CCTKi_ScheduleGroup(const char *realname,
   attribute = CreateAttribute(where,name,description, NULL, thorn, implementation,
                               n_mem_groups, n_comm_groups, n_trigger_groups,
                               n_sync_groups, n_options, timelevels, &ap);
-  modifier  = CreateModifiers(n_before, n_after, n_while, &ap);
+  modifier  = CreateModifiers(n_before, n_after, n_while, n_if, &ap);
 
   va_end(ap);
 
   ValidateModifiers(modifier);
 
-  if(attribute && (modifier || (n_before == 0 && n_after == 0 && n_while == 0)))
+  if(attribute && (modifier || (n_before == 0 && n_after == 0 &&
+                                n_while == 0 && n_if == 0)))
   {
     retcode = CCTKi_DoScheduleGroup(where, name, realname, modifier, (void *)attribute);
 
@@ -1237,6 +1261,7 @@ static int ScheduleTraverse(const char *where,
      (int (*)(void *, void *))                    CCTKi_ScheduleCallEntry,
      (int (*)(void *, void *))                    CCTKi_ScheduleCallExit,
      (int (*)(int, char **, void *, void *, int)) CCTKi_ScheduleCallWhile,
+     (int (*)(int, char **, void *, void *))      CCTKi_ScheduleCallIf,
      (int (*)(void *, void *, void *))            calling_function,
      (void *)&data);
 
@@ -1473,6 +1498,11 @@ static t_attribute *CreateAttribute(const char *where,
    @vtype   int
    @vio     in
    @endvar
+   @var     n_if
+   @vdesc   Number of vars to schedule if
+   @vtype   int
+   @vio     in
+   @endvar
    @var     ap
    @vdesc   options
    @vtype   va_list of multiple const char *
@@ -1489,6 +1519,7 @@ static t_attribute *CreateAttribute(const char *where,
 static t_sched_modifier *CreateModifiers(int n_before,
                                          int n_after,
                                          int n_while,
+                                         int n_if,
                                          va_list *ap)
 {
   t_sched_modifier *modifier;
@@ -1496,6 +1527,7 @@ static t_sched_modifier *CreateModifiers(int n_before,
   modifier = CreateTypedModifier(NULL, "before", n_before, ap);
   modifier = CreateTypedModifier(modifier, "after", n_after, ap);
   modifier = CreateTypedModifier(modifier, "while", n_while, ap);
+  modifier = CreateTypedModifier(modifier, "if", n_if, ap);
 
   return modifier;
 }
@@ -1506,7 +1538,7 @@ static t_sched_modifier *CreateModifiers(int n_before,
    @author     Gabrielle Allen
    @desc
    Validates a schedule modifier list. At the moment just check that
-   the while modifier uses a CCTK_INT grid variable.
+   the while and if modifiers use a CCTK_INT grid variable.
    @enddesc
    @calls
 
@@ -1541,6 +1573,18 @@ int ValidateModifiers(t_sched_modifier *modifier)
         retval = -1;
       }
     }
+    else if (modifier->type == sched_if)
+    {
+      vindex = CCTK_VarIndex(modifier->argument);
+      type = CCTK_VarTypeI(vindex);
+      if (type != CCTK_VARIABLE_INT)
+      {
+        CCTK_VWarn(0,__LINE__,__FILE__,"Cactus",
+                   "If qualifier %s is not a CCTK_INT grid variable",
+                   modifier->argument);
+        retval = -1;
+      }
+    }
   }
   return retval;
 }
@@ -1779,7 +1823,7 @@ static int ParseOption(t_attribute *attribute,
    @vtype   const char *
    @vio     in
    @vcomment
-   before, after, while
+   before, after, while, if
    @endvar
    @var     n_items
    @vdesc   Number of items on list
@@ -1910,10 +1954,11 @@ static int SchedulePrint(const char *where)
   if(where)
   {
     retcode = CCTKi_DoScheduleTraverse(where,
-       (int (*)(void *, void *))                    CCTKi_SchedulePrintEntry,
-       (int (*)(void *, void *))                    CCTKi_SchedulePrintExit,
-       (int  (*)(int, char **, void *, void *, int))CCTKi_SchedulePrintWhile,
-       (int (*)(void *, void *, void *))            CCTKi_SchedulePrintFunction,
+       (int (*)(void *, void *))                   CCTKi_SchedulePrintEntry,
+       (int (*)(void *, void *))                   CCTKi_SchedulePrintExit,
+       (int (*)(int, char **, void *, void *, int))CCTKi_SchedulePrintWhile,
+       (int (*)(int, char **, void *, void *, int))CCTKi_SchedulePrintIf,
+       (int (*)(void *, void *, void *))           CCTKi_SchedulePrintFunction,
        (void *)&data);
   }
   else
@@ -1966,7 +2011,7 @@ static int SchedulePrintTimes(const char *where, t_sched_data *data)
     memset (data->total_time->vals, 0,
             data->total_time->n_vals * sizeof (data->total_time->vals[0]));
 
-    retcode = CCTKi_DoScheduleTraverse(where, NULL, NULL, NULL,
+    retcode = CCTKi_DoScheduleTraverse(where, NULL, NULL, NULL, NULL,
        (int (*)(void *, void *, void *)) CCTKi_SchedulePrintTimesFunction,
        (void *)data);
 
@@ -2157,6 +2202,84 @@ static int CCTKi_SchedulePrintWhile(int n_whiles,
 }
 
 /*@@
+   @routine    CCTKi_SchedulePrintIf
+   @date       Dec 27, 2005
+   @author     Erik Schnetter
+   @desc
+   Routine called for if of a group when traversing for printing.
+   @enddesc
+   @calls
+
+   @var     n_ifs
+   @vdesc   number of if statements
+   @vtype   int
+   @vio     in
+   @endvar
+   @var     ifs
+   @vdesc   if statements
+   @vtype   char **
+   @vio     in
+   @endvar
+   @var     attribute
+   @vdesc   schedule item attributes
+   @vtype   t_attribute *
+   @vio     in
+   @endvar
+   @var     data
+   @vdesc   data associated with schedule item
+   @vtype   t_sched_data
+   @vio     in
+   @endvar
+   @var     first
+   @vdesc   flag - is this the first time we are checking if on this schedule item
+   @vtype   int
+   @vio     in
+   @endvar
+
+   @returntype int
+   @returndesc
+   0 - schedule item is inactive
+   1 - schedule item is active
+   @endreturndesc
+@@*/
+static int CCTKi_SchedulePrintIf(int n_ifs,
+                                 char **ifs,
+                                 t_attribute *attribute,
+                                 t_sched_data *data,
+                                 int first)
+{
+  int i;
+
+  /* prevent compiler warnings about unused parameters */
+  attribute = attribute;
+  data = data;
+
+  if(first)
+  {
+    printf("%*s", indent_level + 2 + 7, "if (");
+
+    for(i = 0; i < n_ifs; i++)
+    {
+      if(i > 0)
+      {
+        printf(" && ");
+      }
+
+      printf(ifs[i]);
+    }
+    printf(")\n");
+    indent_level += 2;
+  }
+  else
+  {
+    indent_level -= 2;
+    printf("%*s\n", indent_level + 9, "end if");
+  }
+
+  return first;
+}
+
+/*@@
    @routine    CCTKi_SchedulePrintFunction
    @date       Sun Sep 19 13:36:25 1999
    @author     Tom Goodale
@@ -2466,6 +2589,64 @@ static int CCTKi_ScheduleCallWhile(int n_whiles,
 }
 
 /*@@
+   @routine    CCTKi_ScheduleCallIf
+   @date       Dec 2007, 2005
+   @author     Erik Schnetter
+   @desc
+   Routine called to check variables to see if a group or function should be executed.
+   @enddesc
+   @calls
+
+   @var     n_ifs
+   @vdesc   number of if statements
+   @vtype   int
+   @vio     in
+   @endvar
+   @var     ifs
+   @vdesc   if statements
+   @vtype   char **
+   @vio     in
+   @endvar
+   @var     attribute
+   @vdesc   schedule item attributes
+   @vtype   t_attribute *
+   @vio     in
+   @endvar
+   @var     data
+   @vdesc   data associated with schedule item
+   @vtype   t_sched_data
+   @vio     in
+   @endvar
+
+   @returntype int
+   @returndesc
+   0 - schedule item is inactive
+   1 - schedule item is active
+   @endreturndesc
+@@*/
+static int CCTKi_ScheduleCallIf(int n_ifs,
+                                char **ifs,
+                                t_attribute *attribute,
+                                t_sched_data *data)
+{
+  int i;
+  int retcode;
+
+  /* prevent compiler warnings about unused parameters */
+  attribute = attribute;
+
+  retcode = 1;
+
+  /* FIXME - should do a lot of validation either here or on registration */
+  for(i = 0; i < n_ifs; i++)
+  {
+    retcode = retcode && *((CCTK_INT *)CCTK_VarDataPtr(data->GH, 0, ifs[i]));
+  }
+
+  return retcode;
+}
+
+/*@@
    @routine    CCTKi_ScheduleCallFunction
    @date       Sun Sep 19 13:29:14 1999
    @author     Tom Goodale
diff --git a/src/schedule/Schedule.h b/src/schedule/Schedule.h
index 5074e87a..bea93775 100644
--- a/src/schedule/Schedule.h
+++ b/src/schedule/Schedule.h
@@ -55,6 +55,8 @@ typedef struct
 
   int n_whiles;
   char **whiles;
+  int n_ifs;
+  char **ifs;
 
   void *attributes;
 
diff --git a/src/schedule/ScheduleCreater.c b/src/schedule/ScheduleCreater.c
index 7aef2a5a..ace2c9a7 100644
--- a/src/schedule/ScheduleCreater.c
+++ b/src/schedule/ScheduleCreater.c
@@ -48,6 +48,7 @@ static int ScheduleItemNumber(t_sched_group *group,
 
 
 static int ScheduleSetupWhiles(t_sched_item *item);
+static int ScheduleSetupIfs(t_sched_item *item);
 
 /********************************************************************
  ********************* Other Routine Prototypes *********************
@@ -533,8 +534,11 @@ static t_sched_item *ScheduleCreateItem(const char *name, t_sched_modifier *modi
 
       this->n_whiles = 0;
       this->whiles = NULL;
+      this->n_ifs = 0;
+      this->ifs = NULL;
 
       ScheduleSetupWhiles(this);
+      ScheduleSetupIfs(this);
 
       this->attributes = attributes;
 
@@ -676,6 +680,10 @@ static t_sched_modifier_type ScheduleTranslateModifierType(const char *modifier)
   {
     retval = sched_while;
   }
+  else if(!strcmp(modifier, "if"))
+  {
+    retval = sched_if;
+  }
 
 #ifdef DEBUG_SCHEDULAR
   printf("Translated modifier type %s to %d\n", modifier, retval);
@@ -747,7 +755,7 @@ static int ScheduleSortGroup(t_sched_group *group)
 #endif
     for(modifier = group->scheditems[item].modifiers; modifier; modifier = modifier->next)
     {
-      if(modifier->type == sched_while)
+      if(modifier->type == sched_while || modifier->type == sched_if)
       {
         continue;
       }
@@ -969,6 +977,70 @@ static int ScheduleSetupWhiles(t_sched_item *item)
   return retval;
 }
 
+ /*@@
+   @routine    ScheduleSetupIfs
+   @date       Dec 27, 2005
+   @author     Erik Schnetter
+   @desc 
+   Make an array of all the ifs in the modifier list for a schedule item.
+   @enddesc 
+   @calls     
+   @calledby   
+   @history 
+ 
+   @endhistory 
+   @var     item
+   @vdesc   The schedule item to work on
+   @vtype   t_sched_item *
+   @vio     inout
+   @vcomment 
+ 
+   @endvar 
+   @returntype int
+   @returndesc 
+   Number of whiles
+   @endreturndesc
+@@*/
+static int ScheduleSetupIfs(t_sched_item *item)
+{
+  int retval;
+  t_sched_modifier *modifier;
+  char **temp;
+
+  retval = 0;
+
+  for(modifier = item->modifiers; modifier; modifier = modifier->next)
+  {
+    if(modifier->type == sched_if)
+    {
+      item->n_ifs++;
+      temp = (char **)realloc(item->ifs, item->n_ifs*sizeof(char *));
+
+      if(temp)
+      {
+        item->ifs = temp;
+
+        temp[item->n_ifs-1] = (char *)malloc((strlen(modifier->argument)+1)*sizeof(char));
+        if(temp[item->n_ifs-1])
+        {
+          strcpy(temp[item->n_ifs-1], modifier->argument);
+        }
+        else
+        {
+          item->n_ifs--;
+          retval--;
+        }
+      }
+      else
+      {
+        retval--;
+      }
+    }
+  }
+
+  return retval;
+}
+
 /********************************************************************
  ********************************************************************
  ********************************************************************/
diff --git a/src/schedule/ScheduleTraverse.c b/src/schedule/ScheduleTraverse.c
index 30908371..1baa0ad3 100644
--- a/src/schedule/ScheduleTraverse.c
+++ b/src/schedule/ScheduleTraverse.c
@@ -34,9 +34,12 @@ static int ScheduleTraverseGroup(cHandledData *schedule_groups,
                                  void *attributes,
                                  int n_whiles,
                                  char **whiles,
+                                 int n_ifs,
+                                 char **ifs,
                                  int (*item_entry)(void *, void *),
                                  int (*item_exit)(void *, void *),
-                                 int  (*while_check)(int, char **, void *, void *, int),
+                                 int (*while_check)(int, char **, void *, void *, int),
+                                 int (*if_check)(int, char **, void *, void *),
                                  int (*function_process)(void *, void *, void *),
                                  void *data);
 
@@ -44,9 +47,12 @@ static int ScheduleTraverseFunction(void *function,
                                     void *attributes,
                                     int n_whiles,
                                     char **whiles,
+                                    int n_ifs,
+                                    char **ifs,
                                     int (*item_entry)(void *, void *),
                                     int (*item_exit)(void *, void *),
-                                    int  (*while_check)(int, char **, void *, void *, int),
+                                    int (*while_check)(int, char **, void *, void *, int),
+                                    int (*if_check)(int, char **, void *, void *),
                                     int (*function_process)(void *, void *, void *),
                                     void *data);
 
@@ -102,6 +108,13 @@ static int ScheduleTraverseFunction(void *function,
    @vcomment 
  
    @endvar 
+   @var     if_check
+   @vdesc   function to be called to check an if statement
+   @vtype   int (*)(int, char **, void *, void *, int)
+   @vio     in
+   @vcomment 
+ 
+   @endvar 
    @var     function_process
    @vdesc   function to be called on any function
    @vtype   int (*)(void *, void *, void *)
@@ -126,7 +139,8 @@ static int ScheduleTraverseFunction(void *function,
 int CCTKi_DoScheduleTraverse(const char *group_name,
                              int (*item_entry)(void *, void *),
                              int (*item_exit)(void *, void *),
-                             int  (*while_check)(int, char **, void *, void *, int),
+                             int (*while_check)(int, char **, void *, void *, int),
+                             int (*if_check)(int, char **, void *, void *),
                              int (*function_process)(void *, void *, void *),
                              void *data)
 {
@@ -146,9 +160,12 @@ int CCTKi_DoScheduleTraverse(const char *group_name,
                                     NULL,
                                     0,
                                     NULL,
+                                    0,
+                                    NULL,
                                     item_entry, 
                                     item_exit, 
                                     while_check, 
+                                    if_check, 
                                     function_process,
                                     data);
   }
@@ -211,6 +228,20 @@ int CCTKi_DoScheduleTraverse(const char *group_name,
    @vcomment 
  
    @endvar 
+   @var     n_ifs
+   @vdesc   number of ifs
+   @vtype   int
+   @vio     in
+   @vcomment 
+ 
+   @endvar 
+   @var     ifs
+   @vdesc   array of if strings
+   @vtype   char **
+   @vio     in
+   @vcomment 
+ 
+   @endvar 
    @var     item_entry
    @vdesc   function to be called on entry to an item
    @vtype   int (*)(void *, void *)
@@ -232,6 +263,13 @@ int CCTKi_DoScheduleTraverse(const char *group_name,
    @vcomment 
  
    @endvar 
+   @var     if_check
+   @vdesc   function to be called to check a if statement
+   @vtype   int (*)(int, char **, void *, void *, int)
+   @vio     in
+   @vcomment 
+ 
+   @endvar 
    @var     function_process
    @vdesc   function to be called on any function
    @vtype   int (*)(void *, void *, void *)
@@ -257,9 +295,12 @@ static int ScheduleTraverseGroup(cHandledData *schedule_groups,
                                  void *attributes,
                                  int n_whiles,
                                  char **whiles,
+                                 int n_ifs,
+                                 char **ifs,
                                  int (*item_entry)(void *, void *),
                                  int (*item_exit)(void *, void *),
-                                 int  (*while_check)(int, char **, void *, void *, int),
+                                 int (*while_check)(int, char **, void *, void *, int),
+                                 int (*if_check)(int, char **, void *, void *),
                                  int (*function_process)(void *, void *, void *),
                                  void *data)
 {
@@ -268,17 +309,35 @@ static int ScheduleTraverseGroup(cHandledData *schedule_groups,
   int called_item_entry;
   t_sched_group *newgroup;
 
-  /* If there is a while-list associated with this item, check if the group should be
-   * exectuted at all.
+  doit = 1;
+
+  /* If there is an if-list associated with this item, check if the
+   * group should be exectuted at all.
    */
 
-  if(n_whiles > 0 && while_check)
+  if(n_ifs > 0 && if_check)
   {
-    doit = while_check(n_whiles, whiles, attributes, data,1);
+    doit = doit && if_check(n_ifs, ifs, attributes, data);
   }
-  else
+
+  /* If there is a while-list associated with this item, check if the
+   * group should be exectuted at all.
+   *
+   * If there are both an if-list and a while-list, then both are
+   * checked when the group is entered, but only the while-list is
+   * checked to determine whether the loop should continue.  This
+   * means that the if-statement is outside the while-statement, as in
+   *
+   * IF (...)
+   *   WHILE (...)
+   *     schedule stuff
+   *   END WHILE
+   * END IF
+   */
+
+  if(n_whiles > 0 && while_check)
   {
-    doit = 1;
+    doit = doit && while_check(n_whiles, whiles, attributes, data,1);
   }
 
   /* Call a item entry function if it is defined. */
@@ -297,7 +356,7 @@ static int ScheduleTraverseGroup(cHandledData *schedule_groups,
   }
 
   /* Now traverse the group. */
-  while(doit )
+  while(doit)
   {
       
     /* Traverse in the sorted order - assumes group has been sorted ! */
@@ -310,9 +369,12 @@ static int ScheduleTraverseGroup(cHandledData *schedule_groups,
                                    group->scheditems[group->order[item]].attributes,
                                    group->scheditems[group->order[item]].n_whiles,
                                    group->scheditems[group->order[item]].whiles,
+                                   group->scheditems[group->order[item]].n_ifs,
+                                   group->scheditems[group->order[item]].ifs,
                                    item_entry,
-                                   item_exit,                                  
+                                   item_exit,
                                    while_check,
+                                   if_check,
                                    function_process,
                                    data);
           break;
@@ -324,9 +386,12 @@ static int ScheduleTraverseGroup(cHandledData *schedule_groups,
                                 group->scheditems[group->order[item]].attributes,
                                 group->scheditems[group->order[item]].n_whiles,
                                 group->scheditems[group->order[item]].whiles,
+                                group->scheditems[group->order[item]].n_ifs,
+                                group->scheditems[group->order[item]].ifs,
                                 item_entry, 
                                 item_exit, 
                                 while_check, 
+                                if_check, 
                                 function_process,
                                 data);
           break;
@@ -398,6 +463,20 @@ static int ScheduleTraverseGroup(cHandledData *schedule_groups,
    @vcomment 
  
    @endvar 
+   @var     n_ifs
+   @vdesc   number of ifs
+   @vtype   int
+   @vio     in
+   @vcomment 
+ 
+   @endvar 
+   @var     ifs
+   @vdesc   array of if strings
+   @vtype   char **
+   @vio     in
+   @vcomment 
+ 
+   @endvar 
    @var     item_entry
    @vdesc   function to be called on entry to an item
    @vtype   int (*)(void *, void *)
@@ -419,6 +498,13 @@ static int ScheduleTraverseGroup(cHandledData *schedule_groups,
    @vcomment 
  
    @endvar 
+   @var     if_check
+   @vdesc   function to be called to check a if statement
+   @vtype   int (*)(int, char **, void *, void *, int)
+   @vio     in
+   @vcomment 
+ 
+   @endvar 
    @var     function_process
    @vdesc   function to be called on any function
    @vtype   int (*)(void *, void *, void *)
@@ -443,26 +529,36 @@ static int ScheduleTraverseFunction(void *function,
                                     void *attributes,
                                     int n_whiles,
                                     char **whiles,
+                                    int n_ifs,
+                                    char **ifs,
                                     int (*item_entry)(void *, void *),
                                     int (*item_exit)(void *, void *),
-                                    int  (*while_check)(int, char **, void *, void *, int),
+                                    int (*while_check)(int, char **, void *, void *, int),
+                                    int (*if_check)(int, char **, void *, void *),
                                     int (*function_process)(void *, void *, void *),
                                     void *data)
 {
   int doit;
   int called_item_entry;
 
-  /* If there is a while-list associated with this function, check if the function should be
-   * executed at all.
+  doit = 1;
+
+  /* If there is an if-list associated with this function, check if
+   * the function should be executed at all.
    */
 
-  if(n_whiles > 0 && while_check)
+  if(n_ifs > 0 && if_check)
   {
-    doit = while_check(n_whiles, whiles, attributes, data,1);
+    doit = doit && if_check(n_ifs, ifs, attributes, data);
   }
-  else
+
+  /* If there is a while-list associated with this function, check if
+   * the function should be executed at all.
+   */
+
+  if(n_whiles > 0 && while_check)
   {
-    doit = 1;
+    doit = doit && while_check(n_whiles, whiles, attributes, data,1);
   }
 
   /* Call a item entry function if it is defined. */
@@ -481,7 +577,7 @@ static int ScheduleTraverseFunction(void *function,
   }
 
   /* Now traverse the . */
-  while(doit )
+  while(doit)
   {
     
     /* Now actually do something with the function. */
@@ -493,7 +589,6 @@ static int ScheduleTraverseFunction(void *function,
       doit = while_check(n_whiles, whiles, attributes, data,0) ;
     }
     else
-
     {
       doit = 0;
     }