File content as of revision 0:9ce7c170cb66:

/*! \file scheduler.c \brief Simple Task Scheduler. */
//*****************************************************************************
//
// File Name    : 'scheduler.c'
// Title        : Simple Task Scheduler
// Author       : Pascal Stang - Copyright (C) 2006
// Created      : 2006.05.24
// Revised      : 2006.05.26
// Version      : 0.1
// Target MCU   : Atmel AVR Series
// Editor Tabs  : 4
//
// NOTE: This code is currently below version 1.0, and therefore is considered
// to be lacking in some functionality or documentation, or may not be fully
// tested.  Nonetheless, you can expect most functions to work.
//
// This code is distributed under the GNU Public License
//      which can be found at http://www.gnu.org/licenses/gpl.txt
//
//*****************************************************************************
 
#include "scheduler.h"

// the task list
struct task TaskList[TASKLIST_SIZE];
 
// functions
void schedulerInit(void)
{
     int i;
     
     // reset task list
     for(i=0; i<TASKLIST_SIZE; i++)
     {
         // initialize task list
         TaskList[i].runtime = 0;
         TaskList[i].funcptr = 0;
     }
 }
 
void schedulerRun(int systime)
{
     int i;
     
     // locate active task slots
     for(i=0; i<TASKLIST_SIZE; i++)
     {
         if(TaskList[i].funcptr)
         {
             // check systime against runtime
             if(systime >= TaskList[i].runtime)
             {
                 // run task, then update it
                 TaskList[i].funcptr(i,systime);
                 
                 if(TaskList[i].nrepeat)
                 {
                     TaskList[i].runtime += TaskList[i].interval;
                     TaskList[i].nrepeat--;
                     // task has expired, remove it now
                     if(!TaskList[i].nrepeat)
                         schedulerRemoveTask(i);
                 }
                 else
                 {
                     // nrepeat==0 means run forever
                     TaskList[i].runtime += TaskList[i].interval;
                 }
                 
             }
         }
     }
 
     // increment scheduler timer
     //SchedulerTimer++;
}
 
int schedulerAddTask(int runtime, int nrepeat, int interval, taskfuncptr taskfunc)
{
    int i;
    
    // locate empty scheduler slot
    for(i=0; i<TASKLIST_SIZE; i++)
    {
        //CRITICAL_SECTION_BEGIN;
        if(!TaskList[i].funcptr)
        {
            // setup entry
            TaskList[i].funcptr = taskfunc;
            TaskList[i].runtime = runtime;
            TaskList[i].nrepeat = nrepeat;
            TaskList[i].interval = interval;
            
            // return task handle
            return i;
        }
        //CRITICAL_SECTION_END;
    }
    // error - no task slots left
    return -1;
}

int schedulerRemoveTask(int taskhandle)
{
    // clear the task entry
    TaskList[taskhandle].runtime = 0;
    TaskList[taskhandle].interval = 0;
    TaskList[taskhandle].nrepeat = 0;
    TaskList[taskhandle].funcptr = 0;
    
    return taskhandle;
}
 
int schedulerRemoveTaskFunc(taskfuncptr funcptr)
{
    int i;
    int taskhandle = -1;
    
    // locate the task
    for(i=0; i<TASKLIST_SIZE; i++)
    {
        // on match, disable the task
        if(TaskList[i].funcptr == funcptr) taskhandle = schedulerRemoveTask(i);
    }
    return taskhandle;
}