SPINLOCK.C

//this is Coto's spinlock , requires spinlock_sched() to be glued to some kind of irq trigger so it runs regardless the main program core.

#include "spinlock.h"

u32cback_ptr cb_handler; //global callbacku32handler
int counter = 0; //counter on hblank
volatile spinlock_table spinlock_handler[spinlock_elements];

//spinlock create process | spinlock_createproc(u8 process_id,u8 status,u32cback_ptr new_callback)
//returns 0 if created | returns 1 if already exists (failure)
u32 spinlock_createproc(u8 process_id,u8 status,u32cback_ptr new_callback){
        if(!spinlock_handler[process_id].spinlock_id){
                spinlock_handler[process_id].spinlock_id = process_id;
                spinlock_handler[process_id].status = status;
                spinlock_handler[process_id].func_ptr = (u32)new_callback;
        }
        else
                return 1;
return 0;
}

//Modifies an existing spinlock process
//returns 0 if created | returns 1 if doesnot exists (failure)
u32 spinlock_modifyproc(u8 process_id,u8 status,u32cback_ptr new_callback){
        if(spinlock_handler[process_id].spinlock_id){
                //spinlock_handler[process_id].spinlock_id = process_id; //Modify keeps the actual index/ID
                spinlock_handler[process_id].status = status;
                spinlock_handler[process_id].func_ptr = (u32)new_callback;
        }
        else
                return 1;
return 0;
}

//Deletes an existing spinlock process
//returns 0 if created | returns 1 if doesnot exists (failure)
u32 spinlock_deleteproc(u8 process_id){
        if(spinlock_handler[process_id].spinlock_id){
                spinlock_handler[process_id].spinlock_id =      (u32)NULL_VAR;
                spinlock_handler[process_id].status =           (u32)NULL_VAR;
                spinlock_handler[process_id].func_ptr =         (u32)NULL_VAR;
        }
        else
                return 1;
return 0;
}


//spinlock scheduler //executes all threads set to unlock
u32 __attribute__ ((hot)) spinlock_sched(){

        switch(spinlock_handler[counter].status){
                case(0):
                        cb_handler = (u32cback_ptr) spinlock_handler[counter].func_ptr;
                        //spinlock_handler[counter].status=1;
                        cb_handler();
                break;
                default:
                        counter++; //if this thread isn't runnable index++
                break;
        }

        if (counter>((int)spinlock_linearelements))
                counter=0;

return 0;
}

//spinlock permission enable/disable
//returns 0 if set permission | returns 1 if process don't exists (failure)
u32 spinlock_perm(u8 process_id,u8 status){
        if(spinlock_handler[process_id].spinlock_id){
                spinlock_handler[process_id].status=status;
                return 0;
        }
        else
                return 1;

return 1;
}