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Fixed negative effective priorities problem
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Refactored reset priorities to reset the priorities of a BCP list
instead of resetting only the ready list.
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@Mithrandir0x
Mithrandir0x committed Apr 2, 2014
1 parent 912ca6b commit c0d0506
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Showing 2 changed files with 63 additions and 31 deletions.
92 changes: 62 additions & 30 deletions P2-S2/minikernel/kernel.c
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Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,11 @@ static int buscar_BCP_libre();
static void insertar_ultimo(lista_BCPs *lista, BCP * proc);
static void eliminar_primero(lista_BCPs *lista);
static void eliminar_elem(lista_BCPs *lista, BCP * proc);

/**
* Print helper function declarations
*/
static char* get_state_string(int state);
static void print_bcp_list(lista_BCPs *list);
static void print_bcp(BCP *bcp, char *function);

Expand All @@ -44,7 +49,7 @@ static void unblock_process(BCP* bcp);
/**
* Interruption treatment and auxiliary function declarations
*/
static void reset_priorities();
static void reset_priorities(lista_BCPs *list);
static void update_slept_process();
static void update_working_process();
static void exc_arit();
Expand Down Expand Up @@ -169,16 +174,30 @@ static void print_bcp_list(lista_BCPs *list)
printk("\x1B[31m[KRN][-1][%16.16s] }\x1B[0m\n", "print_bcp_list");
}

static char* get_state_string(int state)
{
switch ( state )
{
case 0: return "TERMINADO";
case 1: return "LISTO";
case 2: return "EJECUCION";
case 3: return "BLOQUEADO";
}

return "UNKNOWN";
}

static void print_bcp(BCP *bcp, char *function)
{
if ( p_proc_actual )
printk("\x1B[31m[KRN][%2d]", p_proc_actual->id);
else
printk("\x1B[31m[KRN][-1]");

printk("[%16.16s] [%2d] {BP: [%2d], EP: [%2d]}\x1B[0m\n",
printk("[%16.16s] [%2d] {S: [%9s], BP: [%2d], EP: [%2d]}\x1B[0m\n",
function,
bcp->id,
get_state_string(bcp->estado),
bcp->base_priority,
bcp->effective_priority
);
Expand All @@ -187,21 +206,33 @@ static void print_bcp(BCP *bcp, char *function)
static BCP* get_max_priority_bcp(lista_BCPs *list)
{
unsigned int max = MIN_PRIO;
int reset_all_bcps_priorities = true;
BCP *p = list->primero;
BCP *p_max = p;

for ( ; p ; p = p->siguiente )
{
if ( p->base_priority == MAX_PRIO )
if ( p->effective_priority == 0 )
continue;
else
reset_all_bcps_priorities = false;

if ( p->effective_priority == MAX_PRIO )
return p;

if ( p->base_priority > max )
if ( p->effective_priority > max )
{
p_max = p;
max = p->base_priority;
max = p->effective_priority;
}
}

if ( reset_all_bcps_priorities )
{
reset_priorities(&lista_listos);
reset_priorities(&l_slept_procs);
}

return p_max;
}

Expand Down Expand Up @@ -288,6 +319,7 @@ static void liberar_proceso(){

//printk("\x1B[31m[KRN][%2d][%16.16s] MADE FREE PROCESS [%2d] STACK.\x1B[0m\n", p_proc_actual->id, "liberar_proceso", p_proc_anterior->id);

p_proc_actual->estado = EJECUCION;
cambio_contexto(NULL, &(p_proc_actual->contexto_regs));

return; /* no debería llegar aqui */
Expand Down Expand Up @@ -334,6 +366,7 @@ static void block_process()
* Do save old context to be swapped, so that it is
* possible to restore it after being awaken.
*/
p_proc_actual->estado = EJECUCION;
cambio_contexto(&(p_proc_anterior->contexto_regs), &(p_proc_actual->contexto_regs));
}

Expand Down Expand Up @@ -397,41 +430,34 @@ static void update_slept_process()
}
}

static void reset_priorities()
static void reset_priorities(lista_BCPs *list)
{
BCP* p = lista_listos.primero;
BCP* p = list->primero;

//printk("\x1B[31m[KRN][%2d][%16.16s] RESETTING EFFECTIVE PRIORITIES OF READY LIST\x1B[0m\n", p_proc_actual->id, "reset_priorities");
printk("\x1B[31m[KRN][%2d][%16.16s] RESETTING EFFECTIVE PRIORITIES\x1B[0m\n", p_proc_actual->id, "reset_priorities");

for ( ; p ; p = p->siguiente )
{
p->effective_priority = p->base_priority;
p->effective_priority = ( p->effective_priority / 2 ) + p->base_priority;
}

print_bcp_list(list);
}

static void update_working_process()
{
int reset_all_bcps_priorities = true;
BCP* p = lista_listos.primero;

p_proc_actual->effective_priority--;

if ( !p_proc_actual->effective_priority && lista_listos.length != 1 )
if ( p_proc_actual->estado == EJECUCION && p_proc_actual->effective_priority > 0 )
{
printk("\x1B[31m[KRN][%2d][%16.16s] PROCESS HAS CONSUMED ALL ITS CPU TIME\x1B[0m\n", p_proc_actual->id, "update_working_process");
SIGNAL_RESCHEDULLING();
}
p_proc_actual->effective_priority--;

for ( ; reset_all_bcps_priorities && p ; p = p->siguiente )
{
if ( p->effective_priority )
printk("\x1B[31m[KRN][%2d][%16.16s] CURRENT PROCESS UPDATED EP: [%d]\x1B[0m\n", p_proc_actual->id, "update_working_process", p_proc_actual->effective_priority);

if ( !p_proc_actual->effective_priority )
{
reset_all_bcps_priorities = false;
printk("\x1B[31m[KRN][%2d][%16.16s] PROCESS HAS CONSUMED ALL ITS CPU TIME\x1B[0m\n", p_proc_actual->id, "update_working_process");
SIGNAL_RESCHEDULLING();
}
}

if ( reset_all_bcps_priorities )
reset_priorities();
}

/*
Expand Down Expand Up @@ -529,13 +555,18 @@ static void int_sw()
p_proc_anterior = p_proc_actual;
liberar_pila(p_proc_anterior->pila);
p_proc_actual = planificador();

printk("\x1B[31m[KRN][%2d][%16.16s] PRIORITIZED PROCESS. CHANGING CONTEXT: [%2d] => [%2d]\x1B[0m\n", p_proc_actual->id, "int_sw", p_proc_anterior->id, p_proc_actual->id);

//printk("\x1B[31m[KRN][%2d][%16.16s] READY BCP LIST: \x1B[0m\n", p_proc_actual->id, "int_sw");
//print_bcp_list(&lista_listos);
if ( p_proc_actual->id != p_proc_anterior->id )
{
printk("\x1B[31m[KRN][%2d][%16.16s] PRIORITIZED PROCESS. CHANGING CONTEXT: [%2d] => [%2d]\x1B[0m\n", p_proc_actual->id, "int_sw", p_proc_anterior->id, p_proc_actual->id);

//printk("\x1B[31m[KRN][%2d][%16.16s] READY BCP LIST: \x1B[0m\n", p_proc_actual->id, "int_sw");
//print_bcp_list(&lista_listos);

cambio_contexto(&(p_proc_anterior->contexto_regs), &(p_proc_actual->contexto_regs));
p_proc_anterior->estado = LISTO;
p_proc_actual->estado = EJECUCION;
cambio_contexto(&(p_proc_anterior->contexto_regs), &(p_proc_actual->contexto_regs));
}
}

return;
Expand Down Expand Up @@ -761,6 +792,7 @@ int main(){

/* activa proceso inicial */
p_proc_actual=planificador();
p_proc_actual->estado = EJECUCION;
cambio_contexto(NULL, &(p_proc_actual->contexto_regs));
panico("\033[1m\033[31m[KRN][-1][ main] >> KERNEL_EXCEPTION [S.O. Unexpected reactivation] <<\x1B[0m");
return 0;
Expand Down
2 changes: 1 addition & 1 deletion P2-S2/usuario/init.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -15,7 +15,7 @@ int main()
printf("init: comienza\n");

// Has priority 20 and does not sleep
crear_proceso("longsum");
//crear_proceso("longsum");

// Has priority 40, but sleeps for 2 seconds
crear_proceso("simplon_prio");
Expand Down

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