Program loses memory references as it progresses - c

Question

I have a project that consists of several processes running in different computers. It is similar to a "OS Simulator", mainly task scheduling and resource allocation.
There's a main process, "Platform" or "Server", that planifies/schedules the different processes that connect to it, by using a queue with the available processes that are ready to execute.
As time passes however, the pointers lose the memory address of some of them, or the reference to it, or the memory to which it points is either freed or just used for some other variable. This then leads to the process that's supposed to run just halting and waiting for the Platform to schedule it, which never happens because the element from the queue no longer references the process(which we handle with file descriptors). Is there anyway to prevent this from happening??
Here's the portion of the code where we think the problem is:
response = string_substring_from(response, sizeof(FREERESC));
char** data = string_split(response, COMA);
t_queue *temporaryQueue = queue_create();
t_scheduler_queue *queues = dictionary_get(levels_queues, data[0]);
pthread_mutex_lock(queues->mutex);
t_queue *anotherQueue = queue_create();
long o = 0;
if (queue_size(queues->character_queue) > 0)
{
log_info(log, "Mas de un personaje listo");
for (o = 0; o < queue_size(queues->character_queue); o++)
{
personaje_planificador *personajeEnLista = queue_pop(
queues->character_queue);
personaje_planificador *nuevoPersonaje = (personaje_planificador*) malloc(sizeof(personaje_planificador));
// long *hola = (long*) malloc(sizeof(long));
// memcpy(hola, &(personajeEnLista->fd), sizeof(long));
// nuevoPersonaje->fd = hola;
nuevoPersonaje->fd = personajeEnLista->fd;
nuevoPersonaje->nombre = string_from_format("%s", personajeEnLista->nombre);
queue_push(anotherQueue, nuevoPersonaje);
}
}
char** simbolos;
long j = 2;
t_dictionary *recursosDisponibles = dictionary_create();
for (j = 2; j < list_size(queues->simbolos) + 2; j++)
{
simbolos = string_split(data[j], DOSPUNTOS);
long *temporary = (long*) malloc(sizeof(long));
*temporary = atoi(simbolos[1]);
dictionary_put(recursosDisponibles, simbolos[0], temporary);
}
if (queue_size(queues->blocked_queue) > 0)
{
log_info(log, "Mas de un personaje bloqueado");
long i = 0;
long k = 0;
for (i = 0; i < queue_size(queues->blocked_queue); i++)
{
blocked_character *blockedCharacter = queue_pop(queues->blocked_queue);
for (k = 0; k < list_size(queues->simbolos); k++)
{
if (blockedCharacter->recurso == ((char*) list_get(queues->simbolos, k))[0])
{
if (giveResource(queues, dictionary_get(recursosDisponibles, list_get(queues->simbolos, k)), blockedCharacter) == 1)
{
personaje_planificador *nuevoPersonajeAgain = (personaje_planificador*) malloc(sizeof(personaje_planificador));
nuevoPersonajeAgain->fd =
blockedCharacter->personaje->fd;
nuevoPersonajeAgain->nombre = blockedCharacter->personaje->nombre;
queue_push(temporaryQueue, nuevoPersonajeAgain);
//TODO log
}
else
{
queue_push(queues->blocked_queue, blockedCharacter);
}
}
}
k = 0;
}
}
o = 0;
for (o = 0; o < queue_size(temporaryQueue); o++)
{
queue_push(anotherQueue, queue_pop(temporaryQueue));
}
queues->character_queue = anotherQueue;
pthread_mutex_unlock(queues->mutex);
t_level_address *addresses = (t_level_address*) dictionary_get(levelsMap, data[0]);
char **levelSocket = string_split(addresses->nivel, DOSPUNTOS);
long fdNivel = openSocketClient(levelSocket[1], levelSocket[0]);
sendMessage(fdNivel, stringRecursos(queues->simbolos, recursosDisponibles, atoi(data[1])));
free(recursosDisponibles);
log_info(log, "Liberar recursos.");
if (flagTerminoUnPersonaje == TRUE)
{
executeKoopa(niveles, levels_queues, orquestador_config);
}
Let me know if a portion of the code is unclear (it has some things written in Spanish), or if you need another part where you think the problem may be in.

Answer 1

Somebody mentioned "ValGrind" in one of the comments.
Try one of the products mentioned here: http://en.wikipedia.org/wiki/BoundsChecker
You should be able to find a free trial if not an outright free version. (it's been about 10 years since I regularly maintained other people's C and had to use Purify and Insure to hunt down this kind of aliasing and leaking)