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#include "itc.h"
#include "utils.h"
#include <semaphore.h>
#include <stdlib.h>
#include <sys/time.h>
struct itc {
int nslots;
void **slots;
int inputidx;
int outputidx;
sem_t emptied;
sem_t occupied;
};
itc *itc_alloc(int nslots)
{
itc *ctx;
if (nslots <= 0) {
return NULL;
}
ctx = calloc(1, sizeof(*ctx));
ctx->nslots = nslots;
ctx->slots = calloc(nslots, sizeof(*ctx->slots));
sem_init(&ctx->emptied, 0, nslots);
sem_init(&ctx->occupied, 0, 0);
return ctx;
}
void itc_free(itc **ctx, itc_free_element free_element)
{
if (ctx == NULL || *ctx == NULL) {
return;
}
itc_drop(*ctx, free_element);
sem_destroy(&(*ctx)->emptied);
sem_destroy(&(*ctx)->occupied);
free((*ctx)->slots);
free(*ctx);
*ctx = NULL;
}
void *itc_retrive(itc *ctx, int timeout_ms)
{
struct timespec ts;
void *element;
if (ctx == NULL) {
return NULL;
}
timespec_add_ms(gettimespec(&ts), timeout_ms);
if (sem_timedwait(&ctx->occupied, &ts)) {
return NULL;
}
element = ctx->slots[ctx->outputidx];
ctx->outputidx = (ctx->outputidx + 1) % ctx->nslots;
sem_post(&ctx->emptied);
return element;
}
int itc_inject(itc *ctx, int timeout_ms, void *element)
{
struct timespec ts;
if (ctx == NULL) {
return -1;
}
timespec_add_ms(gettimespec(&ts), timeout_ms);
if (sem_timedwait(&ctx->emptied, &ts)) {
return -1;
}
ctx->slots[ctx->inputidx] = element;
ctx->inputidx = (ctx->inputidx + 1) % ctx->nslots;
sem_post(&ctx->occupied);
return 0;
}
void itc_flush(itc *ctx)
{
int i;
if (ctx == NULL) {
return;
}
for (i = 0; i < ctx->nslots; i++) {
sem_wait(&ctx->emptied);
sem_post(&ctx->emptied);
}
}
void itc_drop(itc *ctx, itc_free_element free_element)
{
void *element;
if (ctx == NULL) {
return;
}
while ((element = itc_retrive(ctx, 0)) != NULL) {
if (free_element != NULL) {
free_element(element);
}
}
}
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