1 files changed, 104 insertions, 0 deletions
diff --git a/src/itc.c b/src/itc.c
new file mode 100644
index 0000000..6171d4e
--- /dev/null
+++ b/src/itc.c
@@ -0,0 +1,104 @@
+#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_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);
+                }
+        }
+}
+