1 files changed, 64 insertions(+), 10 deletions(-)

M emulator/test_kia.c

@@ 2,6 2,7 @@
 #include <stdlib.h>
 #include <stdint.h>
 #include <string.h>
+#include <stdbool.h>
 
 /**
  * @brief The KIA queue depth.


@@ 10,6 11,12 @@
  */
 #define KIA_QUEUE_DEPTH 16
 
+typedef struct {
+  int     read_ptr;
+  int     write_ptr;
+  uint8_t queue[KIA_QUEUE_DEPTH];
+} KIA_t;
+
 /**
  * @brief Answers with the slot index after the one provided.
  */


@@ 18,11 25,21 @@ next_slot(int slot) {
   return (slot + 1) % KIA_QUEUE_DEPTH;
 }
 
-typedef struct {
-  int     read_ptr;
-  int     write_ptr;
-  uint8_t queue;
-} KIA_t;
+/**
+ * @brief Answers true if the queue is empty.
+ */
+bool
+kia_is_empty(KIA_t *pk) {
+  return (pk->read_ptr) == (pk->write_ptr);
+}
+
+/**
+ * @brief Answers true if the queue is not empty.
+ */
+bool
+kia_isnt_empty(KIA_t *pk) {
+  return !kia_is_empty(pk);
+}
 
 /**
  * @brief Resets the KIA_t instance to its empty-queue condition.


@@ 61,7 78,8 @@ kia_test_get_pointers(
  * @brief Pops the input queue.
  */
 void
-kia_pop(void) {
+kia_pop(KIA_t *pk) {
+  if(kia_isnt_empty(pk)) pk->read_ptr = next_slot(pk->read_ptr);
 }
 
 /**


@@ 71,8 89,9 @@ kia_pop(void) {
  */
 void
 kia_push(KIA_t *pk, uint8_t byte) {
-  ++pk->write_ptr;
-  pk->queue = byte;
+  int wp = pk->write_ptr;
+  pk->write_ptr = next_slot(wp);
+  pk->queue[wp] = byte;
 }
 
 /**


@@ 84,7 103,7 @@ kia_push(KIA_t *pk, uint8_t byte) {
  */
 uint8_t
 kia_peek(KIA_t *pk) {
-  return pk->queue;
+  return pk->queue[pk->read_ptr];
 }
 
 static int erc = 0;


@@ 101,7 120,7 @@ test_pop_empty() {
   int old_read, old_write;
   kia_test_get_pointers(pk, &old_read, &old_write);
 
-  kia_pop();
+  kia_pop(pk);
 
   int new_read, new_write;
   kia_test_get_pointers(pk, &new_read, &new_write);


@@ 145,10 164,45 @@ write_ptr_fail: ++erc;
 read_ptr_fail:  ++erc;
 }
 
+void
+test_pop_nonempty() {
+  if(erc) return;
+  printf("test_pop_nonempty\n");
+
+  KIA_t *pk = kia_new();
+
+  int old_read, old_write;
+  kia_test_get_pointers(pk, &old_read, &old_write);
+
+  kia_push(pk, 0x11);
+  kia_push(pk, 0x22);
+  if(kia_peek(pk) != 0x11) goto first_push_data_fail;
+
+  kia_pop(pk);
+
+  int new_read, new_write;
+  kia_test_get_pointers(pk, &new_read, &new_write);
+
+  if(new_read != next_slot(old_read)) goto read_ptr_fail;
+  if(new_write != next_slot(next_slot(old_write))) {
+    goto write_ptr_fail;
+  }
+
+  if(kia_peek(pk) != 0x22) goto second_push_data_fail;
+
+  return;
+
+second_push_data_fail:  ++erc;
+write_ptr_fail:         ++erc;
+read_ptr_fail:          ++erc;
+first_push_data_fail:   ++erc;
+}
+
 int
 main() {
   test_pop_empty();
   test_push_byte();
+  test_pop_nonempty();
 
   return erc;
 }