From c219824ea8ebd862530a3d10bccac5303c7e240b Mon Sep 17 00:00:00 2001
From: Robert Gustafsson <robg@student.chalmers.se>
Date: Sat, 14 Oct 2017 10:29:44 +0200
Subject: Add define to use policy drop first element

---
 broccoli/src/fifoqueue.c   | 16 ++++++++++++----
 broccoli/src/midbropasad.c | 12 ++++++------
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/broccoli/src/fifoqueue.c b/broccoli/src/fifoqueue.c
index aeeced9..9b4b75e 100644
--- a/broccoli/src/fifoqueue.c
+++ b/broccoli/src/fifoqueue.c
@@ -13,6 +13,7 @@ init_queue(int size)
     q->tail = NULL;
     q->maxSize = size;
     q->currentSize = 0;
+    /*Queue empty from the beginning (block)*/
     sem_init(&q->bufferEmptyBlock, 0, 0);
     sem_init(&q->lock, 0, 1);
     return q;
@@ -40,12 +41,16 @@ is_empty(Fifo_q * q)
 add_to_queue(Fifo_q * q, Sensor_t * sensor)
 {
 
-    /* TODO delete first one if full */
     if(q == NULL){
+        printf("Error: Queue not initialized\n");
         return -1;    
     } 
     else if(is_full(q)){
-        return -1;
+        /* Drop Least Recently or Drop Most Recently */
+        #ifdef DLR
+            pop_from_queue(q);
+        #endif
+        return 0;
     }
     sem_wait(&q->lock);
     Queue_t * new_elem = (Queue_t *) malloc(sizeof(Queue_t));
@@ -75,11 +80,13 @@ pop_from_queue(Fifo_q * q)
     sem_wait(&q->lock);
     Queue_t * head = q->head;
     Sensor_t * sensor = head->sensor;
+    /* If dequeue the last element */
     if(q->currentSize == 1){
         q->head = NULL;
         q->tail = NULL;
+        /* Read current semaphore value */
         sem_getvalue(&q->bufferEmptyBlock, &semStat);
-        if(semStat == 1)
+        if(semStat == 1) /* Mark buffer as empty if last elem */
             sem_wait(&q->bufferEmptyBlock);
     }else{
         q->head = head->next;
@@ -91,7 +98,8 @@ pop_from_queue(Fifo_q * q)
 } 
 
     Sensor_t *
-create_sensor_object(int value, int uid){
+create_sensor_object(int value, int uid)
+{
     Sensor_t * sensor = (Sensor_t *) malloc(sizeof(Sensor_t));
     sensor->value = value;
     sensor->uid = uid;
diff --git a/broccoli/src/midbropasad.c b/broccoli/src/midbropasad.c
index cc93e7f..a745091 100644
--- a/broccoli/src/midbropasad.c
+++ b/broccoli/src/midbropasad.c
@@ -6,7 +6,7 @@
 #include <broccoli.h>
 #endif
 
-Fifo_q * q;
+Fifo_q * queue;
 
     void
 request_n_values(int number, int arrayOfValues[])
@@ -14,7 +14,7 @@ request_n_values(int number, int arrayOfValues[])
     int i;
     Sensor_t * sensor;
     for(i=0; i<number; ++i){
-        sensor = pop_from_queue(q);
+        sensor = pop_from_queue(queue);
         arrayOfValues[i] = sensor->value;
         free(sensor);
     }
@@ -25,7 +25,7 @@ request_value()
 {
     int value;
     Sensor_t * sensor;
-    sensor = pop_from_queue(q);
+    sensor = pop_from_queue(queue);
     value = sensor->value;
     free(sensor);
     printf("Release 1 sensor data value\n");
@@ -35,11 +35,11 @@ request_value()
     void
 start_data_capture()
 {
-
-    q = init_queue(50);
     int res;
+    queue = init_queue(500000); /* Initiate queue with fixed size */
     pthread_t event_listener;
-    res = pthread_create(&event_listener, NULL, bro_event_listener, q);
+    /* Create producer thread that listen for bro events */
+    res = pthread_create(&event_listener, NULL, bro_event_listener, queue);
     if(res){
         perror("Unable to create thread");
         exit(-1);
-- 
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