From a8ad8cbeda0e0dd5d29c5d4dc5afeaa9c4fccfdf Mon Sep 17 00:00:00 2001
From: Robert Gustafsson <robg@student.chalmers.se>
Date: Fri, 27 Oct 2017 09:17:21 +0200
Subject: Add semaphore to block producer if buffer is full

---
 broccoli/includes/types.h |  1 +
 broccoli/src/fifoqueue.c  | 18 ++++++++++--------
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/broccoli/includes/types.h b/broccoli/includes/types.h
index b23da1a..149415e 100644
--- a/broccoli/includes/types.h
+++ b/broccoli/includes/types.h
@@ -30,6 +30,7 @@ struct fifo_q{
     int valuesReceived;
     int valuesReleased;
     sem_t bufferEmptyBlock;
+    sem_t bufferFullBlock;
     sem_t lock;
 };
 
diff --git a/broccoli/src/fifoqueue.c b/broccoli/src/fifoqueue.c
index 3911eb7..a02f55c 100644
--- a/broccoli/src/fifoqueue.c
+++ b/broccoli/src/fifoqueue.c
@@ -19,6 +19,7 @@ init_queue(int size)
     q->valuesReleased = 0;
     /*Queue empty from the beginning (block)*/
     sem_init(&q->bufferEmptyBlock, 0, 0);
+    sem_init(&q->bufferFullBlock, 0, size);
     sem_init(&q->lock, 0, 1);
     return q;
 }
@@ -50,15 +51,16 @@ add_to_queue(Fifo_q * q, Sensor_t * sensor)
         free(sensor); //free if not appended
         return -1;    
     } 
-    else if(is_full(q)){
-        /* Drop Least Recently or Drop Most Recently */
-        #ifdef DLR
-            pop_from_queue(q);
-        #endif
+    /* Drop Least Recently or Drop Most Recently */
+    #ifdef DLR
+    if(is_full(q)){
+        pop_from_queue(q);
         q->droppedValues++;
-        free(sensor); //free if not appended
         return 0;
     }
+    #else
+    sem_wait(&q->bufferFullBlock);
+    #endif
     sem_wait(&q->lock);
     Queue_t * new_elem = (Queue_t *) malloc(sizeof(Queue_t));
     new_elem->next = NULL;
@@ -94,10 +96,10 @@ pop_from_queue(Fifo_q * q)
     }
     free(head);
     q->currentSize--;
+    sem_post(&q->lock);
     #ifndef DLR
-    q->valuesReleased++;
+    sem_post(&q->bufferFullBlock);
     #endif
-    sem_post(&q->lock);
     return sensor;
 } 
 
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