make ringbuffer thread safety optional

controller/controller.c

@@ -1,3 +1,5 @@
+#define RINGBUFFER_THREAD_SAFE
+
 #include <linux/i2c-dev.h>
 #include <i2c/smbus.h>
 #include <sys/ioctl.h>
@@ -9,7 +11,6 @@
 #include <stdint.h>
 #include <stdarg.h>
 #include <stdlib.h>
-#include <pthread.h>
 
 #include "global.h"
 #include "ringbuffer.h"

controller/ringbuffer.c

@@ -1,9 +1,12 @@
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
-
 #include <stdio.h>
 
+#ifdef RINGBUFFER_THREAD_SAFE
+#include <pthread.h>
+#endif 
+
 #include "ringbuffer.h"
 
 void _ringBufferIncReader(struct ringBuffer *buf) {
@@ -34,32 +37,46 @@ void ringBufferCreate(int blocks, size_t blockSize, struct ringBuffer *out) {
   out->blockSize = blockSize;
   out->reader = out->buffer;
   out->writer = out->buffer;
+#ifdef RINGBUFFER_THREAD_SAFE
   pthread_mutex_init(&out->mutex, NULL);
+#endif
 }
 
 void ringBufferDestroy(struct ringBuffer *buf) {
   free(buf->buffer);
+#ifdef RINGBUFFER_THREAD_SAFE
   pthread_mutex_destroy(&buf->mutex);
+#endif
 }
 
 int ringBufferRead(struct ringBuffer *buf, void *out) {
+#ifdef RINGBUFFER_THREAD_SAFE
   pthread_mutex_lock(&buf->mutex);
+#endif
   if (buf->reader != buf->writer) {
     // we have data to read
     memcpy(out, buf->reader, buf->blockSize);
     _ringBufferIncReader(buf);
+#ifdef RINGBUFFER_THREAD_SAFE
     pthread_mutex_unlock(&buf->mutex);
+#endif
     return 0;
   } else {
     // nothing to read
+#ifdef RINGBUFFER_THREAD_SAFE
     pthread_mutex_unlock(&buf->mutex);
+#endif
     return 1;
   }
 }
 
 void ringBufferWrite(struct ringBuffer *buf, void *in) {
+#ifdef RINGBUFFER_THREAD_SAFE
   pthread_mutex_lock(&buf->mutex);
+#endif
   memcpy(buf->writer, in, buf->blockSize);
   _ringBufferIncWriter(buf);
+#ifdef RINGBUFFER_THREAD_SAFE
   pthread_mutex_unlock(&buf->mutex);
+#endif
 }

controller/ringbuffer.h

@@ -6,7 +6,9 @@ struct ringBuffer {
   size_t blockSize;
   void *reader;
   void *writer;
+#ifdef RINGBUFFER_THREAD_SAFE
   pthread_mutex_t mutex;
+#endif
 };
 
 void ringBufferCreate(int blocks, size_t blockSize, struct ringBuffer *out);