1 files changed, 71 insertions, 0 deletions
diff --git a/fs/ringbuffer.c b/fs/ringbuffer.c
new file mode 100644
index 0000000..ca5870f
--- /dev/null
+++ b/fs/ringbuffer.c
@@ -0,0 +1,71 @@
+#define FOOLOS_MODULE_NAME "fifo"
+#include "lib/logger/log.h"
+
+#include "fifo.h"
+
+static int sl=9;
+
+fifo fifo_init(uint32_t size)
+{
+    fifo f;
+    f.data=kballoc(size);
+    f.size=size*4096;
+    f.front=f.size-1;
+    f.back=f.size-1;
+    return f;
+}
+
+bool fifo_put(fifo* f,uint8_t c)
+{
+    x86_int_disable();
+    lock_spin(sl);
+
+    if((f->back-1+f->size)%f->size==f->front)
+    {
+	lock_release(sl);
+	log(FOOLOS_MODULE_NAME,FOOLOS_LOG_FINE,"unlocked by put");
+	x86_int_enable();
+	return false;
+    }
+
+    f->data[f->back]=c;
+    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_FINE,"put %d %d (%c)", f->back, f->front,c);
+    f->back--;
+    f->back+=f->size;
+    f->back%=f->size;
+
+    lock_release(sl);
+    x86_int_enable();
+    
+    return true;
+}
+
+uint8_t fifo_get(fifo* f)	    // blocking
+{
+
+    char c;
+
+    x86_int_disable();
+    lock_spin(sl);
+
+    if(f->front==f->back)
+    {
+	lock_release(sl);
+	log(FOOLOS_MODULE_NAME,FOOLOS_LOG_FINE,"unlocked by get");
+	x86_int_enable();
+	c='_';
+	return false;
+    }
+
+    c=f->data[f->front];
+    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_FINE,"get %d %d (%c)", f->back, f->front,c);
+
+    f->front--;
+    f->front+=f->size;
+    f->front%=f->size;
+
+    lock_release(sl);
+    x86_int_enable();
+
+    return true;
+}