Drop rconn's responsibility for limiting the tx queue.

[openvswitch] / lib / queue.c

diff --git a/lib/queue.c b/lib/queue.c
index 49b9d808d305967d49f5752d384e211a6b845ae1..f06c8e9a77ba51b3dd51fc6dc4942a20398faddb 100644 (file)
--- a/lib/queue.c
+++ b/lib/queue.c
@@ -31,12 +31,14 @@
  * derivatives without specific, written prior permission.
  */
 
+#include <config.h>
 #include "queue.h"
 #include <assert.h>
 #include "buffer.h"
 
 static void check_queue(struct queue *q);
 
+/* Initializes 'q' as an empty packet queue. */
 void
 queue_init(struct queue *q)
 {
@@ -45,6 +47,7 @@ queue_init(struct queue *q)
     q->tail = NULL;
 }
 
+/* Destroys 'q' and all of the packets that it contains. */
 void
 queue_destroy(struct queue *q)
 {
@@ -55,6 +58,7 @@ queue_destroy(struct queue *q)
     }
 }
 
+/* Removes and destroys all of the packets in 'q', rendering it empty. */
 void
 queue_clear(struct queue *q)
 {
@@ -62,6 +66,12 @@ queue_clear(struct queue *q)
     queue_init(q);
 }
 
+/* Advances the first packet in 'q' from 'q->head' to 'next', which should be
+ * the second packet in the queue.
+ *
+ * The odd, unsafe interface here allows the first packet in the queue to be
+ * passed to a function for possible consumption (and destruction) and only
+ * dropped from the queue if that function actually accepts it. */
 void
 queue_advance_head(struct queue *q, struct buffer *next)
 {
@@ -74,6 +84,7 @@ queue_advance_head(struct queue *q, struct buffer *next)
     q->n--;
 }
 
+/* Appends 'b' to the tail of 'q'. */
 void
 queue_push_tail(struct queue *q, struct buffer *b)
 {
@@ -90,6 +101,18 @@ queue_push_tail(struct queue *q, struct buffer *b)
     check_queue(q);
 }
 
+/* Removes the first buffer from 'q', which must not be empty, and returns
+ * it.  The caller must free the buffer (with buffer_delete()) when it is no
+ * longer needed. */
+struct buffer *
+queue_pop_head(struct queue *q)
+{
+    struct buffer *head = q->head;
+    queue_advance_head(q, head->next);
+    return head;
+}
+
+/* Checks the internal integrity of 'q'.  For use in debugging. */
 static void
 check_queue(struct queue *q)
 {