X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fbyteq.c;h=3f865cf9e2029fd3ad5927d4a611464d4220e0c1;hb=fd76a6f94338b668175336434b156827458b5e7d;hp=2ee4a65698a37b75ecb9fe09231f54308a41ce08;hpb=d1673b006d53fdea72c0744e835362ed1917f879;p=sliver-openvswitch.git

diff --git a/lib/byteq.c b/lib/byteq.c
index 2ee4a6569..3f865cf9e 100644
--- a/lib/byteq.c
+++ b/lib/byteq.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2008, 2009, 2012 Nicira, Inc.
+/* Copyright (c) 2008, 2009, 2012, 2013 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,13 +20,17 @@
 #include <unistd.h>
 #include "util.h"
 
-/* The queue size must be a power of 2. */
-BUILD_ASSERT_DECL(!(BYTEQ_SIZE & (BYTEQ_SIZE - 1)));
-
-/* Initializes 'q' as empty. */
+/* Initializes 'q' as an empty byteq that uses the 'size' bytes of 'buffer' to
+ * store data.  'size' must be a power of 2.
+ *
+ * The caller must ensure that 'buffer' remains available to the byteq as long
+ * as 'q' is in use. */
 void
-byteq_init(struct byteq *q)
+byteq_init(struct byteq *q, uint8_t *buffer, size_t size)
 {
+    ovs_assert(is_pow2(size));
+    q->buffer = buffer;
+    q->size = size;
     q->head = q->tail = 0;
 }
 
@@ -41,7 +45,7 @@ byteq_used(const struct byteq *q)
 int
 byteq_avail(const struct byteq *q)
 {
-    return BYTEQ_SIZE - byteq_used(q);
+    return q->size - byteq_used(q);
 }
 
 /* Returns true if no bytes are queued in 'q',
@@ -147,7 +151,7 @@ int
 byteq_tailroom(const struct byteq *q)
 {
     int used = byteq_used(q);
-    int tail_to_end = BYTEQ_SIZE - (q->tail & (BYTEQ_SIZE - 1));
+    int tail_to_end = q->size - (q->tail & (q->size - 1));
     return MIN(used, tail_to_end);
 }
 
@@ -156,7 +160,7 @@ byteq_tailroom(const struct byteq *q)
 const uint8_t *
 byteq_tail(const struct byteq *q)
 {
-    return &q->buffer[q->tail & (BYTEQ_SIZE - 1)];
+    return &q->buffer[q->tail & (q->size - 1)];
 }
 
 /* Removes 'n' bytes from the tail of 'q', which must have at least 'n' bytes
@@ -173,7 +177,7 @@ byteq_advance_tail(struct byteq *q, unsigned int n)
 uint8_t *
 byteq_head(struct byteq *q)
 {
-    return &q->buffer[q->head & (BYTEQ_SIZE - 1)];
+    return &q->buffer[q->head & (q->size - 1)];
 }
 
 /* Returns the number of contiguous bytes of free space starting at the head
@@ -182,7 +186,7 @@ int
 byteq_headroom(const struct byteq *q)
 {
     int avail = byteq_avail(q);
-    int head_to_end = BYTEQ_SIZE - (q->head & (BYTEQ_SIZE - 1));
+    int head_to_end = q->size - (q->head & (q->size - 1));
     return MIN(avail, head_to_end);
 }