On Mon, Aug 1, 2011 at 3:23 PM, Anthony Liguori<address@hidden> wrote:
While the front tx queue has no flow control, the backend tx queue uses a
polling function to determine when the front end can receive data.
To convert this to the new queue model, we simply try to flush the backend tx
queue whenever we poll. We then return the remaining space in the queue as
the value of the polling function.
Signed-off-by: Anthony Liguori<address@hidden>
---
qemu-char.c | 49 ++++++++++++++++++++++++++++++++++++++++---------
qemu-char.h | 3 ++-
2 files changed, 42 insertions(+), 10 deletions(-)
diff --git a/qemu-char.c b/qemu-char.c
index 3f9b32c..2746652 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -173,6 +173,11 @@ static size_t char_queue_read(CharQueue *q, void *data,
size_t size)
return i;
}
+static uint32_t char_queue_get_avail(CharQueue *q)
+{
+ return sizeof(q->ring) - (q->prod - q->cons);
+}
"avail" confuses me. How many bytes are available for the consumer?
How many bytes are available for the producer?
How about char_queue_get_space() or char_queue_get_nfree()?