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[Qemu-devel] [PATCH 07/12] char: add backend edge notification interface
From: |
Anthony Liguori |
Subject: |
[Qemu-devel] [PATCH 07/12] char: add backend edge notification interface |
Date: |
Mon, 1 Aug 2011 09:23:05 -0500 |
Signed-off-by: Anthony Liguori <address@hidden>
---
qemu-char.c | 38 ++++++++++++++++++++++++++++++++++----
qemu-char.h | 2 ++
2 files changed, 36 insertions(+), 4 deletions(-)
diff --git a/qemu-char.c b/qemu-char.c
index 9e40e04..4ba18e2 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -188,6 +188,11 @@ static void qemu_chr_flush_fe_tx(CharDriverState *s)
uint8_t buf[MAX_CHAR_QUEUE_RING];
int len;
+ /* Don't use polling queue if new style handlers are registered */
+ if (s->be_read || s->be_write) {
+ return;
+ }
+
/* Drain the queue into a flat buffer */
len = char_queue_read(&s->fe_tx, buf, sizeof(buf));
@@ -199,9 +204,20 @@ static void qemu_chr_flush_fe_tx(CharDriverState *s)
int qemu_chr_fe_write(CharDriverState *s, const uint8_t *buf, int len)
{
int ret;
+ bool is_empty;
+
+ is_empty = char_queue_get_empty(&s->fe_tx);
ret = char_queue_write(&s->fe_tx, buf, len);
+ /* If the queue was empty, and now it's not, generate a read edge
+ * event for the backend. */
+ if (is_empty && !char_queue_get_empty(&s->fe_tx)) {
+ if (s->be_read) {
+ s->be_read(s->opaque);
+ }
+ }
+
qemu_chr_flush_fe_tx(s);
return ret;
@@ -209,7 +225,22 @@ int qemu_chr_fe_write(CharDriverState *s, const uint8_t
*buf, int len)
int qemu_chr_fe_read(CharDriverState *s, uint8_t *buf, int len)
{
- return char_queue_read(&s->be_tx, buf, len);
+ bool is_full;
+ int ret;
+
+ is_full = (char_queue_get_avail(&s->be_tx) == 0);
+
+ ret = char_queue_read(&s->be_tx, buf, len);
+
+ /* If the queue was empty, and now its not, generate a write edge
+ * event for the backend. */
+ if (is_full && char_queue_get_avail(&s->be_tx)) {
+ if (s->be_write) {
+ s->be_write(s->opaque);
+ }
+ }
+
+ return ret;
}
void qemu_chr_fe_set_handlers(CharDriverState *s,
@@ -259,7 +290,7 @@ static void qemu_chr_flush_be_tx(CharDriverState *s)
/* We only drained what we knew the be could handle so we don't need to
* requeue any data. */
- s->chr_read(s, buf, len);
+ s->chr_read(s->handler_opaque, buf, len);
}
int qemu_chr_be_can_write(CharDriverState *s)
@@ -282,8 +313,7 @@ int qemu_chr_be_write(CharDriverState *s, uint8_t *buf, int
len)
/* If the queue was empty, and now it's not, trigger a read edge
* event. */
- if ((s->fe_read || s->fe_write) &&
- (is_empty && !char_queue_get_empty(&s->be_tx))) {
+ if (is_empty && !char_queue_get_empty(&s->be_tx)) {
if (s->fe_read) {
s->fe_read(s->handler_opaque);
}
diff --git a/qemu-char.h b/qemu-char.h
index 84fd628..c5bbaf6 100644
--- a/qemu-char.h
+++ b/qemu-char.h
@@ -63,6 +63,8 @@ typedef struct CharQueue
struct CharDriverState {
void (*init)(struct CharDriverState *s);
int (*chr_write)(struct CharDriverState *s, const uint8_t *buf, int len);
+ IOHandler *be_read;
+ IOHandler *be_write;
void (*chr_update_read_handler)(struct CharDriverState *s);
int (*chr_ioctl)(struct CharDriverState *s, int cmd, void *arg);
int (*get_msgfd)(struct CharDriverState *s);
--
1.7.4.1
- [Qemu-devel] [PATCH 01/12] char: rename qemu_chr_write() to qemu_chr_fe_write(), (continued)
[Qemu-devel] [PATCH 03/12] char: introduce tx queue to enable Unix style flow control, Anthony Liguori, 2011/08/01
[Qemu-devel] [PATCH 07/12] char: add backend edge notification interface,
Anthony Liguori <=
[Qemu-devel] [PATCH 05/12] char: add read functions for backend and frontend, Anthony Liguori, 2011/08/01
[Qemu-devel] [PATCH 06/12] char: add an edge event API for the front ends, Anthony Liguori, 2011/08/01
[Qemu-devel] [PATCH 09/12] char: rename qemu_chr_guest_open() -> qemu_chr_fe_open(), Anthony Liguori, 2011/08/01
[Qemu-devel] [PATCH 11/12] char: make all devices do qemu_chr_fe_open(), Anthony Liguori, 2011/08/01
[Qemu-devel] [PATCH 08/12] char: make monitor use new style interface, Anthony Liguori, 2011/08/01
[Qemu-devel] [PATCH 10/12] char: rename qemu_chr_guest_close() -> qemu_chr_fe_close(), Anthony Liguori, 2011/08/01
[Qemu-devel] [PATCH 12/12] char: enforce the use of qemu_chr_guest_open(), Anthony Liguori, 2011/08/01