From 59ff8a6457e82aadad7529602da68406de374a33 Mon Sep 17 00:00:00 2001

From: Amit Shah <amit.shah@redhat.com>

Date: Mon, 21 Mar 2011 21:41:42 +0100

Subject: [PATCH 28/35] char: Add framework for a 'write unblocked' callback

The char layer can let users know that the driver will block on further

input.  For users interested in not blocking, they can assign a function

pointer that will be called back when the driver becomes writable.  This

patch just adds the function pointers to the CharDriverState structure,

future patches will enable the nonblocking and callback functionality.

Signed-off-by: Amit Shah <amit.shah@redhat.com>

---

 qemu-char.c |    3 +++

 qemu-char.h |    4 ++++

 2 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/qemu-char.c b/qemu-char.c

index ee763d5..830f0c3 100644

--- a/qemu-char.c

+++ b/qemu-char.c

@@ -209,11 +209,14 @@ void qemu_chr_add_handlers(CharDriverState *s,

     }

     s->chr_can_read = handlers->fd_can_read;

     s->chr_read = handlers->fd_read;

+    s->chr_write_unblocked = handlers->fd_write_unblocked;

     s->chr_event = handlers->fd_event;

     s->handler_opaque = opaque;

     if (s->chr_update_read_handler)

         s->chr_update_read_handler(s);

+    s->write_blocked = false;

+

     /* We're connecting to an already opened device, so let's make sure we

        also get the open event */

     if (s->opened) {

diff --git a/qemu-char.h b/qemu-char.h

index 7d5dc6c..e942bdf 100644

--- a/qemu-char.h

+++ b/qemu-char.h

@@ -61,6 +61,9 @@ struct CharDriverState {

     IOEventHandler *chr_event;

     IOCanReadHandler *chr_can_read;

     IOReadHandler *chr_read;

+    IOHandler *chr_write_unblocked;

+    void (*chr_enable_write_fd_handler)(struct CharDriverState *chr);

+    void (*chr_disable_write_fd_handler)(struct CharDriverState *chr);

     void *handler_opaque;

     void (*chr_send_event)(struct CharDriverState *chr, int event);

     void (*chr_close)(struct CharDriverState *chr);

@@ -74,6 +77,7 @@ struct CharDriverState {

     char *filename;

     int opened;

     int avail_connections;

+    bool write_blocked; /* Are we in a blocked state? */

     QTAILQ_ENTRY(CharDriverState) next;

 };

-- 

1.7.5.1