|
 |
f375e62 |
From f249489e3f81a99bb60d1c008aabf9c8ad90b381 Mon Sep 17 00:00:00 2001
|
|
 |
d4cdad5 |
From: Amit Shah <amit.shah@redhat.com>
|
|
|
d4cdad5 |
Date: Mon, 21 Mar 2011 22:02:47 +0100
|
|
|
5544c1b |
Subject: [PATCH] char: Equip the unix/tcp backend to handle nonblocking
|
|
|
5544c1b |
writes#
|
|
|
d4cdad5 |
|
|
|
d4cdad5 |
Now that the infrastructure is in place to return -EAGAIN to callers,
|
|
|
d4cdad5 |
individual char drivers can set their update_fd_handlers() function to
|
|
|
d4cdad5 |
set or remove an fd's write handler. This handler checks if the driver
|
|
|
d4cdad5 |
became writable.
|
|
|
d4cdad5 |
|
|
|
d4cdad5 |
A generic callback routine is used for unblocking writes and letting
|
|
|
d4cdad5 |
users of chardevs know that a driver became writable again.
|
|
|
d4cdad5 |
|
|
|
d4cdad5 |
Signed-off-by: Amit Shah <amit.shah@redhat.com>
|
|
|
bd56df9 |
Signed-off-by: Cole Robinson <crobinso@redhat.com>
|
|
|
d4cdad5 |
---
|
|
|
b6dd5ac |
qemu-char.c | 34 ++++++++++++++++++++++++++++++++++
|
|
 |
329b588 |
1 file changed, 34 insertions(+)
|
|
|
d4cdad5 |
|
|
|
d4cdad5 |
diff --git a/qemu-char.c b/qemu-char.c
|
|
|
5544c1b |
index b46cc97..9f8608a 100644
|
|
|
d4cdad5 |
--- a/qemu-char.c
|
|
|
d4cdad5 |
+++ b/qemu-char.c
|
|
|
d4cdad5 |
@@ -106,6 +106,19 @@
|
|
|
d4cdad5 |
static QTAILQ_HEAD(CharDriverStateHead, CharDriverState) chardevs =
|
|
|
d4cdad5 |
QTAILQ_HEAD_INITIALIZER(chardevs);
|
|
|
329b588 |
|
|
|
d4cdad5 |
+/*
|
|
|
d4cdad5 |
+ * Generic routine that gets called when chardev becomes writable.
|
|
|
d4cdad5 |
+ * Lets chardev user know it's OK to send more data.
|
|
|
d4cdad5 |
+ */
|
|
|
d4cdad5 |
+static void char_write_unblocked(void *opaque)
|
|
|
d4cdad5 |
+{
|
|
|
d4cdad5 |
+ CharDriverState *chr = opaque;
|
|
|
d4cdad5 |
+
|
|
|
d4cdad5 |
+ chr->write_blocked = false;
|
|
|
d4cdad5 |
+ chr->chr_disable_write_fd_handler(chr);
|
|
|
d4cdad5 |
+ chr->chr_write_unblocked(chr->handler_opaque);
|
|
|
d4cdad5 |
+}
|
|
|
d4cdad5 |
+
|
|
|
d4cdad5 |
void qemu_chr_be_event(CharDriverState *s, int event)
|
|
|
d4cdad5 |
{
|
|
|
d4cdad5 |
/* Keep track if the char device is open */
|
|
|
5544c1b |
@@ -2503,6 +2516,25 @@ static void tcp_chr_close(CharDriverState *chr)
|
|
|
d4cdad5 |
qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
|
|
|
d4cdad5 |
}
|
|
|
329b588 |
|
|
|
d4cdad5 |
+static void tcp_enable_write_fd_handler(CharDriverState *chr)
|
|
|
d4cdad5 |
+{
|
|
|
d4cdad5 |
+ TCPCharDriver *s = chr->opaque;
|
|
|
d4cdad5 |
+
|
|
|
d4cdad5 |
+ /*
|
|
|
d4cdad5 |
+ * This function is called only after tcp_chr_connect() is called
|
|
|
d4cdad5 |
+ * (either in 'server' mode or client mode. So we're sure of
|
|
|
d4cdad5 |
+ * s->fd being initialised.
|
|
|
d4cdad5 |
+ */
|
|
|
d4cdad5 |
+ enable_write_fd_handler(s->fd, char_write_unblocked);
|
|
|
d4cdad5 |
+}
|
|
|
d4cdad5 |
+
|
|
|
d4cdad5 |
+static void tcp_disable_write_fd_handler(CharDriverState *chr)
|
|
|
d4cdad5 |
+{
|
|
|
d4cdad5 |
+ TCPCharDriver *s = chr->opaque;
|
|
|
d4cdad5 |
+
|
|
|
d4cdad5 |
+ disable_write_fd_handler(s->fd);
|
|
|
d4cdad5 |
+}
|
|
|
d4cdad5 |
+
|
|
|
329b588 |
static CharDriverState *qemu_chr_open_socket(QemuOpts *opts)
|
|
|
d4cdad5 |
{
|
|
|
d4cdad5 |
CharDriverState *chr = NULL;
|
|
|
5544c1b |
@@ -2557,6 +2589,8 @@ static CharDriverState *qemu_chr_open_socket(QemuOpts *opts)
|
|
|
d4cdad5 |
chr->chr_close = tcp_chr_close;
|
|
|
d4cdad5 |
chr->get_msgfd = tcp_get_msgfd;
|
|
|
d4cdad5 |
chr->chr_add_client = tcp_chr_add_client;
|
|
|
d4cdad5 |
+ chr->chr_enable_write_fd_handler = tcp_enable_write_fd_handler;
|
|
|
d4cdad5 |
+ chr->chr_disable_write_fd_handler = tcp_disable_write_fd_handler;
|
|
|
329b588 |
|
|
|
d4cdad5 |
if (is_listen) {
|
|
|
d4cdad5 |
s->listen_fd = fd;
|