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[Qemu-devel] [PATCH 5/5] char: Equip the unix/tcp backend to handle nonb
From: |
Amit Shah |
Subject: |
[Qemu-devel] [PATCH 5/5] char: Equip the unix/tcp backend to handle nonblocking writes |
Date: |
Tue, 11 Jan 2011 16:40:34 +0530 |
Now that the infrastructure is in place to return -EAGAIN to callers,
individual char drivers can set their update_fd_handlers() function to
set or remove an fd's write handler. This handler checks if the driver
became writable.
A generic callback routine is used for unblocking writes and letting
users of chardevs know that a driver became writable again.
Signed-off-by: Amit Shah <address@hidden>
---
qemu-char.c | 27 +++++++++++++++++++++++++++
1 files changed, 27 insertions(+), 0 deletions(-)
diff --git a/qemu-char.c b/qemu-char.c
index 6e02334..55d442d 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -235,6 +235,19 @@ static int char_remove_fd_handlers(int fd)
return qemu_set_fd_handler2(fd, NULL, NULL, NULL, NULL);
}
+/*
+ * Generic routine that gets called when chardev becomes writable.
+ * Lets chardev user know it's OK to send more data.
+ */
+static void char_write_unblocked(void *opaque)
+{
+ CharDriverState *chr = opaque;
+
+ chr->write_blocked = false;
+ chr->update_fd_handlers(chr, false);
+ chr->chr_write_unblocked(chr->handler_opaque);
+}
+
static int null_chr_write(CharDriverState *chr, const uint8_t *buf, int len)
{
return len;
@@ -2269,6 +2282,19 @@ static void tcp_chr_close(CharDriverState *chr)
qemu_chr_event(chr, CHR_EVENT_CLOSED);
}
+static void tcp_update_fd_handlers(CharDriverState *chr, bool poll_out)
+{
+ TCPCharDriver *s = chr->opaque;
+
+ /*
+ * This function is called only after tcp_chr_connect() is called
+ * (either in 'server' mode or client mode. So we're sure of
+ * s->fd being initialised.
+ */
+ char_set_fd_handlers(s->fd, tcp_chr_read_poll, tcp_chr_read,
+ char_write_unblocked, chr, poll_out);
+}
+
static CharDriverState *qemu_chr_open_socket(QemuOpts *opts)
{
CharDriverState *chr = NULL;
@@ -2321,6 +2347,7 @@ static CharDriverState *qemu_chr_open_socket(QemuOpts
*opts)
chr->chr_write = tcp_chr_write;
chr->chr_close = tcp_chr_close;
chr->get_msgfd = tcp_get_msgfd;
+ chr->update_fd_handlers = tcp_update_fd_handlers;
if (is_listen) {
s->listen_fd = fd;
--
1.7.3.4
- Re: [Qemu-devel] [PATCH 1/5] char: Add a QemuChrHandlers struct to initialise chardev handlers, (continued)
[Qemu-devel] [PATCH 3/5] char: Add framework for a 'write unblocked' callback, Amit Shah, 2011/01/11
[Qemu-devel] [PATCH 4/5] char: Update send_all() to handle nonblocking chardev write requests, Amit Shah, 2011/01/11
[Qemu-devel] [PATCH 5/5] char: Equip the unix/tcp backend to handle nonblocking writes,
Amit Shah <=