On 09/27/2011 10:28 AM, Jan Kiszka wrote:
On 2011-09-27 17:17, Stefan Hajnoczi wrote:
On Tue, Sep 27, 2011 at 3:26 PM, Avi Kivity<a...@redhat.com> wrote:
Has no business in hw/.
Signed-off-by: Avi Kivity<a...@redhat.com>
---
hw/event_notifier.c => event_notifier.c | 1 -
hw/event_notifier.h => event_notifier.h | 0
2 files changed, 0 insertions(+), 1 deletions(-)
rename hw/event_notifier.c => event_notifier.c (98%)
rename hw/event_notifier.h => event_notifier.h (100%)
Yay. Now perhaps we can kill qemu_eventfd(), whose users are
typically poking around with write(2) and read(2) when really they
could use the high-level event_notifier.h API.
EventNotifiers will have to be superseded by something more generic
first. It's not fully covering the use cases of cpus.c and
posix-aio-compat.c.
Actually, for posix-aio, we can just switch to using g_idle_add(). g_idle_add()
uses g_source_attach which is thread safe. g_idle_add() gives you a thread safe
mechanism to defer a piece of work to the main loop which is really what we want
here.
This can actually be made to work with sync I/O emulation too by having another
GMainLoop in the sync I/O loop although I thought I recalled a patch series to
remove that stuff.
Kevin/Stefan, what's the plans for sync I/O emulation?
See untested patch below.
Regards,
Anthony Liguori
Jan
>From cf036a192f09ea76d89648b83ec84a4226d14172 Mon Sep 17 00:00:00 2001
From: Anthony Liguori <aligu...@us.ibm.com>
Date: Tue, 27 Sep 2011 11:01:51 -0500
Subject: [PATCH] posix-aio-compat: use g_idle_add()
Signed-off-by: Anthony Liguori <aligu...@us.ibm.com>
---
posix-aio-compat.c | 51 +++++++--------------------------------------------
1 files changed, 7 insertions(+), 44 deletions(-)
diff --git a/posix-aio-compat.c b/posix-aio-compat.c
index d3c1174..1f746be 100644
--- a/posix-aio-compat.c
+++ b/posix-aio-compat.c
@@ -52,7 +52,6 @@ struct qemu_paiocb {
};
typedef struct PosixAioState {
- int rfd, wfd;
struct qemu_paiocb *first_aio;
} PosixAioState;
@@ -466,7 +465,7 @@ static int qemu_paio_error(struct qemu_paiocb *aiocb)
return ret;
}
-static int posix_aio_process_queue(void *opaque)
+static gboolean posix_aio_process_queue(void *opaque)
{
PosixAioState *s = opaque;
struct qemu_paiocb *acb, **pacb;
@@ -477,8 +476,9 @@ static int posix_aio_process_queue(void *opaque)
pacb = &s->first_aio;
for(;;) {
acb = *pacb;
- if (!acb)
- return result;
+ if (!acb) {
+ goto out;
+ }
ret = qemu_paio_error(acb);
if (ret == ECANCELED) {
@@ -513,27 +513,8 @@ static int posix_aio_process_queue(void *opaque)
}
}
- return result;
-}
-
-static void posix_aio_read(void *opaque)
-{
- PosixAioState *s = opaque;
- ssize_t len;
-
- /* read all bytes from signal pipe */
- for (;;) {
- char bytes[16];
-
- len = read(s->rfd, bytes, sizeof(bytes));
- if (len == -1 && errno == EINTR)
- continue; /* try again */
- if (len == sizeof(bytes))
- continue; /* more to read */
- break;
- }
-
- posix_aio_process_queue(s);
+out:
+ return FALSE;
}
static int posix_aio_flush(void *opaque)
@@ -546,12 +527,7 @@ static PosixAioState *posix_aio_state;
static void posix_aio_notify_event(void)
{
- char byte = 0;
- ssize_t ret;
-
- ret = write(posix_aio_state->wfd, &byte, sizeof(byte));
- if (ret < 0 && errno != EAGAIN)
- die("write()");
+ g_idle_add(posix_aio_process_queue, posix_aio_state);
}
static void paio_remove(struct qemu_paiocb *acb)
@@ -665,19 +641,6 @@ int paio_init(void)
s = g_malloc(sizeof(PosixAioState));
s->first_aio = NULL;
- if (qemu_pipe(fds) == -1) {
- fprintf(stderr, "failed to create pipe\n");
- return -1;
- }
-
- s->rfd = fds[0];
- s->wfd = fds[1];
-
- fcntl(s->rfd, F_SETFL, O_NONBLOCK);
- fcntl(s->wfd, F_SETFL, O_NONBLOCK);
-
- qemu_aio_set_fd_handler(s->rfd, posix_aio_read, NULL, posix_aio_flush,
- posix_aio_process_queue, s);
ret = pthread_attr_init(&attr);
if (ret)
--
1.7.4.1
