Re: [Qemu-devel] [PATCH] ccid-card-emulated: use EventNotifier
Il 23/06/2014 12:38, Alon Levy ha scritto:
> {
> -EmulatedState *card = opaque;
> +EmulatedState *card = container_of(notifier, EmulatedState, notifier);
> EmulEvent *event, *next;
> -char dummy;
> -int len;
>
> -do {
> -len = read(card->pipe[0], &dummy, sizeof(dummy));
> -} while (len == sizeof(dummy));
> +event_notifier_test_and_clear(&card->notifier);
Shouldn't the ignored return value be marked somehow?
It's a pretty common idiom to test-and-clear the event notifier. Really
hot paths have a while() loop, but for ccid-card-emulated it's simpler
to just go through the main loop again. In fact, it was just what the
pipe-based code used to do. :)
Paolo
Re: [Qemu-devel] [PATCH] ccid-card-emulated: use EventNotifier
> Shut up Coverity's complaint about unchecked fcntl return values,
> and especially make the code simpler and more efficient.
>
> Signed-off-by: Paolo Bonzini
Reviewed-by: Alon Levy
one question below.
> ---
> hw/usb/ccid-card-emulated.c | 29 ++---
> 1 file changed, 10 insertions(+), 19 deletions(-)
>
> diff --git a/hw/usb/ccid-card-emulated.c b/hw/usb/ccid-card-emulated.c
> index 7213c89..aa1c37a 100644
> --- a/hw/usb/ccid-card-emulated.c
> +++ b/hw/usb/ccid-card-emulated.c
> @@ -126,7 +126,7 @@ struct EmulatedState {
> QemuMutex vreader_mutex; /* and guest_apdu_list mutex */
> QemuMutex handle_apdu_mutex;
> QemuCond handle_apdu_cond;
> -int pipe[2];
> +EventNotifier notifier;
> int quit_apdu_thread;
> QemuThread apdu_thread_id;
> };
> @@ -162,9 +162,7 @@ static void emulated_push_event(EmulatedState *card,
> EmulEvent *event)
> qemu_mutex_lock(&card->event_list_mutex);
> QSIMPLEQ_INSERT_TAIL(&(card->event_list), event, entry);
> qemu_mutex_unlock(&card->event_list_mutex);
> -if (write(card->pipe[1], card, 1) != 1) {
> -DPRINTF(card, 1, "write to pipe failed\n");
> -}
> +event_notifier_set(&card->notifier);
> }
>
> static void emulated_push_type(EmulatedState *card, uint32_t type)
> @@ -358,16 +356,12 @@ static void *event_thread(void *arg)
> return NULL;
> }
>
> -static void pipe_read(void *opaque)
> +static void card_event_handler(EventNotifier *notifier)
> {
> -EmulatedState *card = opaque;
> +EmulatedState *card = container_of(notifier, EmulatedState, notifier);
> EmulEvent *event, *next;
> -char dummy;
> -int len;
>
> -do {
> -len = read(card->pipe[0], &dummy, sizeof(dummy));
> -} while (len == sizeof(dummy));
> +event_notifier_test_and_clear(&card->notifier);
Shouldn't the ignored return value be marked somehow?
> qemu_mutex_lock(&card->event_list_mutex);
> QSIMPLEQ_FOREACH_SAFE(event, &card->event_list, entry, next) {
> DPRINTF(card, 2, "event %s\n",
> emul_event_to_string(event->p.gen.type));
> @@ -404,16 +398,13 @@ static void pipe_read(void *opaque)
> qemu_mutex_unlock(&card->event_list_mutex);
> }
>
> -static int init_pipe_signaling(EmulatedState *card)
> +static int init_event_notifier(EmulatedState *card)
> {
> -if (pipe(card->pipe) < 0) {
> -DPRINTF(card, 2, "pipe creation failed\n");
> +if (event_notifier_init(&card->notifier, false) < 0) {
> +DPRINTF(card, 2, "event notifier creation failed\n");
> return -1;
> }
> -fcntl(card->pipe[0], F_SETFL, O_NONBLOCK);
> -fcntl(card->pipe[1], F_SETFL, O_NONBLOCK);
> -fcntl(card->pipe[0], F_SETOWN, getpid());
> -qemu_set_fd_handler(card->pipe[0], pipe_read, NULL, card);
> +event_notifier_set_handler(&card->notifier, card_event_handler);
> return 0;
> }
>
> @@ -500,7 +491,7 @@ static int emulated_initfn(CCIDCardState *base)
> qemu_cond_init(&card->handle_apdu_cond);
> card->reader = NULL;
> card->quit_apdu_thread = 0;
> -if (init_pipe_signaling(card) < 0) {
> +if (init_event_notifier(card) < 0) {
> return -1;
> }
>
> --
> 1.9.3
>
>
>
[Qemu-devel] [PATCH] ccid-card-emulated: use EventNotifier
Shut up Coverity's complaint about unchecked fcntl return values,
and especially make the code simpler and more efficient.
Signed-off-by: Paolo Bonzini
---
hw/usb/ccid-card-emulated.c | 29 ++---
1 file changed, 10 insertions(+), 19 deletions(-)
diff --git a/hw/usb/ccid-card-emulated.c b/hw/usb/ccid-card-emulated.c
index 7213c89..aa1c37a 100644
--- a/hw/usb/ccid-card-emulated.c
+++ b/hw/usb/ccid-card-emulated.c
@@ -126,7 +126,7 @@ struct EmulatedState {
QemuMutex vreader_mutex; /* and guest_apdu_list mutex */
QemuMutex handle_apdu_mutex;
QemuCond handle_apdu_cond;
-int pipe[2];
+EventNotifier notifier;
int quit_apdu_thread;
QemuThread apdu_thread_id;
};
@@ -162,9 +162,7 @@ static void emulated_push_event(EmulatedState *card,
EmulEvent *event)
qemu_mutex_lock(&card->event_list_mutex);
QSIMPLEQ_INSERT_TAIL(&(card->event_list), event, entry);
qemu_mutex_unlock(&card->event_list_mutex);
-if (write(card->pipe[1], card, 1) != 1) {
-DPRINTF(card, 1, "write to pipe failed\n");
-}
+event_notifier_set(&card->notifier);
}
static void emulated_push_type(EmulatedState *card, uint32_t type)
@@ -358,16 +356,12 @@ static void *event_thread(void *arg)
return NULL;
}
-static void pipe_read(void *opaque)
+static void card_event_handler(EventNotifier *notifier)
{
-EmulatedState *card = opaque;
+EmulatedState *card = container_of(notifier, EmulatedState, notifier);
EmulEvent *event, *next;
-char dummy;
-int len;
-do {
-len = read(card->pipe[0], &dummy, sizeof(dummy));
-} while (len == sizeof(dummy));
+event_notifier_test_and_clear(&card->notifier);
qemu_mutex_lock(&card->event_list_mutex);
QSIMPLEQ_FOREACH_SAFE(event, &card->event_list, entry, next) {
DPRINTF(card, 2, "event %s\n",
emul_event_to_string(event->p.gen.type));
@@ -404,16 +398,13 @@ static void pipe_read(void *opaque)
qemu_mutex_unlock(&card->event_list_mutex);
}
-static int init_pipe_signaling(EmulatedState *card)
+static int init_event_notifier(EmulatedState *card)
{
-if (pipe(card->pipe) < 0) {
-DPRINTF(card, 2, "pipe creation failed\n");
+if (event_notifier_init(&card->notifier, false) < 0) {
+DPRINTF(card, 2, "event notifier creation failed\n");
return -1;
}
-fcntl(card->pipe[0], F_SETFL, O_NONBLOCK);
-fcntl(card->pipe[1], F_SETFL, O_NONBLOCK);
-fcntl(card->pipe[0], F_SETOWN, getpid());
-qemu_set_fd_handler(card->pipe[0], pipe_read, NULL, card);
+event_notifier_set_handler(&card->notifier, card_event_handler);
return 0;
}
@@ -500,7 +491,7 @@ static int emulated_initfn(CCIDCardState *base)
qemu_cond_init(&card->handle_apdu_cond);
card->reader = NULL;
card->quit_apdu_thread = 0;
-if (init_pipe_signaling(card) < 0) {
+if (init_event_notifier(card) < 0) {
return -1;
}
--
1.9.3
