@@ -10,51 +10,82 @@
* the COPYING file in the top-level directory.
*/
+#include "qemu-common.h"
#include "event_notifier.h"
#include "qemu-char.h"
-#ifdef CONFIG_EVENTFD
-#include <sys/eventfd.h>
-#endif
int event_notifier_init(EventNotifier *e, int active)
{
-#ifdef CONFIG_EVENTFD
- int fd = eventfd(!!active, EFD_NONBLOCK | EFD_CLOEXEC);
- if (fd < 0)
+ int fds[2];
+ int err;
+ if (qemu_eventfd (fds) < 0)
return -errno;
- e->fd = fd;
+
+ err = fcntl_setfl(fds[0], O_NONBLOCK);
+ if (err < 0)
+ goto fail;
+
+ err = fcntl_setfl(fds[1], O_NONBLOCK);
+ if (err < 0)
+ goto fail;
+
+ e->rfd = fds[0];
+ e->wfd = fds[1];
+ if (active)
+ event_notifier_set(e);
return 0;
-#else
- return -ENOSYS;
-#endif
+
+fail:
+ close(fds[0]);
+ close(fds[1]);
+ return err;
}
void event_notifier_cleanup(EventNotifier *e)
{
- close(e->fd);
+ close(e->rfd);
+ close(e->wfd);
}
int event_notifier_get_fd(EventNotifier *e)
{
- return e->fd;
+ return e->wfd;
}
int event_notifier_set_handler(EventNotifier *e,
EventNotifierHandler *handler)
{
- return qemu_set_fd_handler(e->fd, (IOHandler *)handler, NULL, e);
+ return qemu_set_fd_handler(e->rfd, (IOHandler *)handler, NULL, e);
}
int event_notifier_set(EventNotifier *e)
{
- uint64_t value = 1;
- int r = write(e->fd, &value, sizeof(value));
- return r == sizeof(value);
+ static const uint64_t value = 1;
+ ssize_t ret;
+
+ do {
+ ret = write(e->wfd, &value, sizeof(value));
+ } while (ret < 0 && errno == EINTR);
+
+ /* EAGAIN is fine, a read must be pending. */
+ if (ret < 0 && errno != EAGAIN) {
+ return -1;
+ }
+ return 0;
}
int event_notifier_test_and_clear(EventNotifier *e)
{
- uint64_t value;
- int r = read(e->fd, &value, sizeof(value));
- return r == sizeof(value);
+ int value;
+ ssize_t len;
+ char buffer[512];
+
+ /* Drain the notify pipe. For eventfd, only 8 bytes will be read. */
+ value = 0;
+ do {
+ len = read(e->rfd, buffer, sizeof(buffer));
+ value |= (len > 0);
+ } while ((len == -1 && errno == EINTR) || len == sizeof(buffer));
+
+ return value;
}
@@ -4,7 +4,8 @@
#include "qemu-common.h"
struct EventNotifier {
- int fd;
+ int rfd;
+ int wfd;
};
typedef void EventNotifierHandler(EventNotifier *);
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- event_notifier.c | 69 +++++++++++++++++++++++++++++++++++++++--------------- event_notifier.h | 3 +- 2 files changed, 52 insertions(+), 20 deletions(-)