dataplane: remove EventPoll in favor of AioContext

During the review of the dataplane code, the EventPoll API morphed itself
(not concidentially) into something very very similar to an AioContext.
Thus, it is trivial to convert virtio-blk-dataplane to use AioContext,
and a first baby step towards letting dataplane talk directly to the
QEMU block layer.

The only interesting note is the value-copy of EventNotifiers.  At least
in my opinion this is part of the EventNotifier API and is even portable
to Windows.  Of course, in this case you should not close the notifier's
underlying file descriptors or handle with event_notifier_cleanup.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 0 insertions, 100 deletions

diff --git a/hw/dataplane/event-poll.c b/hw/dataplane/event-poll.c
deleted file mode 100644
index 2b55c6e255..0000000000
--- a/hw/dataplane/event-poll.c
+++ /dev/null
@@ -1,100 +0,0 @@
-/*
- * Event loop with file descriptor polling
- *
- * Copyright 2012 IBM, Corp.
- * Copyright 2012 Red Hat, Inc. and/or its affiliates
- *
- * Authors:
- *   Stefan Hajnoczi <stefanha@redhat.com>
- *
- * This work is licensed under the terms of the GNU GPL, version 2 or later.
- * See the COPYING file in the top-level directory.
- *
- */
-
-#include <sys/epoll.h>
-#include "hw/dataplane/event-poll.h"
-
-/* Add an event notifier and its callback for polling */
-void event_poll_add(EventPoll *poll, EventHandler *handler,
-                    EventNotifier *notifier, EventCallback *callback)
-{
-    struct epoll_event event = {
-        .events = EPOLLIN,
-        .data.ptr = handler,
-    };
-    handler->notifier = notifier;
-    handler->callback = callback;
-    if (epoll_ctl(poll->epoll_fd, EPOLL_CTL_ADD,
-                  event_notifier_get_fd(notifier), &event) != 0) {
-        fprintf(stderr, "failed to add event handler to epoll: %m\n");
-        exit(1);
-    }
-}
-
-/* Event callback for stopping event_poll() */
-static void handle_stop(EventHandler *handler)
-{
-    /* Do nothing */
-}
-
-void event_poll_init(EventPoll *poll)
-{
-    /* Create epoll file descriptor */
-    poll->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
-    if (poll->epoll_fd < 0) {
-        fprintf(stderr, "epoll_create1 failed: %m\n");
-        exit(1);
-    }
-
-    /* Set up stop notifier */
-    if (event_notifier_init(&poll->stop_notifier, 0) < 0) {
-        fprintf(stderr, "failed to init stop notifier\n");
-        exit(1);
-    }
-    event_poll_add(poll, &poll->stop_handler,
-                   &poll->stop_notifier, handle_stop);
-}
-
-void event_poll_cleanup(EventPoll *poll)
-{
-    event_notifier_cleanup(&poll->stop_notifier);
-    close(poll->epoll_fd);
-    poll->epoll_fd = -1;
-}
-
-/* Block until the next event and invoke its callback */
-void event_poll(EventPoll *poll)
-{
-    EventHandler *handler;
-    struct epoll_event event;
-    int nevents;
-
-    /* Wait for the next event.  Only do one event per call to keep the
-     * function simple, this could be changed later. */
-    do {
-        nevents = epoll_wait(poll->epoll_fd, &event, 1, -1);
-    } while (nevents < 0 && errno == EINTR);
-    if (unlikely(nevents != 1)) {
-        fprintf(stderr, "epoll_wait failed: %m\n");
-        exit(1); /* should never happen */
-    }
-
-    /* Find out which event handler has become active */
-    handler = event.data.ptr;
-
-    /* Clear the eventfd */
-    event_notifier_test_and_clear(handler->notifier);
-
-    /* Handle the event */
-    handler->callback(handler);
-}
-
-/* Stop event_poll()
- *
- * This function can be used from another thread.
- */
-void event_poll_notify(EventPoll *poll)
-{
-    event_notifier_set(&poll->stop_notifier);
-}