[Qemu-devel] [PATCH v1 01/14] util: introduce gsource event abstraction

[Liu Ping Fan <qemulist@gmail.com>]

From: Liu Ping Fan <pingfank@linux.vnet.ibm.com>

Introduce two structs EventGSource, EventsGSource
EventGSource is used to abstract the event with single backend file.
EventsGSource is used to abstract the event with dynamically changed
backend file, ex, slirp.

Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
---
 util/Makefile.objs   |    1 +
 util/event_gsource.c |  157 ++++++++++++++++++++++++++++++++++++++++++++++++++
 util/event_gsource.h |   49 ++++++++++++++++
 3 files changed, 207 insertions(+), 0 deletions(-)
 create mode 100644 util/event_gsource.c
 create mode 100644 util/event_gsource.h

diff --git a/util/Makefile.objs b/util/Makefile.objs
index 495a178..a676d7d 100644
--- a/util/Makefile.objs
+++ b/util/Makefile.objs
@@ -8,3 +8,4 @@ util-obj-y += error.o qemu-error.o
 util-obj-$(CONFIG_POSIX) += compatfd.o
 util-obj-y += iov.o aes.o qemu-config.o qemu-sockets.o uri.o notify.o
 util-obj-y += qemu-option.o qemu-progress.o
+util-obj-y += event_gsource.o
diff --git a/util/event_gsource.c b/util/event_gsource.c
new file mode 100644
index 0000000..12b5967
--- /dev/null
+++ b/util/event_gsource.c
@@ -0,0 +1,157 @@
+/*
+ *  Copyright (C) 2013 IBM
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; under version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "event_gsource.h"
+#include "qemu/bitops.h"
+
+static gboolean prepare(GSource *src, gint *time)
+{
+    EventGSource *nsrc = (EventGSource *)src;
+    int events = 0;
+
+    if (!nsrc->readable && !nsrc->writable) {
+        return false;
+    }
+    if (nsrc->readable) {
+        events = nsrc->readable(nsrc->opaque);
+    }
+    if ((nsrc->writable)) {
+        events |= nsrc->writable(nsrc->opaque);
+    }
+    nsrc->gfd.events = events;
+
+    return false;
+}
+
+static gboolean check(GSource *src)
+{
+    EventGSource *nsrc = (EventGSource *)src;
+
+    if (nsrc->gfd.revents & nsrc->gfd.events) {
+        return true;
+    }
+    return false;
+}
+
+static gboolean dispatch(GSource *src, GSourceFunc cb, gpointer data)
+{
+    gboolean ret = false;
+
+    if (cb) {
+        ret = cb(data);
+    }
+    return ret;
+}
+
+static GSourceFuncs net_gsource_funcs = {
+    prepare,
+    check,
+    dispatch,
+    NULL
+};
+
+EventGSource *event_source_new(int fd, GSourceFunc dispatch_cb, void *opaque)
+{
+    EventGSource *nsrc = (EventGSource *)g_source_new(&net_gsource_funcs,
+                                                    sizeof(EventGSource));
+    nsrc->gfd.fd = fd;
+    nsrc->opaque = opaque;
+    g_source_set_callback(&nsrc->source, dispatch_cb, nsrc, NULL);
+    g_source_add_poll(&nsrc->source, &nsrc->gfd);
+
+    return nsrc;
+}
+
+void event_source_release(EventGSource *src)
+{
+    g_source_destroy(&src->source);
+}
+
+GPollFD *events_source_add_gfd(EventsGSource *src, int fd)
+{
+    GPollFD *retfd;
+
+    retfd = g_slice_alloc(sizeof(GPollFD));
+    retfd->events = 0;
+    retfd->fd = fd;
+    src->pollfds_list = g_list_append(src->pollfds_list, retfd);
+    if (fd >= 0) {
+        g_source_add_poll(&src->source, retfd);
+    }
+
+    return retfd;
+}
+
+void events_source_remove_gfd(EventsGSource *src, GPollFD *pollfd)
+{
+    g_source_remove_poll(&src->source, pollfd);
+    src->pollfds_list = g_list_remove(src->pollfds_list, pollfd);
+    g_slice_free(GPollFD, pollfd);
+}
+
+static gboolean events_source_check(GSource *src)
+{
+    EventsGSource *nsrc = (EventsGSource *)src;
+    GList *cur;
+    GPollFD *gfd;
+
+    cur = nsrc->pollfds_list;
+    while (cur) {
+        gfd = cur->data;
+        if (gfd->fd >= 0 && (gfd->revents & gfd->events)) {
+            return true;
+        }
+        cur = g_list_next(cur);
+    }
+
+    return false;
+}
+
+static gboolean events_source_dispatch(GSource *src, GSourceFunc cb,
+    gpointer data)
+{
+    gboolean ret = false;
+
+    if (cb) {
+        ret = cb(data);
+    }
+    return ret;
+}
+
+EventsGSource *events_source_new(GPrepare prepare, GSourceFunc dispatch_cb,
+    void *opaque)
+{
+    EventsGSource *src;
+    GSourceFuncs *gfuncs = g_new0(GSourceFuncs, 1);
+    gfuncs->prepare = prepare;
+    gfuncs->check = events_source_check,
+    gfuncs->dispatch = events_source_dispatch,
+
+    src = (EventsGSource *)g_source_new(gfuncs, sizeof(EventsGSource));
+    src->gfuncs = gfuncs;
+    src->pollfds_list = NULL;
+    src->opaque = opaque;
+    g_source_set_callback(&src->source, dispatch_cb, src, NULL);
+
+    return src;
+}
+
+void events_source_release(EventsGSource *src)
+{
+    assert(!src->pollfds_list);
+    g_free(src->gfuncs);
+    g_source_destroy(&src->source);
+}
diff --git a/util/event_gsource.h b/util/event_gsource.h
new file mode 100644
index 0000000..25b15d7
--- /dev/null
+++ b/util/event_gsource.h
@@ -0,0 +1,49 @@
+/*
+ *  Copyright (C) 2013 IBM
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; under version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef EVENT_GSOURCE_H
+#define EVENT_GSOURCE_H
+#include "qemu-common.h"
+
+typedef gushort (*Pollable)(void *opaque);
+typedef gboolean (*GPrepare)(GSource *source, gint *timeout_);
+
+/* single fd drive gsource */
+typedef struct EventGSource {
+    GSource source;
+    GPollFD gfd;
+    Pollable readable;
+    Pollable writable;
+    void *opaque;
+} EventGSource;
+
+EventGSource *event_source_new(int fd, GSourceFunc dispatch_cb, void *opaque);
+void event_source_release(EventGSource *src);
+
+/* multi fd drive gsource*/
+typedef struct EventsGSource {
+    GSource source;
+    GList *pollfds_list;
+    GSourceFuncs *gfuncs;
+    void *opaque;
+} EventsGSource;
+
+EventsGSource *events_source_new(GPrepare prepare, GSourceFunc dispatch_cb,
+    void *opaque);
+void events_source_release(EventsGSource *src);
+GPollFD *events_source_add_gfd(EventsGSource *src, int fd);
+void events_source_remove_gfd(EventsGSource *src, GPollFD *pollfd);
+#endif
-- 
1.7.4.4