[Qemu-devel] [PATCH v1 1/5] util: introduce gsource event abstraction

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

Introduce struct EventsGSource. It will ease the usage of GSource
associated with a group of files, which are dynamically allocated
and release, ex, slirp.

Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
---
 util/Makefile.objs   |  1 +
 util/event_gsource.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 util/event_gsource.h | 37 +++++++++++++++++++++
 3 files changed, 132 insertions(+)
 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 dc72ab0..eec55bd 100644
--- a/util/Makefile.objs
+++ b/util/Makefile.objs
@@ -11,3 +11,4 @@ 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 += hexdump.o
 util-obj-y += crc32c.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..4b9fa89
--- /dev/null
+++ b/util/event_gsource.c
@@ -0,0 +1,94 @@
+/*
+ *  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"
+
+GPollFD *events_source_add_pollfd(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_pollfd(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..8755952
--- /dev/null
+++ b/util/event_gsource.h
@@ -0,0 +1,37 @@
+/*
+ *  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 gboolean (*GPrepare)(GSource *source, gint *timeout_);
+
+/* multi fd drive GSource*/
+typedef struct EventsGSource {
+    GSource source;
+    /* a group of GPollFD which dynamically join or leave the GSource */
+    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_pollfd(EventsGSource *src, int fd);
+void events_source_remove_pollfd(EventsGSource *src, GPollFD *pollfd);
+#endif
-- 
1.8.1.4