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authorDaniel P. Berrange <berrange@redhat.com>2015-03-03 12:59:16 +0000
committerDaniel P. Berrange <berrange@redhat.com>2015-12-18 12:18:05 +0000
commit1c809fa01df0c638417480dfd446415615bfd217 (patch)
tree445e90c439c67a7c9b25f376e295edfcee2c0fbe /io
parent666a3af9c858c22d254e545de3ffc3fb197a3187 (diff)
downloadqemu-arm-1c809fa01df0c638417480dfd446415615bfd217.tar.gz
io: add helper module for creating watches on FDs
A number of the channel implementations will require the ability to create watches on file descriptors / sockets. To avoid duplicating this code in each channel, provide a helper API for dealing with file descriptor watches. There are two watch implementations provided. The first is useful for bi-directional file descriptors such as sockets, regular files, character devices, etc. The second works with a pair of unidirectional file descriptors such as pipes. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Diffstat (limited to 'io')
-rw-r--r--io/Makefile.objs1
-rw-r--r--io/channel-watch.c198
2 files changed, 199 insertions, 0 deletions
diff --git a/io/Makefile.objs b/io/Makefile.objs
index a6ed3619b4..b02ea908ef 100644
--- a/io/Makefile.objs
+++ b/io/Makefile.objs
@@ -1 +1,2 @@
io-obj-y = channel.o
+io-obj-y += channel-watch.o
diff --git a/io/channel-watch.c b/io/channel-watch.c
new file mode 100644
index 0000000000..2f745f16c4
--- /dev/null
+++ b/io/channel-watch.c
@@ -0,0 +1,198 @@
+/*
+ * QEMU I/O channels watch helper APIs
+ *
+ * Copyright (c) 2015 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "io/channel-watch.h"
+
+typedef struct QIOChannelFDSource QIOChannelFDSource;
+struct QIOChannelFDSource {
+ GSource parent;
+ GPollFD fd;
+ QIOChannel *ioc;
+ GIOCondition condition;
+};
+
+
+typedef struct QIOChannelFDPairSource QIOChannelFDPairSource;
+struct QIOChannelFDPairSource {
+ GSource parent;
+ GPollFD fdread;
+ GPollFD fdwrite;
+ QIOChannel *ioc;
+ GIOCondition condition;
+};
+
+
+static gboolean
+qio_channel_fd_source_prepare(GSource *source G_GNUC_UNUSED,
+ gint *timeout)
+{
+ *timeout = -1;
+
+ return FALSE;
+}
+
+
+static gboolean
+qio_channel_fd_source_check(GSource *source)
+{
+ QIOChannelFDSource *ssource = (QIOChannelFDSource *)source;
+
+ return ssource->fd.revents & ssource->condition;
+}
+
+
+static gboolean
+qio_channel_fd_source_dispatch(GSource *source,
+ GSourceFunc callback,
+ gpointer user_data)
+{
+ QIOChannelFunc func = (QIOChannelFunc)callback;
+ QIOChannelFDSource *ssource = (QIOChannelFDSource *)source;
+
+ return (*func)(ssource->ioc,
+ ssource->fd.revents & ssource->condition,
+ user_data);
+}
+
+
+static void
+qio_channel_fd_source_finalize(GSource *source)
+{
+ QIOChannelFDSource *ssource = (QIOChannelFDSource *)source;
+
+ object_unref(OBJECT(ssource->ioc));
+}
+
+
+static gboolean
+qio_channel_fd_pair_source_prepare(GSource *source G_GNUC_UNUSED,
+ gint *timeout)
+{
+ *timeout = -1;
+
+ return FALSE;
+}
+
+
+static gboolean
+qio_channel_fd_pair_source_check(GSource *source)
+{
+ QIOChannelFDPairSource *ssource = (QIOChannelFDPairSource *)source;
+ GIOCondition poll_condition = ssource->fdread.revents |
+ ssource->fdwrite.revents;
+
+ return poll_condition & ssource->condition;
+}
+
+
+static gboolean
+qio_channel_fd_pair_source_dispatch(GSource *source,
+ GSourceFunc callback,
+ gpointer user_data)
+{
+ QIOChannelFunc func = (QIOChannelFunc)callback;
+ QIOChannelFDPairSource *ssource = (QIOChannelFDPairSource *)source;
+ GIOCondition poll_condition = ssource->fdread.revents |
+ ssource->fdwrite.revents;
+
+ return (*func)(ssource->ioc,
+ poll_condition & ssource->condition,
+ user_data);
+}
+
+
+static void
+qio_channel_fd_pair_source_finalize(GSource *source)
+{
+ QIOChannelFDPairSource *ssource = (QIOChannelFDPairSource *)source;
+
+ object_unref(OBJECT(ssource->ioc));
+}
+
+
+GSourceFuncs qio_channel_fd_source_funcs = {
+ qio_channel_fd_source_prepare,
+ qio_channel_fd_source_check,
+ qio_channel_fd_source_dispatch,
+ qio_channel_fd_source_finalize
+};
+
+
+GSourceFuncs qio_channel_fd_pair_source_funcs = {
+ qio_channel_fd_pair_source_prepare,
+ qio_channel_fd_pair_source_check,
+ qio_channel_fd_pair_source_dispatch,
+ qio_channel_fd_pair_source_finalize
+};
+
+
+GSource *qio_channel_create_fd_watch(QIOChannel *ioc,
+ int fd,
+ GIOCondition condition)
+{
+ GSource *source;
+ QIOChannelFDSource *ssource;
+
+ source = g_source_new(&qio_channel_fd_source_funcs,
+ sizeof(QIOChannelFDSource));
+ ssource = (QIOChannelFDSource *)source;
+
+ ssource->ioc = ioc;
+ object_ref(OBJECT(ioc));
+
+ ssource->condition = condition;
+
+ ssource->fd.fd = fd;
+ ssource->fd.events = condition;
+
+ g_source_add_poll(source, &ssource->fd);
+
+ return source;
+}
+
+
+GSource *qio_channel_create_fd_pair_watch(QIOChannel *ioc,
+ int fdread,
+ int fdwrite,
+ GIOCondition condition)
+{
+ GSource *source;
+ QIOChannelFDPairSource *ssource;
+
+ source = g_source_new(&qio_channel_fd_pair_source_funcs,
+ sizeof(QIOChannelFDPairSource));
+ ssource = (QIOChannelFDPairSource *)source;
+
+ ssource->ioc = ioc;
+ object_ref(OBJECT(ioc));
+
+ ssource->condition = condition;
+
+ ssource->fdread.fd = fdread;
+ ssource->fdread.events = condition & G_IO_IN;
+
+ ssource->fdwrite.fd = fdwrite;
+ ssource->fdwrite.events = condition & G_IO_OUT;
+
+ g_source_add_poll(source, &ssource->fdread);
+ g_source_add_poll(source, &ssource->fdwrite);
+
+ return source;
+}