From 1c809fa01df0c638417480dfd446415615bfd217 Mon Sep 17 00:00:00 2001 From: "Daniel P. Berrange" Date: Tue, 3 Mar 2015 12:59:16 +0000 Subject: 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 --- io/Makefile.objs | 1 + io/channel-watch.c | 198 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 199 insertions(+) create mode 100644 io/channel-watch.c (limited to 'io') 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 . + * + */ + +#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; +} -- cgit v1.2.3