From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37846) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZXWiD-0006s7-TW for qemu-devel@nongnu.org; Thu, 03 Sep 2015 11:46:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZXWiA-0001ka-L6 for qemu-devel@nongnu.org; Thu, 03 Sep 2015 11:46:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43668) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZXWiA-0001kW-C1 for qemu-devel@nongnu.org; Thu, 03 Sep 2015 11:46:02 -0400 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (Postfix) with ESMTPS id 63B4BC1A1234 for ; Thu, 3 Sep 2015 15:40:02 +0000 (UTC) From: "Daniel P. Berrange" Date: Thu, 3 Sep 2015 16:38:49 +0100 Message-Id: <1441294768-8712-8-git-send-email-berrange@redhat.com> In-Reply-To: <1441294768-8712-1-git-send-email-berrange@redhat.com> References: <1441294768-8712-1-git-send-email-berrange@redhat.com> Subject: [Qemu-devel] [PATCH FYI 07/46] io: add helper module for creating watches on FDs List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Juan Quintela , "Dr. David Alan Gilbert" , Gerd Hoffmann , Amit Shah , Paolo Bonzini 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 --- include/io/channel-watch.h | 72 ++++++++++++++++ io/Makefile.objs | 1 + io/channel-watch.c | 200 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 273 insertions(+) create mode 100644 include/io/channel-watch.h create mode 100644 io/channel-watch.c diff --git a/include/io/channel-watch.h b/include/io/channel-watch.h new file mode 100644 index 0000000..656358a --- /dev/null +++ b/include/io/channel-watch.h @@ -0,0 +1,72 @@ +/* + * 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 . + * + */ + +#ifndef QIO_CHANNEL_WATCH_H__ +#define QIO_CHANNEL_WATCH_H__ + +#include "io/channel.h" + +/* + * This module provides helper functions that will be needed by + * the various QIOChannel implementations, for creating watches + * on file descriptors / sockets + */ + +/** + * qio_channel_create_fd_watch: + * @ioc: the channel object + * @fd: the file descriptor + * @condition: the I/O condition + * + * Create a new main loop source that is able to + * monitor the file descriptor @fd for the + * I/O conditions in @condition. This is able + * monitor block devices, character devices, + * sockets, pipes but not plain files. + * + * Returns: the new main loop source + */ +GSource *qio_channel_create_fd_watch(QIOChannel *ioc, + int fd, + GIOCondition condition); + +/** + * qio_channel_create_fd_pair_watch: + * @ioc: the channel object + * @fdread: the file descriptor for reading + * @fdwrite: the file descriptor for writing + * @condition: the I/O condition + * + * Create a new main loop source that is able to + * monitor the pair of file descriptors @fdread + * and @fdwrite for the I/O conditions in @condition. + * This is intended for monitoring unidirectional + * file descriptors such as pipes, where a pair + * of descriptors is required for bidirectional + * I/O + * + * Returns: the new main loop source + */ +GSource *qio_channel_create_fd_pair_watch(QIOChannel *ioc, + int fdread, + int fdwrite, + GIOCondition condition); + +#endif /* QIO_CHANNEL_WATCH_H__ */ diff --git a/io/Makefile.objs b/io/Makefile.objs index a6ed361..b02ea90 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 0000000..9564605 --- /dev/null +++ b/io/channel-watch.c @@ -0,0 +1,200 @@ +/* + * 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)); + g_source_set_name(source, "QIOChannelFD"); + 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)); + g_source_set_name(source, "QIOChannelFDPair"); + 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; +} -- 2.4.3