diff --git a/include/io/channel-watch.h b/include/io/channel-watch.h new file mode 100644 index 0000000000..656358ad64 --- /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 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; +}