diff options
Diffstat (limited to 'io/channel.c')
| -rw-r--r-- | io/channel.c | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/io/channel.c b/io/channel.c new file mode 100644 index 0000000000..5e94469de2 --- /dev/null +++ b/io/channel.c @@ -0,0 +1,291 @@ +/* + * QEMU I/O channels + * + * 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.h" +#include "qemu/coroutine.h" + +bool qio_channel_has_feature(QIOChannel *ioc, + QIOChannelFeature feature) +{ + return ioc->features & (1 << feature); +} + + +ssize_t qio_channel_readv_full(QIOChannel *ioc, + const struct iovec *iov, + size_t niov, + int **fds, + size_t *nfds, + Error **errp) +{ + QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); + + if ((fds || nfds) && + !(ioc->features & (1 << QIO_CHANNEL_FEATURE_FD_PASS))) { + error_setg_errno(errp, EINVAL, + "Channel does not support file descriptor passing"); + return -1; + } + + return klass->io_readv(ioc, iov, niov, fds, nfds, errp); +} + + +ssize_t qio_channel_writev_full(QIOChannel *ioc, + const struct iovec *iov, + size_t niov, + int *fds, + size_t nfds, + Error **errp) +{ + QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); + + if ((fds || nfds) && + !(ioc->features & (1 << QIO_CHANNEL_FEATURE_FD_PASS))) { + error_setg_errno(errp, EINVAL, + "Channel does not support file descriptor passing"); + return -1; + } + + return klass->io_writev(ioc, iov, niov, fds, nfds, errp); +} + + +ssize_t qio_channel_readv(QIOChannel *ioc, + const struct iovec *iov, + size_t niov, + Error **errp) +{ + return qio_channel_readv_full(ioc, iov, niov, NULL, NULL, errp); +} + + +ssize_t qio_channel_writev(QIOChannel *ioc, + const struct iovec *iov, + size_t niov, + Error **errp) +{ + return qio_channel_writev_full(ioc, iov, niov, NULL, 0, errp); +} + + +ssize_t qio_channel_read(QIOChannel *ioc, + char *buf, + size_t buflen, + Error **errp) +{ + struct iovec iov = { .iov_base = buf, .iov_len = buflen }; + return qio_channel_readv_full(ioc, &iov, 1, NULL, NULL, errp); +} + + +ssize_t qio_channel_write(QIOChannel *ioc, + const char *buf, + size_t buflen, + Error **errp) +{ + struct iovec iov = { .iov_base = (char *)buf, .iov_len = buflen }; + return qio_channel_writev_full(ioc, &iov, 1, NULL, 0, errp); +} + + +int qio_channel_set_blocking(QIOChannel *ioc, + bool enabled, + Error **errp) +{ + QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); + return klass->io_set_blocking(ioc, enabled, errp); +} + + +int qio_channel_close(QIOChannel *ioc, + Error **errp) +{ + QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); + return klass->io_close(ioc, errp); +} + + +GSource *qio_channel_create_watch(QIOChannel *ioc, + GIOCondition condition) +{ + QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); + return klass->io_create_watch(ioc, condition); +} + + +guint qio_channel_add_watch(QIOChannel *ioc, + GIOCondition condition, + QIOChannelFunc func, + gpointer user_data, + GDestroyNotify notify) +{ + GSource *source; + guint id; + + source = qio_channel_create_watch(ioc, condition); + + g_source_set_callback(source, (GSourceFunc)func, user_data, notify); + + id = g_source_attach(source, NULL); + g_source_unref(source); + + return id; +} + + +int qio_channel_shutdown(QIOChannel *ioc, + QIOChannelShutdown how, + Error **errp) +{ + QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); + + if (!klass->io_shutdown) { + error_setg(errp, "Data path shutdown not supported"); + return -1; + } + + return klass->io_shutdown(ioc, how, errp); +} + + +void qio_channel_set_delay(QIOChannel *ioc, + bool enabled) +{ + QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); + + if (klass->io_set_delay) { + klass->io_set_delay(ioc, enabled); + } +} + + +void qio_channel_set_cork(QIOChannel *ioc, + bool enabled) +{ + QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); + + if (klass->io_set_cork) { + klass->io_set_cork(ioc, enabled); + } +} + + +off_t qio_channel_io_seek(QIOChannel *ioc, + off_t offset, + int whence, + Error **errp) +{ + QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); + + if (!klass->io_seek) { + error_setg(errp, "Channel does not support random access"); + return -1; + } + + return klass->io_seek(ioc, offset, whence, errp); +} + + +typedef struct QIOChannelYieldData QIOChannelYieldData; +struct QIOChannelYieldData { + QIOChannel *ioc; + Coroutine *co; +}; + + +static gboolean qio_channel_yield_enter(QIOChannel *ioc, + GIOCondition condition, + gpointer opaque) +{ + QIOChannelYieldData *data = opaque; + qemu_coroutine_enter(data->co, NULL); + return FALSE; +} + + +void coroutine_fn qio_channel_yield(QIOChannel *ioc, + GIOCondition condition) +{ + QIOChannelYieldData data; + + assert(qemu_in_coroutine()); + data.ioc = ioc; + data.co = qemu_coroutine_self(); + qio_channel_add_watch(ioc, + condition, + qio_channel_yield_enter, + &data, + NULL); + qemu_coroutine_yield(); +} + + +static gboolean qio_channel_wait_complete(QIOChannel *ioc, + GIOCondition condition, + gpointer opaque) +{ + GMainLoop *loop = opaque; + + g_main_loop_quit(loop); + return FALSE; +} + + +void qio_channel_wait(QIOChannel *ioc, + GIOCondition condition) +{ + GMainContext *ctxt = g_main_context_new(); + GMainLoop *loop = g_main_loop_new(ctxt, TRUE); + GSource *source; + + source = qio_channel_create_watch(ioc, condition); + + g_source_set_callback(source, + (GSourceFunc)qio_channel_wait_complete, + loop, + NULL); + + g_source_attach(source, ctxt); + + g_main_loop_run(loop); + + g_source_unref(source); + g_main_loop_unref(loop); + g_main_context_unref(ctxt); +} + + +static const TypeInfo qio_channel_info = { + .parent = TYPE_OBJECT, + .name = TYPE_QIO_CHANNEL, + .instance_size = sizeof(QIOChannel), + .abstract = true, + .class_size = sizeof(QIOChannelClass), +}; + + +static void qio_channel_register_types(void) +{ + type_register_static(&qio_channel_info); +} + + +type_init(qio_channel_register_types); |