e0622ae3ca
There is no "version 2" of the "Lesser" General Public License. It is either "GPL version 2.0" or "Lesser GPL version 2.1". This patch replaces all occurrences of "Lesser GPL version 2" with "Lesser GPL version 2.1" in comment section. Signed-off-by: Chetan Pant <chetan4windows@gmail.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
551 lines
15 KiB
C
551 lines
15 KiB
C
/*
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* QEMU I/O channels
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*
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* Copyright (c) 2015 Red Hat, Inc.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include "qemu/osdep.h"
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#include "io/channel.h"
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#include "qapi/error.h"
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#include "qemu/main-loop.h"
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#include "qemu/module.h"
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#include "qemu/iov.h"
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bool qio_channel_has_feature(QIOChannel *ioc,
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QIOChannelFeature feature)
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{
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return ioc->features & (1 << feature);
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}
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void qio_channel_set_feature(QIOChannel *ioc,
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QIOChannelFeature feature)
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{
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ioc->features |= (1 << feature);
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}
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void qio_channel_set_name(QIOChannel *ioc,
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const char *name)
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{
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g_free(ioc->name);
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ioc->name = g_strdup(name);
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}
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ssize_t qio_channel_readv_full(QIOChannel *ioc,
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const struct iovec *iov,
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size_t niov,
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int **fds,
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size_t *nfds,
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Error **errp)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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if ((fds || nfds) &&
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!qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_FD_PASS)) {
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error_setg_errno(errp, EINVAL,
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"Channel does not support file descriptor passing");
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return -1;
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}
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return klass->io_readv(ioc, iov, niov, fds, nfds, errp);
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}
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ssize_t qio_channel_writev_full(QIOChannel *ioc,
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const struct iovec *iov,
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size_t niov,
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int *fds,
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size_t nfds,
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Error **errp)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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if ((fds || nfds) &&
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!qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_FD_PASS)) {
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error_setg_errno(errp, EINVAL,
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"Channel does not support file descriptor passing");
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return -1;
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}
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return klass->io_writev(ioc, iov, niov, fds, nfds, errp);
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}
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int qio_channel_readv_all_eof(QIOChannel *ioc,
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const struct iovec *iov,
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size_t niov,
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Error **errp)
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{
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int ret = -1;
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struct iovec *local_iov = g_new(struct iovec, niov);
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struct iovec *local_iov_head = local_iov;
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unsigned int nlocal_iov = niov;
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bool partial = false;
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nlocal_iov = iov_copy(local_iov, nlocal_iov,
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iov, niov,
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0, iov_size(iov, niov));
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while (nlocal_iov > 0) {
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ssize_t len;
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len = qio_channel_readv(ioc, local_iov, nlocal_iov, errp);
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if (len == QIO_CHANNEL_ERR_BLOCK) {
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if (qemu_in_coroutine()) {
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qio_channel_yield(ioc, G_IO_IN);
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} else {
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qio_channel_wait(ioc, G_IO_IN);
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}
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continue;
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} else if (len < 0) {
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goto cleanup;
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} else if (len == 0) {
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if (partial) {
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error_setg(errp,
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"Unexpected end-of-file before all bytes were read");
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} else {
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ret = 0;
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}
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goto cleanup;
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}
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partial = true;
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iov_discard_front(&local_iov, &nlocal_iov, len);
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}
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ret = 1;
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cleanup:
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g_free(local_iov_head);
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return ret;
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}
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int qio_channel_readv_all(QIOChannel *ioc,
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const struct iovec *iov,
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size_t niov,
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Error **errp)
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{
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int ret = qio_channel_readv_all_eof(ioc, iov, niov, errp);
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if (ret == 0) {
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ret = -1;
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error_setg(errp,
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"Unexpected end-of-file before all bytes were read");
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} else if (ret == 1) {
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ret = 0;
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}
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return ret;
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}
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int qio_channel_writev_all(QIOChannel *ioc,
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const struct iovec *iov,
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size_t niov,
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Error **errp)
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{
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int ret = -1;
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struct iovec *local_iov = g_new(struct iovec, niov);
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struct iovec *local_iov_head = local_iov;
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unsigned int nlocal_iov = niov;
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nlocal_iov = iov_copy(local_iov, nlocal_iov,
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iov, niov,
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0, iov_size(iov, niov));
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while (nlocal_iov > 0) {
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ssize_t len;
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len = qio_channel_writev(ioc, local_iov, nlocal_iov, errp);
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if (len == QIO_CHANNEL_ERR_BLOCK) {
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if (qemu_in_coroutine()) {
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qio_channel_yield(ioc, G_IO_OUT);
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} else {
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qio_channel_wait(ioc, G_IO_OUT);
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}
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continue;
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}
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if (len < 0) {
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goto cleanup;
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}
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iov_discard_front(&local_iov, &nlocal_iov, len);
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}
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ret = 0;
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cleanup:
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g_free(local_iov_head);
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return ret;
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}
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ssize_t qio_channel_readv(QIOChannel *ioc,
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const struct iovec *iov,
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size_t niov,
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Error **errp)
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{
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return qio_channel_readv_full(ioc, iov, niov, NULL, NULL, errp);
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}
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ssize_t qio_channel_writev(QIOChannel *ioc,
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const struct iovec *iov,
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size_t niov,
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Error **errp)
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{
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return qio_channel_writev_full(ioc, iov, niov, NULL, 0, errp);
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}
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ssize_t qio_channel_read(QIOChannel *ioc,
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char *buf,
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size_t buflen,
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Error **errp)
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{
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struct iovec iov = { .iov_base = buf, .iov_len = buflen };
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return qio_channel_readv_full(ioc, &iov, 1, NULL, NULL, errp);
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}
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ssize_t qio_channel_write(QIOChannel *ioc,
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const char *buf,
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size_t buflen,
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Error **errp)
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{
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struct iovec iov = { .iov_base = (char *)buf, .iov_len = buflen };
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return qio_channel_writev_full(ioc, &iov, 1, NULL, 0, errp);
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}
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int qio_channel_read_all_eof(QIOChannel *ioc,
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char *buf,
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size_t buflen,
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Error **errp)
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{
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struct iovec iov = { .iov_base = buf, .iov_len = buflen };
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return qio_channel_readv_all_eof(ioc, &iov, 1, errp);
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}
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int qio_channel_read_all(QIOChannel *ioc,
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char *buf,
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size_t buflen,
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Error **errp)
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{
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struct iovec iov = { .iov_base = buf, .iov_len = buflen };
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return qio_channel_readv_all(ioc, &iov, 1, errp);
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}
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int qio_channel_write_all(QIOChannel *ioc,
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const char *buf,
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size_t buflen,
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Error **errp)
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{
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struct iovec iov = { .iov_base = (char *)buf, .iov_len = buflen };
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return qio_channel_writev_all(ioc, &iov, 1, errp);
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}
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int qio_channel_set_blocking(QIOChannel *ioc,
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bool enabled,
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Error **errp)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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return klass->io_set_blocking(ioc, enabled, errp);
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}
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int qio_channel_close(QIOChannel *ioc,
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Error **errp)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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return klass->io_close(ioc, errp);
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}
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GSource *qio_channel_create_watch(QIOChannel *ioc,
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GIOCondition condition)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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GSource *ret = klass->io_create_watch(ioc, condition);
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if (ioc->name) {
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g_source_set_name(ret, ioc->name);
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}
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return ret;
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}
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void qio_channel_set_aio_fd_handler(QIOChannel *ioc,
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AioContext *ctx,
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IOHandler *io_read,
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IOHandler *io_write,
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void *opaque)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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klass->io_set_aio_fd_handler(ioc, ctx, io_read, io_write, opaque);
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}
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guint qio_channel_add_watch_full(QIOChannel *ioc,
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GIOCondition condition,
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QIOChannelFunc func,
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gpointer user_data,
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GDestroyNotify notify,
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GMainContext *context)
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{
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GSource *source;
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guint id;
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source = qio_channel_create_watch(ioc, condition);
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g_source_set_callback(source, (GSourceFunc)func, user_data, notify);
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id = g_source_attach(source, context);
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g_source_unref(source);
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return id;
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}
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guint qio_channel_add_watch(QIOChannel *ioc,
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GIOCondition condition,
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QIOChannelFunc func,
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gpointer user_data,
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GDestroyNotify notify)
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{
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return qio_channel_add_watch_full(ioc, condition, func,
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user_data, notify, NULL);
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}
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GSource *qio_channel_add_watch_source(QIOChannel *ioc,
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GIOCondition condition,
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QIOChannelFunc func,
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gpointer user_data,
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GDestroyNotify notify,
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GMainContext *context)
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{
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GSource *source;
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guint id;
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id = qio_channel_add_watch_full(ioc, condition, func,
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user_data, notify, context);
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source = g_main_context_find_source_by_id(context, id);
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g_source_ref(source);
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return source;
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}
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int qio_channel_shutdown(QIOChannel *ioc,
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QIOChannelShutdown how,
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Error **errp)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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if (!klass->io_shutdown) {
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error_setg(errp, "Data path shutdown not supported");
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return -1;
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}
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return klass->io_shutdown(ioc, how, errp);
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}
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void qio_channel_set_delay(QIOChannel *ioc,
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bool enabled)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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if (klass->io_set_delay) {
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klass->io_set_delay(ioc, enabled);
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}
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}
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void qio_channel_set_cork(QIOChannel *ioc,
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bool enabled)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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if (klass->io_set_cork) {
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klass->io_set_cork(ioc, enabled);
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}
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}
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off_t qio_channel_io_seek(QIOChannel *ioc,
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off_t offset,
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int whence,
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Error **errp)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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if (!klass->io_seek) {
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error_setg(errp, "Channel does not support random access");
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return -1;
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}
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return klass->io_seek(ioc, offset, whence, errp);
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}
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static void qio_channel_restart_read(void *opaque)
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{
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QIOChannel *ioc = opaque;
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Coroutine *co = ioc->read_coroutine;
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/* Assert that aio_co_wake() reenters the coroutine directly */
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assert(qemu_get_current_aio_context() ==
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qemu_coroutine_get_aio_context(co));
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aio_co_wake(co);
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}
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static void qio_channel_restart_write(void *opaque)
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{
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QIOChannel *ioc = opaque;
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Coroutine *co = ioc->write_coroutine;
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/* Assert that aio_co_wake() reenters the coroutine directly */
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assert(qemu_get_current_aio_context() ==
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qemu_coroutine_get_aio_context(co));
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aio_co_wake(co);
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}
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static void qio_channel_set_aio_fd_handlers(QIOChannel *ioc)
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{
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IOHandler *rd_handler = NULL, *wr_handler = NULL;
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AioContext *ctx;
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if (ioc->read_coroutine) {
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rd_handler = qio_channel_restart_read;
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}
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if (ioc->write_coroutine) {
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wr_handler = qio_channel_restart_write;
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}
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ctx = ioc->ctx ? ioc->ctx : iohandler_get_aio_context();
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qio_channel_set_aio_fd_handler(ioc, ctx, rd_handler, wr_handler, ioc);
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}
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void qio_channel_attach_aio_context(QIOChannel *ioc,
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AioContext *ctx)
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{
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assert(!ioc->read_coroutine);
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assert(!ioc->write_coroutine);
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ioc->ctx = ctx;
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}
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void qio_channel_detach_aio_context(QIOChannel *ioc)
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{
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ioc->read_coroutine = NULL;
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ioc->write_coroutine = NULL;
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qio_channel_set_aio_fd_handlers(ioc);
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ioc->ctx = NULL;
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}
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void coroutine_fn qio_channel_yield(QIOChannel *ioc,
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GIOCondition condition)
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{
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assert(qemu_in_coroutine());
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if (condition == G_IO_IN) {
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assert(!ioc->read_coroutine);
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ioc->read_coroutine = qemu_coroutine_self();
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} else if (condition == G_IO_OUT) {
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assert(!ioc->write_coroutine);
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ioc->write_coroutine = qemu_coroutine_self();
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} else {
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abort();
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}
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qio_channel_set_aio_fd_handlers(ioc);
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qemu_coroutine_yield();
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/* Allow interrupting the operation by reentering the coroutine other than
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* through the aio_fd_handlers. */
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if (condition == G_IO_IN && ioc->read_coroutine) {
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ioc->read_coroutine = NULL;
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qio_channel_set_aio_fd_handlers(ioc);
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} else if (condition == G_IO_OUT && ioc->write_coroutine) {
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ioc->write_coroutine = NULL;
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qio_channel_set_aio_fd_handlers(ioc);
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}
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}
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static gboolean qio_channel_wait_complete(QIOChannel *ioc,
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GIOCondition condition,
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gpointer opaque)
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{
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GMainLoop *loop = opaque;
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g_main_loop_quit(loop);
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return FALSE;
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}
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void qio_channel_wait(QIOChannel *ioc,
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GIOCondition condition)
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{
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GMainContext *ctxt = g_main_context_new();
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GMainLoop *loop = g_main_loop_new(ctxt, TRUE);
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GSource *source;
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source = qio_channel_create_watch(ioc, condition);
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g_source_set_callback(source,
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(GSourceFunc)qio_channel_wait_complete,
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loop,
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NULL);
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g_source_attach(source, ctxt);
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g_main_loop_run(loop);
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g_source_unref(source);
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g_main_loop_unref(loop);
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g_main_context_unref(ctxt);
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}
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static void qio_channel_finalize(Object *obj)
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{
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QIOChannel *ioc = QIO_CHANNEL(obj);
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g_free(ioc->name);
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#ifdef _WIN32
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if (ioc->event) {
|
|
CloseHandle(ioc->event);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
static const TypeInfo qio_channel_info = {
|
|
.parent = TYPE_OBJECT,
|
|
.name = TYPE_QIO_CHANNEL,
|
|
.instance_size = sizeof(QIOChannel),
|
|
.instance_finalize = qio_channel_finalize,
|
|
.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);
|