qemu/include/io/channel-command.h
Marc-André Lureau ec5b6c9c5d io/command: implement support for win32
The initial implementation was changing the pipe state created by GLib
to PIPE_NOWAIT, but it turns out it doesn't work (read/write returns an
error). Since reading may return less than the requested amount, it
seems to be non-blocking already. However, the IO operation may block
until the FD is ready, I can't find good sources of information, to be
safe we can just poll for readiness before.

Alternatively, we could setup the FDs ourself, and use UNIX sockets on
Windows, which can be used in blocking/non-blocking mode. I haven't
tried it, as I am not sure it is necessary.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20221006113657.2656108-6-marcandre.lureau@redhat.com>
2022-10-12 19:22:01 +04:00

69 lines
1.9 KiB
C

/*
* QEMU I/O channels external command driver
*
* 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 2.1 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/>.
*
*/
#ifndef QIO_CHANNEL_COMMAND_H
#define QIO_CHANNEL_COMMAND_H
#include "io/channel.h"
#include "qom/object.h"
#define TYPE_QIO_CHANNEL_COMMAND "qio-channel-command"
OBJECT_DECLARE_SIMPLE_TYPE(QIOChannelCommand, QIO_CHANNEL_COMMAND)
/**
* QIOChannelCommand:
*
* The QIOChannelCommand class provides a channel implementation
* that can transport data with an externally running command
* via its stdio streams.
*/
struct QIOChannelCommand {
QIOChannel parent;
int writefd;
int readfd;
GPid pid;
#ifdef WIN32
bool blocking;
#endif
};
/**
* qio_channel_command_new_spawn:
* @argv: the NULL terminated list of command arguments
* @flags: the I/O mode, one of O_RDONLY, O_WRONLY, O_RDWR
* @errp: pointer to a NULL-initialized error object
*
* Create a channel for performing I/O with the
* command to be spawned with arguments @argv.
*
* Returns: the command channel object, or NULL on error
*/
QIOChannelCommand *
qio_channel_command_new_spawn(const char *const argv[],
int flags,
Error **errp);
#endif /* QIO_CHANNEL_COMMAND_H */