include/io/channel-util.h

   1 /*
   2  * QEMU I/O channels utility APIs
   3  *
   4  * Copyright (c) 2016 Red Hat, Inc.
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  *
  19  */
  20
  21 #ifndef QIO_CHANNEL_UTIL_H
  22 #define QIO_CHANNEL_UTIL_H
  23
  24 #include "io/channel.h"
  25
  26 /*
  27  * This module provides helper functions that are useful when dealing
  28  * with QIOChannel objects
  29  */
  30
  31
  32 /**
  33  * qio_channel_new_fd:
  34  * @fd: the file descriptor
  35  * @errp: pointer to a NULL-initialized error object
  36  *
  37  * Create a channel for performing I/O on the file
  38  * descriptor @fd. The particular subclass of QIOChannel
  39  * that is returned will depend on what underlying object
  40  * the file descriptor is associated with. It may be either
  41  * a QIOChannelSocket or a QIOChannelFile instance. Upon
  42  * success, the returned QIOChannel instance will own
  43  * the @fd file descriptor, and take responsibility for
  44  * closing it when no longer required. On failure, the
  45  * caller is responsible for closing @fd.
  46  *
  47  * Returns: the channel object, or NULL on error
  48  */
  49 QIOChannel *qio_channel_new_fd(int fd,
  50                                Error **errp);
  51
  52 /**
  53  * qio_channel_util_set_aio_fd_handler:
  54  * @read_fd: the file descriptor for the read handler
  55  * @read_ctx: the AioContext for the read handler
  56  * @io_read: the read handler
  57  * @write_fd: the file descriptor for the write handler
  58  * @write_ctx: the AioContext for the write handler
  59  * @io_write: the write handler
  60  * @opaque: the opaque argument to the read and write handler
  61  *
  62  * Set the read and write handlers when @read_ctx and @write_ctx are non-NULL,
  63  * respectively. To leave a handler in its current state, pass a NULL
  64  * AioContext. To clear a handler, pass a non-NULL AioContext and a NULL
  65  * handler.
  66  */
  67 void qio_channel_util_set_aio_fd_handler(int read_fd,
  68                                          AioContext *read_ctx,
  69                                          IOHandler *io_read,
  70                                          int write_fd,
  71                                          AioContext *write_ctx,
  72                                          IOHandler *io_write,
  73                                          void *opaque);
  74
  75 #endif /* QIO_CHANNEL_UTIL_H */