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		bebab91ebd
		
	
	
	
	
		
			
			Adds qio_channel_readv_full_all_eof() and qio_channel_readv_full_all() to read both data and FDs. Refactors existing code to use these helpers. Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com> Signed-off-by: John G Johnson <john.g.johnson@oracle.com> Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> Acked-by: Daniel P. Berrangé <berrange@redhat.com> Message-id: b059c4cc0fb741e794d644c144cc21372cad877d.1611938319.git.jag.raman@oracle.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
		
			
				
	
	
		
			859 lines
		
	
	
		
			29 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			859 lines
		
	
	
		
			29 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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| 
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| #ifndef QIO_CHANNEL_H
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| #define QIO_CHANNEL_H
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| 
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| #include "qom/object.h"
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| #include "qemu/coroutine.h"
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| #include "block/aio.h"
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| 
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| #define TYPE_QIO_CHANNEL "qio-channel"
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| OBJECT_DECLARE_TYPE(QIOChannel, QIOChannelClass,
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|                     QIO_CHANNEL)
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| 
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| 
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| #define QIO_CHANNEL_ERR_BLOCK -2
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| 
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| typedef enum QIOChannelFeature QIOChannelFeature;
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| 
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| enum QIOChannelFeature {
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|     QIO_CHANNEL_FEATURE_FD_PASS,
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|     QIO_CHANNEL_FEATURE_SHUTDOWN,
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|     QIO_CHANNEL_FEATURE_LISTEN,
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| };
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| 
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| 
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| typedef enum QIOChannelShutdown QIOChannelShutdown;
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| 
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| enum QIOChannelShutdown {
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|     QIO_CHANNEL_SHUTDOWN_READ = 1,
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|     QIO_CHANNEL_SHUTDOWN_WRITE = 2,
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|     QIO_CHANNEL_SHUTDOWN_BOTH = 3,
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| };
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| 
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| typedef gboolean (*QIOChannelFunc)(QIOChannel *ioc,
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|                                    GIOCondition condition,
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|                                    gpointer data);
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| 
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| /**
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|  * QIOChannel:
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|  *
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|  * The QIOChannel defines the core API for a generic I/O channel
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|  * class hierarchy. It is inspired by GIOChannel, but has the
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|  * following differences
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|  *
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|  *  - Use QOM to properly support arbitrary subclassing
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|  *  - Support use of iovecs for efficient I/O with multiple blocks
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|  *  - None of the character set translation, binary data exclusively
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|  *  - Direct support for QEMU Error object reporting
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|  *  - File descriptor passing
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|  *
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|  * This base class is abstract so cannot be instantiated. There
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|  * will be subclasses for dealing with sockets, files, and higher
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|  * level protocols such as TLS, WebSocket, etc.
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|  */
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| 
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| struct QIOChannel {
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|     Object parent;
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|     unsigned int features; /* bitmask of QIOChannelFeatures */
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|     char *name;
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|     AioContext *ctx;
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|     Coroutine *read_coroutine;
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|     Coroutine *write_coroutine;
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| #ifdef _WIN32
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|     HANDLE event; /* For use with GSource on Win32 */
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| #endif
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| };
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| 
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| /**
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|  * QIOChannelClass:
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|  *
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|  * This class defines the contract that all subclasses
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|  * must follow to provide specific channel implementations.
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|  * The first five callbacks are mandatory to support, others
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|  * provide additional optional features.
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|  *
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|  * Consult the corresponding public API docs for a description
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|  * of the semantics of each callback. io_shutdown in particular
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|  * must be thread-safe, terminate quickly and must not block.
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|  */
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| struct QIOChannelClass {
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|     ObjectClass parent;
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| 
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|     /* Mandatory callbacks */
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|     ssize_t (*io_writev)(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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|     ssize_t (*io_readv)(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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|     int (*io_close)(QIOChannel *ioc,
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|                     Error **errp);
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|     GSource * (*io_create_watch)(QIOChannel *ioc,
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|                                  GIOCondition condition);
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|     int (*io_set_blocking)(QIOChannel *ioc,
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|                            bool enabled,
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|                            Error **errp);
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| 
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|     /* Optional callbacks */
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|     int (*io_shutdown)(QIOChannel *ioc,
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|                        QIOChannelShutdown how,
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|                        Error **errp);
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|     void (*io_set_cork)(QIOChannel *ioc,
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|                         bool enabled);
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|     void (*io_set_delay)(QIOChannel *ioc,
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|                          bool enabled);
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|     off_t (*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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|     void (*io_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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| 
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| /* General I/O handling functions */
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| 
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| /**
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|  * qio_channel_has_feature:
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|  * @ioc: the channel object
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|  * @feature: the feature to check support of
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|  *
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|  * Determine whether the channel implementation supports
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|  * the optional feature named in @feature.
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|  *
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|  * Returns: true if supported, false otherwise.
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|  */
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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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| /**
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|  * qio_channel_set_feature:
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|  * @ioc: the channel object
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|  * @feature: the feature to set support for
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|  *
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|  * Add channel support for the feature named in @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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| /**
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|  * qio_channel_set_name:
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|  * @ioc: the channel object
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|  * @name: the name of the channel
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|  *
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|  * Sets the name of the channel, which serves as an aid
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|  * to debugging. The name is used when creating GSource
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|  * watches for this channel.
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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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| /**
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|  * qio_channel_readv_full:
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|  * @ioc: the channel object
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|  * @iov: the array of memory regions to read data into
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|  * @niov: the length of the @iov array
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|  * @fds: pointer to an array that will received file handles
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|  * @nfds: pointer filled with number of elements in @fds on return
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Read data from the IO channel, storing it in the
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|  * memory regions referenced by @iov. Each element
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|  * in the @iov will be fully populated with data
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|  * before the next one is used. The @niov parameter
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|  * specifies the total number of elements in @iov.
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|  *
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|  * It is not required for all @iov to be filled with
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|  * data. If the channel is in blocking mode, at least
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|  * one byte of data will be read, but no more is
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|  * guaranteed. If the channel is non-blocking and no
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|  * data is available, it will return QIO_CHANNEL_ERR_BLOCK
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|  *
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|  * If the channel has passed any file descriptors,
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|  * the @fds array pointer will be allocated and
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|  * the elements filled with the received file
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|  * descriptors. The @nfds pointer will be updated
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|  * to indicate the size of the @fds array that
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|  * was allocated. It is the callers responsibility
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|  * to call close() on each file descriptor and to
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|  * call g_free() on the array pointer in @fds.
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|  *
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|  * It is an error to pass a non-NULL @fds parameter
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|  * unless qio_channel_has_feature() returns a true
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|  * value for the QIO_CHANNEL_FEATURE_FD_PASS constant.
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|  *
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|  * Returns: the number of bytes read, or -1 on error,
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|  * or QIO_CHANNEL_ERR_BLOCK if no data is available
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|  * and the channel is non-blocking
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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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| 
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| /**
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|  * qio_channel_writev_full:
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|  * @ioc: the channel object
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|  * @iov: the array of memory regions to write data from
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|  * @niov: the length of the @iov array
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|  * @fds: an array of file handles to send
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|  * @nfds: number of file handles in @fds
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Write data to the IO channel, reading it from the
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|  * memory regions referenced by @iov. Each element
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|  * in the @iov will be fully sent, before the next
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|  * one is used. The @niov parameter specifies the
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|  * total number of elements in @iov.
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|  *
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|  * It is not required for all @iov data to be fully
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|  * sent. If the channel is in blocking mode, at least
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|  * one byte of data will be sent, but no more is
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|  * guaranteed. If the channel is non-blocking and no
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|  * data can be sent, it will return QIO_CHANNEL_ERR_BLOCK
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|  *
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|  * If there are file descriptors to send, the @fds
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|  * array should be non-NULL and provide the handles.
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|  * All file descriptors will be sent if at least one
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|  * byte of data was sent.
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|  *
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|  * It is an error to pass a non-NULL @fds parameter
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|  * unless qio_channel_has_feature() returns a true
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|  * value for the QIO_CHANNEL_FEATURE_FD_PASS constant.
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|  *
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|  * Returns: the number of bytes sent, or -1 on error,
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|  * or QIO_CHANNEL_ERR_BLOCK if no data is can be sent
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|  * and the channel is non-blocking
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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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| /**
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|  * qio_channel_readv_all_eof:
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|  * @ioc: the channel object
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|  * @iov: the array of memory regions to read data into
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|  * @niov: the length of the @iov array
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Read data from the IO channel, storing it in the
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|  * memory regions referenced by @iov. Each element
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|  * in the @iov will be fully populated with data
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|  * before the next one is used. The @niov parameter
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|  * specifies the total number of elements in @iov.
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|  *
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|  * The function will wait for all requested data
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|  * to be read, yielding from the current coroutine
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|  * if required.
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|  *
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|  * If end-of-file occurs before any data is read,
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|  * no error is reported; otherwise, if it occurs
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|  * before all requested data has been read, an error
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|  * will be reported.
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|  *
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|  * Returns: 1 if all bytes were read, 0 if end-of-file
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|  *          occurs without data, or -1 on error
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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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| /**
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|  * qio_channel_readv_all:
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|  * @ioc: the channel object
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|  * @iov: the array of memory regions to read data into
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|  * @niov: the length of the @iov array
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Read data from the IO channel, storing it in the
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|  * memory regions referenced by @iov. Each element
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|  * in the @iov will be fully populated with data
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|  * before the next one is used. The @niov parameter
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|  * specifies the total number of elements in @iov.
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|  *
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|  * The function will wait for all requested data
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|  * to be read, yielding from the current coroutine
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|  * if required.
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|  *
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|  * If end-of-file occurs before all requested data
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|  * has been read, an error will be reported.
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|  *
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|  * Returns: 0 if all bytes were read, or -1 on error
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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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| 
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| /**
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|  * qio_channel_writev_all:
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|  * @ioc: the channel object
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|  * @iov: the array of memory regions to write data from
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|  * @niov: the length of the @iov array
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Write data to the IO channel, reading it from the
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|  * memory regions referenced by @iov. Each element
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|  * in the @iov will be fully sent, before the next
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|  * one is used. The @niov parameter specifies the
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|  * total number of elements in @iov.
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|  *
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|  * The function will wait for all requested data
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|  * to be written, yielding from the current coroutine
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|  * if required.
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|  *
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|  * Returns: 0 if all bytes were written, or -1 on error
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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 **erp);
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| 
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| /**
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|  * qio_channel_readv:
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|  * @ioc: the channel object
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|  * @iov: the array of memory regions to read data into
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|  * @niov: the length of the @iov array
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Behaves as qio_channel_readv_full() but does not support
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|  * receiving of file handles.
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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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| /**
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|  * qio_channel_writev:
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|  * @ioc: the channel object
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|  * @iov: the array of memory regions to write data from
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|  * @niov: the length of the @iov array
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Behaves as qio_channel_writev_full() but does not support
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|  * sending of file handles.
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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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| /**
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|  * qio_channel_read:
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|  * @ioc: the channel object
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|  * @buf: the memory region to read data into
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|  * @buflen: the length of @buf
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Behaves as qio_channel_readv_full() but does not support
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|  * receiving of file handles, and only supports reading into
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|  * a single memory region.
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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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| /**
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|  * qio_channel_write:
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|  * @ioc: the channel object
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|  * @buf: the memory regions to send data from
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|  * @buflen: the length of @buf
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Behaves as qio_channel_writev_full() but does not support
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|  * sending of file handles, and only supports writing from a
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|  * single memory region.
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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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| /**
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|  * qio_channel_read_all_eof:
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|  * @ioc: the channel object
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|  * @buf: the memory region to read data into
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|  * @buflen: the number of bytes to @buf
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Reads @buflen bytes into @buf, possibly blocking or (if the
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|  * channel is non-blocking) yielding from the current coroutine
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|  * multiple times until the entire content is read. If end-of-file
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|  * occurs immediately it is not an error, but if it occurs after
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|  * data has been read it will return an error rather than a
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|  * short-read. Otherwise behaves as qio_channel_read().
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|  *
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|  * Returns: 1 if all bytes were read, 0 if end-of-file occurs
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|  *          without data, or -1 on error
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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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| /**
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|  * qio_channel_read_all:
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|  * @ioc: the channel object
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|  * @buf: the memory region to read data into
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|  * @buflen: the number of bytes to @buf
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Reads @buflen bytes into @buf, possibly blocking or (if the
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|  * channel is non-blocking) yielding from the current coroutine
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|  * multiple times until the entire content is read. If end-of-file
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|  * occurs it will return an error rather than a short-read. Otherwise
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|  * behaves as qio_channel_read().
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|  *
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|  * Returns: 0 if all bytes were read, or -1 on error
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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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| /**
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|  * qio_channel_write_all:
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|  * @ioc: the channel object
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|  * @buf: the memory region to write data into
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|  * @buflen: the number of bytes to @buf
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Writes @buflen bytes from @buf, possibly blocking or (if the
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|  * channel is non-blocking) yielding from the current coroutine
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|  * multiple times until the entire content is written.  Otherwise
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|  * behaves as qio_channel_write().
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|  *
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|  * Returns: 0 if all bytes were written, or -1 on error
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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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| /**
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|  * qio_channel_set_blocking:
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|  * @ioc: the channel object
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|  * @enabled: the blocking flag state
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * If @enabled is true, then the channel is put into
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|  * blocking mode, otherwise it will be non-blocking.
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|  *
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|  * In non-blocking mode, read/write operations may
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|  * return QIO_CHANNEL_ERR_BLOCK if they would otherwise
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|  * block on I/O
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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);
 | |
| 
 | |
| /**
 | |
|  * qio_channel_close:
 | |
|  * @ioc: the channel object
 | |
|  * @errp: pointer to a NULL-initialized error object
 | |
|  *
 | |
|  * Close the channel, flushing any pending I/O
 | |
|  *
 | |
|  * Returns: 0 on success, -1 on error
 | |
|  */
 | |
| int qio_channel_close(QIOChannel *ioc,
 | |
|                       Error **errp);
 | |
| 
 | |
| /**
 | |
|  * qio_channel_shutdown:
 | |
|  * @ioc: the channel object
 | |
|  * @how: the direction to shutdown
 | |
|  * @errp: pointer to a NULL-initialized error object
 | |
|  *
 | |
|  * Shutdowns transmission and/or receiving of data
 | |
|  * without closing the underlying transport.
 | |
|  *
 | |
|  * Not all implementations will support this facility,
 | |
|  * so may report an error. To avoid errors, the
 | |
|  * caller may check for the feature flag
 | |
|  * QIO_CHANNEL_FEATURE_SHUTDOWN prior to calling
 | |
|  * this method.
 | |
|  *
 | |
|  * This function is thread-safe, terminates quickly and does not block.
 | |
|  *
 | |
|  * Returns: 0 on success, -1 on error
 | |
|  */
 | |
| int qio_channel_shutdown(QIOChannel *ioc,
 | |
|                          QIOChannelShutdown how,
 | |
|                          Error **errp);
 | |
| 
 | |
| /**
 | |
|  * qio_channel_set_delay:
 | |
|  * @ioc: the channel object
 | |
|  * @enabled: the new flag state
 | |
|  *
 | |
|  * Controls whether the underlying transport is
 | |
|  * permitted to delay writes in order to merge
 | |
|  * small packets. If @enabled is true, then the
 | |
|  * writes may be delayed in order to opportunistically
 | |
|  * merge small packets into larger ones. If @enabled
 | |
|  * is false, writes are dispatched immediately with
 | |
|  * no delay.
 | |
|  *
 | |
|  * When @enabled is false, applications may wish to
 | |
|  * use the qio_channel_set_cork() method to explicitly
 | |
|  * control write merging.
 | |
|  *
 | |
|  * On channels which are backed by a socket, this
 | |
|  * API corresponds to the inverse of TCP_NODELAY flag,
 | |
|  * controlling whether the Nagle algorithm is active.
 | |
|  *
 | |
|  * This setting is merely a hint, so implementations are
 | |
|  * free to ignore this without it being considered an
 | |
|  * error.
 | |
|  */
 | |
| void qio_channel_set_delay(QIOChannel *ioc,
 | |
|                            bool enabled);
 | |
| 
 | |
| /**
 | |
|  * qio_channel_set_cork:
 | |
|  * @ioc: the channel object
 | |
|  * @enabled: the new flag state
 | |
|  *
 | |
|  * Controls whether the underlying transport is
 | |
|  * permitted to dispatch data that is written.
 | |
|  * If @enabled is true, then any data written will
 | |
|  * be queued in local buffers until @enabled is
 | |
|  * set to false once again.
 | |
|  *
 | |
|  * This feature is typically used when the automatic
 | |
|  * write coalescing facility is disabled via the
 | |
|  * qio_channel_set_delay() method.
 | |
|  *
 | |
|  * On channels which are backed by a socket, this
 | |
|  * API corresponds to the TCP_CORK flag.
 | |
|  *
 | |
|  * This setting is merely a hint, so implementations are
 | |
|  * free to ignore this without it being considered an
 | |
|  * error.
 | |
|  */
 | |
| void qio_channel_set_cork(QIOChannel *ioc,
 | |
|                           bool enabled);
 | |
| 
 | |
| 
 | |
| /**
 | |
|  * qio_channel_seek:
 | |
|  * @ioc: the channel object
 | |
|  * @offset: the position to seek to, relative to @whence
 | |
|  * @whence: one of the (POSIX) SEEK_* constants listed below
 | |
|  * @errp: pointer to a NULL-initialized error object
 | |
|  *
 | |
|  * Moves the current I/O position within the channel
 | |
|  * @ioc, to be @offset. The value of @offset is
 | |
|  * interpreted relative to @whence:
 | |
|  *
 | |
|  * SEEK_SET - the position is set to @offset bytes
 | |
|  * SEEK_CUR - the position is moved by @offset bytes
 | |
|  * SEEK_END - the position is set to end of the file plus @offset bytes
 | |
|  *
 | |
|  * Not all implementations will support this facility,
 | |
|  * so may report an error.
 | |
|  *
 | |
|  * Returns: the new position on success, (off_t)-1 on failure
 | |
|  */
 | |
| off_t qio_channel_io_seek(QIOChannel *ioc,
 | |
|                           off_t offset,
 | |
|                           int whence,
 | |
|                           Error **errp);
 | |
| 
 | |
| 
 | |
| /**
 | |
|  * qio_channel_create_watch:
 | |
|  * @ioc: the channel object
 | |
|  * @condition: the I/O condition to monitor
 | |
|  *
 | |
|  * Create a new main loop source that is used to watch
 | |
|  * for the I/O condition @condition. Typically the
 | |
|  * qio_channel_add_watch() method would be used instead
 | |
|  * of this, since it directly attaches a callback to
 | |
|  * the source
 | |
|  *
 | |
|  * Returns: the new main loop source.
 | |
|  */
 | |
| GSource *qio_channel_create_watch(QIOChannel *ioc,
 | |
|                                   GIOCondition condition);
 | |
| 
 | |
| /**
 | |
|  * qio_channel_add_watch:
 | |
|  * @ioc: the channel object
 | |
|  * @condition: the I/O condition to monitor
 | |
|  * @func: callback to invoke when the source becomes ready
 | |
|  * @user_data: opaque data to pass to @func
 | |
|  * @notify: callback to free @user_data
 | |
|  *
 | |
|  * Create a new main loop source that is used to watch
 | |
|  * for the I/O condition @condition. The callback @func
 | |
|  * will be registered against the source, to be invoked
 | |
|  * when the source becomes ready. The optional @user_data
 | |
|  * will be passed to @func when it is invoked. The @notify
 | |
|  * callback will be used to free @user_data when the
 | |
|  * watch is deleted
 | |
|  *
 | |
|  * The returned source ID can be used with g_source_remove()
 | |
|  * to remove and free the source when no longer required.
 | |
|  * Alternatively the @func callback can return a FALSE
 | |
|  * value.
 | |
|  *
 | |
|  * Returns: the source ID
 | |
|  */
 | |
| guint qio_channel_add_watch(QIOChannel *ioc,
 | |
|                             GIOCondition condition,
 | |
|                             QIOChannelFunc func,
 | |
|                             gpointer user_data,
 | |
|                             GDestroyNotify notify);
 | |
| 
 | |
| /**
 | |
|  * qio_channel_add_watch_full:
 | |
|  * @ioc: the channel object
 | |
|  * @condition: the I/O condition to monitor
 | |
|  * @func: callback to invoke when the source becomes ready
 | |
|  * @user_data: opaque data to pass to @func
 | |
|  * @notify: callback to free @user_data
 | |
|  * @context: the context to run the watch source
 | |
|  *
 | |
|  * Similar as qio_channel_add_watch(), but allows to specify context
 | |
|  * to run the watch source.
 | |
|  *
 | |
|  * Returns: the source ID
 | |
|  */
 | |
| guint qio_channel_add_watch_full(QIOChannel *ioc,
 | |
|                                  GIOCondition condition,
 | |
|                                  QIOChannelFunc func,
 | |
|                                  gpointer user_data,
 | |
|                                  GDestroyNotify notify,
 | |
|                                  GMainContext *context);
 | |
| 
 | |
| /**
 | |
|  * qio_channel_add_watch_source:
 | |
|  * @ioc: the channel object
 | |
|  * @condition: the I/O condition to monitor
 | |
|  * @func: callback to invoke when the source becomes ready
 | |
|  * @user_data: opaque data to pass to @func
 | |
|  * @notify: callback to free @user_data
 | |
|  * @context: gcontext to bind the source to
 | |
|  *
 | |
|  * Similar as qio_channel_add_watch(), but allows to specify context
 | |
|  * to run the watch source, meanwhile return the GSource object
 | |
|  * instead of tag ID, with the GSource referenced already.
 | |
|  *
 | |
|  * Note: callers is responsible to unref the source when not needed.
 | |
|  *
 | |
|  * Returns: the source pointer
 | |
|  */
 | |
| GSource *qio_channel_add_watch_source(QIOChannel *ioc,
 | |
|                                       GIOCondition condition,
 | |
|                                       QIOChannelFunc func,
 | |
|                                       gpointer user_data,
 | |
|                                       GDestroyNotify notify,
 | |
|                                       GMainContext *context);
 | |
| 
 | |
| /**
 | |
|  * qio_channel_attach_aio_context:
 | |
|  * @ioc: the channel object
 | |
|  * @ctx: the #AioContext to set the handlers on
 | |
|  *
 | |
|  * Request that qio_channel_yield() sets I/O handlers on
 | |
|  * the given #AioContext.  If @ctx is %NULL, qio_channel_yield()
 | |
|  * uses QEMU's main thread event loop.
 | |
|  *
 | |
|  * You can move a #QIOChannel from one #AioContext to another even if
 | |
|  * I/O handlers are set for a coroutine.  However, #QIOChannel provides
 | |
|  * no synchronization between the calls to qio_channel_yield() and
 | |
|  * qio_channel_attach_aio_context().
 | |
|  *
 | |
|  * Therefore you should first call qio_channel_detach_aio_context()
 | |
|  * to ensure that the coroutine is not entered concurrently.  Then,
 | |
|  * while the coroutine has yielded, call qio_channel_attach_aio_context(),
 | |
|  * and then aio_co_schedule() to place the coroutine on the new
 | |
|  * #AioContext.  The calls to qio_channel_detach_aio_context()
 | |
|  * and qio_channel_attach_aio_context() should be protected with
 | |
|  * aio_context_acquire() and aio_context_release().
 | |
|  */
 | |
| void qio_channel_attach_aio_context(QIOChannel *ioc,
 | |
|                                     AioContext *ctx);
 | |
| 
 | |
| /**
 | |
|  * qio_channel_detach_aio_context:
 | |
|  * @ioc: the channel object
 | |
|  *
 | |
|  * Disable any I/O handlers set by qio_channel_yield().  With the
 | |
|  * help of aio_co_schedule(), this allows moving a coroutine that was
 | |
|  * paused by qio_channel_yield() to another context.
 | |
|  */
 | |
| void qio_channel_detach_aio_context(QIOChannel *ioc);
 | |
| 
 | |
| /**
 | |
|  * qio_channel_yield:
 | |
|  * @ioc: the channel object
 | |
|  * @condition: the I/O condition to wait for
 | |
|  *
 | |
|  * Yields execution from the current coroutine until the condition
 | |
|  * indicated by @condition becomes available.  @condition must
 | |
|  * be either %G_IO_IN or %G_IO_OUT; it cannot contain both.  In
 | |
|  * addition, no two coroutine can be waiting on the same condition
 | |
|  * and channel at the same time.
 | |
|  *
 | |
|  * This must only be called from coroutine context. It is safe to
 | |
|  * reenter the coroutine externally while it is waiting; in this
 | |
|  * case the function will return even if @condition is not yet
 | |
|  * available.
 | |
|  */
 | |
| void coroutine_fn qio_channel_yield(QIOChannel *ioc,
 | |
|                                     GIOCondition condition);
 | |
| 
 | |
| /**
 | |
|  * qio_channel_wait:
 | |
|  * @ioc: the channel object
 | |
|  * @condition: the I/O condition to wait for
 | |
|  *
 | |
|  * Block execution from the current thread until
 | |
|  * the condition indicated by @condition becomes
 | |
|  * available.
 | |
|  *
 | |
|  * This will enter a nested event loop to perform
 | |
|  * the wait.
 | |
|  */
 | |
| void qio_channel_wait(QIOChannel *ioc,
 | |
|                       GIOCondition condition);
 | |
| 
 | |
| /**
 | |
|  * qio_channel_set_aio_fd_handler:
 | |
|  * @ioc: the channel object
 | |
|  * @ctx: the AioContext to set the handlers on
 | |
|  * @io_read: the read handler
 | |
|  * @io_write: the write handler
 | |
|  * @opaque: the opaque value passed to the handler
 | |
|  *
 | |
|  * This is used internally by qio_channel_yield().  It can
 | |
|  * be used by channel implementations to forward the handlers
 | |
|  * to another channel (e.g. from #QIOChannelTLS to the
 | |
|  * underlying socket).
 | |
|  */
 | |
| void qio_channel_set_aio_fd_handler(QIOChannel *ioc,
 | |
|                                     AioContext *ctx,
 | |
|                                     IOHandler *io_read,
 | |
|                                     IOHandler *io_write,
 | |
|                                     void *opaque);
 | |
| 
 | |
| /**
 | |
|  * qio_channel_readv_full_all_eof:
 | |
|  * @ioc: the channel object
 | |
|  * @iov: the array of memory regions to read data to
 | |
|  * @niov: the length of the @iov array
 | |
|  * @fds: an array of file handles to read
 | |
|  * @nfds: number of file handles in @fds
 | |
|  * @errp: pointer to a NULL-initialized error object
 | |
|  *
 | |
|  *
 | |
|  * Performs same function as qio_channel_readv_all_eof.
 | |
|  * Additionally, attempts to read file descriptors shared
 | |
|  * over the channel. The function will wait for all
 | |
|  * requested data to be read, yielding from the current
 | |
|  * coroutine if required. data refers to both file
 | |
|  * descriptors and the iovs.
 | |
|  *
 | |
|  * Returns: 1 if all bytes were read, 0 if end-of-file
 | |
|  *          occurs without data, or -1 on error
 | |
|  */
 | |
| 
 | |
| int qio_channel_readv_full_all_eof(QIOChannel *ioc,
 | |
|                                    const struct iovec *iov,
 | |
|                                    size_t niov,
 | |
|                                    int **fds, size_t *nfds,
 | |
|                                    Error **errp);
 | |
| 
 | |
| /**
 | |
|  * qio_channel_readv_full_all:
 | |
|  * @ioc: the channel object
 | |
|  * @iov: the array of memory regions to read data to
 | |
|  * @niov: the length of the @iov array
 | |
|  * @fds: an array of file handles to read
 | |
|  * @nfds: number of file handles in @fds
 | |
|  * @errp: pointer to a NULL-initialized error object
 | |
|  *
 | |
|  *
 | |
|  * Performs same function as qio_channel_readv_all_eof.
 | |
|  * Additionally, attempts to read file descriptors shared
 | |
|  * over the channel. The function will wait for all
 | |
|  * requested data to be read, yielding from the current
 | |
|  * coroutine if required. data refers to both file
 | |
|  * descriptors and the iovs.
 | |
|  *
 | |
|  * Returns: 0 if all bytes were read, or -1 on error
 | |
|  */
 | |
| 
 | |
| int qio_channel_readv_full_all(QIOChannel *ioc,
 | |
|                                const struct iovec *iov,
 | |
|                                size_t niov,
 | |
|                                int **fds, size_t *nfds,
 | |
|                                Error **errp);
 | |
| 
 | |
| /**
 | |
|  * qio_channel_writev_full_all:
 | |
|  * @ioc: the channel object
 | |
|  * @iov: the array of memory regions to write data from
 | |
|  * @niov: the length of the @iov array
 | |
|  * @fds: an array of file handles to send
 | |
|  * @nfds: number of file handles in @fds
 | |
|  * @errp: pointer to a NULL-initialized error object
 | |
|  *
 | |
|  *
 | |
|  * Behaves like qio_channel_writev_full but will attempt
 | |
|  * to send all data passed (file handles and memory regions).
 | |
|  * The function will wait for all requested data
 | |
|  * to be written, yielding from the current coroutine
 | |
|  * if required.
 | |
|  *
 | |
|  * Returns: 0 if all bytes were written, or -1 on error
 | |
|  */
 | |
| 
 | |
| int qio_channel_writev_full_all(QIOChannel *ioc,
 | |
|                                 const struct iovec *iov,
 | |
|                                 size_t niov,
 | |
|                                 int *fds, size_t nfds,
 | |
|                                 Error **errp);
 | |
| 
 | |
| #endif /* QIO_CHANNEL_H */
 |