--- /dev/null
+/*
+ * Copyright (c) 2009-2013 Apple Inc. All rights reserved.
+ *
+ * @APPLE_APACHE_LICENSE_HEADER_START@
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * @APPLE_APACHE_LICENSE_HEADER_END@
+ */
+
+/*
+ * IMPORTANT: This header file describes INTERNAL interfaces to libdispatch
+ * which are subject to change in future releases of Mac OS X. Any applications
+ * relying on these interfaces WILL break.
+ */
+
+#ifndef __DISPATCH_IO_PRIVATE__
+#define __DISPATCH_IO_PRIVATE__
+
+#ifndef __DISPATCH_INDIRECT__
+#error "Please #include <dispatch/dispatch.h> instead of this file directly."
+#include <dispatch/base.h> // for HeaderDoc
+#endif
+
+__BEGIN_DECLS
+
+/*!
+ * @function dispatch_read_f
+ * Schedule a read operation for asynchronous execution on the specified file
+ * descriptor. The specified handler is enqueued with the data read from the
+ * file descriptor when the operation has completed or an error occurs.
+ *
+ * The data object passed to the handler will be automatically released by the
+ * system when the handler returns. It is the responsibility of the application
+ * to retain, concatenate or copy the data object if it is needed after the
+ * handler returns.
+ *
+ * The data object passed to the handler will only contain as much data as is
+ * currently available from the file descriptor (up to the specified length).
+ *
+ * If an unrecoverable error occurs on the file descriptor, the handler will be
+ * enqueued with the appropriate error code along with a data object of any data
+ * that could be read successfully.
+ *
+ * An invocation of the handler with an error code of zero and an empty data
+ * object indicates that EOF was reached.
+ *
+ * The system takes control of the file descriptor until the handler is
+ * enqueued, and during this time file descriptor flags such as O_NONBLOCK will
+ * be modified by the system on behalf of the application. It is an error for
+ * the application to modify a file descriptor directly while it is under the
+ * control of the system, but it may create additional dispatch I/O convenience
+ * operations or dispatch I/O channels associated with that file descriptor.
+ *
+ * @param fd The file descriptor from which to read the data.
+ * @param length The length of data to read from the file descriptor,
+ * or SIZE_MAX to indicate that all of the data currently
+ * available from the file descriptor should be read.
+ * @param queue The dispatch queue to which the handler should be
+ * submitted.
+ * @param context The application-defined context parameter to pass to
+ * the handler function.
+ * @param handler The handler to enqueue when data is ready to be
+ * delivered.
+ * @param context Application-defined context parameter.
+ * @param data The data read from the file descriptor.
+ * @param error An errno condition for the read operation or
+ * zero if the read was successful.
+ */
+__OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_7_0)
+DISPATCH_EXPORT DISPATCH_NONNULL3 DISPATCH_NONNULL5 DISPATCH_NOTHROW
+void
+dispatch_read_f(dispatch_fd_t fd,
+ size_t length,
+ dispatch_queue_t queue,
+ void *context,
+ void (*handler)(void *context, dispatch_data_t data, int error));
+
+/*!
+ * @function dispatch_write_f
+ * Schedule a write operation for asynchronous execution on the specified file
+ * descriptor. The specified handler is enqueued when the operation has
+ * completed or an error occurs.
+ *
+ * If an unrecoverable error occurs on the file descriptor, the handler will be
+ * enqueued with the appropriate error code along with the data that could not
+ * be successfully written.
+ *
+ * An invocation of the handler with an error code of zero indicates that the
+ * data was fully written to the channel.
+ *
+ * The system takes control of the file descriptor until the handler is
+ * enqueued, and during this time file descriptor flags such as O_NONBLOCK will
+ * be modified by the system on behalf of the application. It is an error for
+ * the application to modify a file descriptor directly while it is under the
+ * control of the system, but it may create additional dispatch I/O convenience
+ * operations or dispatch I/O channels associated with that file descriptor.
+ *
+ * @param fd The file descriptor to which to write the data.
+ * @param data The data object to write to the file descriptor.
+ * @param queue The dispatch queue to which the handler should be
+ * submitted.
+ * @param context The application-defined context parameter to pass to
+ * the handler function.
+ * @param handler The handler to enqueue when the data has been written.
+ * @param context Application-defined context parameter.
+ * @param data The data that could not be written to the I/O
+ * channel, or NULL.
+ * @param error An errno condition for the write operation or
+ * zero if the write was successful.
+ */
+__OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_7_0)
+DISPATCH_EXPORT DISPATCH_NONNULL2 DISPATCH_NONNULL3 DISPATCH_NONNULL5
+DISPATCH_NOTHROW
+void
+dispatch_write_f(dispatch_fd_t fd,
+ dispatch_data_t data,
+ dispatch_queue_t queue,
+ void *context,
+ void (*handler)(void *context, dispatch_data_t data, int error));
+
+/*!
+ * @function dispatch_io_create_f
+ * Create a dispatch I/O channel associated with a file descriptor. The system
+ * takes control of the file descriptor until the channel is closed, an error
+ * occurs on the file descriptor or all references to the channel are released.
+ * At that time the specified cleanup handler will be enqueued and control over
+ * the file descriptor relinquished.
+ *
+ * While a file descriptor is under the control of a dispatch I/O channel, file
+ * descriptor flags such as O_NONBLOCK will be modified by the system on behalf
+ * of the application. It is an error for the application to modify a file
+ * descriptor directly while it is under the control of a dispatch I/O channel,
+ * but it may create additional channels associated with that file descriptor.
+ *
+ * @param type The desired type of I/O channel (DISPATCH_IO_STREAM
+ * or DISPATCH_IO_RANDOM).
+ * @param fd The file descriptor to associate with the I/O channel.
+ * @param queue The dispatch queue to which the handler should be submitted.
+ * @param context The application-defined context parameter to pass to
+ * the cleanup handler function.
+ * @param cleanup_handler The handler to enqueue when the system
+ * relinquishes control over the file descriptor.
+ * @param context Application-defined context parameter.
+ * @param error An errno condition if control is relinquished
+ * because channel creation failed, zero otherwise.
+ * @result The newly created dispatch I/O channel or NULL if an error
+ * occurred (invalid type specified).
+ */
+__OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_7_0)
+DISPATCH_EXPORT DISPATCH_MALLOC DISPATCH_RETURNS_RETAINED DISPATCH_WARN_RESULT
+DISPATCH_NOTHROW
+dispatch_io_t
+dispatch_io_create_f(dispatch_io_type_t type,
+ dispatch_fd_t fd,
+ dispatch_queue_t queue,
+ void *context,
+ void (*cleanup_handler)(void *context, int error));
+
+/*!
+ * @function dispatch_io_create_with_path_f
+ * Create a dispatch I/O channel associated with a path name. The specified
+ * path, oflag and mode parameters will be passed to open(2) when the first I/O
+ * operation on the channel is ready to execute and the resulting file
+ * descriptor will remain open and under the control of the system until the
+ * channel is closed, an error occurs on the file descriptor or all references
+ * to the channel are released. At that time the file descriptor will be closed
+ * and the specified cleanup handler will be enqueued.
+ *
+ * @param type The desired type of I/O channel (DISPATCH_IO_STREAM
+ * or DISPATCH_IO_RANDOM).
+ * @param path The absolute path to associate with the I/O channel.
+ * @param oflag The flags to pass to open(2) when opening the file at
+ * path.
+ * @param mode The mode to pass to open(2) when creating the file at
+ * path (i.e. with flag O_CREAT), zero otherwise.
+ * @param queue The dispatch queue to which the handler should be
+ * submitted.
+ * @param context The application-defined context parameter to pass to
+ * the cleanup handler function.
+ * @param cleanup_handler The handler to enqueue when the system
+ * has closed the file at path.
+ * @param context Application-defined context parameter.
+ * @param error An errno condition if control is relinquished
+ * because channel creation or opening of the
+ * specified file failed, zero otherwise.
+ * @result The newly created dispatch I/O channel or NULL if an error
+ * occurred (invalid type or non-absolute path specified).
+ */
+__OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_7_0)
+DISPATCH_EXPORT DISPATCH_NONNULL2 DISPATCH_MALLOC DISPATCH_RETURNS_RETAINED
+DISPATCH_WARN_RESULT DISPATCH_NOTHROW
+dispatch_io_t
+dispatch_io_create_with_path_f(dispatch_io_type_t type,
+ const char *path, int oflag, mode_t mode,
+ dispatch_queue_t queue,
+ void *context,
+ void (*cleanup_handler)(void *context, int error));
+
+/*!
+ * @function dispatch_io_create_with_io_f
+ * Create a new dispatch I/O channel from an existing dispatch I/O channel.
+ * The new channel inherits the file descriptor or path name associated with
+ * the existing channel, but not its channel type or policies.
+ *
+ * If the existing channel is associated with a file descriptor, control by the
+ * system over that file descriptor is extended until the new channel is also
+ * closed, an error occurs on the file descriptor, or all references to both
+ * channels are released. At that time the specified cleanup handler will be
+ * enqueued and control over the file descriptor relinquished.
+ *
+ * While a file descriptor is under the control of a dispatch I/O channel, file
+ * descriptor flags such as O_NONBLOCK will be modified by the system on behalf
+ * of the application. It is an error for the application to modify a file
+ * descriptor directly while it is under the control of a dispatch I/O channel,
+ * but it may create additional channels associated with that file descriptor.
+ *
+ * @param type The desired type of I/O channel (DISPATCH_IO_STREAM
+ * or DISPATCH_IO_RANDOM).
+ * @param io The existing channel to create the new I/O channel from.
+ * @param queue The dispatch queue to which the handler should be submitted.
+ * @param context The application-defined context parameter to pass to
+ * the cleanup handler function.
+ * @param cleanup_handler The handler to enqueue when the system
+ * relinquishes control over the file descriptor
+ * (resp. closes the file at path) associated with
+ * the existing channel.
+ * @param context Application-defined context parameter.
+ * @param error An errno condition if control is relinquished
+ * because channel creation failed, zero otherwise.
+ * @result The newly created dispatch I/O channel or NULL if an error
+ * occurred (invalid type specified).
+ */
+__OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_7_0)
+DISPATCH_EXPORT DISPATCH_NONNULL2 DISPATCH_MALLOC DISPATCH_RETURNS_RETAINED
+DISPATCH_WARN_RESULT DISPATCH_NOTHROW
+dispatch_io_t
+dispatch_io_create_with_io_f(dispatch_io_type_t type,
+ dispatch_io_t io,
+ dispatch_queue_t queue,
+ void *context,
+ void (*cleanup_handler)(void *context, int error));
+
+/*!
+ * @typedef dispatch_io_handler_function_t
+ * The prototype of I/O handler functions for dispatch I/O operations.
+ *
+ * @param context Application-defined context parameter.
+ * @param done A flag indicating whether the operation is complete.
+ * @param data The data object to be handled.
+ * @param error An errno condition for the operation.
+ */
+typedef void (*dispatch_io_handler_function_t)(void *context, bool done,
+ dispatch_data_t data, int error);
+
+/*!
+ * @function dispatch_io_read_f
+ * Schedule a read operation for asynchronous execution on the specified I/O
+ * channel. The I/O handler is enqueued one or more times depending on the
+ * general load of the system and the policy specified on the I/O channel.
+ *
+ * Any data read from the channel is described by the dispatch data object
+ * passed to the I/O handler. This object will be automatically released by the
+ * system when the I/O handler returns. It is the responsibility of the
+ * application to retain, concatenate or copy the data object if it is needed
+ * after the I/O handler returns.
+ *
+ * Dispatch I/O handlers are not reentrant. The system will ensure that no new
+ * I/O handler instance is invoked until the previously enqueued handler
+ * function has returned.
+ *
+ * An invocation of the I/O handler with the done flag set indicates that the
+ * read operation is complete and that the handler will not be enqueued again.
+ *
+ * If an unrecoverable error occurs on the I/O channel's underlying file
+ * descriptor, the I/O handler will be enqueued with the done flag set, the
+ * appropriate error code and a NULL data object.
+ *
+ * An invocation of the I/O handler with the done flag set, an error code of
+ * zero and an empty data object indicates that EOF was reached.
+ *
+ * @param channel The dispatch I/O channel from which to read the data.
+ * @param offset The offset relative to the channel position from which
+ * to start reading (only for DISPATCH_IO_RANDOM).
+ * @param length The length of data to read from the I/O channel, or
+ * SIZE_MAX to indicate that data should be read until EOF
+ * is reached.
+ * @param queue The dispatch queue to which the I/O handler should be
+ * submitted.
+ * @param context The application-defined context parameter to pass to
+ * the handler function.
+ * @param io_handler The I/O handler to enqueue when data is ready to be
+ * delivered.
+ * @param context Application-defined context parameter.
+ * @param done A flag indicating whether the operation is complete.
+ * @param data An object with the data most recently read from the
+ * I/O channel as part of this read operation, or NULL.
+ * @param error An errno condition for the read operation or zero if
+ * the read was successful.
+ */
+__OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_7_0)
+DISPATCH_EXPORT DISPATCH_NONNULL1 DISPATCH_NONNULL4 DISPATCH_NONNULL6
+DISPATCH_NOTHROW
+void
+dispatch_io_read_f(dispatch_io_t channel,
+ off_t offset,
+ size_t length,
+ dispatch_queue_t queue,
+ void *context,
+ dispatch_io_handler_function_t io_handler);
+
+/*!
+ * @function dispatch_io_write_f
+ * Schedule a write operation for asynchronous execution on the specified I/O
+ * channel. The I/O handler is enqueued one or more times depending on the
+ * general load of the system and the policy specified on the I/O channel.
+ *
+ * Any data remaining to be written to the I/O channel is described by the
+ * dispatch data object passed to the I/O handler. This object will be
+ * automatically released by the system when the I/O handler returns. It is the
+ * responsibility of the application to retain, concatenate or copy the data
+ * object if it is needed after the I/O handler returns.
+ *
+ * Dispatch I/O handlers are not reentrant. The system will ensure that no new
+ * I/O handler instance is invoked until the previously enqueued handler
+ * function has returned.
+ *
+ * An invocation of the I/O handler with the done flag set indicates that the
+ * write operation is complete and that the handler will not be enqueued again.
+ *
+ * If an unrecoverable error occurs on the I/O channel's underlying file
+ * descriptor, the I/O handler will be enqueued with the done flag set, the
+ * appropriate error code and an object containing the data that could not be
+ * written.
+ *
+ * An invocation of the I/O handler with the done flag set and an error code of
+ * zero indicates that the data was fully written to the channel.
+ *
+ * @param channel The dispatch I/O channel on which to write the data.
+ * @param offset The offset relative to the channel position from which
+ * to start writing (only for DISPATCH_IO_RANDOM).
+ * @param data The data to write to the I/O channel. The data object
+ * will be retained by the system until the write operation
+ * is complete.
+ * @param queue The dispatch queue to which the I/O handler should be
+ * submitted.
+ * @param context The application-defined context parameter to pass to
+ * the handler function.
+ * @param io_handler The I/O handler to enqueue when data has been delivered.
+ * @param context Application-defined context parameter.
+ * @param done A flag indicating whether the operation is complete.
+ * @param data An object of the data remaining to be
+ * written to the I/O channel as part of this write
+ * operation, or NULL.
+ * @param error An errno condition for the write operation or zero
+ * if the write was successful.
+ */
+__OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_7_0)
+DISPATCH_EXPORT DISPATCH_NONNULL1 DISPATCH_NONNULL3 DISPATCH_NONNULL4
+DISPATCH_NONNULL6 DISPATCH_NOTHROW
+void
+dispatch_io_write_f(dispatch_io_t channel,
+ off_t offset,
+ dispatch_data_t data,
+ dispatch_queue_t queue,
+ void *context,
+ dispatch_io_handler_function_t io_handler);
+
+/*!
+ * @function dispatch_io_barrier_f
+ * Schedule a barrier operation on the specified I/O channel; all previously
+ * scheduled operations on the channel will complete before the provided
+ * barrier function is enqueued onto the global queue determined by the
+ * channel's target queue, and no subsequently scheduled operations will start
+ * until the barrier function has returned.
+ *
+ * If multiple channels are associated with the same file descriptor, a barrier
+ * operation scheduled on any of these channels will act as a barrier across all
+ * channels in question, i.e. all previously scheduled operations on any of the
+ * channels will complete before the barrier function is enqueued, and no
+ * operations subsequently scheduled on any of the channels will start until the
+ * barrier function has returned.
+ *
+ * While the barrier function is running, it may safely operate on the channel's
+ * underlying file descriptor with fsync(2), lseek(2) etc. (but not close(2)).
+ *
+ * @param channel The dispatch I/O channel to schedule the barrier on.
+ * @param context The application-defined context parameter to pass to
+ * the barrier function.
+ * @param barrier The barrier function.
+ */
+__OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_7_0)
+DISPATCH_EXPORT DISPATCH_NONNULL1 DISPATCH_NONNULL3 DISPATCH_NOTHROW
+void
+dispatch_io_barrier_f(dispatch_io_t channel,
+ void *context,
+ dispatch_function_t barrier);
+
+__END_DECLS
+
+#endif /* __DISPATCH_IO_PRIVATE__ */
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