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/*
* Copyright (c) 2017-2019 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@
*/
#ifndef __DISPATCH_WORKLOOP__
#define __DISPATCH_WORKLOOP__
#ifndef __DISPATCH_INDIRECT__
#error "Please #include <dispatch/dispatch.h> instead of this file directly."
#include <dispatch/base.h> // for HeaderDoc
#endif
DISPATCH_ASSUME_NONNULL_BEGIN
DISPATCH_ASSUME_ABI_SINGLE_BEGIN
__BEGIN_DECLS
/*!
* @typedef dispatch_workloop_t
*
* @abstract
* Dispatch workloops invoke workitems submitted to them in priority order.
*
* @discussion
* A dispatch workloop is a flavor of dispatch_queue_t that is a priority
* ordered queue (using the QOS class of the submitted workitems as the
* ordering). Dispatch workloops are an exclusion context and it is guaranteed
* that only one work item submitted to the dispatch workloop will be invoked at
* a time.
*
* Between each workitem invocation, the workloop will evaluate whether higher
* priority workitems have since been submitted, either directly to the
* workloop or to any queues that target the workloop, and execute these first.
*
* Serial queues targeting a workloop maintain FIFO execution of their
* workitems. However, the workloop may reorder workitems submitted to
* independent serial queues targeting it with respect to each other,
* based on their priorities, while preserving FIFO execution with respect to
* each serial queue.
*
* A dispatch workloop is a "subclass" of dispatch_queue_t which can be passed
* to all APIs accepting a dispatch queue, except for functions from the
* dispatch_sync() family. dispatch_async_and_wait() must be used for workloop
* objects. Functions from the dispatch_sync() family on queues targeting
* a workloop are still permitted but discouraged for performance reasons.
*/
API_AVAILABLE(macos(10.14), ios(12.0), tvos(12.0), watchos(5.0))
DISPATCH_DECL_SERIAL_EXECUTOR_SWIFT(dispatch_workloop, DispatchWorkloop);
/*!
* @function dispatch_workloop_create
*
* @abstract
* Creates a new dispatch workloop to which workitems may be submitted.
*
* @param label
* A string label to attach to the workloop.
*
* @result
* The newly created dispatch workloop.
*/
API_AVAILABLE(macos(10.14), ios(12.0), tvos(12.0), watchos(5.0))
DISPATCH_EXPORT DISPATCH_MALLOC DISPATCH_RETURNS_RETAINED DISPATCH_WARN_RESULT
DISPATCH_NOTHROW
DISPATCH_REFINED_FOR_SWIFT
dispatch_workloop_t
dispatch_workloop_create(const char *DISPATCH_UNSAFE_INDEXABLE _Nullable label);
/*!
* @function dispatch_workloop_create_inactive
*
* @abstract
* Creates a new inactive dispatch workloop that can be setup and then
* activated.
*
* @discussion
* Creating an inactive workloop allows for it to receive further configuration
* before it is activated, and workitems can be submitted to it.
*
* Submitting workitems to an inactive workloop is undefined and will cause the
* process to be terminated.
*
* @param label
* A string label to attach to the workloop.
*
* @result
* The newly created dispatch workloop.
*/
API_AVAILABLE(macos(10.14), ios(12.0), tvos(12.0), watchos(5.0))
DISPATCH_EXPORT DISPATCH_MALLOC DISPATCH_RETURNS_RETAINED DISPATCH_WARN_RESULT
DISPATCH_NOTHROW
DISPATCH_REFINED_FOR_SWIFT DISPATCH_SWIFT_NAME(DispatchWorkloop.init(__label:))
dispatch_workloop_t
dispatch_workloop_create_inactive(const char *DISPATCH_UNSAFE_INDEXABLE _Nullable label);
/*!
* @function dispatch_workloop_set_autorelease_frequency
*
* @abstract
* Sets the autorelease frequency of the workloop.
*
* @discussion
* See dispatch_queue_attr_make_with_autorelease_frequency().
* The default policy for a workloop is
* DISPATCH_AUTORELEASE_FREQUENCY_WORK_ITEM.
*
* @param workloop
* The dispatch workloop to modify.
*
* This workloop must be inactive, passing an activated object is undefined
* and will cause the process to be terminated.
*
* @param frequency
* The requested autorelease frequency.
*/
API_AVAILABLE(macos(10.14), ios(12.0), tvos(12.0), watchos(5.0))
DISPATCH_EXPORT DISPATCH_NONNULL_ALL DISPATCH_NOTHROW
DISPATCH_REFINED_FOR_SWIFT
void
dispatch_workloop_set_autorelease_frequency(dispatch_workloop_t workloop,
dispatch_autorelease_frequency_t frequency);
/*!
* @function dispatch_workloop_set_os_workgroup
*
* @abstract
* Associates an os_workgroup_t with the specified dispatch workloop.
*
* The worker thread will be a member of the specified os_workgroup_t while executing
* work items submitted to the workloop.
*
* Using both dispatch_workloop_set_scheduler_priority() and
* dispatch_workloop_set_os_workgroup() will prefer scheduling policies
* from the workgroup, if they exist.
*
* @param workloop
* The dispatch workloop to modify.
*
* This workloop must be inactive, passing an activated object is undefined
* and will cause the process to be terminated.
*
* @param workgroup
* The workgroup to associate with this workloop.
*
* The workgroup specified is retained and the previously associated workgroup
* (if any) is released.
*/
API_AVAILABLE(macos(11.0), ios(14.0), tvos(14.0), watchos(7.0))
DISPATCH_EXPORT DISPATCH_NONNULL_ALL DISPATCH_NOTHROW
DISPATCH_REFINED_FOR_SWIFT
void
dispatch_workloop_set_os_workgroup(dispatch_workloop_t workloop,
os_workgroup_t workgroup);
__END_DECLS
DISPATCH_ASSUME_ABI_SINGLE_END
DISPATCH_ASSUME_NONNULL_END
#endif
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