/* * Copyright (c) 2008-2013 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_QUEUE_PRIVATE__ #define __DISPATCH_QUEUE_PRIVATE__ #ifndef __DISPATCH_INDIRECT__ #error "Please #include <dispatch/private.h> instead of this file directly." #include <dispatch/base.h> // for HeaderDoc #endif DISPATCH_ASSUME_NONNULL_BEGIN __BEGIN_DECLS /*! * @enum dispatch_queue_flags_t * * @constant DISPATCH_QUEUE_OVERCOMMIT * The queue will create a new thread for invoking blocks, regardless of how * busy the computer is. */ enum { DISPATCH_QUEUE_OVERCOMMIT = 0x2ull, }; #define DISPATCH_QUEUE_FLAGS_MASK (DISPATCH_QUEUE_OVERCOMMIT) /*! * @function dispatch_queue_attr_make_with_overcommit * * @discussion * Returns a dispatch queue attribute value with the overcommit flag set to the * specified value. * * This attribute only makes sense when the specified queue is targeted at * a root queue. Passing this attribute to dispatch_queue_create_with_target() * with a target queue that is not a root queue will result in an assertion and * the process being terminated. * * It is recommended to not specify a target queue at all when using this * attribute and to use dispatch_queue_attr_make_with_qos_class() to select the * appropriate QoS class instead. * * Queues created with this attribute cannot change target after having been * activated. See dispatch_set_target_queue() and dispatch_activate(). * * @param attr * A queue attribute value to be combined with the overcommit flag, or NULL. * * @param overcommit * Boolean overcommit flag. * * @return * Returns an attribute value which may be provided to dispatch_queue_create(). * This new value combines the attributes specified by the 'attr' parameter and * the overcommit flag. */ API_AVAILABLE(macos(10.10), ios(8.0)) DISPATCH_EXPORT DISPATCH_WARN_RESULT DISPATCH_PURE DISPATCH_NOTHROW dispatch_queue_attr_t dispatch_queue_attr_make_with_overcommit(dispatch_queue_attr_t _Nullable attr, bool overcommit); /*! * @typedef dispatch_queue_priority_t * * @constant DISPATCH_QUEUE_PRIORITY_NON_INTERACTIVE * Items dispatched to the queue will run at non-interactive priority. * This priority level is intended for user-initiated application activity that * is long-running and CPU or IO intensive and that the user is actively waiting * on, but that should not interfere with interactive use of the application. * * This global queue priority level is mapped to QOS_CLASS_UTILITY. */ #define DISPATCH_QUEUE_PRIORITY_NON_INTERACTIVE INT8_MIN /*! * @function dispatch_queue_set_label_nocopy * * @abstract * Set the label for a given queue, without copying the input string. * * @discussion * The queue must have been initially created with a NULL label, else using * this function to set the queue label is undefined. * * The caller of this function must make sure the label pointer remains valid * while it is used as the queue label and while any callers to * dispatch_queue_get_label() may have obtained it. Since the queue lifetime * may extend past the last release, it is advised to call this function with * a constant string or NULL before the queue is released, or to destroy the * label from a finalizer for that queue. * * This function should be called before any work item could call * dispatch_queue_get_label(DISPATCH_CURRENT_QUEUE_LABEL) or from the context of * the queue itself. * * @param queue * The queue to adjust. Attempts to set the label of the main queue or a global * concurrent queue will be ignored. * * @param label * The new label for the queue. */ API_AVAILABLE(macos(10.12), ios(10.0), tvos(10.0), watchos(3.0)) DISPATCH_EXPORT DISPATCH_NONNULL1 DISPATCH_NOTHROW void dispatch_queue_set_label_nocopy(dispatch_queue_t queue, const char *label); /*! * @function dispatch_queue_set_width * * @abstract * Set the width of concurrency for a given queue. The width of a serial queue * is one. * * @discussion * This SPI is DEPRECATED and will be removed in a future release. * Uses of this SPI to make a queue concurrent by setting its width to LONG_MAX * should be replaced by passing DISPATCH_QUEUE_CONCURRENT to * dispatch_queue_create(). * Uses of this SPI to limit queue concurrency are not recommended and should * be replaced by alternative mechanisms such as a dispatch semaphore created * with the desired concurrency width. * * @param queue * The queue to adjust. Attempts to set the width of the main queue or a global * concurrent queue will be ignored. * * @param width * The new maximum width of concurrency depending on available resources. * If zero is passed, then the value is promoted to one. * Negative values are magic values that map to automatic width values. * Unknown negative values default to DISPATCH_QUEUE_WIDTH_MAX_LOGICAL_CPUS. */ #define DISPATCH_QUEUE_WIDTH_ACTIVE_CPUS -1 #define DISPATCH_QUEUE_WIDTH_MAX_PHYSICAL_CPUS -2 #define DISPATCH_QUEUE_WIDTH_MAX_LOGICAL_CPUS -3 API_DEPRECATED("Use dispatch_queue_create(name, DISPATCH_QUEUE_CONCURRENT)", macos(10.6,10.10), ios(4.0,8.0)) DISPATCH_EXPORT DISPATCH_NONNULL_ALL DISPATCH_NOTHROW void dispatch_queue_set_width(dispatch_queue_t dq, long width); #ifdef __BLOCKS__ /*! * @function dispatch_pthread_root_queue_create * * @abstract * Creates a new concurrent dispatch root queue with a pthread-based pool of * worker threads owned by the application. * * @discussion * Dispatch pthread root queues are similar to the global concurrent dispatch * queues in that they invoke blocks concurrently, however the blocks are not * executed on ordinary worker threads but use a dedicated pool of pthreads not * shared with the global queues or any other pthread root queues. * * NOTE: this is a special-purpose facility that should only be used in very * limited circumstances, in almost all cases the global concurrent queues * should be preferred. While this facility allows for more flexibility in * configuring worker threads for special needs it comes at the cost of * increased overall memory usage due to reduced thread sharing and higher * latency in worker thread bringup. * * Dispatch pthread root queues do not support suspension, application context * and change of width or of target queue. They can however be used as the * target queue for serial or concurrent queues obtained via * dispatch_queue_create() or dispatch_queue_create_with_target(), which * enables the blocks submitted to those queues to be processed on the root * queue's pthread pool. * * When a dispatch pthread root queue is no longer needed, it should be * released with dispatch_release(). Existing worker pthreads and pending blocks * submitted to the root queue will hold a reference to the queue so it will not * be deallocated until all blocks have finished and worker threads exited. * * @param label * A string label to attach to the queue. * This parameter is optional and may be NULL. * * @param flags * Pass flags value returned by dispatch_pthread_root_queue_flags_pool_size() * or 0 if unused. * * @param attr * Attributes passed to pthread_create(3) when creating worker pthreads. This * parameter is copied and can be destroyed after this call returns. * This parameter is optional and may be NULL. * * @param configure * Configuration block called on newly created worker pthreads before any blocks * for the root queue are executed. The block may configure the current thread * as needed. * This parameter is optional and may be NULL. * * @result * The newly created dispatch pthread root queue. */ API_AVAILABLE(macos(10.9), ios(6.0)) DISPATCH_EXPORT DISPATCH_MALLOC DISPATCH_RETURNS_RETAINED DISPATCH_WARN_RESULT DISPATCH_NOTHROW dispatch_queue_t dispatch_pthread_root_queue_create(const char *_Nullable label, unsigned long flags, const pthread_attr_t *_Nullable attr, dispatch_block_t _Nullable configure); /*! * @function dispatch_pthread_root_queue_flags_pool_size * * @abstract * Returns flags argument to pass to dispatch_pthread_root_queue_create() to * specify the maximum size of the pthread pool to use for a pthread root queue. * * @param pool_size * Maximum size of the pthread pool to use for the root queue. The number of * pthreads created for this root queue will never exceed this number but there * is no guarantee that the specified number will be reached. * Pass 0 to specify that a default pool size determined by the system should * be used. * NOTE: passing pool_size == 1 does NOT make the pthread root queue equivalent * to a serial queue. * * @result * The flags argument to pass to dispatch_pthread_root_queue_create(). */ DISPATCH_INLINE DISPATCH_ALWAYS_INLINE unsigned long dispatch_pthread_root_queue_flags_pool_size(uint8_t pool_size) { #define _DISPATCH_PTHREAD_ROOT_QUEUE_FLAG_POOL_SIZE (0x80000000ul) return (_DISPATCH_PTHREAD_ROOT_QUEUE_FLAG_POOL_SIZE | (unsigned long)pool_size); } #endif /* __BLOCKS__ */ /*! * @function dispatch_pthread_root_queue_copy_current * * @abstract * Returns a reference to the pthread root queue object that has created the * currently executing thread, or NULL if the current thread is not associated * to a pthread root queue. * * @result * A new reference to a pthread root queue object or NULL. */ API_AVAILABLE(macos(10.12), ios(10.0), tvos(10.0), watchos(3.0)) DISPATCH_EXPORT DISPATCH_RETURNS_RETAINED DISPATCH_WARN_RESULT DISPATCH_NOTHROW dispatch_queue_t _Nullable dispatch_pthread_root_queue_copy_current(void); /*! * @constant DISPATCH_APPLY_CURRENT_ROOT_QUEUE * * @discussion * This constant is deprecated, please use DISPATCH_APPLY_AUTO. * * DISPATCH_APPLY_AUTO also selects the current pthread root queue if * applicable. */ #define DISPATCH_APPLY_CURRENT_ROOT_QUEUE ((dispatch_queue_t _Nonnull)0) /*! * @function dispatch_async_enforce_qos_class_f * * @abstract * Submits a function for asynchronous execution on a dispatch queue. * * @discussion * See dispatch_async() for details. The QOS will be enforced as if * this was called: * <code> * dispatch_async(queue, dispatch_block_create(DISPATCH_BLOCK_ENFORCE_QOS_CLASS, ^{ * work(context); * }); * </code> * * @param queue * The target dispatch queue to which the function is submitted. * The system will hold a reference on the target queue until the function * has returned. * The result of passing NULL in this parameter is undefined. * * @param context * The application-defined context parameter to pass to the function. * * @param work * The application-defined function to invoke on the target queue. The first * parameter passed to this function is the context provided to * dispatch_async_f(). * The result of passing NULL in this parameter is undefined. */ API_AVAILABLE(macos(10.11), ios(9.0)) DISPATCH_EXPORT DISPATCH_NONNULL1 DISPATCH_NONNULL3 DISPATCH_NOTHROW void dispatch_async_enforce_qos_class_f(dispatch_queue_t queue, void *_Nullable context, dispatch_function_t work); #ifdef __ANDROID__ /*! * @function _dispatch_install_thread_detach_callback * * @param callback * Function to be called before each worker thread exits to detach JVM. * * Hook to be able to detach threads from the Java JVM before they exit. * If JNI has been used on a thread on Android it needs to have been * "detached" before the thread exits or the application will crash. */ DISPATCH_EXPORT void _dispatch_install_thread_detach_callback(dispatch_function_t cb); #endif __END_DECLS DISPATCH_ASSUME_NONNULL_END #endif