Nicolas Borla / Mbed OS BBR_1Ebene

BBR 1 Ebene

mbed-os/events/mbed_shared_queues.h@0:fbdae7e6d805, 2018-05-14 (annotated)

Committer:
borlanic
Date:
Mon May 14 11:29:06 2018 +0000
Revision:
0:fbdae7e6d805
BBR

Who changed what in which revision?

UserRevisionLine numberNew contents of line
borlanic 0:fbdae7e6d805 1
borlanic 0:fbdae7e6d805 2 /** \addtogroup events */
borlanic 0:fbdae7e6d805 3 /** @{*/
borlanic 0:fbdae7e6d805 4 /* events
borlanic 0:fbdae7e6d805 5 * Copyright (c) 2017 ARM Limited
borlanic 0:fbdae7e6d805 6 *
borlanic 0:fbdae7e6d805 7 * Licensed under the Apache License, Version 2.0 (the "License");
borlanic 0:fbdae7e6d805 8 * you may not use this file except in compliance with the License.
borlanic 0:fbdae7e6d805 9 * You may obtain a copy of the License at
borlanic 0:fbdae7e6d805 10 *
borlanic 0:fbdae7e6d805 11 * http://www.apache.org/licenses/LICENSE-2.0
borlanic 0:fbdae7e6d805 12 *
borlanic 0:fbdae7e6d805 13 * Unless required by applicable law or agreed to in writing, software
borlanic 0:fbdae7e6d805 14 * distributed under the License is distributed on an "AS IS" BASIS,
borlanic 0:fbdae7e6d805 15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
borlanic 0:fbdae7e6d805 16 * See the License for the specific language governing permissions and
borlanic 0:fbdae7e6d805 17 * limitations under the License.
borlanic 0:fbdae7e6d805 18 */
borlanic 0:fbdae7e6d805 19 #ifndef MBED_SHARED_QUEUES_H
borlanic 0:fbdae7e6d805 20 #define MBED_SHARED_QUEUES_H
borlanic 0:fbdae7e6d805 21
borlanic 0:fbdae7e6d805 22 #include "events/EventQueue.h"
borlanic 0:fbdae7e6d805 23
borlanic 0:fbdae7e6d805 24 namespace mbed {
borlanic 0:fbdae7e6d805 25
borlanic 0:fbdae7e6d805 26 /**
borlanic 0:fbdae7e6d805 27 * Return a pointer to an EventQueue, on which normal tasks can be queued.
borlanic 0:fbdae7e6d805 28 *
borlanic 0:fbdae7e6d805 29 * All calls to this return the same EventQueue - it and its dispatch thread
borlanic 0:fbdae7e6d805 30 * are created on the first call to this function. The dispatch thread
borlanic 0:fbdae7e6d805 31 * runs at default priority (currently osPriorityNormal).
borlanic 0:fbdae7e6d805 32 *
borlanic 0:fbdae7e6d805 33 * The EventQueue returned may be used to call() Events, or to chain() other
borlanic 0:fbdae7e6d805 34 * EventQueues so that they are run in the same context.
borlanic 0:fbdae7e6d805 35 *
borlanic 0:fbdae7e6d805 36 * Events (or chained EventQueues) executing on the normal event queue should
borlanic 0:fbdae7e6d805 37 * normally take less than 10ms to execute, to avoid starving other users. As
borlanic 0:fbdae7e6d805 38 * such, users can expect that event latency will typically be 10ms or less,
borlanic 0:fbdae7e6d805 39 * but could occasionally be significantly higher if many events are queued.
borlanic 0:fbdae7e6d805 40 *
borlanic 0:fbdae7e6d805 41 * If an RTOS is not present or the configuration option
borlanic 0:fbdae7e6d805 42 * `events.shared-dispatch-from-application` is set to true, then this
borlanic 0:fbdae7e6d805 43 * does not create a dedicated dispatch thread - instead the application is
borlanic 0:fbdae7e6d805 44 * expected to run the EventQueue's dispatch, eg from main. This is necessary
borlanic 0:fbdae7e6d805 45 * for the event loop to work without an RTOS, or an RTOS system can can save
borlanic 0:fbdae7e6d805 46 * memory by reusing the main stack.
borlanic 0:fbdae7e6d805 47 *
borlanic 0:fbdae7e6d805 48 * @note
borlanic 0:fbdae7e6d805 49 * mbed_event_queue is not itself IRQ safe. To use the mbed_event_queue in
borlanic 0:fbdae7e6d805 50 * interrupt context, you must first call `mbed_event_queue()` in threaded
borlanic 0:fbdae7e6d805 51 * context and store the pointer for later use.
borlanic 0:fbdae7e6d805 52 *
borlanic 0:fbdae7e6d805 53 * @return pointer to event queue
borlanic 0:fbdae7e6d805 54 */
borlanic 0:fbdae7e6d805 55 events::EventQueue *mbed_event_queue();
borlanic 0:fbdae7e6d805 56
borlanic 0:fbdae7e6d805 57 #ifdef MBED_CONF_RTOS_PRESENT
borlanic 0:fbdae7e6d805 58 /**
borlanic 0:fbdae7e6d805 59 * Return a pointer to an EventQueue, on which small high-priority tasks can
borlanic 0:fbdae7e6d805 60 * be queues, such as simple deferrals from interrupt.
borlanic 0:fbdae7e6d805 61 *
borlanic 0:fbdae7e6d805 62 * All calls to this return the same EventQueue - it and its thread are
borlanic 0:fbdae7e6d805 63 * created on the first call to this function. The dispatch thread
borlanic 0:fbdae7e6d805 64 * runs at a high priority (currently osPriorityHigh).
borlanic 0:fbdae7e6d805 65 *
borlanic 0:fbdae7e6d805 66 * The EventQueue returned may be used to call() Events, or to chain() other
borlanic 0:fbdae7e6d805 67 * EventQueues so that they are run in the same context.
borlanic 0:fbdae7e6d805 68 *
borlanic 0:fbdae7e6d805 69 * Events (or chained EventQueues) executing on the high-priority event queue
borlanic 0:fbdae7e6d805 70 * should normally take less than 100us to execute, to avoid starving other
borlanic 0:fbdae7e6d805 71 * users. As such, users can expect that event latency will typically be 100us
borlanic 0:fbdae7e6d805 72 * or less, but could occasionally be significantly higher if many events are
borlanic 0:fbdae7e6d805 73 * queued.
borlanic 0:fbdae7e6d805 74 *
borlanic 0:fbdae7e6d805 75 * @note
borlanic 0:fbdae7e6d805 76 * mbed_highprio_event_queue is not itself IRQ safe. To use the
borlanic 0:fbdae7e6d805 77 * mbed_highprio_event_queue in interrupt context, you must first call
borlanic 0:fbdae7e6d805 78 * `mbed_event_queue()` in threaded context and store the pointer for
borlanic 0:fbdae7e6d805 79 * later use.
borlanic 0:fbdae7e6d805 80 *
borlanic 0:fbdae7e6d805 81 * @return pointer to high-priority event queue
borlanic 0:fbdae7e6d805 82 */
borlanic 0:fbdae7e6d805 83
borlanic 0:fbdae7e6d805 84 events::EventQueue *mbed_highprio_event_queue();
borlanic 0:fbdae7e6d805 85
borlanic 0:fbdae7e6d805 86 #endif // MBED_CONF_RTOS_PRESENT
borlanic 0:fbdae7e6d805 87
borlanic 0:fbdae7e6d805 88 };
borlanic 0:fbdae7e6d805 89
borlanic 0:fbdae7e6d805 90 #endif
borlanic 0:fbdae7e6d805 91
borlanic 0:fbdae7e6d805 92 /** @}*/