anchao commented on code in PR #12802: URL: https://github.com/apache/nuttx/pull/12802#discussion_r1701375276
########## Documentation/reference/os/events.rst: ########## @@ -0,0 +1,113 @@ +============== +Events +============== + +Events groups are synchronization primitives that allow tasks to wait +for multiple conditions to be met before proceeding. They are particularly +useful in scenarios where a task needs to wait for several events to occur +simultaneously. +This concept can be particularly powerful in real-time operating systems (RTOS). + +Overview +========================= + +An event group consists of a set of binary flags, each representing a +specific event. Tasks can set, clear, and wait on these flags. When a +task waits on an event group, it can specify which flags it is interested +in and whether it wants to wait for all specified flags to be set or just +any one of them. + +Configuration Options +===================== + +``CONFIG_SCHED_EVENTS`` + This option enables event objects. Threads may wait on event + objects for specific events, but both threads and ISRs may deliver + events to event objects. + +Common Events Interfaces +================================ + +Events Types +-------------------- + +- ``nxevent_t``. Defines one event group entry. +- ``nxevent_mask_t``. Defines one events mask value. + +Notifier Chain Interfaces +------------------------- + +.. c:function:: int nxevent_init(FAR nxevent_t *event, nxevent_mask_t events) + + Initializes an event object, Set of default events to post + to event. + + :param event: Address of the event object + :param events: Set of events to event + +.. c:function:: int nxevent_destroy(FAR nxevent_t *event) + + This function is used to destroy the event. + + :param event: Address of the event object + +.. c:function:: int nxevent_reset(FAR nxevent_t *event, nxevent_mask_t events) + + Reset events mask to a specific value. + + :param event: Address of the event object + :param events: Set of events to event + +.. c:function:: int nxevent_post(FAR nxevent_t *event, nxevent_mask_t events) + + Post one or more events to an event object. + + This routine posts one or more events to an event object. All tasks + waiting on the event object event whose waiting conditions become + met by this posting immediately unpend. + + Posting differs from setting in that posted events are merged together + with the current set of events tracked by the event object. + + :param event: Address of the event object + :param events: Set of events to post to event + If set events to 0, the waiting event will be ignored + and wake up waiting thread immediately + +.. c:function:: nxevent_mask_t nxevent_wait(FAR nxevent_t *event, nxevent_mask_t events) + + Wait for all of the specified events. + + This routine waits on event object event until any of the specified + events have been delivered to the event object. A thread may wait on + up to 32 distinctly numbered events that are expressed as bits in a + single 32-bit word. + + :param event: Address of the event object + :param events: Set of events to wait, 0 will indicate wait from any events + +.. c:function:: nxevent_mask_t nxevent_tickwait(FAR nxevent_t *event, nxevent_mask_t events, uint32_t delay) + + Wait for all of the specified events from the specified tick time. Review Comment: Done ########## include/nuttx/event.h: ########## @@ -0,0 +1,252 @@ +/**************************************************************************** + * include/nuttx/event.h + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. The + * ASF licenses this file to you 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. + * + ****************************************************************************/ + +#ifndef __INCLUDE_NUTTX_EVENT_H +#define __INCLUDE_NUTTX_EVENT_H + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <errno.h> +#include <stdint.h> +#include <semaphore.h> + +#include <nuttx/irq.h> +#include <nuttx/semaphore.h> +#include <nuttx/clock.h> + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/* Initializers */ + +#define NXEVENT_INITIALIZER(e) {SEM_INITIALIZER(0), e} + +/**************************************************************************** + * Public Type Definitions + ****************************************************************************/ + +typedef struct nxevent_s nxevent_t; +typedef uint32_t nxevent_mask_t; Review Comment: Done -- This is an automated message from the Apache Git Service. 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