kernel_liteos_a/kernel/include/los_event.h

/*
 * Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved.
 * Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this list of
 *    conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list
 *    of conditions and the following disclaimer in the documentation and/or other materials
 *    provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors may be used
 *    to endorse or promote products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @defgroup los_event Event
 * @ingroup kernel
 */

#ifndef _LOS_EVENT_H
#define _LOS_EVENT_H

#include "los_base.h"
#include "los_list.h"

#ifdef __cplusplus
#if __cplusplus
extern "C" {
#endif /* __cplusplus */
#endif /* __cplusplus */

/**
 * @ingroup los_event
 * Event reading mode: The task waits for all its expected events to occur.
 */
#define LOS_WAITMODE_AND                    4U

/**
 * @ingroup los_event
 * Event reading mode: The task waits for any of its expected events to occur.
 */
#define LOS_WAITMODE_OR                     2U

/**
 * @ingroup los_event
 * Event reading mode: The event flag is immediately cleared after the event is read.
 */
#define LOS_WAITMODE_CLR                    1U

/**
 * @ingroup los_event
 * Bit 25 of the event mask cannot be set to an event because it is set to an error code.
 *
 * Value: 0x02001c00
 *
 * Solution: Set bits excluding bit 25 of the event mask to events.
 */
#define LOS_ERRNO_EVENT_SETBIT_INVALID      LOS_ERRNO_OS_ERROR(LOS_MOD_EVENT, 0x00)

/**
 * @ingroup los_event
 * Event reading error code: Event reading times out.
 *
 * Value: 0x02001c01
 *
 * Solution: Increase the waiting time for event reading, or make another task write a mask for the event.
 */
#define LOS_ERRNO_EVENT_READ_TIMEOUT        LOS_ERRNO_OS_ERROR(LOS_MOD_EVENT, 0x01)

/**
 * @ingroup los_event
 * Event reading error code: The EVENTMASK input parameter value is valid. The input parameter value must not be 0.
 *
 * Value: 0x02001c02
 *
 * Solution: Pass in a valid EVENTMASK value.
 */
#define LOS_ERRNO_EVENT_EVENTMASK_INVALID   LOS_ERRNO_OS_ERROR(LOS_MOD_EVENT, 0x02)

/**
 * @ingroup los_event
 * Event reading error code: The event is being read during an interrupt.
 *
 * Value: 0x02001c03
 *
 * Solution: Read the event in a task.
 */
#define LOS_ERRNO_EVENT_READ_IN_INTERRUPT   LOS_ERRNO_OS_ERROR(LOS_MOD_EVENT, 0x03)

/**
 * @ingroup los_event
 * Event reading error code: The flag input parameter value used in the event reading API is invalid.
 * This input parameter value is obtained by performing an OR operation on corresponding bits of either OS_EVENT_ANY or
 * OS_EVENT_ANY and corresponding bits of either OS_EVENT_WAIT or OS_EVENT_NOWAIT. The waiting time must be set to
 * a nonzero value when an event is read in the mode of OS_EVENT_WAIT.
 *
 * Value: 0x02001c04
 *
 * Solution: Pass in a valid flag value.
 */
#define LOS_ERRNO_EVENT_FLAGS_INVALID       LOS_ERRNO_OS_ERROR(LOS_MOD_EVENT, 0x04)

/**
 * @ingroup los_event
 * Event reading error code: The task is locked and is unable to read the event.
 *
 * Value: 0x02001c05
 *
 * Solution: Unlock the task and read the event.
 */
#define LOS_ERRNO_EVENT_READ_IN_LOCK        LOS_ERRNO_OS_ERROR(LOS_MOD_EVENT, 0x05)

/**
 * @ingroup los_event
 * Event reading error code: Null pointer.
 *
 * Value: 0x02001c06
 *
 * Solution: Check whether the input parameter is null.
 */
#define LOS_ERRNO_EVENT_PTR_NULL            LOS_ERRNO_OS_ERROR(LOS_MOD_EVENT, 0x06)

/**
 * @ingroup los_event
 * Event reading error code: The event is being read in system-level task.
 *                old usage: The event is being read in software timer task. (LOS_ERRNO_EVENT_READ_IN_SWTMR_TSK)
 * Value: 0x02001c07
 *
 * Solution: Read the event in a vailid task.
 */
#define LOS_ERRNO_EVENT_READ_IN_SYSTEM_TASK LOS_ERRNO_OS_ERROR(LOS_MOD_EVENT, 0x07)

/**
 * @ingroup los_event
 * Event reading error code: should not be distory.
 *
 * Value: 0x02001c08
 *
 * Solution: Check whether the event list is not empty.
 */
#define LOS_ERRNO_EVENT_SHOULD_NOT_DESTORY  LOS_ERRNO_OS_ERROR(LOS_MOD_EVENT, 0x08)

/**
 * @ingroup los_event
 * Event control structure
 */
typedef struct tagEvent {
    UINT32 uwEventID;        /**< Event mask in the event control block,
                                  indicating the event that has been logically processed. */
    LOS_DL_LIST stEventList; /**< Event control block linked list */
} EVENT_CB_S, *PEVENT_CB_S;

/**
 * @ingroup los_event
 * @brief Initialize an event control block.
 *
 * @par Description:
 * This API is used to initialize the event control block pointed to by eventCB.
 * @attention
 * <ul>
 * <li>None.</li>
 * </ul>
 *
 * @param eventCB [IN/OUT] Pointer to the event control block to be initialized.
 *
 * @retval #LOS_ERRNO_EVENT_PTR_NULL  Null pointer.
 * @retval #LOS_OK                    The event control block is successfully initialized.
 * @par Dependency:
 * <ul><li>los_event.h: the header file that contains the API declaration.</li></ul>
 * @see LOS_EventClear
 */
extern UINT32 LOS_EventInit(PEVENT_CB_S eventCB);

/**
 * @ingroup los_event
 * @brief Obtain an event specified by the event ID.
 *
 * @par Description:
 * This API is used to check whether an event expected by the user occurs according to the event ID, event mask,
 * and event reading mode, and process the event based on the event reading mode. The event ID must point to
 * valid memory.
 * @attention
 * <ul>
 * <li>When the mode is LOS_WAITMODE_CLR, the eventID is passed-out.</li>
 * <li>Otherwise the eventID is passed-in.</li>
 * <li>An error code and an event return value can be same. To differentiate the error code and return value, bit 25 of
 * the event mask is forbidden to be used.</li>
 * </ul>
 *
 * @param eventID      [IN/OUT] Pointer to the ID of the event to be checked.
 * @param eventMask    [IN] Mask of the event expected to occur by the user, indicating the event obtained after
 *                          it is logically processed that matches the ID pointed to by eventID.
 * @param mode         [IN] Event reading mode. The modes include LOS_WAITMODE_AND, LOS_WAITMODE_OR, LOS_WAITMODE_CLR.
 *
 * @retval #LOS_ERRNO_EVENT_SETBIT_INVALID     Bit 25 of the event mask cannot be set because it is set to an
 *                                             error number.
 * @retval #LOS_ERRNO_EVENT_EVENTMASK_INVALID  The passed-in event mask is incorrect.
 * @retval #LOS_ERRNO_EVENT_FLAGS_INVALID      The passed-in event mode is invalid.
 * @retval #LOS_ERRNO_EVENT_PTR_NULL           The passed-in pointer is null.
 * @retval 0                                   The event expected by the user does not occur.
 * @retval #UINT32                             The event expected by the user occurs.
 * @par Dependency:
 * <ul><li>los_event.h: the header file that contains the API declaration.</li></ul>
 * @see LOS_EventRead | LOS_EventWrite
 */
extern UINT32 LOS_EventPoll(UINT32 *eventID, UINT32 eventMask, UINT32 mode);

/**
 * @ingroup los_event
 * @brief Read an event.
 *
 * @par Description:
 * This API is used to block or schedule a task that reads an event of which the event control block, event mask,
 * reading mode, and timeout information are specified.
 * </ul>
 * @attention
 * <ul>
 * <li>An error code and an event return value can be same. To differentiate the error code and return value, bit 25 of
 * the event mask is forbidden to be used.</li>
 * </ul>
 *
 * @param eventCB      [IN/OUT] Pointer to the event control block to be checked. This parameter must point
 *                              to valid memory.
 * @param eventMask    [IN] Mask of the event expected to occur by the user, indicating the event obtained after
 *                          it is logically processed that matches the ID pointed to by eventID.
 * @param mode         [IN] Event reading mode.
 * @param timeout      [IN] Timeout interval of event reading (unit: Tick).
 *
 * @retval #LOS_ERRNO_EVENT_SETBIT_INVALID     Bit 25 of the event mask cannot be set because it is set to an
 *                                             error number.
 * @retval #LOS_ERRNO_EVENT_EVENTMASK_INVALID  The passed-in event reading mode is incorrect.
 * @retval #LOS_ERRNO_EVENT_READ_IN_INTERRUPT  The event is being read during an interrupt.
 * @retval #LOS_ERRNO_EVENT_FLAGS_INVALID      The event mode is invalid.
 * @retval #LOS_ERRNO_EVENT_READ_IN_LOCK       The event reading task is locked.
 * @retval #LOS_ERRNO_EVENT_PTR_NULL           The passed-in pointer is null.
 * @retval 0                                   The event expected by the user does not occur.
 * @retval #UINT32                             The event expected by the user occurs.
 * @par Dependency:
 * <ul><li>los_event.h: the header file that contains the API declaration.</li></ul>
 * @see LOS_EventPoll | LOS_EventWrite
 */
extern UINT32 LOS_EventRead(PEVENT_CB_S eventCB, UINT32 eventMask, UINT32 mode, UINT32 timeout);

/**
 * @ingroup los_event
 * @brief Write an event.
 *
 * @par Description:
 * This API is used to write an event specified by the passed-in event mask into an event control block
 * pointed to by eventCB.
 * @attention
 * <ul>
 * <li>To determine whether the LOS_EventRead API returns an event or an error code, bit 25 of the event mask
 * is forbidden to be used.</li>
 * </ul>
 *
 * @param eventCB  [IN/OUT] Pointer to the event control block into which an event is to be written.
 *                          This parameter must point to valid memory.
 * @param events   [IN] Event mask to be written.
 *
 * @retval #LOS_ERRNO_EVENT_SETBIT_INVALID  Bit 25 of the event mask cannot be set to an event
 * because it is set to an error code.
 * @retval #LOS_ERRNO_EVENT_PTR_NULL        Null pointer.
 * @retval #LOS_OK                          The event is successfully written.
 * @par Dependency:
 * <ul><li>los_event.h: the header file that contains the API declaration.</li></ul>
 * @see LOS_EventPoll | LOS_EventRead
 */
extern UINT32 LOS_EventWrite(PEVENT_CB_S eventCB, UINT32 events);

/**
 * @ingroup los_event
 * @brief Clear the event occurring in a specified task.
 *
 * @par Description:
 * <ul>
 * <li>This API is used to set the ID of an event that has a specified mask and of which the information is stored in
 * an event control block pointed to by eventCB to 0. eventCB must point to valid memory.</li>
 * </ul>
 * @attention
 * <ul>
 * <li>The value of events needs to be reversed when it is passed-in.</li>
 * </ul>
 *
 * @param eventCB     [IN/OUT] Pointer to the event control block to be cleared.
 * @param events      [IN] Mask of the event to be cleared.
 *
 * @retval #LOS_ERRNO_EVENT_PTR_NULL  Null pointer.
 * @retval #LOS_OK                    The event is successfully cleared.
 * @par Dependency:
 * <ul><li>los_event.h: the header file that contains the API declaration.</li></ul>
 * @see LOS_EventPoll | LOS_EventRead | LOS_EventWrite
 */
extern UINT32 LOS_EventClear(PEVENT_CB_S eventCB, UINT32 events);

/**
 * @ingroup los_event
 * @brief Destroy a event.
 *
 * @par Description:
 * <ul>
 * <li>This API is used to Destroy a event.</li>
 * </ul>
 * @attention
 * <ul>
 * <li>The specific event should be a valid one.</li>
 * </ul>
 *
 * @param eventCB     [IN/OUT] Pointer to the event control block to be destroyed.
 *
 * @retval #LOS_ERRNO_EVENT_PTR_NULL Null pointer.
 * @retval #LOS_OK                   The event is successfully cleared.
 * @par Dependency:
 * <ul><li>los_event.h: the header file that contains the API declaration.</li></ul>
 * @see LOS_EventPoll | LOS_EventRead | LOS_EventWrite
 */
extern UINT32 LOS_EventDestroy(PEVENT_CB_S eventCB);

#ifdef __cplusplus
#if __cplusplus
}
#endif /* __cplusplus */
#endif /* __cplusplus */

#endif /* _LOS_EVENT_H */