mbed-os/rtos/EventFlags.h

/* mbed Microcontroller Library
 * Copyright (c) 2006-2019 ARM Limited
 * SPDX-License-Identifier: MIT
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#ifndef EVENT_FLAG_H
#define EVENT_FLAG_H

#include <cstddef>
#include <stdint.h>
#include "rtos/mbed_rtos_types.h"
#include "rtos/mbed_rtos1_types.h"
#include "rtos/mbed_rtos_storage.h"

#include "platform/NonCopyable.h"

namespace rtos {
/** \addtogroup rtos-public-api */
/** @{*/

/**
 * \defgroup rtos_EventFlags EventFlags class
 * @{
 */

/** The EventFlags class is used to control event flags or wait for event flags other threads control.

 @note
 EventFlags support 31 flags. The MSB flag is ignored. It is used to return an error code (@a osFlagsError).

 @note
 Memory considerations: The EventFlags control structures will be created on the current thread's stack, both for the Mbed OS
 and underlying RTOS objects (static or dynamic RTOS memory pools are not being used).
*/
class EventFlags : private mbed::NonCopyable<EventFlags> {
public:
    /** Create and initialize an EventFlags object.
     *
     * @note You cannot call this function from ISR context.
    */
    EventFlags();

    /** Create and initialize an EventFlags object.

     @param name name to be used for this EventFlags. It has to stay allocated for the lifetime of the thread.

     @note You cannot call this function from ISR context.
    */
    EventFlags(const char *name);

    /** Set the specified event flags.
      @param   flags the flags that will be set.
      @return  event flags after setting or error code if highest bit set (see @a osFlagsError for details).

      @note This function may be called from ISR context.
     */
    uint32_t set(uint32_t flags);

    /** Clear the specified event flags.
      @param   flags the flags that will be cleared (default: 0x7fffffff -- all flags).
      @return  event flags before clearing or error code if highest bit set (see @a osFlagsError for details).

      @note You may call this function from ISR context.
     */
    uint32_t clear(uint32_t flags = 0x7fffffff);

    /** Get the currently set event flags.
      @return  current event flags.

      @note You may call this function from ISR context.
     */
    uint32_t get() const;

    /** Wait for all of the specified event flags to become signaled.
      @param   flags    the flags to wait for (default: 0 -- no flags).
      @param   millisec timeout value (default: osWaitForever).
      @param   clear    clear specified event flags after waiting for them (default: true).
      @return  event flags before clearing or error code if highest bit set (see @a osFlagsError for details).

      @note You may call this function from ISR context if the millisec parameter is set to 0.
     */
    uint32_t wait_all(uint32_t flags = 0, uint32_t millisec = osWaitForever, bool clear = true);

    /** Wait for any of the specified event flags to become signaled.
      @param   flags    the flags to wait for (default: 0 -- no flags).
      @param   millisec timeout value (default: osWaitForever).
      @param   clear    clear specified event flags after waiting for them (default: true).
      @return  event flags before clearing or error code if highest bit set (see @a osFlagsError for details).

      @note This function may be called from ISR context if the millisec parameter is set to 0.
     */
    uint32_t wait_any(uint32_t flags = 0, uint32_t millisec = osWaitForever, bool clear = true);

    /** EventFlags destructor.

      @note You cannot call this function from ISR context.
    */
    ~EventFlags();

private:
    void constructor(const char *name = nullptr);
    uint32_t wait(uint32_t flags, uint32_t opt, uint32_t millisec, bool clear);
#if MBED_CONF_RTOS_PRESENT
    osEventFlagsId_t                _id;
    mbed_rtos_storage_event_flags_t _obj_mem;
#else
    uint32_t _flags;
#endif
};

/** @}*/
/** @}*/

}
#endif