corerwlockimpl.h

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/* SPDX-License-Identifier: BSD-2-Clause */

 
/*
 *  COPYRIGHT (c) 1989-2008.
 *  On-Line Applications Research Corporation (OAR).
 *
 * 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.
 *
 * 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 OWNER 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; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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 */
 
#ifndef _RTEMS_SCORE_CORERWLOCKIMPL_H
#define _RTEMS_SCORE_CORERWLOCKIMPL_H
 
#include <rtems/score/percpu.h>
#include <rtems/score/status.h>
#include <rtems/score/thread.h>
#include <rtems/score/threadqimpl.h>
#include <rtems/score/watchdog.h>

 
#ifdef __cplusplus
extern "C" {
#endif
 
#define CORE_RWLOCK_TQ_OPERATIONS &_Thread_queue_Operations_FIFO

#define CORE_RWLOCK_THREAD_WAITING_FOR_READ  0

#define CORE_RWLOCK_THREAD_WAITING_FOR_WRITE 1

typedef enum {
  CORE_RWLOCK_UNLOCKED,
  CORE_RWLOCK_LOCKED_FOR_READING,
  CORE_RWLOCK_LOCKED_FOR_WRITING
}   CORE_RWLock_States;

typedef struct {
  Thread_queue_Syslock_queue Queue;

  CORE_RWLock_States current_state;

  unsigned int number_of_readers;
}   CORE_RWLock_Control;

void _CORE_RWLock_Initialize(
  CORE_RWLock_Control *the_rwlock
);

static inline void _CORE_RWLock_Destroy(
  CORE_RWLock_Control *the_rwlock
)
{
  (void) the_rwlock;
}

static inline Thread_Control *_CORE_RWLock_Acquire(
  CORE_RWLock_Control  *the_rwlock,
  Thread_queue_Context *queue_context
)
{
  ISR_Level       level;
  Thread_Control *executing;
 
  _Thread_queue_Context_ISR_disable( queue_context, level );
  _Thread_queue_Context_set_ISR_level( queue_context, level );
  executing = _Thread_Executing;
  _Thread_queue_Queue_acquire_critical(
    &the_rwlock->Queue.Queue,
    &executing->Potpourri_stats,
    &queue_context->Lock_context.Lock_context
  );
 
  return executing;
}

static inline void _CORE_RWLock_Release(
  CORE_RWLock_Control  *the_rwlock,
  Thread_queue_Context *queue_context
)
{
  _Thread_queue_Queue_release(
    &the_rwlock->Queue.Queue,
    &queue_context->Lock_context.Lock_context
  );
}

 
Status_Control _CORE_RWLock_Seize_for_reading(
  CORE_RWLock_Control  *the_rwlock,
  bool                  wait,
  Thread_queue_Context *queue_context
);

Status_Control _CORE_RWLock_Seize_for_writing(
  CORE_RWLock_Control  *the_rwlock,
  bool                  wait,
  Thread_queue_Context *queue_context
);

Status_Control _CORE_RWLock_Surrender( CORE_RWLock_Control *the_rwlock );

 
#ifdef __cplusplus
}
#endif
 
#endif
/* end of include file */