text: /*
  *********************************************************************************************************
  *                                                uC/OS-II
  *                                          The Real-Time Kernel
  *                                        MESSAGE QUEUE MANAGEMENT
  *
  *                              (c) Copyright 1992-2012, Micrium, Weston, FL
  *                                           All Rights Reserved
  *
  * File    : OS_Q.C
  * By      : Jean J. Labrosse
  * Version : V2.92.07
  *
  * LICENSING TERMS:
  * ---------------
  *   uC/OS-II is provided in source form for FREE evaluation, for educational use or for peaceful research.
  * If you plan on using  uC/OS-II  in a commercial product you need to contact Micrium to properly license
  * its use in your product. We provide ALL the source code for your convenience and to help you experience
  * uC/OS-II.   The fact that the  source is provided does  NOT  mean that you can use it without  paying a
  * licensing fee.
  *********************************************************************************************************
  */
  
  #define  MICRIUM_SOURCE
  
  #ifndef  OS_MASTER_FILE
  #include <ucos_ii.h>
  #endif
  
  #if (OS_Q_EN > 0u) && (OS_MAX_QS > 0u)
  /*
  *********************************************************************************************************
  *                                      ACCEPT MESSAGE FROM QUEUE
  *
  * Description: This function checks the queue to see if a message is available.  Unlike OSQPend(),
  *              OSQAccept() does not suspend the calling task if a message is not available.
  *
  * Arguments  : pevent        is a pointer to the event control block
  *
  *              perr          is a pointer to where an error message will be deposited.  Possible error
  *                            messages are:
  *
  *                            OS_ERR_NONE         The call was successful and your task received a
  *                                                message.
  *                            OS_ERR_EVENT_TYPE   You didn't pass a pointer to a queue
  *                            OS_ERR_PEVENT_NULL  If 'pevent' is a NULL pointer
  *                            OS_ERR_Q_EMPTY      The queue did not contain any messages
  *
  * Returns    : != (void *)0  is the message in the queue if one is available.  The message is removed
  *                            from the so the next time OSQAccept() is called, the queue will contain
  *                            one less entry.
  *              == (void *)0  if you received a NULL pointer message
  *                            if the queue is empty or,
  *                            if 'pevent' is a NULL pointer or,
  *                            if you passed an invalid event type
  *
  * Note(s)    : As of V2.60, you can now pass NULL pointers through queues.  Because of this, the argument
  *              'perr' has been added to the API to tell you about the outcome of the call.
  *********************************************************************************************************
  */
  
  #if OS_Q_ACCEPT_EN > 0u
  void  *OSQAccept (OS_EVENT  *pevent,
                    INT8U     *perr)
  {
      void      *pmsg;
      OS_Q      *pq;
  #if OS_CRITICAL_METHOD == 3u                     /* Allocate storage for CPU status register           */
      OS_CPU_SR  cpu_sr = 0u;
  #endif
  
  
  
  #ifdef OS_SAFETY_CRITICAL
      if (perr == (INT8U *)0) {
          OS_SAFETY_CRITICAL_EXCEPTION();
          return ((void *)0);
      }
  #endif
  
  #if OS_ARG_CHK_EN > 0u
      if (pevent == (OS_EVENT *)0) {               /* Validate 'pevent'                                  */
          *perr = OS_ERR_PEVENT_NULL;
          return ((void *)0);
      }
  #endif
      if (pevent->OSEventType != OS_EVENT_TYPE_Q) {/* Validate event block type                          */
          *perr = OS_ERR_EVENT_TYPE;
          return ((void *)0);
      }
      OS_ENTER_CRITICAL();
      pq = (OS_Q *)pevent->OSEventPtr;             /* Point at queue control block                       */
      if (pq->OSQEntries > 0u) {                   /* See if any messages in the queue                   */
          pmsg = *pq->OSQOut++;                    /* Yes, extract oldest message from the queue         */
          pq->OSQEntries--;                        /* Update the number of entries in the queue          */
          if (pq->OSQOut == pq->OSQEnd) {          /* Wrap OUT pointer if we are at the end of the queue */
              pq->OSQOut = pq->OSQStart;
          }
          *perr = OS_ERR_NONE;
      } else {
          *perr = OS_ERR_Q_EMPTY;
          pmsg  = (void *)0;                       /* Queue is empty                                     */
      }
      OS_EXIT_CRITICAL();
      return (pmsg);                               /* Return message received (or NULL)                  */
  }
  #endif
  /*$PAGE*/
  /*
  *********************************************************************************************************
  *                                       CREATE A MESSAGE QUEUE
  *
  * Description: This function creates a message queue if free event control blocks are available.
  *
  * Arguments  : start         is a pointer to the base address of the message queue storage area.  The
  *                            storage area MUST be declared as an array of pointers to 'void' as follows
  *
  *                            void *MessageStorage[size]
  *
  *              size          is the number of elements in the storage area
  *
  * Returns    : != (OS_EVENT *)0  is a pointer to the event control clock (OS_EVENT) associated with the
  *                                created queue
  *              == (OS_EVENT *)0  if no event control blocks were available or an error was detected
  *********************************************************************************************************
  */
  
  OS_EVENT  *OSQCreate (void    **start,
                        INT16U    size)
  {
      OS_EVENT  *pevent;
      OS_Q      *pq;
  #if OS_CRITICAL_METHOD == 3u                     /* Allocate storage for CPU status register           */
      OS_CPU_SR  cpu_sr = 0u;
  #endif
  
  
  
  #ifdef OS_SAFETY_CRITICAL_IEC61508
      if (OSSafetyCriticalStartFlag == OS_TRUE) {
          OS_SAFETY_CRITICAL_EXCEPTION();
          return ((OS_EVENT *)0);
      }
  #endif
  
      if (OSIntNesting > 0u) {                     /* See if called from ISR ...                         */
          return ((OS_EVENT *)0);                  /* ... can't CREATE from an ISR                       */
      }
      OS_ENTER_CRITICAL();
      pevent = OSEventFreeList;                    /* Get next free event control block                  */
      if (OSEventFreeList != (OS_EVENT *)0) {      /* See if pool of free ECB pool was empty             */
          OSEventFreeList = (OS_EVENT *)OSEventFreeList->OSEventPtr;
      }
      OS_EXIT_CRITICAL();
      if (pevent != (OS_EVENT *)0) {               /* See if we have an event control block              */
          OS_ENTER_CRITICAL();
          pq = OSQFreeList;                        /* Get a free queue control block                     */
          if (pq != (OS_Q *)0) {                   /* Were we able to get a queue control block ?        */
              OSQFreeList            = OSQFreeList->OSQPtr; /* Yes, Adjust free list pointer to next free*/
              OS_EXIT_CRITICAL();
              pq->OSQStart           = start;               /*      Initialize the queue                 */
              pq->OSQEnd             = &start[size];
              pq->OSQIn              = start;
              pq->OSQOut             = start;
              pq->OSQSize            = size;
              pq->OSQEntries         = 0u;
              pevent->OSEventType    = OS_EVENT_TYPE_Q;
              pevent->OSEventCnt     = 0u;
              pevent->OSEventPtr     = pq;
  #if OS_EVENT_NAME_EN > 0u
              pevent->OSEventName    = (INT8U *)(void *)"?";
  #endif
              OS_EventWaitListInit(pevent);                 /*      Initialize the wait list             */
          } else {
              pevent->OSEventPtr = (void *)OSEventFreeList; /* No,  Return event control block on error  */
              OSEventFreeList    = pevent;
              OS_EXIT_CRITICAL();
              pevent = (OS_EVENT *)0;
          }
      }
      return (pevent);
  }
  /*$PAGE*/
  /*
  *********************************************************************************************************
  *                                       DELETE A MESSAGE QUEUE
  *
  * Description: This function deletes a message queue and readies all tasks pending on the queue.
  *
  * Arguments  : pevent        is a pointer to the event control block associated with the desired
  *                            queue.
  *
  *              opt           determines delete options as follows:
  *                            opt == OS_DEL_NO_PEND   Delete the queue ONLY if no task pending
  *                            opt == OS_DEL_ALWAYS    Deletes the queue even if tasks are waiting.
  *                                                    In this case, all the tasks pending will be readied.
  *
  *              perr          is a pointer to an error code that can contain one of the following values:
  *                            OS_ERR_NONE             The call was successful and the queue was deleted
  *                            OS_ERR_DEL_ISR          If you tried to delete the queue from an ISR
  *                            OS_ERR_INVALID_OPT      An invalid option was specified
  *                            OS_ERR_TASK_WAITING     One or more tasks were waiting on the queue
  *                            OS_ERR_EVENT_TYPE       If you didn't pass a pointer to a queue
  *                            OS_ERR_PEVENT_NULL      If 'pevent' is a NULL pointer.
  *
  * Returns    : pevent        upon error
  *              (OS_EVENT *)0 if the queue was successfully deleted.
  *
  * Note(s)    : 1) This function must be used with care.  Tasks that would normally expect the presence of
  *                 the queue MUST check the return code of OSQPend().
  *              2) OSQAccept() callers will not know that the intended queue has been deleted unless
  *                 they check 'pevent' to see that it's a NULL pointer.
  *              3) This call can potentially disable interrupts for a long time.  The interrupt disable
  *                 time is directly proportional to the number of tasks waiting on the queue.
  *              4) Because ALL tasks pending on the queue will be readied, you MUST be careful in
  *                 applications where the queue is used for mutual exclusion because the resource(s)
  *                 will no longer be guarded by the queue.
  *              5) If the storage for the message queue was allocated dynamically (i.e. using a malloc()
  *                 type call) then your application MUST release the memory storage by call the counterpart
  *                 call of the dynamic allocation scheme used.  If the queue storage was created statically
  *                 then, the storage can be reused.
  *              6) All tasks that were waiting for the queue will be readied and returned an 
  *                 OS_ERR_PEND_ABORT if OSQDel() was called with OS_DEL_ALWAYS
  *********************************************************************************************************
  */
  
  #if OS_Q_DEL_EN > 0u
  OS_EVENT  *OSQDel (OS_EVENT  *pevent,
                     INT8U      opt,
                     INT8U     *perr)
  {
      BOOLEAN    tasks_waiting;
      OS_EVENT  *pevent_return;
      OS_Q      *pq;
  #if OS_CRITICAL_METHOD == 3u                               /* Allocate storage for CPU status register */
      OS_CPU_SR  cpu_sr = 0u;
  #endif
  
  
  
  #ifdef OS_SAFETY_CRITICAL
      if (perr == (INT8U *)0) {
          OS_SAFETY_CRITICAL_EXCEPTION();
          return ((OS_EVENT *)0);
      }
  #endif
  
  #if OS_ARG_CHK_EN > 0u
      if (pevent == (OS_EVENT *)0) {                         /* Validate 'pevent'                        */
          *perr = OS_ERR_PEVENT_NULL;
          return (pevent);
      }
  #endif
      if (pevent->OSEventType != OS_EVENT_TYPE_Q) {          /* Validate event block type                */
          *perr = OS_ERR_EVENT_TYPE;
          return (pevent);
      }
      if (OSIntNesting > 0u) {                               /* See if called from ISR ...               */
          *perr = OS_ERR_DEL_ISR;                            /* ... can't DELETE from an ISR             */
          return (pevent);
      }
      OS_ENTER_CRITICAL();
      if (pevent->OSEventGrp != 0u) {                        /* See if any tasks waiting on queue        */
          tasks_waiting = OS_TRUE;                           /* Yes                                      */
      } else {
          tasks_waiting = OS_FALSE;                          /* No                                       */
      }
      switch (opt) {
          case OS_DEL_NO_PEND:                               /* Delete queue only if no task waiting     */
               if (tasks_waiting == OS_FALSE) {
  #if OS_EVENT_NAME_EN > 0u
                   pevent->OSEventName    = (INT8U *)(void *)"?";
  #endif
                   pq                     = (OS_Q *)pevent->OSEventPtr;  /* Return OS_Q to free list     */
                   pq->OSQPtr             = OSQFreeList;
                   OSQFreeList            = pq;
                   pevent->OSEventType    = OS_EVENT_TYPE_UNUSED;
                   pevent->OSEventPtr     = OSEventFreeList; /* Return Event Control Block to free list  */
                   pevent->OSEventCnt     = 0u;
                   OSEventFreeList        = pevent;          /* Get next free event control block        */
                   OS_EXIT_CRITICAL();
                   *perr                  = OS_ERR_NONE;
                   pevent_return          = (OS_EVENT *)0;   /* Queue has been deleted                   */
               } else {
                   OS_EXIT_CRITICAL();
                   *perr                  = OS_ERR_TASK_WAITING;
                   pevent_return          = pevent;
               }
               break;
  
          case OS_DEL_ALWAYS:                                /* Always delete the queue                  */
               while (pevent->OSEventGrp != 0u) {            /* Ready ALL tasks waiting for queue        */
                   (void)OS_EventTaskRdy(pevent, (void *)0, OS_STAT_Q, OS_STAT_PEND_ABORT);
               }
  #if OS_EVENT_NAME_EN > 0u
               pevent->OSEventName    = (INT8U *)(void *)"?";
  #endif
               pq                     = (OS_Q *)pevent->OSEventPtr;   /* Return OS_Q to free list        */
               pq->OSQPtr             = OSQFreeList;
               OSQFreeList            = pq;
               pevent->OSEventType    = OS_EVENT_TYPE_UNUSED;
               pevent->OSEventPtr     = OSEventFreeList;     /* Return Event Control Block to free list  */
               pevent->OSEventCnt     = 0u;
               OSEventFreeList        = pevent;              /* Get next free event control block        */
               OS_EXIT_CRITICAL();
               if (tasks_waiting == OS_TRUE) {               /* Reschedule only if task(s) were waiting  */
                   OS_Sched();                               /* Find highest priority task ready to run  */
               }
               *perr                  = OS_ERR_NONE;
               pevent_return          = (OS_EVENT *)0;       /* Queue has been deleted                   */
               break;
  
          default:
               OS_EXIT_CRITICAL();
               *perr                  = OS_ERR_INVALID_OPT;
               pevent_return          = pevent;
               break;
      }
      return (pevent_return);
  }
  #endif
  
  /*$PAGE*/
  /*
  *********************************************************************************************************
  *                                             FLUSH QUEUE
  *
  * Description : This function is used to flush the contents of the message queue.
  *
  * Arguments   : none
  *
  * Returns     : OS_ERR_NONE         upon success
  *               OS_ERR_EVENT_TYPE   If you didn't pass a pointer to a queue
  *               OS_ERR_PEVENT_NULL  If 'pevent' is a NULL pointer
  *
  * WARNING     : You should use this function with great care because, when to flush the queue, you LOOSE
  *               the references to what the queue entries are pointing to and thus, you could cause
  *               'memory leaks'.  In other words, the data you are pointing to that's being referenced
  *               by the queue entries should, most likely, need to be de-allocated (i.e. freed).
  *********************************************************************************************************
  */
  
  #if OS_Q_FLUSH_EN > 0u
  INT8U  OSQFlush (OS_EVENT *pevent)
  {
      OS_Q      *pq;
  #if OS_CRITICAL_METHOD == 3u                          /* Allocate storage for CPU status register      */
      OS_CPU_SR  cpu_sr = 0u;
  #endif
  
  
  
  #if OS_ARG_CHK_EN > 0u
      if (pevent == (OS_EVENT *)0) {                    /* Validate 'pevent'                             */
          return (OS_ERR_PEVENT_NULL);
      }
      if (pevent->OSEventType != OS_EVENT_TYPE_Q) {     /* Validate event block type                     */
          return (OS_ERR_EVENT_TYPE);
      }
  #endif
      OS_ENTER_CRITICAL();
      pq             = (OS_Q *)pevent->OSEventPtr;      /* Point to queue storage structure              */
      pq->OSQIn      = pq->OSQStart;
      pq->OSQOut     = pq->OSQStart;
      pq->OSQEntries = 0u;
      OS_EXIT_CRITICAL();
      return (OS_ERR_NONE);
  }
  #endif
  
  /*$PAGE*/
  /*
  *********************************************************************************************************
  *                                    PEND ON A QUEUE FOR A MESSAGE
  *
  * Description: This function waits for a message to be sent to a queue
  *
  * Arguments  : pevent        is a pointer to the event control block associated with the desired queue
  *
  *              timeout       is an optional timeout period (in clock ticks).  If non-zero, your task will
  *                            wait for a message to arrive at the queue up to the amount of time
  *                            specified by this argument.  If you specify 0, however, your task will wait
  *                            forever at the specified queue or, until a message arrives.
  *
  *              perr          is a pointer to where an error message will be deposited.  Possible error
  *                            messages are:
  *
  *                            OS_ERR_NONE         The call was successful and your task received a
  *                                                message.
  *                            OS_ERR_TIMEOUT      A message was not received within the specified 'timeout'.
  *                            OS_ERR_PEND_ABORT   The wait on the queue was aborted.
  *                            OS_ERR_EVENT_TYPE   You didn't pass a pointer to a queue
  *                            OS_ERR_PEVENT_NULL  If 'pevent' is a NULL pointer
  *                            OS_ERR_PEND_ISR     If you called this function from an ISR and the result
  *                                                would lead to a suspension.
  *                            OS_ERR_PEND_LOCKED  If you called this function with the scheduler is locked
  *
  * Returns    : != (void *)0  is a pointer to the message received
  *              == (void *)0  if you received a NULL pointer message or,
  *                            if no message was received or,
  *                            if 'pevent' is a NULL pointer or,
  *                            if you didn't pass a pointer to a queue.
  *
  * Note(s)    : As of V2.60, this function allows you to receive NULL pointer messages.
  *********************************************************************************************************
  */
  
  void  *OSQPend (OS_EVENT  *pevent,
                  INT32U     timeout,
                  INT8U     *perr)
  {
      void      *pmsg;
      OS_Q      *pq;
  #if OS_CRITICAL_METHOD == 3u                     /* Allocate storage for CPU status register           */
      OS_CPU_SR  cpu_sr = 0u;
  #endif
  
  
  
  #ifdef OS_SAFETY_CRITICAL
      if (perr == (INT8U *)0) {
          OS_SAFETY_CRITICAL_EXCEPTION();
          return ((void *)0);
      }
  #endif
  
  #if OS_ARG_CHK_EN > 0u
      if (pevent == (OS_EVENT *)0) {               /* Validate 'pevent'                                  */
          *perr = OS_ERR_PEVENT_NULL;
          return ((void *)0);
      }
  #endif
      if (pevent->OSEventType != OS_EVENT_TYPE_Q) {/* Validate event block type                          */
          *perr = OS_ERR_EVENT_TYPE;
          return ((void *)0);
      }
      if (OSIntNesting > 0u) {                     /* See if called from ISR ...                         */
          *perr = OS_ERR_PEND_ISR;                 /* ... can't PEND from an ISR                         */
          return ((void *)0);
      }
      if (OSLockNesting > 0u) {                    /* See if called with scheduler locked ...            */
          *perr = OS_ERR_PEND_LOCKED;              /* ... can't PEND when locked                         */
          return ((void *)0);
      }
      OS_ENTER_CRITICAL();
      pq = (OS_Q *)pevent->OSEventPtr;             /* Point at queue control block                       */
      if (pq->OSQEntries > 0u) {                   /* See if any messages in the queue                   */
          pmsg = *pq->OSQOut++;                    /* Yes, extract oldest message from the queue         */
          pq->OSQEntries--;                        /* Update the number of entries in the queue          */
          if (pq->OSQOut == pq->OSQEnd) {          /* Wrap OUT pointer if we are at the end of the queue */
              pq->OSQOut = pq->OSQStart;
          }
          OS_EXIT_CRITICAL();
          *perr = OS_ERR_NONE;
          return (pmsg);                           /* Return message received                            */
      }
      OSTCBCur->OSTCBStat     |= OS_STAT_Q;        /* Task will have to pend for a message to be posted  */
      OSTCBCur->OSTCBStatPend  = OS_STAT_PEND_OK;
      OSTCBCur->OSTCBDly       = timeout;          /* Load timeout into TCB                              */
      OS_EventTaskWait(pevent);                    /* Suspend task until event or timeout occurs         */
      OS_EXIT_CRITICAL();
      OS_Sched();                                  /* Find next highest priority task ready to run       */
      OS_ENTER_CRITICAL();
      switch (OSTCBCur->OSTCBStatPend) {                /* See if we timed-out or aborted                */
          case OS_STAT_PEND_OK:                         /* Extract message from TCB (Put there by QPost) */
               pmsg =  OSTCBCur->OSTCBMsg;
              *perr =  OS_ERR_NONE;
               break;
  
          case OS_STAT_PEND_ABORT:
               pmsg = (void *)0;
              *perr =  OS_ERR_PEND_ABORT;               /* Indicate that we aborted                      */
               break;
  
          case OS_STAT_PEND_TO:
          default:
               OS_EventTaskRemove(OSTCBCur, pevent);
               pmsg = (void *)0;
              *perr =  OS_ERR_TIMEOUT;                  /* Indicate that we didn't get event within TO   */
               break;
      }
      OSTCBCur->OSTCBStat          =  OS_STAT_RDY;      /* Set   task  status to ready                   */
      OSTCBCur->OSTCBStatPend      =  OS_STAT_PEND_OK;  /* Clear pend  status                            */
      OSTCBCur->OSTCBEventPtr      = (OS_EVENT  *)0;    /* Clear event pointers                          */
  #if (OS_EVENT_MULTI_EN > 0u)
      OSTCBCur->OSTCBEventMultiPtr = (OS_EVENT **)0;
  #endif
      OSTCBCur->OSTCBMsg           = (void      *)0;    /* Clear  received message                       */
      OS_EXIT_CRITICAL();
      return (pmsg);                                    /* Return received message                       */
  }
  /*$PAGE*/
  /*
  *********************************************************************************************************
  *                                  ABORT WAITING ON A MESSAGE QUEUE
  *
  * Description: This function aborts & readies any tasks currently waiting on a queue.  This function
  *              should be used to fault-abort the wait on the queue, rather than to normally signal
  *              the queue via OSQPost(), OSQPostFront() or OSQPostOpt().
  *
  * Arguments  : pevent        is a pointer to the event control block associated with the desired queue.
  *
  *              opt           determines the type of ABORT performed:
  *                            OS_PEND_OPT_NONE         ABORT wait for a single task (HPT) waiting on the
  *                                                     queue
  *                            OS_PEND_OPT_BROADCAST    ABORT wait for ALL tasks that are  waiting on the
  *                                                     queue
  *
  *              perr          is a pointer to where an error message will be deposited.  Possible error
  *                            messages are:
  *
  *                            OS_ERR_NONE         No tasks were     waiting on the queue.
  *                            OS_ERR_PEND_ABORT   At least one task waiting on the queue was readied
  *                                                and informed of the aborted wait; check return value
  *                                                for the number of tasks whose wait on the queue
  *                                                was aborted.
  *                            OS_ERR_EVENT_TYPE   If you didn't pass a pointer to a queue.
  *                            OS_ERR_PEVENT_NULL  If 'pevent' is a NULL pointer.
  *
  * Returns    : == 0          if no tasks were waiting on the queue, or upon error.
  *              >  0          if one or more tasks waiting on the queue are now readied and informed.
  *********************************************************************************************************
  */
  
  #if OS_Q_PEND_ABORT_EN > 0u
  INT8U  OSQPendAbort (OS_EVENT  *pevent,
                       INT8U      opt,
                       INT8U     *perr)
  {
      INT8U      nbr_tasks;
  #if OS_CRITICAL_METHOD == 3u                               /* Allocate storage for CPU status register */
      OS_CPU_SR  cpu_sr = 0u;
  #endif
  
  
  
  #ifdef OS_SAFETY_CRITICAL
      if (perr == (INT8U *)0) {
          OS_SAFETY_CRITICAL_EXCEPTION();
          return (0u);
      }
  #endif
  
  #if OS_ARG_CHK_EN > 0u
      if (pevent == (OS_EVENT *)0) {                         /* Validate 'pevent'                        */
          *perr = OS_ERR_PEVENT_NULL;
          return (0u);
      }
  #endif
      if (pevent->OSEventType != OS_EVENT_TYPE_Q) {          /* Validate event block type                */
          *perr = OS_ERR_EVENT_TYPE;
          return (0u);
      }
      OS_ENTER_CRITICAL();
      if (pevent->OSEventGrp != 0u) {                        /* See if any task waiting on queue?        */
          nbr_tasks = 0u;
          switch (opt) {
              case OS_PEND_OPT_BROADCAST:                    /* Do we need to abort ALL waiting tasks?   */
                   while (pevent->OSEventGrp != 0u) {        /* Yes, ready ALL tasks waiting on queue    */
                       (void)OS_EventTaskRdy(pevent, (void *)0, OS_STAT_Q, OS_STAT_PEND_ABORT);
                       nbr_tasks++;
                   }
                   break;
  
              case OS_PEND_OPT_NONE:
              default:                                       /* No,  ready HPT       waiting on queue    */
                   (void)OS_EventTaskRdy(pevent, (void *)0, OS_STAT_Q, OS_STAT_PEND_ABORT);
                   nbr_tasks++;
                   break;
          }
          OS_EXIT_CRITICAL();
          OS_Sched();                                        /* Find HPT ready to run                    */
          *perr = OS_ERR_PEND_ABORT;
          return (nbr_tasks);
      }
      OS_EXIT_CRITICAL();
      *perr = OS_ERR_NONE;
      return (0u);                                           /* No tasks waiting on queue                */
  }
  #endif
  
  /*$PAGE*/
  /*
  *********************************************************************************************************
  *                                       POST MESSAGE TO A QUEUE
  *
  * Description: This function sends a message to a queue
  *
  * Arguments  : pevent        is a pointer to the event control block associated with the desired queue
  *
  *              pmsg          is a pointer to the message to send.
  *
  * Returns    : OS_ERR_NONE           The call was successful and the message was sent
  *              OS_ERR_Q_FULL         If the queue cannot accept any more messages because it is full.
  *              OS_ERR_EVENT_TYPE     If you didn't pass a pointer to a queue.
  *              OS_ERR_PEVENT_NULL    If 'pevent' is a NULL pointer
  *
  * Note(s)    : As of V2.60, this function allows you to send NULL pointer messages.
  *********************************************************************************************************
  */
  
  #if OS_Q_POST_EN > 0u
  INT8U  OSQPost (OS_EVENT  *pevent,
                  void      *pmsg)
  {
      OS_Q      *pq;
  #if OS_CRITICAL_METHOD == 3u                           /* Allocate storage for CPU status register     */
      OS_CPU_SR  cpu_sr = 0u;
  #endif
  
  
  
  #if OS_ARG_CHK_EN > 0u
      if (pevent == (OS_EVENT *)0) {                     /* Validate 'pevent'                            */
          return (OS_ERR_PEVENT_NULL);
      }
  #endif
      if (pevent->OSEventType != OS_EVENT_TYPE_Q) {      /* Validate event block type                    */
          return (OS_ERR_EVENT_TYPE);
      }
      OS_ENTER_CRITICAL();
      if (pevent->OSEventGrp != 0u) {                    /* See if any task pending on queue             */
                                                         /* Ready highest priority task waiting on event */
          (void)OS_EventTaskRdy(pevent, pmsg, OS_STAT_Q, OS_STAT_PEND_OK);
          OS_EXIT_CRITICAL();
          OS_Sched();                                    /* Find highest priority task ready to run      */
          return (OS_ERR_NONE);
      }
      pq = (OS_Q *)pevent->OSEventPtr;                   /* Point to queue control block                 */
      if (pq->OSQEntries >= pq->OSQSize) {               /* Make sure queue is not full                  */
          OS_EXIT_CRITICAL();
          return (OS_ERR_Q_FULL);
      }
      *pq->OSQIn++ = pmsg;                               /* Insert message into queue                    */
      pq->OSQEntries++;                                  /* Update the nbr of entries in the queue       */
      if (pq->OSQIn == pq->OSQEnd) {                     /* Wrap IN ptr if we are at end of queue        */
          pq->OSQIn = pq->OSQStart;
      }
      OS_EXIT_CRITICAL();
      return (OS_ERR_NONE);
  }
  #endif
  /*$PAGE*/
  /*
  *********************************************************************************************************
  *                                POST MESSAGE TO THE FRONT OF A QUEUE
  *
  * Description: This function sends a message to a queue but unlike OSQPost(), the message is posted at
  *              the front instead of the end of the queue.  Using OSQPostFront() allows you to send
  *              'priority' messages.
  *
  * Arguments  : pevent        is a pointer to the event control block associated with the desired queue
  *
  *              pmsg          is a pointer to the message to send.
  *
  * Returns    : OS_ERR_NONE           The call was successful and the message was sent
  *              OS_ERR_Q_FULL         If the queue cannot accept any more messages because it is full.
  *              OS_ERR_EVENT_TYPE     If you didn't pass a pointer to a queue.
  *              OS_ERR_PEVENT_NULL    If 'pevent' is a NULL pointer
  *
  * Note(s)    : As of V2.60, this function allows you to send NULL pointer messages.
  *********************************************************************************************************
  */
  
  #if OS_Q_POST_FRONT_EN > 0u
  INT8U  OSQPostFront (OS_EVENT  *pevent,
                       void      *pmsg)
  {
      OS_Q      *pq;
  #if OS_CRITICAL_METHOD == 3u                          /* Allocate storage for CPU status register      */
      OS_CPU_SR  cpu_sr = 0u;
  #endif
  
  
  
  #if OS_ARG_CHK_EN > 0u
      if (pevent == (OS_EVENT *)0) {                    /* Validate 'pevent'                             */
          return (OS_ERR_PEVENT_NULL);
      }
  #endif
      if (pevent->OSEventType != OS_EVENT_TYPE_Q) {     /* Validate event block type                     */
          return (OS_ERR_EVENT_TYPE);
      }
      OS_ENTER_CRITICAL();
      if (pevent->OSEventGrp != 0u) {                   /* See if any task pending on queue              */
                                                        /* Ready highest priority task waiting on event  */
          (void)OS_EventTaskRdy(pevent, pmsg, OS_STAT_Q, OS_STAT_PEND_OK);
          OS_EXIT_CRITICAL();
          OS_Sched();                                   /* Find highest priority task ready to run       */
          return (OS_ERR_NONE);
      }
      pq = (OS_Q *)pevent->OSEventPtr;                  /* Point to queue control block                  */
      if (pq->OSQEntries >= pq->OSQSize) {              /* Make sure queue is not full                   */
          OS_EXIT_CRITICAL();
          return (OS_ERR_Q_FULL);
      }
      if (pq->OSQOut == pq->OSQStart) {                 /* Wrap OUT ptr if we are at the 1st queue entry */
          pq->OSQOut = pq->OSQEnd;
      }
      pq->OSQOut--;
      *pq->OSQOut = pmsg;                               /* Insert message into queue                     */
      pq->OSQEntries++;                                 /* Update the nbr of entries in the queue        */
      OS_EXIT_CRITICAL();
      return (OS_ERR_NONE);
  }
  #endif
  /*$PAGE*/
  /*
  *********************************************************************************************************
  *                                       POST MESSAGE TO A QUEUE
  *
  * Description: This function sends a message to a queue.  This call has been added to reduce code size
  *              since it can replace both OSQPost() and OSQPostFront().  Also, this function adds the
  *              capability to broadcast a message to ALL tasks waiting on the message queue.
  *
  * Arguments  : pevent        is a pointer to the event control block associated with the desired queue
  *
  *              pmsg          is a pointer to the message to send.
  *
  *              opt           determines the type of POST performed:
  *                            OS_POST_OPT_NONE         POST to a single waiting task
  *                                                     (Identical to OSQPost())
  *                            OS_POST_OPT_BROADCAST    POST to ALL tasks that are waiting on the queue
  *                            OS_POST_OPT_FRONT        POST as LIFO (Simulates OSQPostFront())
  *                            OS_POST_OPT_NO_SCHED     Indicates that the scheduler will NOT be invoked
  *
  * Returns    : OS_ERR_NONE           The call was successful and the message was sent
  *              OS_ERR_Q_FULL         If the queue cannot accept any more messages because it is full.
  *              OS_ERR_EVENT_TYPE     If you didn't pass a pointer to a queue.
  *              OS_ERR_PEVENT_NULL    If 'pevent' is a NULL pointer
  *
  * Warning    : Interrupts can be disabled for a long time if you do a 'broadcast'.  In fact, the
  *              interrupt disable time is proportional to the number of tasks waiting on the queue.
  *********************************************************************************************************
  */
  
  #if OS_Q_POST_OPT_EN > 0u
  INT8U  OSQPostOpt (OS_EVENT  *pevent,
                     void      *pmsg,
                     INT8U      opt)
  {
      OS_Q      *pq;
  #if OS_CRITICAL_METHOD == 3u                          /* Allocate storage for CPU status register      */
      OS_CPU_SR  cpu_sr = 0u;
  #endif
  
  
  
  #if OS_ARG_CHK_EN > 0u
      if (pevent == (OS_EVENT *)0) {                    /* Validate 'pevent'                             */
          return (OS_ERR_PEVENT_NULL);
      }
  #endif
      if (pevent->OSEventType != OS_EVENT_TYPE_Q) {     /* Validate event block type                     */
          return (OS_ERR_EVENT_TYPE);
      }
      OS_ENTER_CRITICAL();
      if (pevent->OSEventGrp != 0x00u) {                /* See if any task pending on queue              */
          if ((opt & OS_POST_OPT_BROADCAST) != 0x00u) { /* Do we need to post msg to ALL waiting tasks ? */
              while (pevent->OSEventGrp != 0u) {        /* Yes, Post to ALL tasks waiting on queue       */
                  (void)OS_EventTaskRdy(pevent, pmsg, OS_STAT_Q, OS_STAT_PEND_OK);
              }
          } else {                                      /* No,  Post to HPT waiting on queue             */
              (void)OS_EventTaskRdy(pevent, pmsg, OS_STAT_Q, OS_STAT_PEND_OK);
          }
          OS_EXIT_CRITICAL();
          if ((opt & OS_POST_OPT_NO_SCHED) == 0u) {     /* See if scheduler needs to be invoked          */
              OS_Sched();                               /* Find highest priority task ready to run       */
          }
          return (OS_ERR_NONE);
      }
      pq = (OS_Q *)pevent->OSEventPtr;                  /* Point to queue control block                  */
      if (pq->OSQEntries >= pq->OSQSize) {              /* Make sure queue is not full                   */
          OS_EXIT_CRITICAL();
          return (OS_ERR_Q_FULL);
      }
      if ((opt & OS_POST_OPT_FRONT) != 0x00u) {         /* Do we post to the FRONT of the queue?         */
          if (pq->OSQOut == pq->OSQStart) {             /* Yes, Post as LIFO, Wrap OUT pointer if we ... */
              pq->OSQOut = pq->OSQEnd;                  /*      ... are at the 1st queue entry           */
          }
          pq->OSQOut--;
          *pq->OSQOut = pmsg;                           /*      Insert message into queue                */
      } else {                                          /* No,  Post as FIFO                             */
          *pq->OSQIn++ = pmsg;                          /*      Insert message into queue                */
          if (pq->OSQIn == pq->OSQEnd) {                /*      Wrap IN ptr if we are at end of queue    */
              pq->OSQIn = pq->OSQStart;
          }
      }
      pq->OSQEntries++;                                 /* Update the nbr of entries in the queue        */
      OS_EXIT_CRITICAL();
      return (OS_ERR_NONE);
  }
  #endif
  /*$PAGE*/
  /*
  *********************************************************************************************************
  *                                        QUERY A MESSAGE QUEUE
  *
  * Description: This function obtains information about a message queue.
  *
  * Arguments  : pevent        is a pointer to the event control block associated with the desired queue
  *
  *              p_q_data      is a pointer to a structure that will contain information about the message
  *                            queue.
  *
  * Returns    : OS_ERR_NONE         The call was successful and the message was sent
  *              OS_ERR_EVENT_TYPE   If you are attempting to obtain data from a non queue.
  *              OS_ERR_PEVENT_NULL  If 'pevent'   is a NULL pointer
  *              OS_ERR_PDATA_NULL   If 'p_q_data' is a NULL pointer
  *********************************************************************************************************
  */
  
  #if OS_Q_QUERY_EN > 0u
  INT8U  OSQQuery (OS_EVENT  *pevent,
                   OS_Q_DATA *p_q_data)
  {
      OS_Q       *pq;
      INT8U       i;
      OS_PRIO    *psrc;
      OS_PRIO    *pdest;
  #if OS_CRITICAL_METHOD == 3u                           /* Allocate storage for CPU status register     */
      OS_CPU_SR   cpu_sr = 0u;
  #endif
  
  
  
  #if OS_ARG_CHK_EN > 0u
      if (pevent == (OS_EVENT *)0) {                     /* Validate 'pevent'                            */
          return (OS_ERR_PEVENT_NULL);
      }
      if (p_q_data == (OS_Q_DATA *)0) {                  /* Validate 'p_q_data'                          */
          return (OS_ERR_PDATA_NULL);
      }
  #endif
      if (pevent->OSEventType != OS_EVENT_TYPE_Q) {      /* Validate event block type                    */
          return (OS_ERR_EVENT_TYPE);
      }
      OS_ENTER_CRITICAL();
      p_q_data->OSEventGrp = pevent->OSEventGrp;         /* Copy message queue wait list                 */
      psrc                 = &pevent->OSEventTbl[0];
      pdest                = &p_q_data->OSEventTbl[0];
      for (i = 0u; i < OS_EVENT_TBL_SIZE; i++) {
          *pdest++ = *psrc++;
      }
      pq = (OS_Q *)pevent->OSEventPtr;
      if (pq->OSQEntries > 0u) {
          p_q_data->OSMsg = *pq->OSQOut;                 /* Get next message to return if available      */
      } else {
          p_q_data->OSMsg = (void *)0;
      }
      p_q_data->OSNMsgs = pq->OSQEntries;
      p_q_data->OSQSize = pq->OSQSize;
      OS_EXIT_CRITICAL();
      return (OS_ERR_NONE);
  }
  #endif                                                 /* OS_Q_QUERY_EN                                */
  
  /*$PAGE*/
  /*
  *********************************************************************************************************
  *                                     QUEUE MODULE INITIALIZATION
  *
  * Description : This function is called by uC/OS-II to initialize the message queue module.  Your
  *               application MUST NOT call this function.
  *
  * Arguments   :  none
  *
  * Returns     : none
  *
  * Note(s)    : This function is INTERNAL to uC/OS-II and your application should not call it.
  *********************************************************************************************************
  */
  
  void  OS_QInit (void)
  {
  #if OS_MAX_QS == 1u
      OSQFreeList         = &OSQTbl[0];                /* Only ONE queue!                                */
      OSQFreeList->OSQPtr = (OS_Q *)0;
  #endif
  
  #if OS_MAX_QS >= 2u
      INT16U   ix;
      INT16U   ix_next;
      OS_Q    *pq1;
      OS_Q    *pq2;
  
  
  
      OS_MemClr((INT8U *)&OSQTbl[0], sizeof(OSQTbl));  /* Clear the queue table                          */
      for (ix = 0u; ix < (OS_MAX_QS - 1u); ix++) {     /* Init. list of free QUEUE control blocks        */
          ix_next = ix + 1u;
          pq1 = &OSQTbl[ix];
          pq2 = &OSQTbl[ix_next];
          pq1->OSQPtr = pq2;
      }
      pq1         = &OSQTbl[ix];
      pq1->OSQPtr = (OS_Q *)0;
      OSQFreeList = &OSQTbl[0];
  #endif
  }
  #endif                                               /* OS_Q_EN                                        */
  