www.pudn.com > uCOSII_no.rar > OS_Q.C, change:2003-12-20,size:37340b


/* 
********************************************************************************************************* 
*                                                uC/OS-II 
*                                          The Real-Time Kernel 
*                                        MESSAGE QUEUE MANAGEMENT 
* 
*                          (c) Copyright 1992-2003, Jean J. Labrosse, Weston, FL 
*                                           All Rights Reserved 
* 
* File    : OS_Q.C 
* By      : Jean J. Labrosse 
* Version : V2.76 
********************************************************************************************************* 
*/ 
 
#ifndef  OS_MASTER_FILE 
#include <ucos_ii.h> 
#endif 
 
#if (OS_Q_EN > 0) && (OS_MAX_QS > 0) 
/* 
********************************************************************************************************* 
*                                      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 
* 
*              err           is a pointer to where an error message will be deposited.  Possible error 
*                            messages are: 
* 
*                            OS_NO_ERR           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_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 
*              'err' has been added to the API to tell you about the outcome of the call. 
********************************************************************************************************* 
*/ 
 
#if OS_Q_ACCEPT_EN > 0 
void  *OSQAccept (OS_EVENT *pevent, INT8U *err) 
{ 
    void      *msg; 
    OS_Q      *pq; 
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */ 
    OS_CPU_SR  cpu_sr; 
 
 
 
    cpu_sr = 0;                                  /* Prevent compiler warning                           */ 
#endif     
#if OS_ARG_CHK_EN > 0 
    if (pevent == (OS_EVENT *)0) {               /* Validate 'pevent'                                  */ 
        *err = OS_ERR_PEVENT_NULL; 
        return ((void *)0); 
    } 
#endif 
    if (pevent->OSEventType != OS_EVENT_TYPE_Q) {/* Validate event block type                          */ 
        *err = OS_ERR_EVENT_TYPE; 
        return ((void *)0); 
    } 
    OS_ENTER_CRITICAL(); 
    pq = (OS_Q *)pevent->OSEventPtr;             /* Point at queue control block                       */ 
    if (pq->OSQEntries > 0) {                    /* See if any messages in the queue                   */ 
        msg = *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; 
        } 
        *err = OS_NO_ERR; 
    } else { 
        *err = OS_Q_EMPTY; 
        msg  = (void *)0;                        /* Queue is empty                                     */ 
    } 
    OS_EXIT_CRITICAL(); 
    return (msg);                                /* 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 == 3                      /* Allocate storage for CPU status register           */ 
    OS_CPU_SR  cpu_sr; 
 
 
 
    cpu_sr = 0;                                  /* Prevent compiler warning                           */ 
#endif     
    if (OSIntNesting > 0) {                      /* 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         = 0; 
            pevent->OSEventType    = OS_EVENT_TYPE_Q; 
            pevent->OSEventCnt     = 0; 
            pevent->OSEventPtr     = pq; 
#if OS_EVENT_NAME_SIZE > 1 
            pevent->OSEventName[0] = '?';                  /* Unknown name                             */ 
            pevent->OSEventName[1] = OS_ASCII_NUL; 
#endif 
            OS_EventWaitListInit(pevent);                 /*      Initalize 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. 
* 
*              err           is a pointer to an error code that can contain one of the following values: 
*                            OS_NO_ERR               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. 
********************************************************************************************************* 
*/ 
 
#if OS_Q_DEL_EN > 0 
OS_EVENT  *OSQDel (OS_EVENT *pevent, INT8U opt, INT8U *err) 
{ 
    BOOLEAN    tasks_waiting; 
    OS_Q      *pq; 
#if OS_CRITICAL_METHOD == 3                                /* Allocate storage for CPU status register */ 
    OS_CPU_SR  cpu_sr; 
 
 
 
    cpu_sr = 0;                                            /* Prevent compiler warning                 */ 
#endif     
    if (OSIntNesting > 0) {                                /* See if called from ISR ...               */ 
        *err = OS_ERR_DEL_ISR;                             /* ... can't DELETE from an ISR             */ 
        return (pevent); 
    } 
#if OS_ARG_CHK_EN > 0 
    if (pevent == (OS_EVENT *)0) {                         /* Validate 'pevent'                        */ 
        *err = OS_ERR_PEVENT_NULL; 
        return (pevent); 
    } 
#endif 
    if (pevent->OSEventType != OS_EVENT_TYPE_Q) {          /* Validate event block type                */ 
        *err = OS_ERR_EVENT_TYPE; 
        return (pevent); 
    } 
    OS_ENTER_CRITICAL(); 
    if (pevent->OSEventGrp != 0x00) {                      /* See if any tasks waiting on queue        */ 
        tasks_waiting = TRUE;                              /* Yes                                      */ 
    } else { 
        tasks_waiting = FALSE;                             /* No                                       */ 
    } 
    switch (opt) { 
        case OS_DEL_NO_PEND:                               /* Delete queue only if no task waiting     */ 
             if (tasks_waiting == FALSE) { 
#if OS_EVENT_NAME_SIZE > 1 
                 pevent->OSEventName[0] = '?';             /* Unknown name                             */ 
                 pevent->OSEventName[1] = OS_ASCII_NUL; 
#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     = 0; 
                 OSEventFreeList        = pevent;          /* Get next free event control block        */ 
                 OS_EXIT_CRITICAL(); 
                 *err                   = OS_NO_ERR; 
                 return ((OS_EVENT *)0);                   /* Queue has been deleted                   */ 
             } else { 
                 OS_EXIT_CRITICAL(); 
                 *err                   = OS_ERR_TASK_WAITING; 
                 return (pevent); 
             } 
 
        case OS_DEL_ALWAYS:                                /* Always delete the queue                  */ 
             while (pevent->OSEventGrp != 0x00) {          /* Ready ALL tasks waiting for queue        */ 
                 (void)OS_EventTaskRdy(pevent, (void *)0, OS_STAT_Q); 
             } 
#if OS_EVENT_NAME_SIZE > 1 
             pevent->OSEventName[0] = '?';                 /* Unknown name                             */ 
             pevent->OSEventName[1] = OS_ASCII_NUL; 
#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     = 0; 
             OSEventFreeList        = pevent;              /* Get next free event control block        */ 
             OS_EXIT_CRITICAL(); 
             if (tasks_waiting == TRUE) {                  /* Reschedule only if task(s) were waiting  */ 
                 OS_Sched();                               /* Find highest priority task ready to run  */ 
             } 
             *err = OS_NO_ERR; 
             return ((OS_EVENT *)0);                       /* Queue has been deleted                   */ 
 
        default: 
             OS_EXIT_CRITICAL(); 
             *err = OS_ERR_INVALID_OPT; 
             return (pevent); 
    } 
} 
#endif 
 
/*$PAGE*/ 
/* 
********************************************************************************************************* 
*                                             FLUSH QUEUE 
* 
* Description : This function is used to flush the contents of the message queue. 
* 
* Arguments   : none 
* 
* Returns     : OS_NO_ERR           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 > 0 
INT8U  OSQFlush (OS_EVENT *pevent) 
{ 
    OS_Q      *pq; 
#if OS_CRITICAL_METHOD == 3                           /* Allocate storage for CPU status register      */ 
    OS_CPU_SR  cpu_sr; 
 
 
 
    cpu_sr = 0;                                       /* Prevent compiler warning                      */ 
#endif     
#if OS_ARG_CHK_EN > 0 
    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 = 0; 
    OS_EXIT_CRITICAL(); 
    return (OS_NO_ERR); 
} 
#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. 
* 
*              err           is a pointer to where an error message will be deposited.  Possible error 
*                            messages are: 
* 
*                            OS_NO_ERR           The call was successful and your task received a 
*                                                message. 
*                            OS_TIMEOUT          A message was not received within the specified timeout 
*                            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. 
* 
* 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, INT16U timeout, INT8U *err) 
{ 
    void      *msg; 
    OS_Q      *pq; 
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */ 
    OS_CPU_SR  cpu_sr; 
 
 
 
    cpu_sr = 0;                                  /* Prevent compiler warning                           */ 
#endif     
    if (OSIntNesting > 0) {                      /* See if called from ISR ...                         */ 
        *err = OS_ERR_PEND_ISR;                  /* ... can't PEND from an ISR                         */ 
        return ((void *)0); 
    } 
#if OS_ARG_CHK_EN > 0 
    if (pevent == (OS_EVENT *)0) {               /* Validate 'pevent'                                  */ 
        *err = OS_ERR_PEVENT_NULL; 
        return ((void *)0); 
    } 
    if (pevent->OSEventType != OS_EVENT_TYPE_Q) {/* Validate event block type                          */ 
        *err = OS_ERR_EVENT_TYPE; 
        return ((void *)0); 
    } 
#endif 
    OS_ENTER_CRITICAL(); 
    pq = (OS_Q *)pevent->OSEventPtr;             /* Point at queue control block                       */ 
    if (pq->OSQEntries > 0) {                    /* See if any messages in the queue                   */ 
        msg = *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(); 
        *err = OS_NO_ERR; 
        return (msg);                            /* Return message received                            */ 
    } 
    OSTCBCur->OSTCBStat   |= OS_STAT_Q;          /* Task will have to pend for a message to be posted  */ 
    OSTCBCur->OSTCBPendTO  = FALSE; 
    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(); 
    if (OSTCBCur->OSTCBPendTO == TRUE) {         /* Was task readied because of a timeout?             */ 
        OS_EventTO(pevent);                      /* Yes                                                */ 
        OS_EXIT_CRITICAL(); 
        *err = OS_TIMEOUT;                       /*     Indicate a timeout occured                     */ 
        return ((void *)0);                      /*     No message received                            */ 
    } 
    msg                     = OSTCBCur->OSTCBMsg;/* No, Extract message from TCB (Put there by QPost)  */ 
    OSTCBCur->OSTCBMsg      = (void *)0; 
    OSTCBCur->OSTCBStat     = OS_STAT_RDY; 
    OSTCBCur->OSTCBEventPtr = (OS_EVENT *)0;     /*     No longer waiting for event                    */ 
    OS_EXIT_CRITICAL(); 
    *err                    = OS_NO_ERR; 
    return (msg);                                /*     Return message received                        */ 
} 
/*$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 
* 
*              msg           is a pointer to the message to send. 
* 
* Returns    : OS_NO_ERR             The call was successful and the message was sent 
*              OS_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 > 0 
INT8U  OSQPost (OS_EVENT *pevent, void *msg) 
{ 
    OS_Q      *pq; 
#if OS_CRITICAL_METHOD == 3                            /* Allocate storage for CPU status register     */ 
    OS_CPU_SR  cpu_sr; 
 
 
 
    cpu_sr = 0;                                        /* Prevent compiler warning                     */ 
#endif     
#if OS_ARG_CHK_EN > 0 
    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 != 0x00) {                  /* See if any task pending on queue             */ 
        (void)OS_EventTaskRdy(pevent, msg, OS_STAT_Q); /* Ready highest priority task waiting on event */ 
        OS_EXIT_CRITICAL(); 
        OS_Sched();                                    /* Find highest priority task ready to run      */ 
        return (OS_NO_ERR); 
    } 
    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_Q_FULL); 
    } 
    *pq->OSQIn++ = msg;                                /* 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_NO_ERR); 
} 
#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 
* 
*              msg           is a pointer to the message to send. 
* 
* Returns    : OS_NO_ERR             The call was successful and the message was sent 
*              OS_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 > 0 
INT8U  OSQPostFront (OS_EVENT *pevent, void *msg) 
{ 
    OS_Q      *pq; 
#if OS_CRITICAL_METHOD == 3                           /* Allocate storage for CPU status register      */ 
    OS_CPU_SR  cpu_sr; 
 
 
 
    cpu_sr = 0;                                       /* Prevent compiler warning                      */ 
#endif     
#if OS_ARG_CHK_EN > 0 
    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 != 0x00) {                 /* See if any task pending on queue              */ 
        (void)OS_EventTaskRdy(pevent, msg, OS_STAT_Q);/* Ready highest priority task waiting on event  */ 
        OS_EXIT_CRITICAL(); 
        OS_Sched();                                   /* Find highest priority task ready to run       */ 
        return (OS_NO_ERR); 
    } 
    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_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 = msg;                                /* Insert message into queue                     */ 
    pq->OSQEntries++;                                 /* Update the nbr of entries in the queue        */ 
    OS_EXIT_CRITICAL(); 
    return (OS_NO_ERR); 
} 
#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 
* 
*              msg           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()) 
* 
*                            Below is a list of ALL the possible combination of these flags: 
* 
*                                 1) OS_POST_OPT_NONE 
*                                    identical to OSQPost() 
* 
*                                 2) OS_POST_OPT_FRONT 
*                                    identical to OSQPostFront() 
* 
*                                 3) OS_POST_OPT_BROADCAST 
*                                    identical to OSQPost() but will broadcast 'msg' to ALL waiting tasks 
* 
*                                 4) OS_POST_OPT_FRONT + OS_POST_OPT_BROADCAST  is identical to 
*                                    OSQPostFront() except that will broadcast 'msg' to ALL waiting tasks 
* 
* Returns    : OS_NO_ERR             The call was successful and the message was sent 
*              OS_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 > 0 
INT8U  OSQPostOpt (OS_EVENT *pevent, void *msg, INT8U opt) 
{ 
    OS_Q      *pq; 
#if OS_CRITICAL_METHOD == 3                           /* Allocate storage for CPU status register      */ 
    OS_CPU_SR  cpu_sr; 
                      
 
 
    cpu_sr = 0;                                       /* Prevent compiler warning                      */ 
#endif     
#if OS_ARG_CHK_EN > 0 
    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 != 0x00) {                 /* See if any task pending on queue              */ 
        if ((opt & OS_POST_OPT_BROADCAST) != 0x00) {  /* Do we need to post msg to ALL waiting tasks ? */ 
            while (pevent->OSEventGrp != 0x00) {      /* Yes, Post to ALL tasks waiting on queue       */ 
                (void)OS_EventTaskRdy(pevent, msg, OS_STAT_Q); 
            } 
        } else { 
            (void)OS_EventTaskRdy(pevent, msg, OS_STAT_Q);  /* No,  Post to HPT waiting on queue       */ 
        } 
        OS_EXIT_CRITICAL(); 
        OS_Sched();                                         /* Find highest priority task ready to run */ 
        return (OS_NO_ERR); 
    } 
    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_Q_FULL); 
    } 
    if ((opt & OS_POST_OPT_FRONT) != 0x00) {          /* 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 = msg;                            /*      Insert message into queue                */ 
    } else {                                          /* No,  Post as FIFO                             */ 
        *pq->OSQIn++ = msg;                           /*      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_NO_ERR); 
} 
#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_NO_ERR           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 
********************************************************************************************************* 
*/ 
 
#if OS_Q_QUERY_EN > 0 
INT8U  OSQQuery (OS_EVENT *pevent, OS_Q_DATA *p_q_data) 
{ 
    OS_Q      *pq; 
    INT8U     *psrc; 
    INT8U     *pdest; 
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */ 
    OS_CPU_SR  cpu_sr; 
 
 
 
    cpu_sr = 0;                                            /* Prevent compiler warning                 */ 
#endif     
#if OS_ARG_CHK_EN > 0 
    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(); 
    p_q_data->OSEventGrp = pevent->OSEventGrp;             /* Copy message queue wait list             */ 
    psrc                 = &pevent->OSEventTbl[0]; 
    pdest                = &p_q_data->OSEventTbl[0]; 
#if OS_EVENT_TBL_SIZE > 0 
    *pdest++ = *psrc++; 
#endif 
 
#if OS_EVENT_TBL_SIZE > 1 
    *pdest++ = *psrc++; 
#endif 
 
#if OS_EVENT_TBL_SIZE > 2 
    *pdest++ = *psrc++; 
#endif 
 
#if OS_EVENT_TBL_SIZE > 3 
    *pdest++ = *psrc++; 
#endif 
 
#if OS_EVENT_TBL_SIZE > 4 
    *pdest++ = *psrc++; 
#endif 
 
#if OS_EVENT_TBL_SIZE > 5 
    *pdest++ = *psrc++; 
#endif 
 
#if OS_EVENT_TBL_SIZE > 6 
    *pdest++ = *psrc++; 
#endif 
 
#if OS_EVENT_TBL_SIZE > 7 
    *pdest   = *psrc; 
#endif 
    pq = (OS_Q *)pevent->OSEventPtr; 
    if (pq->OSQEntries > 0) { 
        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_NO_ERR); 
} 
#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 == 1 
    OSQFreeList         = &OSQTbl[0];                /* Only ONE queue!                                */ 
    OSQFreeList->OSQPtr = (OS_Q *)0; 
#endif 
 
#if OS_MAX_QS >= 2 
    INT16U  i; 
    OS_Q   *pq1; 
    OS_Q   *pq2; 
 
 
 
    OS_MemClr((INT8U *)&OSQTbl[0], sizeof(OSQTbl));  /* Clear the queue table                          */ 
    pq1 = &OSQTbl[0]; 
    pq2 = &OSQTbl[1]; 
    for (i = 0; i < (OS_MAX_QS - 1); i++) {          /* Init. list of free QUEUE control blocks        */ 
        pq1->OSQPtr = pq2; 
        pq1++; 
        pq2++; 
    } 
    pq1->OSQPtr = (OS_Q *)0; 
    OSQFreeList = &OSQTbl[0]; 
#endif 
} 
#endif                                               /* OS_Q_EN                                        */