www.pudn.com > uCOS-III.zip > os_mutex.c, change:2011-08-02,size:36759b


/* 
************************************************************************************************************************ 
*                                                      uC/OS-III 
*                                                 The Real-Time Kernel 
* 
*                                  (c) Copyright 2009-2011; Micrium, Inc.; Weston, FL 
*                           All rights reserved.  Protected by international copyright laws. 
* 
*                                                   MUTEX MANAGEMENT 
* 
* File    : OS_MUTEX.C 
* By      : JJL 
* Version : V3.02.00 
* 
* LICENSING TERMS: 
* --------------- 
*           uC/OS-III is provided in source form for FREE short-term evaluation, for educational use or  
*           for peaceful research.  If you plan or intend to use uC/OS-III in a commercial application/ 
*           product then, you need to contact Micrium to properly license uC/OS-III for its use in your  
*           application/product.   We provide ALL the source code for your convenience and to help you  
*           experience uC/OS-III.  The fact that the source is provided does NOT mean that you can use  
*           it commercially without paying a licensing fee. 
* 
*           Knowledge of the source code may NOT be used to develop a similar product. 
* 
*           Please help us continue to provide the embedded community with the finest software available. 
*           Your honesty is greatly appreciated. 
* 
*           You can contact us at www.micrium.com, or by phone at +1 (954) 217-2036. 
************************************************************************************************************************ 
*/ 
 
#include <os.h> 
 
#ifdef VSC_INCLUDE_SOURCE_FILE_NAMES 
const  CPU_CHAR  *os_mutex__c = "$Id: $"; 
#endif 
 
 
#if OS_CFG_MUTEX_EN > 0u 
/* 
************************************************************************************************************************ 
*                                                   CREATE A MUTEX 
* 
* Description: This function creates a mutex. 
* 
* Arguments  : p_mutex       is a pointer to the mutex to initialize.  Your application is responsible for allocating 
*                            storage for the mutex. 
* 
*              p_name        is a pointer to the name you would like to give the mutex. 
* 
*              p_err         is a pointer to a variable that will contain an error code returned by this function. 
* 
*                                OS_ERR_NONE                    if the call was successful 
*                                OS_ERR_CREATE_ISR              if you called this function from an ISR 
*                                OS_ERR_ILLEGAL_CREATE_RUN_TIME if you are trying to create the Mutex after you called 
*                                                                 OSSafetyCriticalStart(). 
*                                OS_ERR_NAME                    if 'p_name'  is a NULL pointer 
*                                OS_ERR_OBJ_CREATED             if the mutex has already been created 
*                                OS_ERR_OBJ_PTR_NULL            if 'p_mutex' is a NULL pointer 
* 
* Returns    : none 
************************************************************************************************************************ 
*/ 
 
void  OSMutexCreate (OS_MUTEX    *p_mutex, 
                     CPU_CHAR    *p_name, 
                     OS_ERR      *p_err) 
{ 
    CPU_SR_ALLOC(); 
 
 
 
#ifdef OS_SAFETY_CRITICAL 
    if (p_err == (OS_ERR *)0) { 
        OS_SAFETY_CRITICAL_EXCEPTION(); 
        return; 
    } 
#endif 
 
#ifdef OS_SAFETY_CRITICAL_IEC61508 
    if (OSSafetyCriticalStartFlag == DEF_TRUE) { 
       *p_err = OS_ERR_ILLEGAL_CREATE_RUN_TIME; 
        return; 
    } 
#endif 
 
#if OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u 
    if (OSIntNestingCtr > (OS_NESTING_CTR)0) {              /* Not allowed to be called from an ISR                   */ 
        *p_err = OS_ERR_CREATE_ISR; 
        return; 
    } 
#endif 
 
#if OS_CFG_ARG_CHK_EN > 0u 
    if (p_mutex == (OS_MUTEX *)0) {                         /* Validate 'p_mutex'                                     */ 
        *p_err = OS_ERR_OBJ_PTR_NULL; 
        return; 
    } 
#endif 
 
    CPU_CRITICAL_ENTER(); 
    p_mutex->Type              =  OS_OBJ_TYPE_MUTEX;        /* Mark the data structure as a mutex                     */ 
    p_mutex->NamePtr           =  p_name; 
    p_mutex->OwnerTCBPtr       = (OS_TCB       *)0; 
    p_mutex->OwnerNestingCtr   = (OS_NESTING_CTR)0;         /* Mutex is available                                     */ 
    p_mutex->TS                = (CPU_TS        )0; 
    p_mutex->OwnerOriginalPrio =  OS_CFG_PRIO_MAX; 
    OS_PendListInit(&p_mutex->PendList);                    /* Initialize the waiting list                            */ 
 
#if OS_CFG_DBG_EN > 0u 
    OS_MutexDbgListAdd(p_mutex); 
#endif 
    OSMutexQty++; 
 
    CPU_CRITICAL_EXIT(); 
    *p_err = OS_ERR_NONE; 
} 
 
/*$PAGE*/ 
/* 
************************************************************************************************************************ 
*                                                   DELETE A MUTEX 
* 
* Description: This function deletes a mutex and readies all tasks pending on the mutex. 
* 
* Arguments  : p_mutex       is a pointer to the mutex to delete 
* 
*              opt           determines delete options as follows: 
* 
*                                OS_OPT_DEL_NO_PEND          Delete mutex ONLY if no task pending 
*                                OS_OPT_DEL_ALWAYS           Deletes the mutex even if tasks are waiting. 
*                                                            In this case, all the tasks pending will be readied. 
* 
*              p_err         is a pointer to a variable that will contain an error code returned by this function. 
* 
*                                OS_ERR_NONE                 The call was successful and the mutex was deleted 
*                                OS_ERR_DEL_ISR              If you attempted to delete the mutex from an ISR 
*                                OS_ERR_OBJ_PTR_NULL         If 'p_mutex' is a NULL pointer. 
*                                OS_ERR_OBJ_TYPE             If 'p_mutex' is not pointing to a mutex 
*                                OS_ERR_OPT_INVALID          An invalid option was specified 
*                                OS_ERR_STATE_INVALID        Task is in an invalid state 
*                                OS_ERR_TASK_WAITING         One or more tasks were waiting on the mutex 
* 
* Returns    : == 0          if no tasks were waiting on the mutex, or upon error. 
*              >  0          if one or more tasks waiting on the mutex are now readied and informed. 
* 
* Note(s)    : 1) This function must be used with care.  Tasks that would normally expect the presence of the mutex MUST 
*                 check the return code of OSMutexPend(). 
* 
*              2) OSMutexAccept() callers will not know that the intended mutex has been deleted. 
* 
*              3) Because ALL tasks pending on the mutex will be readied, you MUST be careful in applications where the 
*                 mutex is used for mutual exclusion because the resource(s) will no longer be guarded by the mutex. 
************************************************************************************************************************ 
*/ 
 
#if OS_CFG_MUTEX_DEL_EN > 0u 
OS_OBJ_QTY  OSMutexDel (OS_MUTEX  *p_mutex, 
                        OS_OPT     opt, 
                        OS_ERR    *p_err) 
{ 
    OS_OBJ_QTY     cnt; 
    OS_OBJ_QTY     nbr_tasks; 
    OS_PEND_DATA  *p_pend_data; 
    OS_PEND_LIST  *p_pend_list; 
    OS_TCB        *p_tcb; 
    OS_TCB        *p_tcb_owner; 
    CPU_TS         ts; 
    CPU_SR_ALLOC(); 
 
 
 
#ifdef OS_SAFETY_CRITICAL 
    if (p_err == (OS_ERR *)0) { 
        OS_SAFETY_CRITICAL_EXCEPTION(); 
        return ((OS_OBJ_QTY)0); 
    } 
#endif 
 
#if OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u 
    if (OSIntNestingCtr > (OS_NESTING_CTR)0) {                   /* Not allowed to delete a mutex from an ISR         */ 
       *p_err = OS_ERR_DEL_ISR; 
        return ((OS_OBJ_QTY)0); 
    } 
#endif 
 
#if OS_CFG_ARG_CHK_EN > 0u 
    if (p_mutex == (OS_MUTEX *)0) {                              /* Validate pointer to mutex                         */ 
        *p_err = OS_ERR_OBJ_PTR_NULL; 
        return ((OS_OBJ_QTY)0); 
    } 
#endif 
 
#if OS_CFG_OBJ_TYPE_CHK_EN > 0u 
    if (p_mutex->Type != OS_OBJ_TYPE_MUTEX) {                    /* Make sure mutex was created                       */ 
        *p_err = OS_ERR_OBJ_TYPE; 
        return ((OS_OBJ_QTY)0); 
    } 
#endif 
 
    OS_CRITICAL_ENTER(); 
    p_pend_list = &p_mutex->PendList; 
    cnt         = p_pend_list->NbrEntries; 
    nbr_tasks   = cnt; 
    switch (opt) { 
        case OS_OPT_DEL_NO_PEND:                                 /* Delete mutex only if no task waiting              */ 
             if (nbr_tasks == (OS_OBJ_QTY)0) { 
#if OS_CFG_DBG_EN > 0u 
                 OS_MutexDbgListRemove(p_mutex); 
#endif 
                 OSMutexQty--; 
                 OS_MutexClr(p_mutex); 
                 OS_CRITICAL_EXIT(); 
                 *p_err = OS_ERR_NONE; 
             } else { 
                 OS_CRITICAL_EXIT(); 
                 *p_err = OS_ERR_TASK_WAITING; 
             } 
             break; 
 
        case OS_OPT_DEL_ALWAYS:                                            /* Always delete the mutex                 */ 
             p_tcb_owner = p_mutex->OwnerTCBPtr;                           /* Did we had to change the prio of owner? */ 
             if ((p_tcb_owner       != (OS_TCB *)0) && 
                 (p_tcb_owner->Prio !=  p_mutex->OwnerOriginalPrio)) { 
                 switch (p_tcb_owner->TaskState) {                         /* yes                                     */ 
                     case OS_TASK_STATE_RDY: 
                          OS_RdyListRemove(p_tcb_owner); 
                          p_tcb_owner->Prio = p_mutex->OwnerOriginalPrio;  /* Lower owner's prio back                 */ 
                          OS_PrioInsert(p_tcb_owner->Prio); 
                          OS_RdyListInsertTail(p_tcb_owner);               /* Insert owner in ready list at new prio  */ 
                          break; 
 
                     case OS_TASK_STATE_DLY: 
                     case OS_TASK_STATE_SUSPENDED: 
                     case OS_TASK_STATE_DLY_SUSPENDED: 
                          p_tcb_owner->Prio = p_mutex->OwnerOriginalPrio;  /* Not in any pend list, change the prio   */ 
                          break; 
 
                     case OS_TASK_STATE_PEND: 
                     case OS_TASK_STATE_PEND_TIMEOUT: 
                     case OS_TASK_STATE_PEND_SUSPENDED: 
                     case OS_TASK_STATE_PEND_TIMEOUT_SUSPENDED: 
                          OS_PendListChangePrio(p_tcb_owner,               /* Owner is pending on another object      */ 
                                                p_mutex->OwnerOriginalPrio); 
                          break; 
 
                     default: 
                          OS_CRITICAL_EXIT(); 
                          *p_err = OS_ERR_STATE_INVALID; 
                          return ((OS_OBJ_QTY)0); 
                 } 
             } 
 
             ts = OS_TS_GET();                                             /* Get timestamp                           */ 
             while (cnt > 0u) {                                            /* Remove all tasks from the pend list     */ 
                 p_pend_data = p_pend_list->HeadPtr; 
                 p_tcb       = p_pend_data->TCBPtr; 
                 OS_PendObjDel((OS_PEND_OBJ *)((void *)p_mutex), 
                               p_tcb, 
                               ts); 
                 cnt--; 
             } 
#if OS_CFG_DBG_EN > 0u 
             OS_MutexDbgListRemove(p_mutex); 
#endif 
             OSMutexQty--; 
             OS_MutexClr(p_mutex); 
             OS_CRITICAL_EXIT_NO_SCHED(); 
             OSSched();                                                    /* Find highest priority task ready to run */ 
             *p_err = OS_ERR_NONE; 
             break; 
 
        default: 
             OS_CRITICAL_EXIT(); 
             *p_err = OS_ERR_OPT_INVALID; 
             break; 
    } 
    return (nbr_tasks); 
} 
#endif 
 
/*$PAGE*/ 
/* 
************************************************************************************************************************ 
*                                                    PEND ON MUTEX 
* 
* Description: This function waits for a mutex. 
* 
* Arguments  : p_mutex       is a pointer to the mutex 
* 
*              timeout       is an optional timeout period (in clock ticks).  If non-zero, your task will wait for the 
*                            resource up to the amount of time (in 'ticks') specified by this argument.  If you specify 
*                            0, however, your task will wait forever at the specified mutex or, until the resource 
*                            becomes available. 
* 
*              opt           determines whether the user wants to block if the mutex is not available or not: 
* 
*                                OS_OPT_PEND_BLOCKING 
*                                OS_OPT_PEND_NON_BLOCKING 
* 
*              p_ts          is a pointer to a variable that will receive the timestamp of when the mutex was posted or 
*                            pend aborted or the mutex deleted.  If you pass a NULL pointer (i.e. (CPU_TS *)0) then you 
*                            will not get the timestamp.  In other words, passing a NULL pointer is valid and indicates 
*                            that you don't need the timestamp. 
* 
*              p_err         is a pointer to a variable that will contain an error code returned by this function. 
* 
*                                OS_ERR_NONE               The call was successful and your task owns the resource 
*                                OS_ERR_MUTEX_OWNER        If calling task already owns the mutex 
*                                OS_ERR_OBJ_DEL            If 'p_mutex' was deleted 
*                                OS_ERR_OBJ_PTR_NULL       If 'p_mutex' is a NULL pointer. 
*                                OS_ERR_OBJ_TYPE           If 'p_mutex' is not pointing at a mutex 
*                                OS_ERR_OPT_INVALID        If you didn't specify a valid option 
*                                OS_ERR_PEND_ABORT         If the pend was aborted by another task 
*                                OS_ERR_PEND_ISR           If you called this function from an ISR and the result 
*                                                          would lead to a suspension. 
*                                OS_ERR_PEND_WOULD_BLOCK   If you specified non-blocking but the mutex was not 
*                                                          available. 
*                                OS_ERR_SCHED_LOCKED       If you called this function when the scheduler is locked 
*                                OS_ERR_STATE_INVALID      If the task is in an invalid state 
*                                OS_ERR_STATUS_INVALID     If the pend status has an invalid value 
*                                OS_ERR_TIMEOUT            The mutex was not received within the specified timeout. 
* 
* Returns    : none 
************************************************************************************************************************ 
*/ 
 
void  OSMutexPend (OS_MUTEX   *p_mutex, 
                   OS_TICK     timeout, 
                   OS_OPT      opt, 
                   CPU_TS     *p_ts, 
                   OS_ERR     *p_err) 
{ 
    OS_PEND_DATA  pend_data; 
    OS_TCB       *p_tcb; 
    CPU_SR_ALLOC(); 
 
 
 
#ifdef OS_SAFETY_CRITICAL 
    if (p_err == (OS_ERR *)0) { 
        OS_SAFETY_CRITICAL_EXCEPTION(); 
        return; 
    } 
#endif 
 
#if OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u 
    if (OSIntNestingCtr > (OS_NESTING_CTR)0) {              /* Not allowed to call from an ISR                        */ 
       *p_err = OS_ERR_PEND_ISR; 
        return; 
    } 
#endif 
 
#if OS_CFG_ARG_CHK_EN > 0u 
    if (p_mutex == (OS_MUTEX *)0) {                         /* Validate arguments                                     */ 
        *p_err = OS_ERR_OBJ_PTR_NULL; 
        return; 
    } 
    switch (opt) { 
        case OS_OPT_PEND_BLOCKING: 
        case OS_OPT_PEND_NON_BLOCKING: 
             break; 
 
        default: 
             *p_err = OS_ERR_OPT_INVALID; 
             return; 
    } 
#endif 
 
#if OS_CFG_OBJ_TYPE_CHK_EN > 0u 
    if (p_mutex->Type != OS_OBJ_TYPE_MUTEX) {               /* Make sure mutex was created                            */ 
        *p_err = OS_ERR_OBJ_TYPE; 
        return; 
    } 
#endif 
 
    if (p_ts != (CPU_TS *)0) { 
       *p_ts  = (CPU_TS  )0;                                /* Initialize the returned timestamp                      */ 
    } 
 
    CPU_CRITICAL_ENTER(); 
    if (p_mutex->OwnerNestingCtr == (OS_NESTING_CTR)0) {    /* Resource available?                                    */ 
        p_mutex->OwnerTCBPtr       =  OSTCBCurPtr;          /* Yes, caller may proceed                                */ 
        p_mutex->OwnerOriginalPrio =  OSTCBCurPtr->Prio; 
        p_mutex->OwnerNestingCtr   = (OS_NESTING_CTR)1; 
        if (p_ts != (CPU_TS *)0) { 
           *p_ts                   = p_mutex->TS; 
        } 
        CPU_CRITICAL_EXIT(); 
        *p_err                     =  OS_ERR_NONE; 
        return; 
    } 
 
    if (OSTCBCurPtr == p_mutex->OwnerTCBPtr) {              /* See if current task is already the owner of the mutex  */ 
        p_mutex->OwnerNestingCtr++; 
        if (p_ts != (CPU_TS *)0) { 
           *p_ts  = p_mutex->TS; 
        } 
        CPU_CRITICAL_EXIT(); 
        *p_err = OS_ERR_MUTEX_OWNER;                        /* Indicate that current task already owns the mutex      */ 
        return; 
    } 
 
    if ((opt & OS_OPT_PEND_NON_BLOCKING) != (OS_OPT)0) {    /* Caller wants to block if not available?                */ 
        CPU_CRITICAL_EXIT(); 
        *p_err = OS_ERR_PEND_WOULD_BLOCK;                   /* No                                                     */ 
        return; 
    } else { 
        if (OSSchedLockNestingCtr > (OS_NESTING_CTR)0) {    /* Can't pend when the scheduler is locked                */ 
            CPU_CRITICAL_EXIT(); 
            *p_err = OS_ERR_SCHED_LOCKED; 
            return; 
        } 
    } 
 
    OS_CRITICAL_ENTER_CPU_CRITICAL_EXIT();                  /* Lock the scheduler/re-enable interrupts                */ 
    p_tcb = p_mutex->OwnerTCBPtr;                           /* Point to the TCB of the Mutex owner                    */ 
    if (p_tcb->Prio > OSTCBCurPtr->Prio) {                  /* See if mutex owner has a lower priority than current   */ 
        switch (p_tcb->TaskState) { 
            case OS_TASK_STATE_RDY: 
                 OS_RdyListRemove(p_tcb);                   /* Remove from ready list at current priority             */ 
                 p_tcb->Prio = OSTCBCurPtr->Prio;           /* Raise owner's priority                                 */ 
                 OS_PrioInsert(p_tcb->Prio); 
                 OS_RdyListInsertHead(p_tcb);               /* Insert in ready list at new priority                   */ 
                 break; 
 
            case OS_TASK_STATE_DLY: 
            case OS_TASK_STATE_DLY_SUSPENDED: 
            case OS_TASK_STATE_SUSPENDED: 
                 p_tcb->Prio = OSTCBCurPtr->Prio;           /* Only need to raise the owner's priority                */ 
                 break; 
 
            case OS_TASK_STATE_PEND:                        /* Change the position of the task in the wait list       */ 
            case OS_TASK_STATE_PEND_TIMEOUT: 
            case OS_TASK_STATE_PEND_SUSPENDED: 
            case OS_TASK_STATE_PEND_TIMEOUT_SUSPENDED: 
                 OS_PendListChangePrio(p_tcb, 
                                       OSTCBCurPtr->Prio); 
                 break; 
 
            default: 
                 OS_CRITICAL_EXIT(); 
                 *p_err = OS_ERR_STATE_INVALID; 
                 return; 
        } 
    } 
 
    OS_Pend(&pend_data,                                     /* Block task pending on Mutex                            */ 
            (OS_PEND_OBJ *)((void *)p_mutex), 
             OS_TASK_PEND_ON_MUTEX, 
             timeout); 
 
    OS_CRITICAL_EXIT_NO_SCHED(); 
 
    OSSched();                                              /* Find the next highest priority task ready to run       */ 
 
    CPU_CRITICAL_ENTER(); 
    switch (OSTCBCurPtr->PendStatus) { 
        case OS_STATUS_PEND_OK:                             /* We got the mutex                                       */ 
             if (p_ts != (CPU_TS *)0) { 
                *p_ts  = OSTCBCurPtr->TS; 
             } 
             *p_err = OS_ERR_NONE; 
             break; 
 
        case OS_STATUS_PEND_ABORT:                          /* Indicate that we aborted                               */ 
             if (p_ts != (CPU_TS *)0) { 
                *p_ts  = OSTCBCurPtr->TS; 
             } 
             *p_err = OS_ERR_PEND_ABORT; 
             break; 
 
        case OS_STATUS_PEND_TIMEOUT:                        /* Indicate that we didn't get mutex within timeout       */ 
             if (p_ts != (CPU_TS *)0) { 
                *p_ts  = (CPU_TS  )0; 
             } 
             *p_err = OS_ERR_TIMEOUT; 
             break; 
 
        case OS_STATUS_PEND_DEL:                            /* Indicate that object pended on has been deleted        */ 
             if (p_ts != (CPU_TS *)0) { 
                *p_ts  = OSTCBCurPtr->TS; 
             } 
             *p_err = OS_ERR_OBJ_DEL; 
             break; 
 
        default: 
             *p_err = OS_ERR_STATUS_INVALID; 
             break; 
    } 
    CPU_CRITICAL_EXIT(); 
} 
 
/*$PAGE*/ 
/* 
************************************************************************************************************************ 
*                                               ABORT WAITING ON A MUTEX 
* 
* Description: This function aborts & readies any tasks currently waiting on a mutex.  This function should be used 
*              to fault-abort the wait on the mutex, rather than to normally signal the mutex via OSMutexPost(). 
* 
* Arguments  : p_mutex   is a pointer to the mutex 
* 
*              opt       determines the type of ABORT performed: 
* 
*                            OS_OPT_PEND_ABORT_1          ABORT wait for a single task (HPT) waiting on the mutex 
*                            OS_OPT_PEND_ABORT_ALL        ABORT wait for ALL tasks that are  waiting on the mutex 
*                            OS_OPT_POST_NO_SCHED         Do not call the scheduler 
* 
*              p_err     is a pointer to a variable that will contain an error code returned by this function. 
* 
*                            OS_ERR_NONE                  At least one task waiting on the mutex was readied and 
*                                                         informed of the aborted wait; check return value for the 
*                                                         number of tasks whose wait on the mutex was aborted. 
*                            OS_ERR_OBJ_PTR_NULL          If 'p_mutex' is a NULL pointer. 
*                            OS_ERR_OBJ_TYPE              If 'p_mutex' is not pointing at a mutex 
*                            OS_ERR_OPT_INVALID           If you specified an invalid option 
*                            OS_ERR_PEND_ABORT_ISR        If you attempted to call this function from an ISR 
*                            OS_ERR_PEND_ABORT_NONE       No task were pending 
* 
* Returns    : == 0          if no tasks were waiting on the mutex, or upon error. 
*              >  0          if one or more tasks waiting on the mutex are now readied and informed. 
************************************************************************************************************************ 
*/ 
 
#if OS_CFG_MUTEX_PEND_ABORT_EN > 0u 
OS_OBJ_QTY  OSMutexPendAbort (OS_MUTEX  *p_mutex, 
                              OS_OPT     opt, 
                              OS_ERR    *p_err) 
{ 
    OS_PEND_LIST  *p_pend_list; 
    OS_TCB        *p_tcb; 
    CPU_TS         ts; 
    OS_OBJ_QTY     nbr_tasks; 
    CPU_SR_ALLOC(); 
 
 
 
#ifdef OS_SAFETY_CRITICAL 
    if (p_err == (OS_ERR *)0) { 
        OS_SAFETY_CRITICAL_EXCEPTION(); 
        return ((OS_OBJ_QTY)0u); 
    } 
#endif 
 
#if OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u 
    if (OSIntNestingCtr > (OS_NESTING_CTR)0u) {             /* Not allowed to Pend Abort from an ISR                  */ 
       *p_err =  OS_ERR_PEND_ABORT_ISR; 
        return ((OS_OBJ_QTY)0u); 
    } 
#endif 
 
#if OS_CFG_ARG_CHK_EN > 0u 
    if (p_mutex == (OS_MUTEX *)0) {                         /* Validate 'p_mutex'                                     */ 
       *p_err =  OS_ERR_OBJ_PTR_NULL; 
        return ((OS_OBJ_QTY)0u); 
    } 
    switch (opt) {                                          /* Validate 'opt'                                         */ 
        case OS_OPT_PEND_ABORT_1: 
        case OS_OPT_PEND_ABORT_ALL: 
             break; 
 
        default: 
            *p_err =  OS_ERR_OPT_INVALID; 
             return ((OS_OBJ_QTY)0u); 
    } 
#endif 
 
#if OS_CFG_OBJ_TYPE_CHK_EN > 0u 
    if (p_mutex->Type != OS_OBJ_TYPE_MUTEX) {               /* Make sure mutex was created                            */ 
       *p_err =  OS_ERR_OBJ_TYPE; 
        return ((OS_OBJ_QTY)0u); 
    } 
#endif 
 
    CPU_CRITICAL_ENTER(); 
    p_pend_list = &p_mutex->PendList; 
    if (p_pend_list->NbrEntries == (OS_OBJ_QTY)0u) {        /* Any task waiting on mutex?                             */ 
        CPU_CRITICAL_EXIT();                                /* No                                                     */ 
       *p_err =  OS_ERR_PEND_ABORT_NONE; 
        return ((OS_OBJ_QTY)0u); 
    } 
 
    OS_CRITICAL_ENTER_CPU_CRITICAL_EXIT(); 
    nbr_tasks = 0u; 
    ts        = OS_TS_GET();                                /* Get local time stamp so all tasks get the same time    */ 
    while (p_pend_list->NbrEntries > (OS_OBJ_QTY)0u) { 
        p_tcb = p_pend_list->HeadPtr->TCBPtr; 
        OS_PendAbort((OS_PEND_OBJ *)((void *)p_mutex), 
                     p_tcb, 
                     ts); 
        nbr_tasks++; 
        if (opt != OS_OPT_PEND_ABORT_ALL) {                 /* Pend abort all tasks waiting?                          */ 
            break;                                          /* No                                                     */ 
        } 
    } 
    OS_CRITICAL_EXIT_NO_SCHED(); 
 
    if ((opt & OS_OPT_POST_NO_SCHED) == (OS_OPT)0u) { 
        OSSched();                                          /* Run the scheduler                                      */ 
    } 
 
   *p_err = OS_ERR_NONE; 
    return (nbr_tasks); 
} 
#endif 
 
/*$PAGE*/ 
/* 
************************************************************************************************************************ 
*                                                   POST TO A MUTEX 
* 
* Description: This function signals a mutex 
* 
* Arguments  : p_mutex  is a pointer to the mutex 
* 
*              opt      is an option you can specify to alter the behavior of the post.  The choices are: 
* 
*                           OS_OPT_POST_NONE        No special option selected 
*                           OS_OPT_POST_NO_SCHED    If you don't want the scheduler to be called after the post. 
* 
*              p_err    is a pointer to a variable that will contain an error code returned by this function. 
* 
*                           OS_ERR_NONE             The call was successful and the mutex was signaled. 
*                           OS_ERR_MUTEX_NESTING    Mutex owner nested its use of the mutex 
*                           OS_ERR_MUTEX_NOT_OWNER  If the task posting is not the Mutex owner 
*                           OS_ERR_OBJ_PTR_NULL     If 'p_mutex' is a NULL pointer. 
*                           OS_ERR_OBJ_TYPE         If 'p_mutex' is not pointing at a mutex 
*                           OS_ERR_POST_ISR         If you attempted to post from an ISR 
* 
* Returns    : none 
************************************************************************************************************************ 
*/ 
 
void  OSMutexPost (OS_MUTEX  *p_mutex, 
                   OS_OPT     opt, 
                   OS_ERR    *p_err) 
{ 
    OS_PEND_LIST  *p_pend_list; 
    OS_TCB        *p_tcb; 
    CPU_TS         ts; 
    CPU_SR_ALLOC(); 
 
 
 
#ifdef OS_SAFETY_CRITICAL 
    if (p_err == (OS_ERR *)0) { 
        OS_SAFETY_CRITICAL_EXCEPTION(); 
        return; 
    } 
#endif 
 
#if OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u 
    if (OSIntNestingCtr > (OS_NESTING_CTR)0) {              /* Not allowed to call from an ISR                        */ 
       *p_err = OS_ERR_POST_ISR; 
        return; 
    } 
#endif 
 
#if OS_CFG_ARG_CHK_EN > 0u 
    if (p_mutex == (OS_MUTEX *)0) {                         /* Validate 'p_mutex'                                     */ 
        *p_err = OS_ERR_OBJ_PTR_NULL; 
        return; 
    } 
#endif 
 
#if OS_CFG_OBJ_TYPE_CHK_EN > 0u 
    if (p_mutex->Type != OS_OBJ_TYPE_MUTEX) {               /* Make sure mutex was created                            */ 
        *p_err = OS_ERR_OBJ_TYPE; 
        return; 
    } 
#endif 
 
    CPU_CRITICAL_ENTER(); 
    if (OSTCBCurPtr != p_mutex->OwnerTCBPtr) {              /* Make sure the mutex owner is releasing the mutex       */ 
        CPU_CRITICAL_EXIT(); 
        *p_err = OS_ERR_MUTEX_NOT_OWNER; 
        return; 
    } 
 
    OS_CRITICAL_ENTER_CPU_CRITICAL_EXIT(); 
    ts          = OS_TS_GET();                              /* Get timestamp                                          */ 
    p_mutex->TS = ts; 
    p_mutex->OwnerNestingCtr--;                             /* Decrement owner's nesting counter                      */ 
    if (p_mutex->OwnerNestingCtr > (OS_NESTING_CTR)0) {     /* Are we done with all nestings?                         */ 
        OS_CRITICAL_EXIT();                                 /* No                                                     */ 
        *p_err = OS_ERR_MUTEX_NESTING; 
        return; 
    } 
 
    p_pend_list = &p_mutex->PendList; 
    if (p_pend_list->NbrEntries == (OS_OBJ_QTY)0) {         /* Any task waiting on mutex?                             */ 
        p_mutex->OwnerTCBPtr     = (OS_TCB       *)0;       /* No                                                     */ 
        p_mutex->OwnerNestingCtr = (OS_NESTING_CTR)0; 
        OS_CRITICAL_EXIT(); 
        *p_err = OS_ERR_NONE; 
        return; 
    } 
                                                            /* Yes                                                    */ 
    if (OSTCBCurPtr->Prio != p_mutex->OwnerOriginalPrio) { 
        OS_RdyListRemove(OSTCBCurPtr); 
        OSTCBCurPtr->Prio = p_mutex->OwnerOriginalPrio;     /* Lower owner's priority back to its original one        */ 
        OS_PrioInsert(OSTCBCurPtr->Prio); 
        OS_RdyListInsertTail(OSTCBCurPtr);                  /* Insert owner in ready list at new priority             */ 
        OSPrioCur         = OSTCBCurPtr->Prio; 
    } 
                                                            /* Get TCB from head of pend list                         */ 
    p_tcb                      = p_pend_list->HeadPtr->TCBPtr; 
    p_mutex->OwnerTCBPtr       = p_tcb;                     /* Give mutex to new owner                                */ 
    p_mutex->OwnerOriginalPrio = p_tcb->Prio; 
    p_mutex->OwnerNestingCtr   = (OS_NESTING_CTR)1; 
                                                            /* Post to mutex                                          */ 
    OS_Post((OS_PEND_OBJ *)((void *)p_mutex), 
            (OS_TCB      *)p_tcb, 
            (void        *)0, 
            (OS_MSG_SIZE  )0, 
            (CPU_TS       )ts); 
 
    OS_CRITICAL_EXIT_NO_SCHED(); 
 
    if ((opt & OS_OPT_POST_NO_SCHED) == (OS_OPT)0) { 
        OSSched();                                          /* Run the scheduler                                      */ 
    } 
 
    *p_err = OS_ERR_NONE; 
} 
 
/*$PAGE*/ 
/* 
************************************************************************************************************************ 
*                                            CLEAR THE CONTENTS OF A MUTEX 
* 
* Description: This function is called by OSMutexDel() to clear the contents of a mutex 
* 
 
* Argument(s): p_mutex      is a pointer to the mutex to clear 
*              ------- 
* 
* Returns    : none 
* 
* Note(s)    : This function is INTERNAL to uC/OS-III and your application should not call it. 
************************************************************************************************************************ 
*/ 
 
void  OS_MutexClr (OS_MUTEX  *p_mutex) 
{ 
    p_mutex->Type              =  OS_OBJ_TYPE_NONE;         /* Mark the data structure as a NONE                      */ 
    p_mutex->NamePtr           = (CPU_CHAR     *)((void *)"?MUTEX"); 
    p_mutex->OwnerTCBPtr       = (OS_TCB       *)0; 
    p_mutex->OwnerNestingCtr   = (OS_NESTING_CTR)0; 
    p_mutex->TS                = (CPU_TS        )0; 
    p_mutex->OwnerOriginalPrio =  OS_CFG_PRIO_MAX; 
    OS_PendListInit(&p_mutex->PendList);                    /* Initialize the waiting list                            */ 
} 
 
/*$PAGE*/ 
/* 
************************************************************************************************************************ 
*                                          ADD/REMOVE MUTEX TO/FROM DEBUG LIST 
* 
* Description: These functions are called by uC/OS-III to add or remove a mutex to/from the debug list. 
* 
* Arguments  : p_mutex     is a pointer to the mutex to add/remove 
* 
* Returns    : none 
* 
* Note(s)    : These functions are INTERNAL to uC/OS-III and your application should not call it. 
************************************************************************************************************************ 
*/ 
 
 
#if OS_CFG_DBG_EN > 0u 
void  OS_MutexDbgListAdd (OS_MUTEX  *p_mutex) 
{ 
    p_mutex->DbgNamePtr               = (CPU_CHAR *)((void *)" "); 
    p_mutex->DbgPrevPtr               = (OS_MUTEX *)0; 
    if (OSMutexDbgListPtr == (OS_MUTEX *)0) { 
        p_mutex->DbgNextPtr           = (OS_MUTEX *)0; 
    } else { 
        p_mutex->DbgNextPtr           =  OSMutexDbgListPtr; 
        OSMutexDbgListPtr->DbgPrevPtr =  p_mutex; 
    } 
    OSMutexDbgListPtr                 =  p_mutex; 
} 
 
 
 
void  OS_MutexDbgListRemove (OS_MUTEX  *p_mutex) 
{ 
    OS_MUTEX  *p_mutex_next; 
    OS_MUTEX  *p_mutex_prev; 
 
 
    p_mutex_prev = p_mutex->DbgPrevPtr; 
    p_mutex_next = p_mutex->DbgNextPtr; 
 
    if (p_mutex_prev == (OS_MUTEX *)0) { 
        OSMutexDbgListPtr = p_mutex_next; 
        if (p_mutex_next != (OS_MUTEX *)0) { 
            p_mutex_next->DbgPrevPtr = (OS_MUTEX *)0; 
        } 
        p_mutex->DbgNextPtr = (OS_MUTEX *)0; 
 
    } else if (p_mutex_next == (OS_MUTEX *)0) { 
        p_mutex_prev->DbgNextPtr = (OS_MUTEX *)0; 
        p_mutex->DbgPrevPtr      = (OS_MUTEX *)0; 
 
    } else { 
        p_mutex_prev->DbgNextPtr =  p_mutex_next; 
        p_mutex_next->DbgPrevPtr =  p_mutex_prev; 
        p_mutex->DbgNextPtr      = (OS_MUTEX *)0; 
        p_mutex->DbgPrevPtr      = (OS_MUTEX *)0; 
    } 
} 
#endif 
 
/*$PAGE*/ 
/* 
************************************************************************************************************************ 
*                                                MUTEX INITIALIZATION 
* 
* Description: This function is called by OSInit() to initialize the mutex management. 
* 
 
* Argument(s): p_err        is a pointer to a variable that will contain an error code returned by this function. 
* 
*                                OS_ERR_NONE     the call was successful 
* 
* Returns    : none 
* 
* Note(s)    : 1) This function is INTERNAL to uC/OS-III and your application MUST NOT call it. 
************************************************************************************************************************ 
*/ 
 
void  OS_MutexInit (OS_ERR  *p_err) 
{ 
#ifdef OS_SAFETY_CRITICAL 
    if (p_err == (OS_ERR *)0) { 
        OS_SAFETY_CRITICAL_EXCEPTION(); 
        return; 
    } 
#endif 
 
#if OS_CFG_DBG_EN > 0u 
    OSMutexDbgListPtr = (OS_MUTEX *)0; 
#endif 
 
    OSMutexQty        = (OS_OBJ_QTY)0; 
    *p_err            =  OS_ERR_NONE; 
} 
 
#endif                                                      /* OS_CFG_MUTEX_EN                                        */