/* ********************************************************************************************************* * uC/OS-II * The Real-Time Kernel * MESSAGE MAILBOX MANAGEMENT * * (c) Copyright 1992-2013, Micrium, Weston, FL * All Rights Reserved * * File : OS_MBOX.C * By : Jean J. Labrosse * Version : V2.92.11 * * 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 #endif #if OS_MBOX_EN > 0u /* ********************************************************************************************************* * ACCEPT MESSAGE FROM MAILBOX * * Description: This function checks the mailbox to see if a message is available. Unlike OSMboxPend(), * OSMboxAccept() does not suspend the calling task if a message is not available. * * Arguments : pevent is a pointer to the event control block * * Returns : != (void *)0 is the message in the mailbox if one is available. The mailbox is cleared * so the next time OSMboxAccept() is called, the mailbox will be empty. * == (void *)0 if the mailbox is empty or, * if 'pevent' is a NULL pointer or, * if you didn't pass the proper event pointer. ********************************************************************************************************* */ #if OS_MBOX_ACCEPT_EN > 0u void *OSMboxAccept (OS_EVENT *pevent) { void *pmsg; #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 ((void *)0); } #endif if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) { /* Validate event block type */ return ((void *)0); } OS_ENTER_CRITICAL(); pmsg = pevent->OSEventPtr; pevent->OSEventPtr = (void *)0; /* Clear the mailbox */ OS_EXIT_CRITICAL(); return (pmsg); /* Return the message received (or NULL) */ } #endif /*$PAGE*/ /* ********************************************************************************************************* * CREATE A MESSAGE MAILBOX * * Description: This function creates a message mailbox if free event control blocks are available. * * Arguments : pmsg is a pointer to a message that you wish to deposit in the mailbox. If * you set this value to the NULL pointer (i.e. (void *)0) then the mailbox * will be considered empty. * * Returns : != (OS_EVENT *)0 is a pointer to the event control clock (OS_EVENT) associated with the * created mailbox * == (OS_EVENT *)0 if no event control blocks were available ********************************************************************************************************* */ OS_EVENT *OSMboxCreate (void *pmsg) { OS_EVENT *pevent; #if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */ OS_CPU_SR cpu_sr = 0u; #endif #ifdef OS_SAFETY_CRITICAL_IEC61508 if (OSSafetyCriticalStartFlag == OS_TRUE) { OS_SAFETY_CRITICAL_EXCEPTION(); return ((OS_EVENT *)0); } #endif if (OSIntNesting > 0u) { /* See if called from ISR ... */ return ((OS_EVENT *)0); /* ... can't CREATE from an ISR */ } OS_ENTER_CRITICAL(); pevent = OSEventFreeList; /* Get next free event control block */ if (OSEventFreeList != (OS_EVENT *)0) { /* See if pool of free ECB pool was empty */ OSEventFreeList = (OS_EVENT *)OSEventFreeList->OSEventPtr; } OS_EXIT_CRITICAL(); if (pevent != (OS_EVENT *)0) { pevent->OSEventType = OS_EVENT_TYPE_MBOX; pevent->OSEventCnt = 0u; pevent->OSEventPtr = pmsg; /* Deposit message in event control block */ #if OS_EVENT_NAME_EN > 0u pevent->OSEventName = (INT8U *)(void *)"?"; #endif OS_EventWaitListInit(pevent); } return (pevent); /* Return pointer to event control block */ } /*$PAGE*/ /* ********************************************************************************************************* * DELETE A MAIBOX * * Description: This function deletes a mailbox and readies all tasks pending on the mailbox. * * Arguments : pevent is a pointer to the event control block associated with the desired * mailbox. * * opt determines delete options as follows: * opt == OS_DEL_NO_PEND Delete the mailbox ONLY if no task pending * opt == OS_DEL_ALWAYS Deletes the mailbox 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 mailbox was deleted * OS_ERR_DEL_ISR If you attempted to delete the mailbox from an ISR * OS_ERR_INVALID_OPT An invalid option was specified * OS_ERR_TASK_WAITING One or more tasks were waiting on the mailbox * OS_ERR_EVENT_TYPE If you didn't pass a pointer to a mailbox * OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer. * * Returns : pevent upon error * (OS_EVENT *)0 if the mailbox was successfully deleted. * * Note(s) : 1) This function must be used with care. Tasks that would normally expect the presence of * the mailbox MUST check the return code of OSMboxPend(). * 2) OSMboxAccept() callers will not know that the intended mailbox has been deleted! * 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 mailbox. * 4) Because ALL tasks pending on the mailbox will be readied, you MUST be careful in * applications where the mailbox is used for mutual exclusion because the resource(s) * will no longer be guarded by the mailbox. * 5) All tasks that were waiting for the mailbox will be readied and returned an * OS_ERR_PEND_ABORT if OSMboxDel() was called with OS_DEL_ALWAYS ********************************************************************************************************* */ #if OS_MBOX_DEL_EN > 0u OS_EVENT *OSMboxDel (OS_EVENT *pevent, INT8U opt, INT8U *perr) { BOOLEAN tasks_waiting; OS_EVENT *pevent_return; #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_MBOX) { /* 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 mailbox */ tasks_waiting = OS_TRUE; /* Yes */ } else { tasks_waiting = OS_FALSE; /* No */ } switch (opt) { case OS_DEL_NO_PEND: /* Delete mailbox only if no task waiting */ if (tasks_waiting == OS_FALSE) { #if OS_EVENT_NAME_EN > 0u pevent->OSEventName = (INT8U *)(void *)"?"; #endif 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; /* Mailbox has been deleted */ } else { OS_EXIT_CRITICAL(); *perr = OS_ERR_TASK_WAITING; pevent_return = pevent; } break; case OS_DEL_ALWAYS: /* Always delete the mailbox */ while (pevent->OSEventGrp != 0u) { /* Ready ALL tasks waiting for mailbox */ (void)OS_EventTaskRdy(pevent, (void *)0, OS_STAT_MBOX, OS_STAT_PEND_ABORT); } #if OS_EVENT_NAME_EN > 0u pevent->OSEventName = (INT8U *)(void *)"?"; #endif 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; /* Mailbox has been deleted */ break; default: OS_EXIT_CRITICAL(); *perr = OS_ERR_INVALID_OPT; pevent_return = pevent; break; } return (pevent_return); } #endif /*$PAGE*/ /* ********************************************************************************************************* * PEND ON MAILBOX FOR A MESSAGE * * Description: This function waits for a message to be sent to a mailbox * * Arguments : pevent is a pointer to the event control block associated with the desired mailbox * * timeout is an optional timeout period (in clock ticks). If non-zero, your task will * wait for a message to arrive at the mailbox up to the amount of time * specified by this argument. If you specify 0, however, your task will wait * forever at the specified mailbox or, until a message arrives. * * perr is a pointer to where an error message will be deposited. Possible error * messages are: * * OS_ERR_NONE The call was successful and your task received a * message. * OS_ERR_TIMEOUT A message was not received within the specified 'timeout'. * OS_ERR_PEND_ABORT The wait on the mailbox was aborted. * OS_ERR_EVENT_TYPE Invalid event type * OS_ERR_PEND_ISR If you called this function from an ISR and the result * would lead to a suspension. * OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer * OS_ERR_PEND_LOCKED If you called this function when the scheduler is locked * * Returns : != (void *)0 is a pointer to the message received * == (void *)0 if no message was received or, * if 'pevent' is a NULL pointer or, * if you didn't pass the proper pointer to the event control block. ********************************************************************************************************* */ /*$PAGE*/ void *OSMboxPend (OS_EVENT *pevent, INT32U timeout, INT8U *perr) { void *pmsg; #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_MBOX) { /* 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(); pmsg = pevent->OSEventPtr; if (pmsg != (void *)0) { /* See if there is already a message */ pevent->OSEventPtr = (void *)0; /* Clear the mailbox */ OS_EXIT_CRITICAL(); *perr = OS_ERR_NONE; return (pmsg); /* Return the message received (or NULL) */ } OSTCBCur->OSTCBStat |= OS_STAT_MBOX; /* Message not available, task will pend */ OSTCBCur->OSTCBStatPend = OS_STAT_PEND_OK; OSTCBCur->OSTCBDly = timeout; /* Load timeout in 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: 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 MAILBOX * * Description: This function aborts & readies any tasks currently waiting on a mailbox. This function * should be used to fault-abort the wait on the mailbox, rather than to normally signal * the mailbox via OSMboxPost() or OSMboxPostOpt(). * * Arguments : pevent is a pointer to the event control block associated with the desired mailbox. * * opt determines the type of ABORT performed: * OS_PEND_OPT_NONE ABORT wait for a single task (HPT) waiting on the * mailbox * OS_PEND_OPT_BROADCAST ABORT wait for ALL tasks that are waiting on the * mailbox * * 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 mailbox. * OS_ERR_PEND_ABORT At least one task waiting on the mailbox was readied * and informed of the aborted wait; check return value * for the number of tasks whose wait on the mailbox * was aborted. * OS_ERR_EVENT_TYPE If you didn't pass a pointer to a mailbox. * OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer. * * Returns : == 0 if no tasks were waiting on the mailbox, or upon error. * > 0 if one or more tasks waiting on the mailbox are now readied and informed. ********************************************************************************************************* */ #if OS_MBOX_PEND_ABORT_EN > 0u INT8U OSMboxPendAbort (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_MBOX) { /* Validate event block type */ *perr = OS_ERR_EVENT_TYPE; return (0u); } OS_ENTER_CRITICAL(); if (pevent->OSEventGrp != 0u) { /* See if any task waiting on mailbox? */ 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 mailbox */ (void)OS_EventTaskRdy(pevent, (void *)0, OS_STAT_MBOX, OS_STAT_PEND_ABORT); nbr_tasks++; } break; case OS_PEND_OPT_NONE: default: /* No, ready HPT waiting on mailbox */ (void)OS_EventTaskRdy(pevent, (void *)0, OS_STAT_MBOX, 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 mailbox */ } #endif /*$PAGE*/ /* ********************************************************************************************************* * POST MESSAGE TO A MAILBOX * * Description: This function sends a message to a mailbox * * Arguments : pevent is a pointer to the event control block associated with the desired mailbox * * pmsg is a pointer to the message to send. You MUST NOT send a NULL pointer. * * Returns : OS_ERR_NONE The call was successful and the message was sent * OS_ERR_MBOX_FULL If the mailbox already contains a message. You can can only send one * message at a time and thus, the message MUST be consumed before you * are allowed to send another one. * OS_ERR_EVENT_TYPE If you are attempting to post to a non mailbox. * OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer * OS_ERR_POST_NULL_PTR If you are attempting to post a NULL pointer * * Note(s) : 1) HPT means Highest Priority Task ********************************************************************************************************* */ #if OS_MBOX_POST_EN > 0u INT8U OSMboxPost (OS_EVENT *pevent, void *pmsg) { #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 (pmsg == (void *)0) { /* Make sure we are not posting a NULL pointer */ return (OS_ERR_POST_NULL_PTR); } #endif if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) { /* Validate event block type */ return (OS_ERR_EVENT_TYPE); } OS_ENTER_CRITICAL(); if (pevent->OSEventGrp != 0u) { /* See if any task pending on mailbox */ /* Ready HPT waiting on event */ (void)OS_EventTaskRdy(pevent, pmsg, OS_STAT_MBOX, OS_STAT_PEND_OK); OS_EXIT_CRITICAL(); OS_Sched(); /* Find highest priority task ready to run */ return (OS_ERR_NONE); } if (pevent->OSEventPtr != (void *)0) { /* Make sure mailbox doesn't already have a msg */ OS_EXIT_CRITICAL(); return (OS_ERR_MBOX_FULL); } pevent->OSEventPtr = pmsg; /* Place message in mailbox */ OS_EXIT_CRITICAL(); return (OS_ERR_NONE); } #endif /*$PAGE*/ /* ********************************************************************************************************* * POST MESSAGE TO A MAILBOX * * Description: This function sends a message to a mailbox * * Arguments : pevent is a pointer to the event control block associated with the desired mailbox * * pmsg is a pointer to the message to send. You MUST NOT send a NULL pointer. * * opt determines the type of POST performed: * OS_POST_OPT_NONE POST to a single waiting task * (Identical to OSMboxPost()) * OS_POST_OPT_BROADCAST POST to ALL tasks that are waiting on the mailbox * * 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_MBOX_FULL If the mailbox already contains a message. You can can only send one * message at a time and thus, the message MUST be consumed before you * are allowed to send another one. * OS_ERR_EVENT_TYPE If you are attempting to post to a non mailbox. * OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer * OS_ERR_POST_NULL_PTR If you are attempting to post a NULL pointer * * Note(s) : 1) HPT means Highest Priority Task * * 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 mailbox. ********************************************************************************************************* */ #if OS_MBOX_POST_OPT_EN > 0u INT8U OSMboxPostOpt (OS_EVENT *pevent, void *pmsg, INT8U opt) { #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 (pmsg == (void *)0) { /* Make sure we are not posting a NULL pointer */ return (OS_ERR_POST_NULL_PTR); } #endif if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) { /* Validate event block type */ return (OS_ERR_EVENT_TYPE); } OS_ENTER_CRITICAL(); if (pevent->OSEventGrp != 0u) { /* See if any task pending on mailbox */ 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 mailbox */ (void)OS_EventTaskRdy(pevent, pmsg, OS_STAT_MBOX, OS_STAT_PEND_OK); } } else { /* No, Post to HPT waiting on mbox */ (void)OS_EventTaskRdy(pevent, pmsg, OS_STAT_MBOX, 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 HPT ready to run */ } return (OS_ERR_NONE); } if (pevent->OSEventPtr != (void *)0) { /* Make sure mailbox doesn't already have a msg */ OS_EXIT_CRITICAL(); return (OS_ERR_MBOX_FULL); } pevent->OSEventPtr = pmsg; /* Place message in mailbox */ OS_EXIT_CRITICAL(); return (OS_ERR_NONE); } #endif /*$PAGE*/ /* ********************************************************************************************************* * QUERY A MESSAGE MAILBOX * * Description: This function obtains information about a message mailbox. * * Arguments : pevent is a pointer to the event control block associated with the desired mailbox * * p_mbox_data is a pointer to a structure that will contain information about the message * mailbox. * * 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 mailbox. * OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer * OS_ERR_PDATA_NULL If 'p_mbox_data' is a NULL pointer ********************************************************************************************************* */ #if OS_MBOX_QUERY_EN > 0u INT8U OSMboxQuery (OS_EVENT *pevent, OS_MBOX_DATA *p_mbox_data) { 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_mbox_data == (OS_MBOX_DATA *)0) { /* Validate 'p_mbox_data' */ return (OS_ERR_PDATA_NULL); } #endif if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) { /* Validate event block type */ return (OS_ERR_EVENT_TYPE); } OS_ENTER_CRITICAL(); p_mbox_data->OSEventGrp = pevent->OSEventGrp; /* Copy message mailbox wait list */ psrc = &pevent->OSEventTbl[0]; pdest = &p_mbox_data->OSEventTbl[0]; for (i = 0u; i < OS_EVENT_TBL_SIZE; i++) { *pdest++ = *psrc++; } p_mbox_data->OSMsg = pevent->OSEventPtr; /* Get message from mailbox */ OS_EXIT_CRITICAL(); return (OS_ERR_NONE); } #endif /* OS_MBOX_QUERY_EN */ #endif /* OS_MBOX_EN */