uC/OS-II 函數之時間相關函數 · uC/OS-II函數介紹

獲得更多資料歡迎進入[我的網站](http://rlovep.com/)或者 [csdn](http://blog.csdn.net/peace1213)或者[博客園](http://www.cnblogs.com/onepeace/) > 對于有熱心的小伙伴在[微博](http://weibo.com/u/2026326475/)上私信我，說我的[uC/OS-II 一些函數簡介](http://blog.csdn.net/peace1213/article/details/47056651)篇幅有些過于長應該分開介紹。應小伙伴的要求，特此將文章分開進行講解。上文主要介紹了任務相關的函數，本文介紹時間相關的函數：OSTimeDly()延時節拍函數，OSTimeDlyHMSM()系統延時函數，OSTimeDlyResume()延時恢復函數 ## OSTimeDly()延時節拍函數 1、主要作用：調用該函數的任務將自己延時一段時間并執行一次任務調度，一旦規定的延時時間完成或有其它的任務通過調用OSTimeDlyResume()取消了延時，調用OSTimeDly()函數的任務馬上進入就緒狀態（前提是先將任務調度后執行的任務執行到程序尾，且調用OSTimeDly的任務此時優先級最高）。 2、函數原型：void OSTimeDly (INT16U ticks); 3、參數說明：ticks為需要延時的時鐘節拍數； 4、返回值：無 5、函數主體在os_time.c中 ## OSTimeDlyHMSM()系統延時函數 1、主要作用：函數是以小時(H)、分(M)、秒(S)和毫秒(m)四個參數來定義延時時間的，函數在內部把這些參數轉換為時鐘節拍，再通過單次或多次調用OSTimeDly()進行延時和任務調度，所以延時原理和調用延時函數OSTimeDly()是一樣的。調用 OSTimeDlyHMSM() 后，如果延時時間不為0，系統將立即進行任務調度。 2、函數原型：INT8U OSTimeDlyHMSM (INT8U hours，INT8U minutes，INT8U seconds，INT16U milli); 3、參數說明： hours 為延時小時數，范圍從0-255。 minutes 為延時分鐘數，范圍從0-59 seconds 為延時秒數，范圍從0-59 milli 為延時毫秒數，范圍從0-999 4、返回值說明： OS_NO_ERR：函數調用成功。 OS_TIME_INVALID_MINUTES：參數錯誤，分鐘數大于59。 OS_TIME_INVALID_SECONDS：參數錯誤，秒數大于59。 OS_TIME_INVALID_MILLI：參數錯誤，毫秒數大于999。 OS_TIME_ZERO_DLY：四個參數全為0。 5、函數主體在os_time.c中 ## OSTimeDlyResume()延時恢復函數 1、主要作用：任務在延時之后，進入阻塞態。當延時時間到了就從阻塞態恢復到就緒態，可以被操作系統調度執行。但是，并非回到就緒態就只有這么一種可能，因為即便任務的延時時間沒到，還是可以通過函數OSTimeDlyResume恢復該任務到就緒態的。另外，OSTimeDlyResume也不僅僅能恢復使用OSTimeDly或OSTimeDlyHMSM而延時的任務。對于因等待事件發生而阻塞的，并且設置了超時（timeout）時間的任務，也可以使用OSTimeDlyResume來恢復。對這些任務使用了OSTimeDlyResume，就好像已經等待超時了一樣。但是，對于采用OSTaskSuspend掛起的任務，是不允許采用OSTimeDlyResume來恢復的。 2、函數原型：INT8U OSTimeDlyResume (INT8U prio) 3.參數說明：prio 被恢復任務的優先級 4、返回值： OS_ERR_TASK_NOT_EXIST：任務優先級指針表中沒有此任務 OS_NO_ERR：函數調用成功。 OS_ERR_PRIO_INVALID：參數指定的優先級大于或等于OS_LOWEST_PRIO。 OS_ERR_TIME_NOT_DLY：任務沒有被延時阻塞 5、函數主體在os_time.c中 ## 附os_time.c代碼 ~~~ /* ********************************************************************************************************* * uC/OS-II * The Real-Time Kernel * TIME MANAGEMENT * * (c) Copyright 1992-2013, Micrium, Weston, FL * All Rights Reserved * * File : OS_TIME.C * By : Jean J. Labrosse * Version : V2.92.08 * * LICENSING TERMS: * --------------- * uC/OS-II is provided in source form for FREE evaluation, for educational use or for peaceful research. * If you plan on using uC/OS-II in a commercial product you need to contact Micrium to properly license * its use in your product. We provide ALL the source code for your convenience and to help you experience * uC/OS-II. The fact that the source is provided does NOT mean that you can use it without paying a * licensing fee. ********************************************************************************************************* */ #define MICRIUM_SOURCE #ifndef OS_MASTER_FILE #include <ucos_ii.h> #endif /* ********************************************************************************************************* * DELAY TASK 'n' TICKS * * Description: This function is called to delay execution of the currently running task until the * specified number of system ticks expires. This, of course, directly equates to delaying * the current task for some time to expire. No delay will result If the specified delay is * 0. If the specified delay is greater than 0 then, a context switch will result. * * Arguments : ticks is the time delay that the task will be suspended in number of clock 'ticks'. * Note that by specifying 0, the task will not be delayed. * * Returns : none ********************************************************************************************************* */ void OSTimeDly (INT32U ticks) { INT8U y; #if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */ OS_CPU_SR cpu_sr = 0u; #endif if (OSIntNesting > 0u) { /* See if trying to call from an ISR */ return; } if (OSLockNesting > 0u) { /* See if called with scheduler locked */ return; } if (ticks > 0u) { /* 0 means no delay! */ OS_ENTER_CRITICAL(); y = OSTCBCur->OSTCBY; /* Delay current task */ OSRdyTbl[y] &= (OS_PRIO)~OSTCBCur->OSTCBBitX; if (OSRdyTbl[y] == 0u) { OSRdyGrp &= (OS_PRIO)~OSTCBCur->OSTCBBitY; } OSTCBCur->OSTCBDly = ticks; /* Load ticks in TCB */ OS_EXIT_CRITICAL(); OS_Sched(); /* Find next task to run! */ } } /*$PAGE*/ /* ********************************************************************************************************* * DELAY TASK FOR SPECIFIED TIME * * Description: This function is called to delay execution of the currently running task until some time * expires. This call allows you to specify the delay time in HOURS, MINUTES, SECONDS and * MILLISECONDS instead of ticks. * * Arguments : hours specifies the number of hours that the task will be delayed (max. is 255) * minutes specifies the number of minutes (max. 59) * seconds specifies the number of seconds (max. 59) * ms specifies the number of milliseconds (max. 999) * * Returns : OS_ERR_NONE * OS_ERR_TIME_INVALID_MINUTES * OS_ERR_TIME_INVALID_SECONDS * OS_ERR_TIME_INVALID_MS * OS_ERR_TIME_ZERO_DLY * OS_ERR_TIME_DLY_ISR * * Note(s) : The resolution on the milliseconds depends on the tick rate. For example, you can't do * a 10 mS delay if the ticker interrupts every 100 mS. In this case, the delay would be * set to 0. The actual delay is rounded to the nearest tick. ********************************************************************************************************* */ #if OS_TIME_DLY_HMSM_EN > 0u INT8U OSTimeDlyHMSM (INT8U hours, INT8U minutes, INT8U seconds, INT16U ms) { INT32U ticks; if (OSIntNesting > 0u) { /* See if trying to call from an ISR */ return (OS_ERR_TIME_DLY_ISR); } if (OSLockNesting > 0u) { /* See if called with scheduler locked */ return (OS_ERR_SCHED_LOCKED); } #if OS_ARG_CHK_EN > 0u if (hours == 0u) { if (minutes == 0u) { if (seconds == 0u) { if (ms == 0u) { return (OS_ERR_TIME_ZERO_DLY); } } } } if (minutes > 59u) { return (OS_ERR_TIME_INVALID_MINUTES); /* Validate arguments to be within range */ } if (seconds > 59u) { return (OS_ERR_TIME_INVALID_SECONDS); } if (ms > 999u) { return (OS_ERR_TIME_INVALID_MS); } #endif /* Compute the total number of clock ticks required.. */ /* .. (rounded to the nearest tick) */ ticks = ((INT32U)hours * 3600uL + (INT32U)minutes * 60uL + (INT32U)seconds) * OS_TICKS_PER_SEC + OS_TICKS_PER_SEC * ((INT32U)ms + 500uL / OS_TICKS_PER_SEC) / 1000uL; OSTimeDly(ticks); return (OS_ERR_NONE); } #endif /*$PAGE*/ /* ********************************************************************************************************* * RESUME A DELAYED TASK * * Description: This function is used resume a task that has been delayed through a call to either * OSTimeDly() or OSTimeDlyHMSM(). Note that you can call this function to resume a * task that is waiting for an event with timeout. This would make the task look * like a timeout occurred. * * Arguments : prio specifies the priority of the task to resume * * Returns : OS_ERR_NONE Task has been resumed * OS_ERR_PRIO_INVALID if the priority you specify is higher that the maximum allowed * (i.e. >= OS_LOWEST_PRIO) * OS_ERR_TIME_NOT_DLY Task is not waiting for time to expire * OS_ERR_TASK_NOT_EXIST The desired task has not been created or has been assigned to a Mutex. ********************************************************************************************************* */ #if OS_TIME_DLY_RESUME_EN > 0u INT8U OSTimeDlyResume (INT8U prio) { OS_TCB *ptcb; #if OS_CRITICAL_METHOD == 3u /* Storage for CPU status register */ OS_CPU_SR cpu_sr = 0u; #endif if (prio >= OS_LOWEST_PRIO) { return (OS_ERR_PRIO_INVALID); } OS_ENTER_CRITICAL(); ptcb = OSTCBPrioTbl[prio]; /* Make sure that task exist */ if (ptcb == (OS_TCB *)0) { OS_EXIT_CRITICAL(); return (OS_ERR_TASK_NOT_EXIST); /* The task does not exist */ } if (ptcb == OS_TCB_RESERVED) { OS_EXIT_CRITICAL(); return (OS_ERR_TASK_NOT_EXIST); /* The task does not exist */ } if (ptcb->OSTCBDly == 0u) { /* See if task is delayed */ OS_EXIT_CRITICAL(); return (OS_ERR_TIME_NOT_DLY); /* Indicate that task was not delayed */ } ptcb->OSTCBDly = 0u; /* Clear the time delay */ if ((ptcb->OSTCBStat & OS_STAT_PEND_ANY) != OS_STAT_RDY) { ptcb->OSTCBStat &= ~OS_STAT_PEND_ANY; /* Yes, Clear status flag */ ptcb->OSTCBStatPend = OS_STAT_PEND_TO; /* Indicate PEND timeout */ } else { ptcb->OSTCBStatPend = OS_STAT_PEND_OK; } if ((ptcb->OSTCBStat & OS_STAT_SUSPEND) == OS_STAT_RDY) { /* Is task suspended? */ OSRdyGrp |= ptcb->OSTCBBitY; /* No, Make ready */ OSRdyTbl[ptcb->OSTCBY] |= ptcb->OSTCBBitX; OS_EXIT_CRITICAL(); OS_Sched(); /* See if this is new highest priority */ } else { OS_EXIT_CRITICAL(); /* Task may be suspended */ } return (OS_ERR_NONE); } #endif /*$PAGE*/ /* ********************************************************************************************************* * GET CURRENT SYSTEM TIME * * Description: This function is used by your application to obtain the current value of the 32-bit * counter which keeps track of the number of clock ticks. * * Arguments : none * * Returns : The current value of OSTime ********************************************************************************************************* */ #if OS_TIME_GET_SET_EN > 0u INT32U OSTimeGet (void) { INT32U ticks; #if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */ OS_CPU_SR cpu_sr = 0u; #endif OS_ENTER_CRITICAL(); ticks = OSTime; OS_EXIT_CRITICAL(); return (ticks); } #endif /* ********************************************************************************************************* * SET SYSTEM CLOCK * * Description: This function sets the 32-bit counter which keeps track of the number of clock ticks. * * Arguments : ticks specifies the new value that OSTime needs to take. * * Returns : none ********************************************************************************************************* */ #if OS_TIME_GET_SET_EN > 0u void OSTimeSet (INT32U ticks) { #if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */ OS_CPU_SR cpu_sr = 0u; #endif OS_ENTER_CRITICAL(); OSTime = ticks; OS_EXIT_CRITICAL(); } #endif ~~~