/* ********************************************************************************************************* * uC/OS-III * The Real-Time Kernel * * Copyright 2009-2020 Silicon Laboratories Inc. www.silabs.com * * SPDX-License-Identifier: APACHE-2.0 * * This software is subject to an open source license and is distributed by * Silicon Laboratories Inc. pursuant to the terms of the Apache License, * Version 2.0 available at www.apache.org/licenses/LICENSE-2.0. * ********************************************************************************************************* */ /* ********************************************************************************************************* * SEMAPHORE MANAGEMENT * * File : os_sem.c * Version : V3.08.00 ********************************************************************************************************* */ #define MICRIUM_SOURCE #include "os.h" #ifdef VSC_INCLUDE_SOURCE_FILE_NAMES const CPU_CHAR *os_sem__c = "$Id: $"; #endif #if (OS_CFG_SEM_EN > 0u) /* ************************************************************************************************************************ * CREATE A SEMAPHORE * * Description: This function creates a semaphore. * * Arguments : p_sem is a pointer to the semaphore to initialize. Your application is responsible for * allocating storage for the semaphore. * * p_name is a pointer to the name you would like to give the semaphore. * * cnt is the initial value for the semaphore. * If used to share resources, you should initialize to the number of resources available. * If used to signal the occurrence of event(s) then you should initialize to 0. * * 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 semaphore after you * called OSSafetyCriticalStart() * OS_ERR_OBJ_PTR_NULL If 'p_sem' is a NULL pointer * OS_ERR_OBJ_CREATED If the semaphore was already created * * Returns : none * * Note(s) : none ************************************************************************************************************************ */ void OSSemCreate (OS_SEM *p_sem, CPU_CHAR *p_name, OS_SEM_CTR cnt, 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 == OS_TRUE) { *p_err = OS_ERR_ILLEGAL_CREATE_RUN_TIME; return; } #endif #if (OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u) if (OSIntNestingCtr > 0u) { /* 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_sem == (OS_SEM *)0) { /* Validate 'p_sem' */ *p_err = OS_ERR_OBJ_PTR_NULL; return; } #endif CPU_CRITICAL_ENTER(); #if (OS_OBJ_TYPE_REQ > 0u) if (p_sem->Type == OS_OBJ_TYPE_SEM) { CPU_CRITICAL_EXIT(); *p_err = OS_ERR_OBJ_CREATED; return; } p_sem->Type = OS_OBJ_TYPE_SEM; /* Mark the data structure as a semaphore */ #endif p_sem->Ctr = cnt; /* Set semaphore value */ #if (OS_CFG_TS_EN > 0u) p_sem->TS = 0u; #endif #if (OS_CFG_DBG_EN > 0u) p_sem->NamePtr = p_name; /* Save the name of the semaphore */ #else (void)p_name; #endif OS_PendListInit(&p_sem->PendList); /* Initialize the waiting list */ #if (OS_CFG_DBG_EN > 0u) OS_SemDbgListAdd(p_sem); OSSemQty++; #endif OS_TRACE_SEM_CREATE(p_sem, p_name); CPU_CRITICAL_EXIT(); *p_err = OS_ERR_NONE; } /* ************************************************************************************************************************ * DELETE A SEMAPHORE * * Description: This function deletes a semaphore. * * Arguments : p_sem is a pointer to the semaphore to delete * * opt determines delete options as follows: * * OS_OPT_DEL_NO_PEND Delete semaphore ONLY if no task pending * OS_OPT_DEL_ALWAYS Deletes the semaphore 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 semaphore was deleted * OS_ERR_DEL_ISR If you attempted to delete the semaphore from an ISR * OS_ERR_ILLEGAL_DEL_RUN_TIME If you are trying to delete the semaphore after you called * OSStart() * OS_ERR_OBJ_PTR_NULL If 'p_sem' is a NULL pointer * OS_ERR_OBJ_TYPE If 'p_sem' is not pointing at a semaphore * OS_ERR_OPT_INVALID An invalid option was specified * OS_ERR_OS_NOT_RUNNING If uC/OS-III is not running yet * OS_ERR_TASK_WAITING One or more tasks were waiting on the semaphore * * Returns : == 0 if no tasks were waiting on the semaphore, or upon error. * > 0 if one or more tasks waiting on the semaphore are now readied and informed. * * Note(s) : 1) This function must be used with care. Tasks that would normally expect the presence of the semaphore * MUST check the return code of OSSemPend(). * 2) Because ALL tasks pending on the semaphore will be readied, you MUST be careful in applications where * the semaphore is used for mutual exclusion because the resource(s) will no longer be guarded by the * semaphore. ************************************************************************************************************************ */ #if (OS_CFG_SEM_DEL_EN > 0u) OS_OBJ_QTY OSSemDel (OS_SEM *p_sem, OS_OPT opt, OS_ERR *p_err) { OS_OBJ_QTY nbr_tasks; 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 (0u); } #endif OS_TRACE_SEM_DEL_ENTER(p_sem, opt); #ifdef OS_SAFETY_CRITICAL_IEC61508 if (OSSafetyCriticalStartFlag == OS_TRUE) { OS_TRACE_SEM_DEL_EXIT(OS_ERR_ILLEGAL_DEL_RUN_TIME); *p_err = OS_ERR_ILLEGAL_DEL_RUN_TIME; return (0u); } #endif #if (OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u) if (OSIntNestingCtr > 0u) { /* Not allowed to delete a semaphore from an ISR */ OS_TRACE_SEM_DEL_EXIT(OS_ERR_DEL_ISR); *p_err = OS_ERR_DEL_ISR; return (0u); } #endif #if (OS_CFG_INVALID_OS_CALLS_CHK_EN > 0u) if (OSRunning != OS_STATE_OS_RUNNING) { /* Is the kernel running? */ OS_TRACE_SEM_DEL_EXIT(OS_ERR_OS_NOT_RUNNING); *p_err = OS_ERR_OS_NOT_RUNNING; return (0u); } #endif #if (OS_CFG_ARG_CHK_EN > 0u) if (p_sem == (OS_SEM *)0) { /* Validate 'p_sem' */ OS_TRACE_SEM_DEL_EXIT(OS_ERR_OBJ_PTR_NULL); *p_err = OS_ERR_OBJ_PTR_NULL; return (0u); } #endif #if (OS_CFG_OBJ_TYPE_CHK_EN > 0u) if (p_sem->Type != OS_OBJ_TYPE_SEM) { /* Make sure semaphore was created */ OS_TRACE_SEM_DEL_EXIT(OS_ERR_OBJ_TYPE); *p_err = OS_ERR_OBJ_TYPE; return (0u); } #endif CPU_CRITICAL_ENTER(); p_pend_list = &p_sem->PendList; nbr_tasks = 0u; switch (opt) { case OS_OPT_DEL_NO_PEND: /* Delete semaphore only if no task waiting */ if (p_pend_list->HeadPtr == (OS_TCB *)0) { #if (OS_CFG_DBG_EN > 0u) OS_SemDbgListRemove(p_sem); OSSemQty--; #endif OS_TRACE_SEM_DEL(p_sem); OS_SemClr(p_sem); CPU_CRITICAL_EXIT(); *p_err = OS_ERR_NONE; } else { CPU_CRITICAL_EXIT(); *p_err = OS_ERR_TASK_WAITING; } break; case OS_OPT_DEL_ALWAYS: /* Always delete the semaphore */ #if (OS_CFG_TS_EN > 0u) ts = OS_TS_GET(); /* Get local time stamp so all tasks get the same time */ #else ts = 0u; #endif while (p_pend_list->HeadPtr != (OS_TCB *)0) { /* Remove all tasks on the pend list */ p_tcb = p_pend_list->HeadPtr; OS_PendAbort(p_tcb, ts, OS_STATUS_PEND_DEL); nbr_tasks++; } #if (OS_CFG_DBG_EN > 0u) OS_SemDbgListRemove(p_sem); OSSemQty--; #endif OS_TRACE_SEM_DEL(p_sem); OS_SemClr(p_sem); CPU_CRITICAL_EXIT(); OSSched(); /* Find highest priority task ready to run */ *p_err = OS_ERR_NONE; break; default: CPU_CRITICAL_EXIT(); *p_err = OS_ERR_OPT_INVALID; break; } OS_TRACE_SEM_DEL_EXIT(*p_err); return (nbr_tasks); } #endif /* ************************************************************************************************************************ * PEND ON SEMAPHORE * * Description: This function waits for a semaphore. * * Arguments : p_sem is a pointer to the semaphore * * 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 semaphore or, until the resource * becomes available (or the event occurs). * * opt determines whether the user wants to block if the semaphore is 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 semaphore was posted * or pend aborted or the semaphore 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 * or, the event you are waiting for occurred * OS_ERR_OBJ_DEL If 'p_sem' was deleted * OS_ERR_OBJ_PTR_NULL If 'p_sem' is a NULL pointer * OS_ERR_OBJ_TYPE If 'p_sem' is not pointing at a semaphore * OS_ERR_OPT_INVALID If you specified an invalid value for 'opt' * OS_ERR_OS_NOT_RUNNING If uC/OS-III is not running yet * 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 semaphore was not * available * OS_ERR_SCHED_LOCKED If you called this function when the scheduler is locked * OS_ERR_STATUS_INVALID Pend status is invalid * OS_ERR_TIMEOUT The semaphore was not received within the specified * timeout * OS_ERR_TICK_DISABLED If kernel ticks are disabled and a timeout is specified * * * Returns : The current value of the semaphore counter or 0 if not available. * * Note(s) : This API 'MUST NOT' be called from a timer callback function. ************************************************************************************************************************ */ OS_SEM_CTR OSSemPend (OS_SEM *p_sem, OS_TICK timeout, OS_OPT opt, CPU_TS *p_ts, OS_ERR *p_err) { OS_SEM_CTR ctr; CPU_SR_ALLOC(); #if (OS_CFG_TS_EN == 0u) (void)p_ts; /* Prevent compiler warning for not using 'ts' */ #endif #ifdef OS_SAFETY_CRITICAL if (p_err == (OS_ERR *)0) { OS_SAFETY_CRITICAL_EXCEPTION(); return (0u); } #endif OS_TRACE_SEM_PEND_ENTER(p_sem, timeout, opt, p_ts); #if (OS_CFG_TICK_EN == 0u) if (timeout != 0u) { *p_err = OS_ERR_TICK_DISABLED; OS_TRACE_SEM_PEND_FAILED(p_sem); OS_TRACE_SEM_PEND_EXIT(OS_ERR_TICK_DISABLED); return (0u); } #endif #if (OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u) if (OSIntNestingCtr > 0u) { /* Not allowed to call from an ISR */ if ((opt & OS_OPT_PEND_NON_BLOCKING) != OS_OPT_PEND_NON_BLOCKING) { OS_TRACE_SEM_PEND_FAILED(p_sem); OS_TRACE_SEM_PEND_EXIT(OS_ERR_PEND_ISR); *p_err = OS_ERR_PEND_ISR; return (0u); } } #endif #if (OS_CFG_INVALID_OS_CALLS_CHK_EN > 0u) if (OSRunning != OS_STATE_OS_RUNNING) { /* Is the kernel running? */ OS_TRACE_SEM_PEND_EXIT(OS_ERR_OS_NOT_RUNNING); *p_err = OS_ERR_OS_NOT_RUNNING; return (0u); } #endif #if (OS_CFG_ARG_CHK_EN > 0u) if (p_sem == (OS_SEM *)0) { /* Validate 'p_sem' */ OS_TRACE_SEM_PEND_EXIT(OS_ERR_OBJ_PTR_NULL); *p_err = OS_ERR_OBJ_PTR_NULL; return (0u); } switch (opt) { /* Validate 'opt' */ case OS_OPT_PEND_BLOCKING: case OS_OPT_PEND_NON_BLOCKING: break; default: OS_TRACE_SEM_PEND_FAILED(p_sem); OS_TRACE_SEM_PEND_EXIT(OS_ERR_OPT_INVALID); *p_err = OS_ERR_OPT_INVALID; return (0u); } #endif #if (OS_CFG_OBJ_TYPE_CHK_EN > 0u) if (p_sem->Type != OS_OBJ_TYPE_SEM) { /* Make sure semaphore was created */ OS_TRACE_SEM_PEND_FAILED(p_sem); OS_TRACE_SEM_PEND_EXIT(OS_ERR_OBJ_TYPE); *p_err = OS_ERR_OBJ_TYPE; return (0u); } #endif CPU_CRITICAL_ENTER(); if (p_sem->Ctr > 0u) { /* Resource available? */ p_sem->Ctr--; /* Yes, caller may proceed */ #if (OS_CFG_TS_EN > 0u) if (p_ts != (CPU_TS *)0) { *p_ts = p_sem->TS; /* get timestamp of last post */ } #endif ctr = p_sem->Ctr; OS_TRACE_SEM_PEND(p_sem); CPU_CRITICAL_EXIT(); OS_TRACE_SEM_PEND_EXIT(OS_ERR_NONE); *p_err = OS_ERR_NONE; return (ctr); } if ((opt & OS_OPT_PEND_NON_BLOCKING) != 0u) { /* Caller wants to block if not available? */ #if (OS_CFG_TS_EN > 0u) if (p_ts != (CPU_TS *)0) { *p_ts = 0u; } #endif ctr = p_sem->Ctr; /* No */ CPU_CRITICAL_EXIT(); OS_TRACE_SEM_PEND_FAILED(p_sem); OS_TRACE_SEM_PEND_EXIT(OS_ERR_PEND_WOULD_BLOCK); *p_err = OS_ERR_PEND_WOULD_BLOCK; return (ctr); } else { /* Yes */ if (OSSchedLockNestingCtr > 0u) { /* Can't pend when the scheduler is locked */ #if (OS_CFG_TS_EN > 0u) if (p_ts != (CPU_TS *)0) { *p_ts = 0u; } #endif CPU_CRITICAL_EXIT(); OS_TRACE_SEM_PEND_FAILED(p_sem); OS_TRACE_SEM_PEND_EXIT(OS_ERR_SCHED_LOCKED); *p_err = OS_ERR_SCHED_LOCKED; return (0u); } } OS_Pend((OS_PEND_OBJ *)((void *)p_sem), /* Block task pending on Semaphore */ OSTCBCurPtr, OS_TASK_PEND_ON_SEM, timeout); CPU_CRITICAL_EXIT(); OS_TRACE_SEM_PEND_BLOCK(p_sem); OSSched(); /* Find the next highest priority task ready to run */ CPU_CRITICAL_ENTER(); switch (OSTCBCurPtr->PendStatus) { case OS_STATUS_PEND_OK: /* We got the semaphore */ #if (OS_CFG_TS_EN > 0u) if (p_ts != (CPU_TS *)0) { *p_ts = OSTCBCurPtr->TS; } #endif OS_TRACE_SEM_PEND(p_sem); *p_err = OS_ERR_NONE; break; case OS_STATUS_PEND_ABORT: /* Indicate that we aborted */ #if (OS_CFG_TS_EN > 0u) if (p_ts != (CPU_TS *)0) { *p_ts = OSTCBCurPtr->TS; } #endif OS_TRACE_SEM_PEND_FAILED(p_sem); *p_err = OS_ERR_PEND_ABORT; break; case OS_STATUS_PEND_TIMEOUT: /* Indicate that we didn't get semaphore within timeout */ #if (OS_CFG_TS_EN > 0u) if (p_ts != (CPU_TS *)0) { *p_ts = 0u; } #endif OS_TRACE_SEM_PEND_FAILED(p_sem); *p_err = OS_ERR_TIMEOUT; break; case OS_STATUS_PEND_DEL: /* Indicate that object pended on has been deleted */ #if (OS_CFG_TS_EN > 0u) if (p_ts != (CPU_TS *)0) { *p_ts = OSTCBCurPtr->TS; } #endif OS_TRACE_SEM_PEND_FAILED(p_sem); *p_err = OS_ERR_OBJ_DEL; break; default: OS_TRACE_SEM_PEND_FAILED(p_sem); *p_err = OS_ERR_STATUS_INVALID; CPU_CRITICAL_EXIT(); OS_TRACE_SEM_PEND_EXIT(*p_err); return (0u); } ctr = p_sem->Ctr; CPU_CRITICAL_EXIT(); OS_TRACE_SEM_PEND_EXIT(*p_err); return (ctr); } /* ************************************************************************************************************************ * ABORT WAITING ON A SEMAPHORE * * Description: This function aborts & readies any tasks currently waiting on a semaphore. This function should be used * to fault-abort the wait on the semaphore, rather than to normally signal the semaphore via OSSemPost(). * * Arguments : p_sem is a pointer to the semaphore * * opt determines the type of ABORT performed: * * OS_OPT_PEND_ABORT_1 ABORT wait for a single task (HPT) waiting on the semaphore * OS_OPT_PEND_ABORT_ALL ABORT wait for ALL tasks that are waiting on the semaphore * 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 semaphore was readied and * informed of the aborted wait; check return value for the * number of tasks whose wait on the semaphore was aborted. * OS_ERR_OBJ_PTR_NULL If 'p_sem' is a NULL pointer. * OS_ERR_OBJ_TYPE If 'p_sem' is not pointing at a semaphore * OS_ERR_OPT_INVALID If you specified an invalid option * OS_ERR_OS_NOT_RUNNING If uC/OS-III is not running yet * OS_ERR_PEND_ABORT_ISR If you called this function from an ISR * OS_ERR_PEND_ABORT_NONE No task were pending * * Returns : == 0 if no tasks were waiting on the semaphore, or upon error. * > 0 if one or more tasks waiting on the semaphore are now readied and informed. * * Note(s) : none ************************************************************************************************************************ */ #if (OS_CFG_SEM_PEND_ABORT_EN > 0u) OS_OBJ_QTY OSSemPendAbort (OS_SEM *p_sem, 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 (0u); } #endif #if (OS_CFG_CALLED_FROM_ISR_CHK_EN > 0u) if (OSIntNestingCtr > 0u) { /* Not allowed to Pend Abort from an ISR */ *p_err = OS_ERR_PEND_ABORT_ISR; return (0u); } #endif #if (OS_CFG_INVALID_OS_CALLS_CHK_EN > 0u) if (OSRunning != OS_STATE_OS_RUNNING) { /* Is the kernel running? */ *p_err = OS_ERR_OS_NOT_RUNNING; return (0u); } #endif #if (OS_CFG_ARG_CHK_EN > 0u) if (p_sem == (OS_SEM *)0) { /* Validate 'p_sem' */ *p_err = OS_ERR_OBJ_PTR_NULL; return (0u); } switch (opt) { /* Validate 'opt' */ case OS_OPT_PEND_ABORT_1: case OS_OPT_PEND_ABORT_ALL: case OS_OPT_PEND_ABORT_1 | OS_OPT_POST_NO_SCHED: case OS_OPT_PEND_ABORT_ALL | OS_OPT_POST_NO_SCHED: break; default: *p_err = OS_ERR_OPT_INVALID; return (0u); } #endif #if (OS_CFG_OBJ_TYPE_CHK_EN > 0u) if (p_sem->Type != OS_OBJ_TYPE_SEM) { /* Make sure semaphore was created */ *p_err = OS_ERR_OBJ_TYPE; return (0u); } #endif CPU_CRITICAL_ENTER(); p_pend_list = &p_sem->PendList; if (p_pend_list->HeadPtr == (OS_TCB *)0) { /* Any task waiting on semaphore? */ CPU_CRITICAL_EXIT(); /* No */ *p_err = OS_ERR_PEND_ABORT_NONE; return (0u); } nbr_tasks = 0u; #if (OS_CFG_TS_EN > 0u) ts = OS_TS_GET(); /* Get local time stamp so all tasks get the same time */ #else ts = 0u; #endif while (p_pend_list->HeadPtr != (OS_TCB *)0) { p_tcb = p_pend_list->HeadPtr; OS_PendAbort(p_tcb, ts, OS_STATUS_PEND_ABORT); nbr_tasks++; if (opt != OS_OPT_PEND_ABORT_ALL) { /* Pend abort all tasks waiting? */ break; /* No */ } } CPU_CRITICAL_EXIT(); if ((opt & OS_OPT_POST_NO_SCHED) == 0u) { OSSched(); /* Run the scheduler */ } *p_err = OS_ERR_NONE; return (nbr_tasks); } #endif /* ************************************************************************************************************************ * POST TO A SEMAPHORE * * Description: This function signals a semaphore. * * Arguments : p_sem is a pointer to the semaphore * * opt determines the type of POST performed: * * OS_OPT_POST_1 POST and ready only the highest priority task waiting on semaphore * (if tasks are waiting). * OS_OPT_POST_ALL POST to ALL tasks that are waiting on the semaphore * * 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 The call was successful and the semaphore was signaled * OS_ERR_OBJ_PTR_NULL If 'p_sem' is a NULL pointer * OS_ERR_OBJ_TYPE If 'p_sem' is not pointing at a semaphore * OS_ERR_OPT_INVALID If you specified an invalid option * OS_ERR_OS_NOT_RUNNING If uC/OS-III is not running yet * OS_ERR_SEM_OVF If the post would cause the semaphore count to overflow * * Returns : The current value of the semaphore counter or 0 upon error. * * Note(s) : 1) OS_OPT_POST_NO_SCHED can be added with one of the other options. ************************************************************************************************************************ */ OS_SEM_CTR OSSemPost (OS_SEM *p_sem, OS_OPT opt, OS_ERR *p_err) { OS_SEM_CTR ctr; OS_PEND_LIST *p_pend_list; OS_TCB *p_tcb; OS_TCB *p_tcb_next; CPU_TS ts; CPU_SR_ALLOC(); #ifdef OS_SAFETY_CRITICAL if (p_err == (OS_ERR *)0) { OS_SAFETY_CRITICAL_EXCEPTION(); return (0u); } #endif OS_TRACE_SEM_POST_ENTER(p_sem, opt); #if (OS_CFG_INVALID_OS_CALLS_CHK_EN > 0u) if (OSRunning != OS_STATE_OS_RUNNING) { /* Is the kernel running? */ OS_TRACE_SEM_POST_EXIT(OS_ERR_OS_NOT_RUNNING); *p_err = OS_ERR_OS_NOT_RUNNING; return (0u); } #endif #if (OS_CFG_ARG_CHK_EN > 0u) if (p_sem == (OS_SEM *)0) { /* Validate 'p_sem' */ OS_TRACE_SEM_POST_FAILED(p_sem); OS_TRACE_SEM_POST_EXIT(OS_ERR_OBJ_PTR_NULL); *p_err = OS_ERR_OBJ_PTR_NULL; return (0u); } switch (opt) { /* Validate 'opt' */ case OS_OPT_POST_1: case OS_OPT_POST_ALL: case OS_OPT_POST_1 | OS_OPT_POST_NO_SCHED: case OS_OPT_POST_ALL | OS_OPT_POST_NO_SCHED: break; default: OS_TRACE_SEM_POST_FAILED(p_sem); OS_TRACE_SEM_POST_EXIT(OS_ERR_OPT_INVALID); *p_err = OS_ERR_OPT_INVALID; return (0u); } #endif #if (OS_CFG_OBJ_TYPE_CHK_EN > 0u) if (p_sem->Type != OS_OBJ_TYPE_SEM) { /* Make sure semaphore was created */ OS_TRACE_SEM_POST_FAILED(p_sem); OS_TRACE_SEM_POST_EXIT(OS_ERR_OBJ_TYPE); *p_err = OS_ERR_OBJ_TYPE; return (0u); } #endif #if (OS_CFG_TS_EN > 0u) ts = OS_TS_GET(); /* Get timestamp */ #else ts = 0u; #endif OS_TRACE_SEM_POST(p_sem); CPU_CRITICAL_ENTER(); p_pend_list = &p_sem->PendList; if (p_pend_list->HeadPtr == (OS_TCB *)0) { /* Any task waiting on semaphore? */ if (p_sem->Ctr == (OS_SEM_CTR)-1) { CPU_CRITICAL_EXIT(); *p_err = OS_ERR_SEM_OVF; OS_TRACE_SEM_POST_EXIT(*p_err); return (0u); } p_sem->Ctr++; /* No */ ctr = p_sem->Ctr; #if (OS_CFG_TS_EN > 0u) p_sem->TS = ts; /* Save timestamp in semaphore control block */ #endif CPU_CRITICAL_EXIT(); *p_err = OS_ERR_NONE; OS_TRACE_SEM_POST_EXIT(*p_err); return (ctr); } p_tcb = p_pend_list->HeadPtr; while (p_tcb != (OS_TCB *)0) { p_tcb_next = p_tcb->PendNextPtr; OS_Post((OS_PEND_OBJ *)((void *)p_sem), p_tcb, (void *)0, 0u, ts); if ((opt & OS_OPT_POST_ALL) == 0u) { /* Post to all tasks waiting? */ break; /* No */ } p_tcb = p_tcb_next; } CPU_CRITICAL_EXIT(); if ((opt & OS_OPT_POST_NO_SCHED) == 0u) { OSSched(); /* Run the scheduler */ } *p_err = OS_ERR_NONE; OS_TRACE_SEM_POST_EXIT(*p_err); return (0u); } /* ************************************************************************************************************************ * SET SEMAPHORE * * Description: This function sets the semaphore count to the value specified as an argument. Typically, this value * would be 0 but of course, we can set the semaphore to any value. * * You would typically use this function when a semaphore is used as a signaling mechanism * and, you want to reset the count value. * * Arguments : p_sem is a pointer to the semaphore * * cnt is the new value for the semaphore count. You would pass 0 to reset the semaphore count. * * 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 semaphore value was set * OS_ERR_OBJ_PTR_NULL If 'p_sem' is a NULL pointer * OS_ERR_OBJ_TYPE If 'p_sem' is not pointing to a semaphore * OS_ERR_SET_ISR If called from an ISR * OS_ERR_TASK_WAITING If tasks are waiting on the semaphore * * Returns : None * * Note(s) : none ************************************************************************************************************************ */ #if (OS_CFG_SEM_SET_EN > 0u) void OSSemSet (OS_SEM *p_sem, OS_SEM_CTR cnt, OS_ERR *p_err) { OS_PEND_LIST *p_pend_list; 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 > 0u) { /* Can't call this function from an ISR */ *p_err = OS_ERR_SET_ISR; return; } #endif #if (OS_CFG_ARG_CHK_EN > 0u) if (p_sem == (OS_SEM *)0) { /* Validate 'p_sem' */ *p_err = OS_ERR_OBJ_PTR_NULL; return; } #endif #if (OS_CFG_OBJ_TYPE_CHK_EN > 0u) if (p_sem->Type != OS_OBJ_TYPE_SEM) { /* Make sure semaphore was created */ *p_err = OS_ERR_OBJ_TYPE; return; } #endif *p_err = OS_ERR_NONE; CPU_CRITICAL_ENTER(); if (p_sem->Ctr > 0u) { /* See if semaphore already has a count */ p_sem->Ctr = cnt; /* Yes, set it to the new value specified. */ } else { p_pend_list = &p_sem->PendList; /* No */ if (p_pend_list->HeadPtr == (OS_TCB *)0) { /* See if task(s) waiting? */ p_sem->Ctr = cnt; /* No, OK to set the value */ } else { *p_err = OS_ERR_TASK_WAITING; } } CPU_CRITICAL_EXIT(); } #endif /* ************************************************************************************************************************ * CLEAR THE CONTENTS OF A SEMAPHORE * * Description: This function is called by OSSemDel() to clear the contents of a semaphore * * Argument(s): p_sem is a pointer to the semaphore to clear * ----- * * Returns : none * * Note(s) : 1) This function is INTERNAL to uC/OS-III and your application MUST NOT call it. ************************************************************************************************************************ */ void OS_SemClr (OS_SEM *p_sem) { #if (OS_OBJ_TYPE_REQ > 0u) p_sem->Type = OS_OBJ_TYPE_NONE; /* Mark the data structure as a NONE */ #endif p_sem->Ctr = 0u; /* Set semaphore value */ #if (OS_CFG_TS_EN > 0u) p_sem->TS = 0u; /* Clear the time stamp */ #endif #if (OS_CFG_DBG_EN > 0u) p_sem->NamePtr = (CPU_CHAR *)((void *)"?SEM"); #endif OS_PendListInit(&p_sem->PendList); /* Initialize the waiting list */ } /* ************************************************************************************************************************ * ADD/REMOVE SEMAPHORE TO/FROM DEBUG LIST * * Description: These functions are called by uC/OS-III to add or remove a semaphore to/from the debug list. * * Arguments : p_sem is a pointer to the semaphore 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_SemDbgListAdd (OS_SEM *p_sem) { p_sem->DbgNamePtr = (CPU_CHAR *)((void *)" "); p_sem->DbgPrevPtr = (OS_SEM *)0; if (OSSemDbgListPtr == (OS_SEM *)0) { p_sem->DbgNextPtr = (OS_SEM *)0; } else { p_sem->DbgNextPtr = OSSemDbgListPtr; OSSemDbgListPtr->DbgPrevPtr = p_sem; } OSSemDbgListPtr = p_sem; } void OS_SemDbgListRemove (OS_SEM *p_sem) { OS_SEM *p_sem_next; OS_SEM *p_sem_prev; p_sem_prev = p_sem->DbgPrevPtr; p_sem_next = p_sem->DbgNextPtr; if (p_sem_prev == (OS_SEM *)0) { OSSemDbgListPtr = p_sem_next; if (p_sem_next != (OS_SEM *)0) { p_sem_next->DbgPrevPtr = (OS_SEM *)0; } p_sem->DbgNextPtr = (OS_SEM *)0; } else if (p_sem_next == (OS_SEM *)0) { p_sem_prev->DbgNextPtr = (OS_SEM *)0; p_sem->DbgPrevPtr = (OS_SEM *)0; } else { p_sem_prev->DbgNextPtr = p_sem_next; p_sem_next->DbgPrevPtr = p_sem_prev; p_sem->DbgNextPtr = (OS_SEM *)0; p_sem->DbgPrevPtr = (OS_SEM *)0; } } #endif #endif