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OpenRTX/rtos/uC-OS3/Source/os_sem.c

967 wiersze
37 KiB
C
Czysty Zwykły widok Historia

Adding uC-OS3
2020-09-25 10:29:06 +00:00
/*
*********************************************************************************************************
* 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