pinebuds/rtos/rtx/TARGET_ARM7/rt_Semaphore.c

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2022-08-15 04:20:27 -05:00
/*----------------------------------------------------------------------------
* RL-ARM - RTX
*----------------------------------------------------------------------------
* Name: RT_SEMAPHORE.C
* Purpose: Implements binary and counting semaphores
* Rev.: V4.60
*----------------------------------------------------------------------------
*
* Copyright (c) 1999-2009 KEIL, 2009-2015 ARM Germany GmbH
* All rights reserved.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - Neither the name of ARM nor the names of its contributors may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDERS AND CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*---------------------------------------------------------------------------*/
#include "rt_TypeDef.h"
#include "RTX_Conf.h"
#include "rt_System.h"
#include "rt_List.h"
#include "rt_Task.h"
#include "rt_Semaphore.h"
#include "rt_HAL_CM.h"
/*----------------------------------------------------------------------------
* Functions
*---------------------------------------------------------------------------*/
/*--------------------------- rt_sem_init -----------------------------------*/
void rt_sem_init (OS_ID semaphore, U16 token_count) {
/* Initialize a semaphore */
P_SCB p_SCB = semaphore;
p_SCB->cb_type = SCB;
p_SCB->p_lnk = NULL;
p_SCB->tokens = token_count;
}
/*--------------------------- rt_sem_delete ---------------------------------*/
#ifdef __CMSIS_RTOS
OS_RESULT rt_sem_delete (OS_ID semaphore) {
/* Delete semaphore */
P_SCB p_SCB = semaphore;
P_TCB p_TCB;
while (p_SCB->p_lnk != NULL) {
/* A task is waiting for token */
p_TCB = rt_get_first ((P_XCB)p_SCB);
rt_ret_val(p_TCB, 0);
rt_rmv_dly(p_TCB);
p_TCB->state = READY;
rt_put_prio (&os_rdy, p_TCB);
}
if (os_rdy.p_lnk && (os_rdy.p_lnk->prio > os_tsk.run->prio)) {
/* preempt running task */
rt_put_prio (&os_rdy, os_tsk.run);
os_tsk.run->state = READY;
rt_dispatch (NULL);
}
p_SCB->cb_type = 0;
return (OS_R_OK);
}
#endif
/*--------------------------- rt_sem_send -----------------------------------*/
OS_RESULT rt_sem_send (OS_ID semaphore) {
/* Return a token to semaphore */
P_SCB p_SCB = semaphore;
P_TCB p_TCB;
if (p_SCB->p_lnk != NULL) {
/* A task is waiting for token */
p_TCB = rt_get_first ((P_XCB)p_SCB);
#ifdef __CMSIS_RTOS
rt_ret_val(p_TCB, 1);
#else
rt_ret_val(p_TCB, OS_R_SEM);
#endif
rt_rmv_dly (p_TCB);
rt_dispatch (p_TCB);
}
else {
/* Store token. */
p_SCB->tokens++;
}
return (OS_R_OK);
}
/*--------------------------- rt_sem_wait -----------------------------------*/
OS_RESULT rt_sem_wait (OS_ID semaphore, U16 timeout) {
/* Obtain a token; possibly wait for it */
P_SCB p_SCB = semaphore;
if (p_SCB->tokens) {
p_SCB->tokens--;
return (OS_R_OK);
}
/* No token available: wait for one */
if (timeout == 0) {
return (OS_R_TMO);
}
if (p_SCB->p_lnk != NULL) {
rt_put_prio ((P_XCB)p_SCB, os_tsk.run);
}
else {
p_SCB->p_lnk = os_tsk.run;
os_tsk.run->p_lnk = NULL;
os_tsk.run->p_rlnk = (P_TCB)p_SCB;
}
rt_block(timeout, WAIT_SEM);
return (OS_R_TMO);
}
/*--------------------------- isr_sem_send ----------------------------------*/
void isr_sem_send (OS_ID semaphore) {
/* Same function as "os_sem"send", but to be called by ISRs */
P_SCB p_SCB = semaphore;
rt_psq_enq (p_SCB, 0);
rt_psh_req ();
}
/*--------------------------- rt_sem_psh ------------------------------------*/
void rt_sem_psh (P_SCB p_CB) {
/* Check if task has to be waken up */
P_TCB p_TCB;
if (p_CB->p_lnk != NULL) {
/* A task is waiting for token */
p_TCB = rt_get_first ((P_XCB)p_CB);
rt_rmv_dly (p_TCB);
p_TCB->state = READY;
#ifdef __CMSIS_RTOS
rt_ret_val(p_TCB, 1);
#else
rt_ret_val(p_TCB, OS_R_SEM);
#endif
rt_put_prio (&os_rdy, p_TCB);
}
else {
/* Store token */
p_CB->tokens++;
}
}
/*----------------------------------------------------------------------------
* end of file
*---------------------------------------------------------------------------*/