Part Number: TMS570LS3137
Other Parts Discussed in Thread: HALCOGEN
Tool/software: TI-RTOS
I have been playing with tasks in freeRTOS, experimenting with notification events and event groups - I got both of those to work (notification works if I bracket the calls to make them privileged) - I found that event groups appear to be faster than notifications, which surprised me. I've subsequently been trying to use binary semaphores without any success. Specifically, it seems I cannot "take" the semaphore - I see that they are actually implemented as queues. I've boiled it down to this simple sample program, which gets stuck with the "sender task" trying to take the semaphore:
/** @file sys_main.c
* @brief Application main file
* @date 02-Mar-2016
* @version 04.05.02
*
* This file contains an empty main function,
* which can be used for the application.
*/
/*
* Copyright (C) 2009-2016 Texas Instruments Incorporated - www.ti.com
*
* .
* .
* .
*
*/
/* USER CODE BEGIN (0) */
/* USER CODE END */
/* Include Files */
#include "sys_common.h"
/* USER CODE BEGIN (1) */
#include <stdio.h>
#include <freeRTOS.h>
#include "os_task.h"
#include "os_semphr.h"
/* USER CODE END */
/* USER CODE BEGIN (2) */
int receiver_task_can_run = 0;
SemaphoreHandle_t start_semaphore = 0;
SemaphoreHandle_t stop_semaphore = 0;
void sender_task(void *p)
{
bool semaphore_take_return = pdFALSE;
semaphore_take_return = pdFALSE;
while (semaphore_take_return == pdFALSE) {
semaphore_take_return = xSemaphoreTake(start_semaphore,200);
if (pdFALSE == semaphore_take_return) printf("sender thread can't get start semaphore\n");
else printf("sender TOOK start_semaphore\n");
};
receiver_task_can_run = 1;
while(1) {};
}
void receiver_task(void *p)
{
int keepGoing = 1;
bool semaphore_take_return = pdFALSE;
vTaskDelay(2000); // let's not get ahead of the sender
while (0 == receiver_task_can_run) {
vTaskDelay(10);
}
while(1 == keepGoing){
//
BaseType_t xRunningPrivileged = prvRaisePrivilege();
semaphore_take_return = pdFALSE;
while (semaphore_take_return == pdFALSE) {
semaphore_take_return = xSemaphoreTake(start_semaphore,2000);
if (pdFALSE == semaphore_take_return) printf("receiver thread can't get start semaphore\n");
else printf("receiver thread TOOK start semaphore\n");
};
}
}
/* USER CODE END */
void main(void)
{
/* USER CODE BEGIN (3) */
BaseType_t xReturned;
puts("this is a test\n\r");
start_semaphore = xSemaphoreCreateBinary();
stop_semaphore = xSemaphoreCreateBinary();
xReturned = xTaskCreate(sender_task, (const char*)"sender_task", 350, NULL, 1, NULL);
printf("sender xReturned: 0x%x\n",xReturned);
xReturned = xTaskCreate(receiver_task, (const char*)"receiver_task", 300, NULL, 1, NULL);
printf("receiver xReturned: 0x%x\n",xReturned);
vTaskStartScheduler();
/* USER CODE END */
}
/* USER CODE BEGIN (4) */
/* USER CODE END */
This is not super-critical to me since I have event groups and notifications working, but I would like to know why this doesn't work. I am using Halcogen 04.05.02 and CCS 6.2.0.00048
