Demo:posix freertos

Demo介绍：

保存在SDK下：bouffalo_sdk/examples/posix/freertos

这段代码主要测试了两个POSIX标准接口在FreeRTOS环境下的功能实现：消息队列(Message Queue)和信号量(Semaphore)。

Posix标准：

这是一个接口标准，由于Linux的各种版本发布非常非常多，导致如果没有标准，那么一个软件要适配所有发行版本的难度极高。IEEE组织设定了一个标准，这解释了为什么个个Linux的命令比如ls clear cd mkdir 等基本命令可以通用。

代码分析：

1. 消息队列测试 (mqueues_test.c):
   • 创建两个消息队列mq1和mq2
   • 创建4个线程：send1、send2和rev1、rev2
   • 每个发送者发送3条不同优先级的消息
   • 每个接收者接收3条消息
2. 测试重点：消息队列的基本操作：mq_open、mq_send、mq_receive、mq_close、mq_unlink 非阻塞模式O_NONBLOCK的工作情况

1. 信号量测试 (semaphores_test.c):
   • 实现了一个经典的生产者-消费者模型
   • occupied: 控制缓冲区可用空间
   • empty: 控制缓冲区已使用空间
   • lock: 互斥锁保护缓冲区访问
2. 测试重点：信号量的基本操作：sem_init、sem_wait、sem_post、sem_destroy,多线程同步和互斥机制，生产者-消费者问题的正确处理

示例输出：

===========================
uart  sig1:ffffffff, sig2:0000f32f
clock gen1:9ffffffd, gen2:0fff0c11
xtal:40000000Hz(crystal)
board init done
===========================
[OS] Starting proc_hellow_entry task...
Enter into send_1 
[1] send 'msg test 1' in thread send_1. 
[2] send 'msg test 2' in thread send_1. 
[3] send 'msg test 3' in thread send_1. 
Enter into send_2 
[1] send 'msg test 1' in thread send_2. 
[2] send 'msg test Enter into receive_1 
[1] receive 'msg test 1' in thread receive_1. 
[2] receive 'msg test 2' in thread receive_1. 
[3] receive 'msg test 3' in thread receive_1. 
Enter into receive_2 
[1] receiv2' in thread send_2. 
[3] send 'msg test 3' in thread send_2. 
e 'msg test 1' in thread receive_2. 
[2] receive 'msg test 2' in thread receive_2. 
[3] receive 'msg test 3' in thread receive_2. 
mq PASS 
producer has added 0 to the buffer[0] 
producer has added 100 to the buffer[1] 
producer has added 200 to the buffer[2] 
producer has added 300 to the buffer[3] 
producer has added 400 to the buffer[4] 
consumer has taken 0 from buffer[0] 
consumer has taken 100 from buffer[1] 
consumer has taken 200 from buffer[2] 
consumer has taken 300 from buffer[3] 
consumer has taken 400 from buffer[4] 
producer has added 500 to the buffer[0] 
producer has added 600 to the buffer[1] 
producer has added 700 to the buffer[2] 
producer has added 800 to the buffer[3] 
producer has added 900 to the buffer[4] 
consumer has taken 500 from buffer[0] 
consumer has taken 600 from buffer[1] 
consumer has taken 700 from buffer[2] 
consumer has taken 800 from buffer[3] 
consumer has taken 900 from buffer[4] 
sema PASS