nuttx杂记
1、设置自启动应用
修改deconfig文件下的“CONFIG_INIT_ENTRYPOINT”参数即可
以下是Nuttx系统中使用queue_create函数创建队列的示例代码：
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <mqueue.h>#define QUEUE_NAME "/my_queue"
#define MAX_MSG_SIZE 256
#define MSG_BUFFER_SIZE (MAX_MSG_SIZE + 10)/*队列生成者*/
void *producer(void *arg)
{mqd_t mq;char buffer[MSG_BUFFER_SIZE];mq = mq_open(QUEUE_NAME, O_WRONLY);if (mq == -1) {perror("mq_open");exit(1);}printf("Producer: Enter message to send, 'exit' to quit\\n");while(1) {fgets(buffer, MSG_BUFFER_SIZE, stdin);if (strncmp(buffer, "exit", 4) == 0) {break;}if (mq_send(mq, buffer, strlen(buffer), 0) == -1) {perror("mq_send");}}mq_close(mq);return NULL;
}/*队列消费者*/
void *consumer(void *arg)
{mqd_t mq;char buffer[MSG_BUFFER_SIZE];ssize_t bytes_read;mq = mq_open(QUEUE_NAME, O_RDONLY);if (mq == -1) {perror("mq_open");exit(1);}while(1) {bytes_read = mq_receive(mq, buffer, MSG_BUFFER_SIZE, NULL);if (bytes_read == -1) {perror("mq_receive");continue;}printf("Consumer: Received message: %s", buffer);}mq_close(mq);return NULL;
}int main(int argc, char **argv)
{pthread_t prod_thread, cons_thread;struct mq_attr attr;attr.mq_flags = 0;attr.mq_maxmsg = 10;attr.mq_msgsize = MAX_MSG_SIZE;attr.mq_curmsgs = 0;mq_unlink(QUEUE_NAME);mqd_t mq = mq_open(QUEUE_NAME, O_CREAT | O_EXCL | O_RDONLY, 0666, &attr);if (mq == -1) {perror("mq_open");exit(1);}mq_close(mq);mq = mq_open(QUEUE_NAME, O_CREAT | O_EXCL | O_WRONLY, 0666, &attr);if (mq == -1) {perror("mq_open");exit(1);}pthread_create(&prod_thread, NULL, producer, NULL);pthread_create(&cons_thread, NULL, consumer, NULL);pthread_join(prod_thread, NULL);pthread_join(cons_thread, NULL);mq_close(mq);mq_unlink(QUEUE_NAME);return 0;
}该示例代码创建了一个名为“my_queue”的消息队列，允许最多10个消息，每个消息的最大大小为256字节。它使用pthread库创建两个线程：一个生产者和一个消费者。生产者从标准输入读取消息并将其发送到消息队列中，而消费者从消息队列中读取消息并将其打印到标准输出中。