模拟因错误而停止：事件已安排：延迟

Question

我正在尝试在 Contiki-ng 上使用 Cooja 模拟器，并且我有如下传感器：

#include "contiki.h"
#include <stdio.h>
#include <stdlib.h>
#include "sys/etimer.h"


static int humidity = 60;  // Initial humidity value (percentage)
int generate_humidity_data(void); // Function declaration

PROCESS(humidity_sensor_process, "Humidity Sensor Process");
AUTOSTART_PROCESSES(&humidity_sensor_process);

PROCESS_THREAD(humidity_sensor_process, ev, data)
{
    PROCESS_BEGIN();
    static struct etimer et_hum;

    etimer_set(&et_hum, 5*CLOCK_SECOND );  // Sample humidity every 20 seconds

    while (1)
    {
    
        PROCESS_WAIT_EVENT_UNTIL(etimer_expired(&et_hum));

    if (ev == PROCESS_EVENT_TIMER && data == &et_hum)
{
      
        humidity = generate_humidity_data();
    printf("Humidity: %d\n", humidity);
        etimer_restart(&et_hum);
}
    }

    PROCESS_END();
}

int generate_humidity_data(void)
{
    // Simulate humidity variation
    humidity += (rand() % 5) - 2;  // Random change between -2% and 2%
    return humidity;
}

每次我在模拟器中添加一个带有其中一个传感器的微尘时，模拟都会在 30 秒后停止并出现以下错误：

FATAL [Thread-3] (Simulation.java:293) - Simulation stopped due to error: Event is already scheduled: DELAY
     [java] java.lang.IllegalStateException: Event is already scheduled: DELAY
     [java]     at org.contikios.cooja.EventQueue.addEvent(EventQueue.java:55)
     [java]     at org.contikios.cooja.EventQueue.addEvent(EventQueue.java:49)
     [java]     at org.contikios.cooja.Simulation.scheduleEvent(Simulation.java:195)
     [java]     at org.contikios.cooja.Simulation$2.execute(Simulation.java:218)
     [java]     at org.contikios.cooja.Simulation.run(Simulation.java:281)
     [java]     at java.lang.Thread.run(Thread.java:748)