pthread读/写同步

Question

This seems to be a simple task, but it doesnt work. My threadfunction runs in a loop and writes data into an array all the time. But sometimes I want to read this data from my main function. Therefore the read-funtion should ideally pause the thread, read the data, and then resume the thread. But the value that is read is not correct and seems corrupted. Maybe there is something wrong:

thread-fct:

void threadfct()
{
    while (1)
    {
        pthread_mutex_lock(&mutex);
        data = write_data();
        pthread_mutex_unlock(&mutex);
    }
}

Function that is called from main-loop should read that data that is written by the thread-function:

void read_data()
{
    printf("Daten: %f\n", data[0]);
}

Answer 1

try this change:

void read_data()
{
    pthread_mutex_lock(&mutex);
    printf("Daten: %f\n", data[0]);
    pthread_mutex_unlock(&mutex);
}