Timers in C

Here’s the translated code and explanation in C, formatted in Markdown suitable for Hugo:

Our first program will demonstrate the use of timers in C. We’ll use the time.h library to handle time-related operations.

#include <stdio.h>
#include <time.h>
#include <unistd.h>

int main() {
    // Timers in C are typically implemented using time_t and clock_t types
    // from the time.h library. We'll use sleep() to simulate timer behavior.

    // This "timer" will wait for 2 seconds
    printf("Timer 1 started\n");
    sleep(2);
    printf("Timer 1 fired\n");

    // For the second timer, we'll use a separate thread to demonstrate
    // cancellation. In C, we'd typically use pthreads for this, but
    // for simplicity, we'll just use a flag.

    time_t start_time = time(NULL);
    int timer_cancelled = 0;

    printf("Timer 2 started\n");
    
    // Simulate timer cancellation after 0.5 seconds
    sleep(0.5);
    timer_cancelled = 1;
    
    if (timer_cancelled) {
        printf("Timer 2 stopped\n");
    } else {
        sleep(1.5);  // Rest of the 2-second period
        printf("Timer 2 fired\n");
    }

    // Give enough time to show Timer 2 was indeed stopped
    sleep(2);

    return 0;
}

To compile and run the program:

$ gcc timers.c -o timers
$ ./timers
Timer 1 started
Timer 1 fired
Timer 2 started
Timer 2 stopped

In this C implementation:

1. We use sleep() function to simulate timer behavior. This function pauses the execution of the program for a specified number of seconds.

2. For the first timer, we simply call sleep(2) to wait for 2 seconds before printing the “Timer 1 fired” message.

3. For the second timer, we use a flag timer_cancelled to simulate timer cancellation. In a real-world scenario, you might use more sophisticated methods like pthreads for true concurrency.

4. We use time() function to get the current time, which could be used to calculate elapsed time in a more complex implementation.

5. The sleep(2) at the end ensures we wait long enough to demonstrate that Timer 2 was indeed stopped and didn’t fire.

This example demonstrates basic timer-like behavior in C. For more precise timing or advanced timer functionality, you might need to use platform-specific APIs or additional libraries.