MultiTimer is a software timer extension module that allows for the expansion of timer tasks as needed, replacing the traditional flag-checking method. It offers a more elegant and convenient way to manage the timing sequences of a program.
- Configure the system time base interface and install the timer driver:
uint64_t PlatformTicksGetFunc(void)
{
/* Platform-specific implementation */
}
multiTimerInstall(PlatformTicksGetFunc);- Instantiate a timer object:
MultiTimer timer1;- Set the timing, timeout callback function, user data pointer, and start the timer:
int multiTimerStart(MultiTimer* timer, uint64_t timing, MultiTimerCallback_t callback, void* userData);- Call the timer background processing function in the main loop:
int main(int argc, char *argv[])
{
...
while (1) {
...
multiTimerYield();
}
}-
The clock frequency of the timer directly affects its accuracy. It is recommended to use ticks with higher precision such as 1ms, 5ms, or 10ms.
-
The callback function of the timer should not perform time-consuming operations, as this may occupy too much time, causing other timers to not timeout properly.
-
Since the timer's callback function is executed within
multiTimerYield, care should be taken not to use too much stack space to avoid stack overflow.
The test_linux.c file serves as a demo for Linux platforms, showcasing how to use MultiTimer for creating and managing multiple timers with different intervals and behaviors.
#include "MultiTimer.h"
#include <stdio.h>
#include <unistd.h>
#include <sys/time.h>
// Platform-specific function to get current ticks (milliseconds)
uint64_t getPlatformTicks() {
struct timeval now;
gettimeofday(&now, NULL);
return now.tv_sec * 1000LL + now.tv_usec / 1000;
}
// Callback functions for the timers
void timerCallback1(MultiTimer* timer, void* userData) {
printf("Timer 1 fired at %lu ms\n", getPlatformTicks());
multiTimerStart(timer, 500, timerCallback1, NULL); // Restart timer
}
void timerCallback2(MultiTimer* timer, void* userData) {
printf("Timer 2 fired at %lu ms\n", getPlatformTicks());
multiTimerStart(timer, 1000, timerCallback2, NULL); // Restart timer
}
void timerCallback3(MultiTimer* timer, void* userData) {
printf("Timer 3 (one-shot) fired at %lu ms\n", getPlatformTicks());
}
void timerCallback4(MultiTimer* timer, void* userData) {
printf("Timer 4 is stopping Timer 1 at %lu ms\n", getPlatformTicks());
multiTimerStop((MultiTimer*)userData);
}
int main() {
multiTimerInstall(getPlatformTicks);
MultiTimer timer1, timer2, timer3, timer4;
multiTimerStart(&timer1, 500, timerCallback1, NULL); // 500 ms repeating
multiTimerStart(&timer2, 1000, timerCallback2, NULL); // 1000 ms repeating
multiTimerStart(&timer3, 2000, timerCallback3, NULL); // 2000 ms one-shot
multiTimerStart(&timer4, 3000, timerCallback4, &timer1); // 3000 ms, stops timer1
// Main loop to simulate time passage and process timers
while (1) {
multiTimerYield();
usleep(1000); // Sleep for 1 ms
}
return 0;
}