❄ frost

❄ Frost ❄ is a cooperative asynchronous task scheduler, uses a deadline-derived urgency score to gradually promote tasks that are closer to, or already past, their scheduled execution time.
This makes it similar in spirit to a lightweight soft-EDF scheduler, but implemented as a portable cooperative event loop.

• cooperative scheduling
• deadline/urgency-based task promotion
• channel-triggered task wakeup
• task local storage
• lightweight awaiter primitives

Frost does not interfere with task execution, offering better cross-platform compatibility,
it features an advanced task scheduler capable of running three types of tasks:

• one-shot: task runs one shot, then deletes itself
• periodic: task runs periodically, with a given period (setInterval)
• awaken-by-chan-write: awake the task when channel is not empty, otherwise turn into freeze state

❄ ToDo

• EDF scheduling
• unfreeze task by channel write
• [] Fix await

❄ Example

This is a simple example of toggling a LED every 1 second in Arduino:

#include <frost/api.h>

void __task_led_toggle() {
  static int led_state = 0;
  digitalWrite(LED_BUILTIN, led_state);
  led_state = !led_state;
}

void setup() {
  
  // frost init
  frost_init();

  // create a periodic task as a 1000ms interval
  frost_task_interval(&__task_led_toggle, 1000, NULL);
}

void loop() {

  // run frost scheduler
  frost_schedule_tasks();
}

❄ Porting

Please port below functions to your platform to work with Frost:

void __frost_log_print(const char* tag, const char* fmt, ...) {
  // Your platform implementation
}

uint64_t __frost_time_tick(uint64_t* tick) {
  // Your platform implementation
}

And pass -DFROST_PORTED_LOG_PRINT and -DFROST_PORTED_TIME_TICK to the compiler.
See more in frost/port.h

❄ LICENSE

Frost is licensed under the MIT License with ❤.