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#include "timer.h"
#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <unistd.h>
#include "block.h"
#include "util.h"
static unsigned int compute_tick(const block *const blocks,
const unsigned short block_count) {
unsigned int tick = 0;
for (unsigned short i = 0; i < block_count; ++i) {
const block *const block = &blocks[i];
tick = gcd(block->interval, tick);
}
return tick;
}
static unsigned int compute_reset_value(const block *const blocks,
const unsigned short block_count) {
unsigned int reset_value = 1;
for (unsigned short i = 0; i < block_count; ++i) {
const block *const block = &blocks[i];
reset_value = MAX(block->interval, reset_value);
}
return reset_value;
}
timer timer_new(const block *const blocks, const unsigned short block_count) {
const unsigned int reset_value = compute_reset_value(blocks, block_count);
timer timer = {
.time = reset_value, // Initial value to execute all blocks.
.tick = compute_tick(blocks, block_count),
.reset_value = reset_value,
};
return timer;
}
int timer_arm(timer *const timer) {
errno = 0;
(void)alarm(timer->tick);
if (errno != 0) {
(void)fprintf(stderr, "error: could not arm timer\n");
return 1;
}
// Wrap `time` to the interval [1, reset_value].
timer->time = (timer->time + timer->tick) % timer->reset_value;
return 0;
}
bool timer_must_run_block(const timer *const timer, const block *const block) {
if (timer == NULL || timer->time == timer->reset_value) {
return true;
}
if (block->interval == 0) {
return false;
}
return timer->time % block->interval == 0;
}
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