use signal ipc instead of sleep loop

1 files changed, 19 insertions, 8 deletions

diff --git a/src/light_thread.c b/src/light_thread.c
index 1d273a0..20b7bb9 100644
--- a/src/light_thread.c
+++ b/src/light_thread.c
@@ -2,14 +2,13 @@
 
 #include <stdio.h>
 
-#include <stdint.h>
-#include <sys/time.h>
-
 #include "common.h"
 #include "consts.h"
 #include "config.h"
 #include "backlight.h"
 
+static pid_t keypress_pid;
+
 uint64_t time_since_press(void) {
 	struct timeval now;
 
@@ -30,12 +29,24 @@ uint64_t time_since_press(void) {
 	return diff;
 }
 
-int light_thread(void) {
-	while (1) {
-		if (time_since_press() > BACKLIGHT_TIME) backlight_off();
-		else								     backlight_on();
+void handler(int _) {
+	if (time_since_press() > BACKLIGHT_TIME) {
+		backlight_off();
+	} else {
+		backlight_on();
 
-		usleep(THREAD_WAIT);
+		handler(_);
+	}
+}
+
+int light_thread(pid_t _keypress_pid) {
+	keypress_pid = _keypress_pid;
+
+	signal(SIGCONT, handler);
+
+	while (1) {
+		pause();
+//		usleep(THREAD_WAIT);
 	}
 
 	return 0;