avoid drift in clocks

This adds a sleep program that wakes up when the time (in seconds) is
divisible by a specific number, so for example passing 60 to it will
make it exit at the beginning of each minute.

This program is also able to exit when the system exits suspend (when
the kernel syncs the clock), which means we don't need to signal the
clocks anymore.

Signed-off-by: Stacy Harper <contact@stacyharper.net>

Makefile

@@ -10,6 +10,7 @@ OPENRC:=1
 
 CC ?= $(CROSS_COMPILE)gcc
 PROGRAMS = \
+	programs/sxmo_aligned_sleep \
 	programs/sxmo_vibrate \
 	programs/sxmo_splitchar
 
@@ -20,14 +21,11 @@ test: shellcheck
 shellcheck:
 	find . -type f -name '*.sh' -print0 | xargs -0 shellcheck -x --shell=sh
 
-programs/sxmo_vibrate: programs/sxmo_vibrate.c
-	$(CC) -o programs/sxmo_vibrate programs/sxmo_vibrate.c
-
-programs/sxmo_splitchar: programs/sxmo_splitchar.c
-	$(CC) -o programs/sxmo_splitchar programs/sxmo_splitchar.c
+programs/%: programs/%.c
+	gcc -o $@ $<
 
 clean:
-	rm -f programs/sxmo_vibrate programs/sxmo_splitchar
+	rm -f programs/sxmo_aligned_sleep programs/sxmo_vibrate programs/sxmo_splitchar
 
 install: $(PROGRAMS)
 	cd configs && find . -type f -not -name sxmo-setpermissions -exec install -D -m 0644 "{}" "$(DESTDIR)$(PREFIX)/share/sxmo/{}" \; && cd ..
@@ -68,6 +66,7 @@ install: $(PROGRAMS)
 	# Bin
 	install -D -t $(DESTDIR)$(PREFIX)/bin scripts/*/*.sh
 
+	install -D programs/sxmo_aligned_sleep $(DESTDIR)$(PREFIX)/bin/
 	install -D programs/sxmo_vibrate $(DESTDIR)$(PREFIX)/bin/
 	install -D programs/sxmo_splitchar $(DESTDIR)$(PREFIX)/bin/
 

configs/default_hooks/one_button_e_reader/sxmo_hook_postwake.sh

@@ -14,7 +14,6 @@
 
 light -S "$(cat "$XDG_RUNTIME_DIR"/sxmo.brightness.presuspend.state)"
 
-sxmo_hook_statusbar.sh time
 sxmo_hook_unlock.sh
 
 # Add here whatever you want to do

configs/default_hooks/one_button_e_reader/sxmo_hook_unlock.sh

@@ -27,5 +27,3 @@ if ! [ -e "$XDG_CACHE_HOME/sxmo/sxmo.nosuspend" ]; then
 		timeout "$((${SXMO_UNLOCK_IDLE_TIME:-120}+10))" 'sxmo_daemons.sh start periodic_state_mutex_check sxmo_run_periodically.sh 10 sxmo_hook_check_state_mutexes.sh' \
 		resume 'sxmo_daemons.sh stop periodic_state_mutex_check'
 fi
-
-sxmo_superd_signal.sh sxmo_desktop_widget -USR2

configs/default_hooks/sxmo_hook_desktop_widget.sh

@@ -19,40 +19,23 @@ pangodraw() {
 }
 
 if [ -n "$WAYLAND_DISPLAY" ] && command -v wayout > /dev/null; then
+	trap 'kill -- $WAYOUT' TERM INT EXIT
+
 	# For wayland we use wayout:
-	tmp="$(mktemp)"
 	(
-		pangodraw
-		pangodraw
+		sleep 1 # wayout misses output sent to it as it's starting
 		while : ; do
-			sleep 60
 			pangodraw
+			sxmo_aligned_sleep 60
 		done
-	) >> "$tmp" &
-	PIDS="$!"
-
-	forceredraw() {
-		pangodraw >> "$tmp"
-		for PID in $PIDS; do
-			wait "$PID"
-		done
-	}
-	trap 'forceredraw' USR2
-
-	tail -f "$tmp" | wayout --font "FiraMono Nerd Font" --foreground-color "#ffffff" --fontsize "80" --height 200 --textalign center --feed-par &
-	PIDS="$! $PIDS"
-
-	finish() {
-		for PID in $PIDS; do
-			kill "$PID"
-		done
-		rm "$tmp"
-	}
-	trap 'finish' TERM INT EXIT
-
-	for PID in $PIDS; do
-		wait "$PID"
-	done
+	) | wayout --font "FiraMono Nerd Font" \
+		--foreground-color "#ffffff" \
+		--fontsize "80" \
+		--height 200 \
+		--textalign center \
+		--feed-par &
+	WAYOUT="$!"
+	wait
 elif [ -n "$DISPLAY" ] && command -v conky > /dev/null; then
 	# For X we use conky (if not already running):
 	exec conky -c "$(xdg_data_path sxmo/appcfg/conky24h.conf)" #24 hour clock

configs/default_hooks/sxmo_hook_start.sh

@@ -60,7 +60,7 @@ superctl start sxmo_desktop_widget
 
 # Periodically update some status bar components
 sxmo_hook_statusbar.sh all
-sxmo_daemons.sh start statusbar_periodics sxmo_run_periodically.sh 55 \
+sxmo_daemons.sh start statusbar_periodics sxmo_run_aligned.sh 60 \
 	sxmo_hook_statusbar.sh periodics
 
 # Monitor the battery

configs/default_hooks/three_button_touchscreen/sxmo_hook_lock.sh

@@ -29,5 +29,3 @@ if ! [ -e "$XDG_CACHE_HOME/sxmo/sxmo.noidle" ]; then
 	sxmo_daemons.sh start idle_locker sxmo_idle.sh -w \
 		timeout 8 "sxmo_hook_screenoff.sh"
 fi
-
-sxmo_superd_signal.sh sxmo_desktop_widget -USR2

configs/default_hooks/three_button_touchscreen/sxmo_hook_postwake.sh

@@ -19,8 +19,6 @@ if [ "$UNSUSPENDREASON" != "modem" ]; then
 	fi
 fi
 
-sxmo_hook_statusbar.sh time
-
 if [ "$UNSUSPENDREASON" = "rtc" ] || [ "$UNSUSPENDREASON" = "usb power" ]; then
 	if grep -q screenoff "$XDG_RUNTIME_DIR/sxmo.state"; then
 		# We stopped it in presuspend

configs/default_hooks/three_button_touchscreen/sxmo_hook_unlock.sh

@@ -44,5 +44,3 @@ else
 			;;
 	esac
 fi
-
-sxmo_superd_signal.sh sxmo_desktop_widget -USR2

programs/sxmo_aligned_sleep.c

@@ -0,0 +1,48 @@
+#include <errno.h>       // error handling
+#include <stdint.h>      // uint64_t type
+#include <stdio.h>       // dprintf
+#include <stdlib.h>      // strtol, exit
+#include <string.h>      // strerror, strcmp
+#include <sys/timerfd.h> // timers
+#include <unistd.h>      // read
+
+static void error(char *message, int err) {
+	dprintf(2, "%s: %s\n", message, strerror(err));
+	exit(1);
+}
+
+int main(int argc, char **argv) {
+	uint64_t buf;
+	long duration = -1;
+	int time_fd;
+
+	struct timespec now;
+	struct itimerspec time = {
+		.it_value = { .tv_sec = 0, .tv_nsec = 0 },
+		.it_interval = { .tv_sec = 0, .tv_nsec = 0 }
+	};
+
+	// Process arguments
+	if (argc >= 2) duration = strtol(argv[1], NULL, 0);
+	if (duration <= 0) {
+		dprintf(2, "Usage: %s <seconds>\n", argv[0]);
+		dprintf(2, "ERROR: duration must be a positive integer\n");
+		return 1;
+	}
+
+	// Setup timer
+	if ((time_fd = timerfd_create(CLOCK_REALTIME, 0)) == -1)
+		error("Failed to create timerfd", errno);
+	if (clock_gettime(CLOCK_REALTIME, &now) == -1)
+		error("Failed to get current time", errno);
+
+	// find the next time that's divisable by the provided number of seconds
+	time.it_value.tv_sec = now.tv_sec + duration - (now.tv_sec % duration);
+
+	if (timerfd_settime(time_fd, TFD_TIMER_ABSTIME | TFD_TIMER_CANCEL_ON_SET, &time, NULL) == -1)
+		error("Failed to set timer",errno);
+
+	// Wait for timer
+	read(time_fd, &buf, sizeof(uint64_t));
+}
+

scripts/core/sxmo_run_aligned.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2022 Sxmo Contributors
+
+timeout="$1"
+shift
+
+finish() {
+	kill "$CMDPID"
+	kill "$SLEEPPID"
+	exit 0
+}
+
+trap 'finish' TERM INT
+
+while : ; do
+	"$@" &
+	CMDPID="$!"
+	wait "$CMDPID"
+
+	sxmo_aligned_sleep "$timeout" &
+	SLEEPPID="$!"
+	wait "$SLEEPPID"
+done