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authorJulian T <julian@jtle.dk>2020-02-11 12:24:56 +0100
committerJulian T <julian@jtle.dk>2020-02-11 12:24:56 +0100
commit6db1a2cdd3b96731f2e092d55d8c2136eabc52d0 (patch)
tree2be8fae8ce82d708ed9f00f376dda14420850e80 /sem3/osc/mm1/mm2
parent57305119e05559c1c37e903aef89cd43f44c42c9 (diff)
Rename and cleanup
Diffstat (limited to 'sem3/osc/mm1/mm2')
-rw-r--r--sem3/osc/mm1/mm2/tprog.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/sem3/osc/mm1/mm2/tprog.c b/sem3/osc/mm1/mm2/tprog.c
new file mode 100644
index 0000000..377555f
--- /dev/null
+++ b/sem3/osc/mm1/mm2/tprog.c
@@ -0,0 +1,71 @@
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
+
+#define STARTSEC 10
+#define ENDUSEC 500000
+#define SPEED 0.8
+
+struct itimerval timer;
+
+void timer_handler(int signum) {
+ /* Handy structure reference */
+ struct timeval *tv = &timer.it_value;
+ printf("Hey we hit the alarm\n\a");
+
+ /* Calculate new alarm */
+ tv->tv_sec *= SPEED;
+ if (tv->tv_sec == 0) {
+ /* If tv_usec is 0 set i to 1 sec otherwise half it */
+ if (tv->tv_usec == 0) {
+ tv->tv_usec = 999999;
+ } else if (tv->tv_usec > ENDUSEC) {
+ tv->tv_usec *= SPEED;
+ if (tv->tv_usec < ENDUSEC) {
+ tv->tv_usec = ENDUSEC;
+ }
+ } else {
+ /* Return letting the timer be set to ENDUSEC */
+ return;
+ }
+ }
+
+ printf("Set to %d and %d\n", timer.it_value.tv_sec, timer.it_value.tv_usec);
+ /* Set alarm */
+ int err = setitimer(ITIMER_REAL, &timer, NULL);
+ if (err) {
+ printf("Hey we got an error guys\n");
+ exit(1);
+ }
+}
+
+int main() {
+ /* Setup handler for timer */
+ struct sigaction sa;
+ memset(&sa, 0, sizeof(sa)); /* Remeber to set all fields to zero */
+
+ sa.sa_handler = &timer_handler;
+ sigaction(SIGALRM, &sa, NULL);
+
+ /* Setup timer values */
+ timer.it_value.tv_sec = STARTSEC;
+ timer.it_value.tv_usec = 0;
+
+ timer.it_interval.tv_sec = 0;
+ timer.it_interval.tv_usec = ENDUSEC;
+
+ /* Start the timer */
+ setitimer(ITIMER_REAL, &timer, NULL);
+
+ /* Select signals */
+ sigset_t sigset;
+ sigemptyset(&sigset);
+ sigaddset(&sigset, SIGTERM);
+
+ /* Wait for termination */
+ sigwait(&sigset, NULL);
+
+ return 0;
+}