1 files changed, 71 insertions, 0 deletions
diff --git a/sem1/osc/mm1/mm2/tprog.c b/sem1/osc/mm1/mm2/tprog.c
new file mode 100644
index 0000000..377555f
--- /dev/null
+++ b/sem1/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;
+}