add new repoHEADmaster

1 files changed, 195 insertions, 0 deletions

diff --git a/Master/Real-Time Systems/Praktikum1/Aufgabe1/src/main.cpp b/Master/Real-Time Systems/Praktikum1/Aufgabe1/src/main.cpp
new file mode 100644
index 0000000..65eef37
--- /dev/null
+++ b/Master/Real-Time Systems/Praktikum1/Aufgabe1/src/main.cpp
@@ -0,0 +1,195 @@
+/*
+ * main.cpp
+ *
+ *  Created on: 31.10.2010
+ *      Author: sven
+ */
+#include <pthread.h>
+#include <semaphore.h>
+#include <time.h>
+#include <sys/time.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+// debug printing
+#ifdef DEBUG_MODE
+#include <stdio.h>
+	#define DEBUG_PRINT(format, args...)\
+			{\
+				static char message[512];\
+				snprintf(message,512,format, ##args);\
+				fprintf(stdout, "[%s: %d] : %s\n", __PRETTY_FUNCTION__,__LINE__, message);\
+				fflush(stdout);\
+			}
+#else
+	#define DEBUG_PRINT(format, args...)
+#endif // DEBUG_MODE
+
+/*
+ * global variables
+ */
+sem_t main_block,timer_block;
+pthread_t timer_thread;
+bool stop_timer_thread = false;
+pthread_mutex_t stop_mutex = PTHREAD_MUTEX_INITIALIZER;
+// 0 sec
+const long TIMER_INTERVAL_SECS = 0;
+// 10 msec
+const long TIMER_INTERVAL_USECS = 10000;
+
+struct sigaction timer_action, quit_action;
+/*
+ * function prototypes
+ */
+void readSensors();
+void initializeClock();
+void initializeMain();
+void WaitForNextCycle();
+void ActuateProcess();
+bool CalculateNewSetValues();
+void Error();
+void* TimerThreadProc(void*);
+void timer_handler(int);
+
+void* TimerThreadProc(void*) {
+	/**
+	 * Timer code originally from
+	 * http://www.informit.com/articles/article.aspx?p=23618&seqNum=14
+	 */
+	DEBUG_PRINT("entry Process: %d Thread: %lu",(int)getpid(),pthread_self());
+	bool stop_me = false;
+	struct itimerval timer;
+	/* Install timer_handler as the signal handler for SIGALRM. */
+	timer_action.sa_handler = timer_handler;
+	sigemptyset(&timer_action.sa_mask);
+	timer_action.sa_flags = 0;
+	sigaction(SIGALRM,&timer_action,NULL);
+
+	/* Configure the timer to expire after
+	 * TIMER_INTERVAL_SECS + TIMER_INTERVAL_USECS... */
+	timer.it_value.tv_sec = TIMER_INTERVAL_SECS;
+	timer.it_value.tv_usec = TIMER_INTERVAL_USECS;
+	/* ... and every TIMER_INTERVAL_SECS+TIMER_INTERVAL_USECS after that. */
+	timer.it_interval.tv_sec = TIMER_INTERVAL_SECS;
+	timer.it_interval.tv_usec = TIMER_INTERVAL_USECS;
+	/* If the timer code is ITIMER_REAL,
+	 * the process is sent a SIGALRM signal after the
+	 * specified wall-clock time has elapsed*/
+	setitimer (ITIMER_REAL, &timer, NULL);
+	while(1) {
+		pthread_mutex_lock(&stop_mutex);
+		stop_me = stop_timer_thread;
+		pthread_mutex_unlock(&stop_mutex);
+		if(stop_me) {
+			DEBUG_PRINT("exiting thread Process: %d Thread: %lu",(int)getpid(),pthread_self());
+			pthread_exit(NULL);
+		}
+		DEBUG_PRINT("waiting for timer_handler Process: %d Thread: %lu",(int)getpid(),pthread_self());
+		sem_wait(&timer_block);
+		DEBUG_PRINT("waking up main Process: %d Thread: %lu",(int)getpid(),pthread_self());
+		sem_post(&main_block);
+	}
+	DEBUG_PRINT("should never happen Process: %d Thread: %lu",(int)getpid(),pthread_self());
+	return NULL;
+}
+
+void timer_handler(int signum) {
+	DEBUG_PRINT("entry Process: %d Thread: %lu",(int)getpid(),pthread_self());
+	static int count = 0;
+	DEBUG_PRINT("timer expired %d times", ++count);
+	sem_post(&timer_block);
+	DEBUG_PRINT("exit");
+}
+
+void quit_handler(int signum) {
+	DEBUG_PRINT("entry Process: %d Thread: %lu",(int)getpid(),pthread_self());
+	int semval;
+	pthread_mutex_lock(&stop_mutex);
+	stop_timer_thread = true;
+	pthread_mutex_unlock(&stop_mutex);
+	sem_getvalue(&timer_block,&semval);
+	if(semval > 0) {
+		DEBUG_PRINT("waking up timer thread");
+		sem_post(&timer_block);
+	}
+	pthread_join(timer_thread,NULL);
+	DEBUG_PRINT("Joined timer thread");
+	//clean up
+	sem_destroy(&timer_block);
+	sem_destroy(&main_block);
+	pthread_mutex_destroy(&stop_mutex);
+	DEBUG_PRINT("exit");
+	exit(EXIT_SUCCESS);
+}
+
+void WaitForNextCycle() {
+	DEBUG_PRINT("entry Process: %d Thread: %lu",(int)getpid(),pthread_self());
+	sem_wait(&main_block);
+	DEBUG_PRINT("exit");
+}
+
+void readSensors() {
+	DEBUG_PRINT("entry Process: %d Thread: %lu",(int)getpid(),pthread_self());
+	struct timeval tv;
+	struct timezone tz;
+	struct tm *tm;
+	gettimeofday(&tv, &tz);
+	tm=localtime(&tv.tv_sec);
+	printf(" %d:%02d:%02d %lu \n", tm->tm_hour, tm->tm_min,
+	    tm->tm_sec, tv.tv_usec);
+	DEBUG_PRINT("exit");
+}
+void Error() {
+	DEBUG_PRINT("entry Process: %d Thread: %lu",(int)getpid(),pthread_self());
+	DEBUG_PRINT("exit");
+}
+bool CalculateNewSetValues() {
+	DEBUG_PRINT("entry Process: %d Thread: %lu",(int)getpid(),pthread_self());
+	DEBUG_PRINT("exit");
+	return true;
+}
+void ActuateProcess() {
+	DEBUG_PRINT("entry Process: %d Thread: %lu",(int)getpid(),pthread_self());
+	DEBUG_PRINT("exit");
+}
+void initializeClock()
+{
+	DEBUG_PRINT("entry Process: %d Thread: %lu",(int)getpid(),pthread_self());
+	pthread_create(&timer_thread,NULL,TimerThreadProc,NULL);
+	DEBUG_PRINT("exit");
+}
+
+void initializeMain() {
+	DEBUG_PRINT("entry Process: %d Thread: %lu",(int)getpid(),pthread_self());
+
+	/* init semaphore as closed */
+	sem_init(&main_block,0,0);
+	sem_init(&timer_block,0,0);
+
+    /* catch all interesting signals */
+	quit_action.sa_handler = quit_handler;
+	sigemptyset(&quit_action.sa_mask);
+	quit_action.sa_flags = 0;
+	sigaction(SIGTERM,&quit_action,NULL);
+	sigaction(SIGQUIT,&quit_action,NULL);
+	sigaction(SIGINT,&quit_action,NULL);
+	sigaction(SIGHUP,&quit_action,NULL);
+    DEBUG_PRINT("exit");
+}
+
+int main(int argc, char* argv[])
+{
+	initializeMain();
+	initializeClock();
+	while(1) {
+		readSensors();
+		if(CalculateNewSetValues())
+			ActuateProcess();
+		else
+			Error();
+		WaitForNextCycle();
+	}
+	return EXIT_SUCCESS;
+}