1 / 16

Vorlesung Echtzeitbetriebssysteme V. Interprozesskoordination

Vorlesung Echtzeitbetriebssysteme V. Interprozesskoordination. Dr.-Ing. Frank Golatowski. Ziele der Vorlesung. Scheduling. SCHED_FIFO SCHED_RR SCHED_OTHER. Scheduling. sched_setscheduler (pid, policy, param) sched_setparam (pid,param) int sched_get_priority_min (policy) in Linux 1

austin-wilcox
Télécharger la présentation

Vorlesung Echtzeitbetriebssysteme V. Interprozesskoordination

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. VorlesungEchtzeitbetriebssysteme V. Interprozesskoordination Dr.-Ing. Frank Golatowski

  2. Ziele der Vorlesung

  3. Scheduling • SCHED_FIFO • SCHED_RR • SCHED_OTHER

  4. Scheduling • sched_setscheduler (pid, policy, param) • sched_setparam (pid,param) • int sched_get_priority_min (policy) in Linux 1 • int sched_get_priority_max (policy) in Linux 99 • sched_yield(void) #include <sched.h> struct sched_param param; main(){ printf("RR min: %ld\n",sched_get_priority_min(SCHED_RR)); printf("RR max: %ld\n",sched_get_priority_max(SCHED_RR)); printf("FIFO min: %ld\n",sched_get_priority_min(SCHED_FIFO)); printf("FIFO max: %ld\n",sched_get_priority_max(SCHED_FIFO)); param.sched_priority = 10; fork(); sched_setscheduler(0,SCHED_FIFO, &param); tue_etwas(); }

  5. Memlock • mlock (address, length) • munlock (address, length) • mlockall (flags) • munlockall (void) #include <sys/mman.h> main(){ mlock(MCL_CURRENT|MCL_FUTURE); /* */ tue_etwas(); }

  6. Shared memory • void *mmap ( start, len, prot, flags, fd, offset) • munmap (start ,len) #include <sys/types.h> #include <unistd.h> #include <sys/mman.h> main(){ fd = open ("kk.ps",O_RDWR); ptr = mmap(NULL, 100*sizeof(int), PROT_READ | PROT_WRITE, MAP_SHARED,fd,0L); } ptr[0]=0; if (fork()==0) { /* Sohn */ while (ptr[0]==0); } else { /* Vater */ ptr[0]=1; }

  7. Synchronisation • sem_id sem_open (name, oflags, mode, init_value) • sem_close (sem_id) • sem_unlink (number)

  8. Semaphore • sem_wait (sem_id) • sem_post (sem_id) • sem_trywait (sem_id) • int sem_get_value (sem_id) #include <time.h> #include <signal.h> #include <semaphore.h> main(){ sem_t *mutex; int x; mutex=sem_open("SEMA",O_CREAT,0,1); if (fork() == 0) { printf("Sohn startet" %d\n",x); sem_wait(mutex); printf("Sohn wird beendet\n"); } else { sleep(2); printf("Vater erwacht\n"); sem_post(mutex); printf("Vater wird beendet"\n"); } }

  9. Signale • SIGILL • SIGSEGV • SIGTERM • SIGALRM • SIGKILL • SIGFPE • SIGSTOP, SIGCONT • SIGUSR1, SIGUSR2 • SIGRTMIN...SIGRTMAX

  10. Signal Handling struct sigaction { void (*sa_handler)(); sigset_t sa_mask; int sa_flags; void (*sa_sigaction)(...); }; • int sigaction (int signal,const struct sigaction *act, struct sigaction *oact); • int kill (pid_t pid, int sig); • int sigprocmask(int how, const sigset_t *set, sigset_t *oset); • int sigsuspend(const sigset_t *set); sigemptyset(*s) sigfillset(*s) sigaddset(*s,n) sigdelset(*s,n) sigismember(*s,n) SIG_BLOCK SIG_UNBLOCK SIG_SETMASK

  11. Signal Beispiel #include <signal.h> void handler (int senyal){ printf("an arithmetical exception has taken place\n"); } main(){ struct sigaction man; float a,b; int x; man.sa_flags = 0; man.sa_handler = handler; sigemptyset(&man.sa_mask); sigaction(SIGFPE, &man, NULL); for (x=0 ; x<100 ; x++) b = a / 0; printf("I am going to finalize\n"); }

  12. Echtzeitsignale

  13. Messagequeues • mq_open • mq_close • mq_unlink • mq_send • mq_receive • mq_setattr

  14. Uhr (Clock) • clock_gettime • clock_getres • nanosleep #include <time.h> main(){ struct timespec B,A; clock_gettime(CLOCK_REALTIME,&A); clock_gettime(CLOCK_REALTIME,&B); printf("Two consecutive calls: %ld nseg\n", 1000000000L*(B.tv_sec-A.tv_sec)+(B.tv_nsec-A.tv_nsec)); }

  15. Timer • timer_create (clock_id, sig_spec, timer_new) • timer_settimer (timer_id, flags, new_interval, old_interval) • timer_gettimer (timer_id, current_interval) • timer_delete (timer_id) struct itimerspec { struct timerspec it_value; struct timespec it_interval; };

  16. Timer main(){ struct timespec B; struct itimerspec tempor_spec; timer_t tempor; struct sigevent evento; signal (SIGRTMIN,handler); evento.sigev_signo = SIGRTMIN; evento.sigev_notify = SIGEV_SIGNAL; timer_create(CLOCK_REALTIME, &evento,&tempor)); tempor_spec.it_value.tv_sec = 5; tempor_spec.it_value.tv_nsec = 0; tempor_spec.it_interval.tv_sec = 1; tempor_spec.it_interval.tv_nsec = 0; timer_settime(tempor, 0, &tempor_spec, NULL); clock_gettime(CLOCK_REALTIME,&B); printf("Instante => seg: %ld, nseg:%ld\n", B.tv_sec, B.tv_nsec); while (1) { sleep(100); } } #include <time.h> #include <signal.h> void handler (){ struct timespec ahora; signal(SIGRTMIN,manejador); clock_gettime(CLOCK_REALTIME,&ahora); printf("Instante => seg: %ld, nseg: %ld\n", ahora.tv_sec, ahorai.tv_nsec); } Noch nicht fertig

More Related