C++ sem_signal函数代码示例

void main (int argc, char *argv[])
{
  sem_t s_procs_completed; // Semaphore to signal the process that we're done
  sem_t s_N2;          //Semaphore as N2
  int num_N2;          //Number of N2
  int i;              //index var
  if (argc != 4) { 
    Printf("Usage: "); Printf(argv[0]); Printf("  <handle_to_pass_complete_signal><s_procs_completed_str> <s_N2_str> <num_N2_str>\n"); 
    Exit();
  } 

  // Convert the command-line strings into integers for use as handles
  s_procs_completed = dstrtol(argv[1], NULL, 10);
  s_N2 = dstrtol(argv[2],NULL,10);
  num_N2 =dstrtol(argv[3],NULL,10);
  
  for(i=0;i<num_N2;i++){
     Printf("Inject a N2\n");
     sem_signal(s_N2);
  }
  // Signal the semaphore to tell the original process that we're done
 //  Printf("injection_n2 completed!\n");
  if(sem_signal(s_procs_completed) != SYNC_SUCCESS) {
    Printf("Bad semaphore s_procs_completed (%d) in ", s_procs_completed); Printf(argv[0]); Printf(", exiting...\n");
    Exit();
  }
}

client()
{
	int	i;

	/*
	 * Tell the server we're here and ready,
	 * then just receive while the server sends us things.
	 */

	sem_wait(clisem);		/* get control of shared memory */
	mesgptr->mesg_len = MESGLEN;
	mesgptr->mesg_type = MESGLEN;
	sem_signal(servsem);		/* wake up server */

	for (i = 0; i < NUMMESG; i++) {
		sem_wait(clisem);	/* wait for server */

		if (mesgptr->mesg_len != MESGLEN)
			err_sys("client: incorrect length");
		if (mesgptr->mesg_type != (i + 1))
			err_sys("client: incorrect type");

		sem_signal(servsem);	/* wake up server */
	}
}

void main (int argc, char *argv[])
{
  sem_t s_procs_completed; // Semaphore to signal the process that we're done
  sem_t s_N;         //Semaphore N
  sem_t s_O2;          //Semaphore O2
  sem_t s_NO2;        //Semaphore NO2
  int num_N_O2_NO2;       //number of reaction
  int i;             //index var

  if (argc != 6) { 
    Printf("Usage: "); Printf(argv[0]); Printf(" <handle_to_signal_complete><s_H2O> <s_H2> <s_O2>  <num_H2O_H2_O2> \n"); 
    Exit();
  } 

  // Convert the command-line strings into integers for use as handles
  s_procs_completed = dstrtol(argv[1], NULL, 10);
  s_N =dstrtol(argv[2],NULL,10);
  s_O2 =dstrtol(argv[3],NULL,10);
  s_NO2 =dstrtol(argv[4],NULL,10);
  num_N_O2_NO2 = dstrtol(argv[5],NULL,10);

  for(i=0;i<num_N_O2_NO2;i++){
      sem_wait(s_N);
      sem_wait(s_O2);
      Printf("Create a NO2\n");
      sem_signal(s_NO2);
  }
     
//  Printf("reaction3 completed\n");
  if(sem_signal(s_procs_completed) != SYNC_SUCCESS) {
    Printf("Bad semaphore s_procs_completed (%d) in ", s_procs_completed); Printf(argv[0]); Printf(", exiting...\n");
    Exit();
}
}

void canarrive(void* daddy) { 
	sem_acquire(&lock);
  numcan++;
	if(numcan == 3 || (numcan > 0 && nummiss == 2)){
	  sem_signal(&can);
		sem_signal(&can);
		printf(1, "\nRow Boat");
		if (nummiss == 3){
		  printf(1, " with 3 missionaries");
			nummiss = 0;
		}
		else if(numcan == 3){
			printf(1, " with 3 cannibals");
			numcan = 0;
		}
		else{
			printf(1, " with 1 cannibal 2 missionaries");
			numcan = numcan - 1;
			nummiss = nummiss -2;
		}

	}
	sem_signal(&lock);
	texit();
}

void dominant_monkey_climb()
{
  sem_acquire(&tree);
printf(1,"dominant Monkey %d gets coconut\n", getpid());
sem_signal(&tree);
  sem_signal(&dominant_monkey);
  texit();
}

/* Transfer one packet of data from the AICA->SH4 queue. Expects to
   find AICA_CMD_MAX_SIZE dwords of space available. Returns -1
   if failure, 0 for no packets available, 1 otherwise. Failure
   might mean a permanent failure since the queue is probably out of sync. */
int snd_aica_to_sh4(void *packetout) {
	uint32	bot, start, stop, top, size, cnt, *pkt32;

	sem_wait(sem_qram);

	/* Set these up for reference */
	bot = SPU_RAM_BASE + AICA_MEM_RESP_QUEUE;
	assert_msg( g2_read_32(bot + offsetof(aica_queue_t, valid)), "Queue is not yet valid" );

	top = SPU_RAM_BASE + AICA_MEM_RESP_QUEUE + g2_read_32(bot + offsetof(aica_queue_t, size));
	start = SPU_RAM_BASE + AICA_MEM_RESP_QUEUE + g2_read_32(bot + offsetof(aica_queue_t, tail));
	stop = SPU_RAM_BASE + AICA_MEM_RESP_QUEUE + g2_read_32(bot + offsetof(aica_queue_t, head));
	cnt = 0;
	pkt32 = (uint32 *)packetout;

	/* Is there anything? */
	if (start == stop) {
		sem_signal(sem_qram);
		return 0;
	}

	/* Check for packet size overflow */
	size = g2_read_32(start + offsetof(aica_cmd_t, size));
	if (cnt >= AICA_CMD_MAX_SIZE) {
		sem_signal(sem_qram);
		dbglog(DBG_ERROR, "snd_aica_to_sh4(): packet larger than %d dwords\n", AICA_CMD_MAX_SIZE);
		return -1;
	}

	/* Find stop point for this packet */
	stop = start + size*4;
	if (stop > top)
		stop -= top - (SPU_RAM_BASE + AICA_MEM_RESP_QUEUE);
	
	while (start != stop) {
		/* Fifo wait if necessary */
		if (!(cnt % 8))
			g2_fifo_wait();
		cnt++;

		/* Read the next dword */
		*pkt32++ = g2_read_32(start);

		/* Move our counters */
		start += 4;
		if (start >= top)
			start = bot;
		cnt++;
	}

	/* Finally, write a new tail value to signify that we've removed a packet */
	g2_write_32(bot + offsetof(aica_queue_t, tail), start - (SPU_RAM_BASE + AICA_MEM_RESP_QUEUE));

	sem_signal(sem_qram);

	return 1;
}

void barber() {
  while(true) {
    sem_wait(customer_waiting);
    sem_wait(seats_mutex);
    free_seats++;
    cut_hair();
    sem_signal(barber_sleeping);
    sem_signal(seats_mutex);
  }
}

void oReady(void *arg_ptr) {
	sem_acquire(&h);
	sem_acquire(&h);
	sem_signal(&o);
	sem_signal(&o);
	lock_acquire(&mutex);
	water_molecules++;
	lock_release(&mutex);
	texit();
}

BOOL append_fat (VOL_PTR tab , const dword chain, dword * addr) {
  
  fat_ptr fat=NULL; 
  dword cluster_ultimo=0, cluster_new=0;
  
  if(!(tab)) {
    set_errno(EINVAL,"Volume errato (%s-line%d)", __FILE__, __LINE__); 
    return FALSE; 
  }
  
  if(chain <2 ) { 
     set_errno(EINVAL,"Cluster riservato");
    return FALSE; 
  }
  
  fat=tab->fat; 
  
  sem_wait(tab->sem_fat); 
  
    if(!get_ultimo_fat(fat, chain, &cluster_ultimo)) {
      sem_signal(tab->sem_fat); 
      return FALSE; 
    }
    
  if(!getFree_fat(fat, tab->size_fat,&cluster_new)) {
     sem_signal(tab->sem_fat);
    return FALSE; 
  }
  
  //devo scrivere nell'ultimo l'indirizzo del nuovo cluster
    
    if(!scrivi_fat(tab, cluster_ultimo, cluster_new))  {
      sem_signal(tab->sem_fat);
      return FALSE; 
    }
    
  if(!scrivi_fat(tab, cluster_new, EOC_32)) {
    // se fallisce provo a ripristinare la situazione precedente
    if(!scrivi_fat(tab, cluster_ultimo,  EOC_32)) 
      set_errno(EIO,"Errore irrecuperabile, possibile perdita di dati");    
      sem_signal(tab->sem_fat); 
     return FALSE; 
    }
  
  // ... ----->Ultimo---->new(EOC); 
  // finito inserimento 

  sem_signal(tab->sem_fat); 
  
  if(addr)
    *addr=cluster_new; 
  
  return TRUE; 
  
}

void main(int argc, char ** argv)
{
    uint32 h_mem;
    sem_t s_procs_completed;

    Molecules * mols;
    int ct;

    if (argc != 3) {
        Printf("Usage: ");
        Printf(argv[0]);
        Printf(" <handle_to_shared_memory_page> <handle_to_page_mapped_semaphore>\n");
        Exit();
    }

    // Convert the command-line strings into integers for use as handles
    h_mem = dstrtol(argv[1], NULL, 10); // The "10" means base 10
    s_procs_completed = dstrtol(argv[2], NULL, 10);

    // Map shared memory page into this process's memory space
    if ((mols = (Molecules *) shmat(h_mem)) == NULL) {
        Printf("Could not map the shared page to virtual address in ");
        Printf(argv[0]);
        Printf(", exiting..\n");
        Exit();
    }

    for(ct = 0; ct < mols->init_so4; ct++) {
        // Consume SO4
        sem_wait(mols->so4);

        // Produce so2
        sem_signal(mols->so2);
        Printf("A molecule SO2 is created\n");

        // Produce O2
        sem_signal(mols->o2);
        Printf("A molecule O2 is created\n");
    }


    // Signal the semaphore to tell the original process that we're done
    Printf("Reaction 2: PID %d is complete.\n", getpid());


    if(sem_signal(s_procs_completed) != SYNC_SUCCESS) {
        Printf("Bad semaphore s_procs_completed (%d) in ", s_procs_completed);
        Printf(argv[0]);
        Printf(", exiting...\n");
        Exit();
    }

    return;
}

void CannibalArrives()
{
	sem_aquire(&boat);
	
	sem_aquire(&display);
	printf(1, "1: (%d) cannibal arrived, %d, %d\n", getpid(), total, con);
	sem_signal(&display);	


	sem_aquire(&mutex2);
	while(total + 2 == 5) { con++;
	sem_signal(&mutex2);
	sem_signal(&boat);
	
	sem_aquire(&display);
	printf(1, "1: (%d) cannibal denied boarding, %d, %d\n", getpid(), total, con);
	sem_signal(&display);

	sem_aquire(&prevention);

	sem_aquire(&display);
	printf(1, "1: (%d) cannibal prevented meal, %d, %d\n", getpid(), total, con);
	sem_signal(&display);

	
	sem_aquire(&boat);
	sem_aquire(&mutex2);
	}
	sem_signal(&mutex2);
	sem_aquire(&mutex2);
	total += 2;
	sem_signal(&mutex2);
	
	sem_aquire(&display);
	printf(1, "2: (%d) cannibal enters boat, %d, %d\n", getpid(), total, con);
	sem_signal(&display);	
	
	sem_aquire(&mutex);
	bp++;
	sem_signal(&mutex);
	if (bp < 3)	sem_aquire(&loading);
	
	
	
	// sem_aquire(&display);
	// printf(1, "bp cannibal: %d\n", bp);
	// sem_signal(&display);
	
	RowBoat();
	sem_signal(&loading);

	
	texit();
}

static void cb_default(const char *str) {
	cb_sem_data_t *t;

	t = malloc(sizeof(cb_sem_data_t));
	sem_wait(cb_mutex);
	strncpy(t->line, str, 255); t->line[255] = '\0';
	t->next = (cb_sem_data_t *)cb_queue;
	cb_queue = t;
	sem_signal(cb_mutex);

	sem_signal(cb_sem);
}

void oReady(void* v)
{
   sem_acquire(&h);
   sem_acquire(&h);
   sem_signal(&o);
   sem_signal(&o);
   sem_acquire(&l);
   water++;
   printf(1,"water molecule created\n");
   sem_signal(&l);

   texit();
}

void MissionaryArrives()
{
	sem_aquire(&boat);
	
	sem_aquire(&display);
	printf(1, "1: (%d) missionary arrived, %d, %d\n", getpid(), total, con);
	sem_signal(&display);


	sem_aquire(&mutex2);	
	while(total + 1 == 5){ con++;
	sem_signal(&mutex2);
	sem_signal(&boat);

	sem_aquire(&display);
	printf(1, "1: (%d) missionary denied boarding, %d, %d\n", getpid(), total, con);
	sem_signal(&display);

	sem_aquire(&prevention);

	sem_aquire(&display);
	printf(1, "1: (%d) missionary prevented death, %d, %d\n", getpid(), total, con);
	sem_signal(&display);
	
	sem_aquire(&boat);
	sem_aquire(&mutex2);
	}
	sem_signal(&mutex2);
	sem_aquire(&mutex2);
	total += 1;
	sem_signal(&mutex2);
	
	sem_aquire(&display);
	printf(1, "2: (%d) missionary enters boat, %d, %d\n", getpid(), total, con);
	sem_signal(&display);

	sem_aquire(&mutex);
	bp++;
	sem_signal(&mutex);
	if (bp < 3)	sem_aquire(&loading);

	// sem_aquire(&display);
	// printf(1, "bp missionary: %d\n", bp);
	// sem_signal(&display);
	
	RowBoat();
	sem_signal(&loading);
	
	
	texit();
}

void customer() {
  sem_wait(seats_mutex);
  if(free_seats > 0) {
    free_seats--;     
    sem_signal(customer_waiting);
    sem_signal(seats_mutex);
    sem_wait(barber_sleeping);
    get_haircut();
  }
  else {
    sem_signal(seats_mutex);
    leave();
  }
}