C++ enter_critical_section函数代码示例

int group_initialize(FAR struct task_tcb_s *tcb)
{
  FAR struct task_group_s *group;
#if defined(HAVE_GROUP_MEMBERS) || defined(CONFIG_ARCH_ADDRENV)
  irqstate_t flags;
#endif

  DEBUGASSERT(tcb && tcb->cmn.group);
  group = tcb->cmn.group;

#ifdef HAVE_GROUP_MEMBERS
  /* Allocate space to hold GROUP_INITIAL_MEMBERS members of the group */

  group->tg_members = (FAR pid_t *)kmm_malloc(GROUP_INITIAL_MEMBERS*sizeof(pid_t));
  if (!group->tg_members)
    {
      kmm_free(group);
      return -ENOMEM;
    }

  /* Assign the PID of this new task as a member of the group. */

  group->tg_members[0] = tcb->cmn.pid;

  /* Initialize the non-zero elements of group structure and assign it to
   * the tcb.
   */

  group->tg_mxmembers  = GROUP_INITIAL_MEMBERS; /* Number of members in allocation */

#endif

#if defined(HAVE_GROUP_MEMBERS) || defined(CONFIG_ARCH_ADDRENV)
  /* Add the initialized entry to the list of groups */

  flags = enter_critical_section();
  group->flink = g_grouphead;
  g_grouphead = group;
  leave_critical_section(flags);

#endif

  /* Save the ID of the main task within the group of threads.  This needed
   * for things like SIGCHILD.  It ID is also saved in the TCB of the main
   * task but is also retained in the group which may persist after the main
   * task has exited.
   */

#if !defined(CONFIG_DISABLE_PTHREAD) && defined(CONFIG_SCHED_HAVE_PARENT)
  group->tg_task = tcb->cmn.pid;
#endif

  /* Mark that there is one member in the group, the main task */

  group->tg_nmembers = 1;
  return OK;
}

FAR struct mqueue_msg_s *mq_msgalloc(void)
{
  FAR struct mqueue_msg_s *mqmsg;
  irqstate_t flags;

  /* If we were called from an interrupt handler, then try to get the message
   * from generally available list of messages. If this fails, then try the
   * list of messages reserved for interrupt handlers
   */

  if (up_interrupt_context())
    {
      /* Try the general free list */

      mqmsg = (FAR struct mqueue_msg_s *)sq_remfirst(&g_msgfree);
      if (mqmsg == NULL)
        {
          /* Try the free list reserved for interrupt handlers */

          mqmsg = (FAR struct mqueue_msg_s *)sq_remfirst(&g_msgfreeirq);
        }
    }

  /* We were not called from an interrupt handler. */

  else
    {
      /* Try to get the message from the generally available free list.
       * Disable interrupts -- we might be called from an interrupt handler.
       */

      flags = enter_critical_section();
      mqmsg = (FAR struct mqueue_msg_s *)sq_remfirst(&g_msgfree);
      leave_critical_section(flags);

      /* If we cannot a message from the free list, then we will have to
       * allocate one.
       */

      if (mqmsg == NULL)
        {
          mqmsg = (FAR struct mqueue_msg_s *)
            kmm_malloc((sizeof (struct mqueue_msg_s)));

          /* Check if we allocated the message */

          if (mqmsg != NULL)
            {
              /* Yes... remember that this message was dynamically allocated */

              mqmsg->type = MQ_ALLOC_DYN;
            }
        }
    }

  return mqmsg;
}

static void l2_inv_all(void)
{
	/* invalidate all ways */
	enter_critical_section();
	PL310_L2CC->InvalidateByWay = way_mask;
	while (PL310_L2CC->InvalidateByWay & way_mask);
	PL310_L2CC->CacheSync = 0;
	exit_critical_section();
}

/****************************************************************************
 * Name: timer_start
 *
 * Description:
 *   Is used to Start a timer. The reload value is copied to the counter.
 *   And the running bit it set. There is no problem in Starting a running
 *   timer. But it will restart the timeout.
 *
 * Input Parameters:
 *   id - Returned from timer_allocate;
 *
 * Returned Value:
 *   None.
 *
 ****************************************************************************/
void timer_start(bl_timer_id id)
{
	DEBUGASSERT(id >= 0 && id < arraySize(timers) && (timers[id].ctl & inuse));
	irqstate_t s = enter_critical_section();
	timers[id].count = timers[id].reload;
	timers[id].ctl |= running;
	leave_critical_section(s);

}

void mm_takesemaphore(FAR struct mm_heap_s *heap)
{
#ifdef CONFIG_SMP
  irqstate_t flags = enter_critical_section();
#endif
  pid_t my_pid = getpid();

  /* Do I already have the semaphore? */

  if (heap->mm_holder == my_pid)
    {
      /* Yes, just increment the number of references that I have */

      heap->mm_counts_held++;
    }
  else
    {
      int ret;

      /* Take the semaphore (perhaps waiting) */

      mseminfo("PID=%d taking\n", my_pid);
      do
        {
          ret = _SEM_WAIT(&heap->mm_semaphore);

          /* The only case that an error should occur here is if the wait
           * was awakened by a signal.
           */

          if (ret < 0)
            {
#if defined(CONFIG_BUILD_FLAT) || defined(__KERNEL__)
              DEBUGASSERT(ret == -EINTR || ret == -ECANCELED);
#else
              int errcode = get_errno();
              DEBUGASSERT(errcode == EINTR || errcode == ECANCELED);
              ret = -errcode;
#endif
            }
        }
      while (ret == -EINTR);

      /* We have it (or some awful, unexpected error occurred).  Claim
       * the semaphore and return.
       */

      heap->mm_holder      = my_pid;
      heap->mm_counts_held = 1;
    }

#ifdef CONFIG_SMP
  leave_critical_section(flags);
#endif
  mseminfo("Holder=%d count=%d\n", heap->mm_holder, heap->mm_counts_held);
}

FAR sigq_t *sig_allocatependingsigaction(void)
{
  FAR sigq_t    *sigq;
  irqstate_t flags;

  /* Check if we were called from an interrupt handler. */

  if (up_interrupt_context())
    {
      /* Try to get the pending signal action structure from the free list */

      sigq = (FAR sigq_t *)sq_remfirst(&g_sigpendingaction);

      /* If so, then try the special list of structures reserved for
       * interrupt handlers
       */

      if (!sigq)
        {
          sigq = (FAR sigq_t *)sq_remfirst(&g_sigpendingirqaction);
        }
    }

  /* If we were not called from an interrupt handler, then we are
   * free to allocate pending signal action structures if necessary. */

  else
    {
      /* Try to get the pending signal action structure from the free list */

      flags = enter_critical_section();
      sigq = (FAR sigq_t *)sq_remfirst(&g_sigpendingaction);
      leave_critical_section(flags);

      /* Check if we got one. */

      if (!sigq)
        {
          /* No...Try the resource pool */

          if (!sigq)
            {
              sigq = (FAR sigq_t *)kmm_malloc((sizeof (sigq_t)));
            }

          /* Check if we got an allocated message */

          if (sigq)
            {
              sigq->type = SIG_ALLOC_DYN;
            }
        }
    }

  return sigq;
}

/* Callback for JVMTI_EVENT_VM_START */
static void JNICALL
cbVMStart(jvmtiEnv *jvmti, JNIEnv *env)
{
    enter_critical_section(jvmti);
    {
        /* Indicate VM has started */
        gdata->vm_is_started = JNI_TRUE;
    }
    exit_critical_section(jvmti);
}

void register_int_handler(unsigned int vector, int_handler func, void *arg)
{
    if (vector >= NR_IRQS)
        return;

    enter_critical_section();
    handler[vector].func = func;
    handler[vector].arg = arg;
    exit_critical_section();
}

void target_shutdown(void)
{
	enter_critical_section();
	
	if(fbcon_display())
		htcleo_display_shutdown();
	platform_exit();
	msm_proc_comm(PCOM_POWER_DOWN, 0, 0);
	for (;;) ;
}

void clock_synchronize(void)
{
  irqstate_t flags;

  /* Re-initialize the time value to match the RTC */

  flags = enter_critical_section();
  clock_inittime();
  leave_critical_section(flags);
}

void nvram_display_list() {
	NvramVar* var = (NvramVar*) gNvramList->next;
	enter_critical_section();
	while(var != (void*) gNvramList) {
		printf("0x%08x: %s = %s\n", var, var->name, var->string);
		var = var->next;
	}
	printf("\n");
	exit_critical_section();
}

void timer_delete(timer_list_t *timer)
{
    enter_critical_section();
    
    if (list_in_list(&timer->node)) {
        list_delete(&timer->node);
    }

    exit_critical_section();
}

xcpt_t board_button_irq(int id, xcpt_t irqhandler)
{
  xcpt_t oldhandler = NULL;

  if (id >=0 && id < NUM_BUTTONS)
    {
      irqstate_t flags;

      /* Disable interrupts until we are done.  This guarantees that the
       * following operations are atomic.
       */

      flags = enter_critical_section();

      /* Get/set the old button handler
       *
       * REVISIT:  Keeping copies of the hander in RAM seems wasteful
       * since the OS already has this information internally.
       */

#if 0 /* REVISIT */
      oldhandler = g_button_handlers[id];
      g_button_handlers[id] = irqhandler;
#else
      oldhandler = NULL;
#endif

      /* Are we attaching or detaching? */

      if (irqhandler != NULL)
        {
          /* Configure the interrupt */

          efm32_gpioirq(g_button_configs[id]);

          /* Attach and enable the interrupt */

          (void)irq_attach(g_button_irqs[id], irqhandler);
          efm32_gpioirqenable(g_button_irqs[id]);
        }
      else
        {
          /* Disable and detach the interrupt */

          efm32_gpioirqdisable(g_button_irqs[id]);
          (void)irq_detach(g_button_irqs[id]);
        }

      leave_critical_section(flags);
    }

  /* Return the old button handler (so that it can be restored) */

  return oldhandler;
}

status_t platform_set_periodic_timer(platform_timer_callback callback,
	void *arg, time_t interval)
{

	enter_critical_section();

	qtimer_set_physical_timer(interval, callback, arg);

	exit_critical_section();
	return 0;
}

static jlong next_thread_id() {
  // mark the thread - with lock
  // TODO replace total ordering lock with private lock - perf. issue
  jlong result = -1;
  enter_critical_section(jvmti_env, threadID_lock);
  {
    result = avail_thread_id++;
  }
  exit_critical_section(jvmti_env, threadID_lock);
  return result;
}