Exemple #1
0
	/**
	 * Adds a message as a task to the task queue.
	 * This blocks if the task queue is full, until there is space.
	 * @param p - the peer that the message was received from
	 * @param msg - the message
	 * @returns 1 on success, 0 on failure (eg. shutdown in progress)
	 */ 
	int put_task(peer *p,AAAMessage *msg)
	{
		lock_get(tasks->lock);
		while ((tasks->end+1)%tasks->max == tasks->start){
			lock_release(tasks->lock);
	
			if (*shutdownx) {
				sem_release(tasks->full);
				return 0;
			}
			
			sem_get(tasks->full);
			
			if (*shutdownx) {
				sem_release(tasks->full);
				return 0;
			}
			
			lock_get(tasks->lock);
		}
		tasks->queue[tasks->end].p = p;
		tasks->queue[tasks->end].msg = msg;
		tasks->end = (tasks->end+1) % tasks->max;
		if (sem_release(tasks->empty)<0)
			LOG(L_WARN,"WARN:put_task(): Error releasing tasks->empty semaphore > %s!\n",strerror(errno));
		lock_release(tasks->lock);
		return 1;
	}
Exemple #2
0
/**
 * Remove and return the first task from the queue (FIFO).
 * This blocks until there is something in the queue.
 * @returns the first task from the queue or an empty task on error (eg. shutdown in progress)
 */
task_t take_task()
{
	task_t t={0,0};
//	LOG(L_CRIT,"-1-\n");
	lock_get(tasks->lock);
//	LOG(L_CRIT,"-2-\n");
	while(tasks->start == tasks->end){
//		LOG(L_CRIT,"-3-\n");
		lock_release(tasks->lock);
//		LOG(L_CRIT,"-4-\n");
		if (*shutdownx) {
			sem_release(tasks->empty);
			return t;
		}
//		LOG(L_ERR,"-");
		sem_get(tasks->empty);
//		LOG(L_CRIT,"-5-\n");
		if (*shutdownx) {
			sem_release(tasks->empty);
			return t;
		}
		
		lock_get(tasks->lock);
//		LOG(L_CRIT,"-6-\n");
	}
//	LOG(L_CRIT,"-7-\n");
	
	t = tasks->queue[tasks->start];
	tasks->queue[tasks->start].msg = 0;
	tasks->start = (tasks->start+1) % tasks->max;
	if (sem_release(tasks->full)<0)
		LOG(L_WARN,"WARN:take_task(): Error releasing tasks->full semaphore > %s!\n",strerror(errno));
	lock_release(tasks->lock);
	return t;
}
Exemple #3
0
/**
 * Remove and return the first task from the queue (FIFO).
 * This blocks until there is something in the queue.
 * @returns the first task from the queue or an empty task on error (eg. shutdown in progress)
 */
task_t take_task() {
    task_t t = {0, 0};
    lock_get(tasks->lock);
    while (tasks->start == tasks->end) {
        lock_release(tasks->lock);
        if (*shutdownx) {
            sem_release(tasks->empty);
            return t;
        }
        sem_get(tasks->empty);
        if (*shutdownx) {
            sem_release(tasks->empty);
            return t;
        }

        lock_get(tasks->lock);
    }

    t = tasks->queue[tasks->start];
    tasks->queue[tasks->start].msg = 0;
    tasks->start = (tasks->start + 1) % tasks->max;
    if (sem_release(tasks->full) < 0)
        LM_WARN("Error releasing tasks->full semaphore > %s!\n", strerror(errno));
    lock_release(tasks->lock);

    //int num_tasks = tasks->end - tasks->start;
    //LM_ERR("Taken task from task queue.  Queue length [%i]", num_tasks);


    return t;
}
Exemple #4
0
void qsem_release (qsem_t *s)
{
#ifdef I386
	/* no atomic_add() in i386 */
	sem_release(s->mutex);
#else
	if (atomic_add (&s->count, 1) < 0)
		sem_release (s->mutex);
#endif
}
Exemple #5
0
/**
 * Destroys the worker structures. 
 */
void worker_destroy()
{
	int i,sval=0;
	if (callbacks){
		while(callbacks->head)
			cb_remove(callbacks->head);
		shm_free(callbacks);
	}

	// to deny runing the poison queue again
	config->workers = 0;
	if (tasks) {
	//	LOG(L_CRIT,"-1-\n");
		lock_get(tasks->lock);
		for(i=0;i<tasks->max;i++){
			if (tasks->queue[i].msg) AAAFreeMessage(&(tasks->queue[i].msg));
			tasks->queue[i].msg = 0;
			tasks->queue[i].p = 0;
		}
		lock_release(tasks->lock);

		LOG(L_INFO,"Unlocking workers waiting on empty queue...\n");
		for(i=0;i<config->workers;i++)
			sem_release(tasks->empty);
		LOG(L_INFO,"Unlocking workers waiting on full queue...\n");
		i=0;
		while(sem_getvalue(tasks->full,&sval)==0)			
			if (sval<=0) {
				sem_release(tasks->full);
				i=1;
			}
			else break;
		sleep(i);
		
		lock_get(tasks->lock);
	//	LOG(L_CRIT,"-2-\n");	
		shm_free(tasks->queue);
		lock_destroy(tasks->lock);
		lock_dealloc((void*)tasks->lock);
	//	LOG(L_CRIT,"-3-\n");	
		
		//lock_release(tasks->empty);
		sem_free(tasks->full);
		sem_free(tasks->empty);
		
		shm_free(tasks);
	}
}
Exemple #6
0
/**
 * Adds a message as a task to the task queue.
 * This blocks if the task queue is full, until there is space.
 * @param p - the peer that the message was received from
 * @param msg - the message
 * @returns 1 on success, 0 on failure (eg. shutdown in progress)
 */
int put_task(peer *p, AAAMessage *msg) {

    struct timeval start, stop;
    long elapsed_useconds=0, elapsed_seconds=0, elapsed_millis=0;
    lock_get(tasks->lock);

    gettimeofday(&start, NULL);
    while ((tasks->end + 1) % tasks->max == tasks->start) {
        lock_release(tasks->lock);

        if (*shutdownx) {
            sem_release(tasks->full);
            return 0;
        }

        sem_get(tasks->full);

        if (*shutdownx) {
            sem_release(tasks->full);
            return 0;
        }

        lock_get(tasks->lock);
    }

    gettimeofday(&stop, NULL);
    elapsed_useconds = stop.tv_usec - start.tv_usec;
    elapsed_seconds = stop.tv_sec - start.tv_sec;

    elapsed_useconds = elapsed_seconds*1000000 + elapsed_useconds;
    elapsed_millis = elapsed_useconds/1000;
    if (elapsed_millis > workerq_latency_threshold) {
        LM_ERR("took too long to put task into task queue > %d - [%ld]\n", workerq_latency_threshold, elapsed_millis);
    }

    tasks->queue[tasks->end].p = p;
    tasks->queue[tasks->end].msg = msg;
    tasks->end = (tasks->end + 1) % tasks->max;
    if (sem_release(tasks->empty) < 0)
        LM_WARN("Error releasing tasks->empty semaphore > %s!\n", strerror(errno));
    lock_release(tasks->lock);

    //int num_tasks = tasks->end - tasks->start;
    //LM_ERR("Added task to task queue.  Queue length [%i]", num_tasks);


    return 1;
}
Exemple #7
0
/*
    block_cache_sync() - flush all dirty blocks.
*/
s32 block_cache_sync()
{
    block_descriptor_t *bd, * const end = bc.descriptors + bc.nblocks;
    u32 one = 1;
    s32 ret;

    for(bd = bc.descriptors; bd != end; ++bd)
    {
        sem_acquire(&bd->sem);

        if(bd->flags & BC_DIRTY)
        {
            void *data = bc.cache + ((bd - bc.descriptors) * BLOCK_SIZE);
            ret = bd->dev->write(bd->dev, bd->block, &one, data);
            if(ret != SUCCESS)
                return ret;

            bd->flags &= ~BC_DIRTY;
        }

        sem_release(&bd->sem);
    }

    return SUCCESS;
}
void kernel_footprint(void)
{
	init();

	// generate code for process
	struct Process *p =
		proc_new(proc1_main, 0, sizeof(proc1_stack), proc1_stack);
	proc_setPri(p, 5);
	proc_yield();

	// generate code for msg
	Msg msg;
	msg_initPort(&in_port, event_createSignal(p, SIG_USER1));
	msg_put(&in_port, &msg);
	msg_peek(&in_port);
	Msg *msg_re = msg_get(&in_port);
	msg_reply(msg_re);

	// generate code for signals
	sig_send(p, SIG_USER0);

	// generate code for msg
	Semaphore sem;
	sem_init(&sem);
	sem_obtain(&sem);
	sem_release(&sem);

	sig_wait(SIG_USER0);
}
Exemple #9
0
int if_output(cbuf *b, ifnet *i)
{
    bool release_sem = false;
    bool enqueue_failed = false;
//printf("if out");

    // stick the buffer on a transmit queue
    mutex_lock(&i->tx_queue_lock);
    if(fixed_queue_enqueue(&i->tx_queue, b) < 0)
        enqueue_failed = true;
    if(i->tx_queue.count == 1)
        release_sem = true;
    mutex_unlock(&i->tx_queue_lock);

    if(enqueue_failed) {
        cbuf_free_chain(b);
        return ERR_NO_MEMORY;
    }

    if(release_sem)
        sem_release(i->tx_queue_sem);

//printf("if %x out ok\n", i);
    return NO_ERROR;
}
Exemple #10
0
/**
 * Poisons the worker queue.
 * Actually it just releases the task queue locks so that the workers get to evaluate
 * if a shutdown is in process and exit.
 */
void worker_poison_queue() {
    int i;
    if (config->workers && tasks)
        for (i = 0; i < config->workers; i++)
            if (sem_release(tasks->empty) < 0)
                LM_WARN("Error releasing tasks->empty semaphore > %s!\n", strerror(errno));
}
Exemple #11
0
float measures_intTemp(void)
{
	sem_obtain(&i2c_sem);
	float res = DEG_T_TO_FLOATDEG(lm75_read(&i2c_bus, LM75_ADDR));
	sem_release(&i2c_sem);

	return res;
}
Exemple #12
0
void consumer(void* arg)
{
	int itm, id;
	id = *(int *)arg;
	printf("Consumer %d\n", id);
	while(1)
	{
		sem_acquire(shared.full);
		sem_acquire(shared.mutex);
		itm = shared.buf[shared.out];
		shared.out = (shared.out + 1) % SH_SIZE;
		printf("Consumer %d consumed item no %d\n", id, itm);
		sem_release(shared.mutex);
		sem_release(shared.empty);
		sleep(rand() % 3);
	}	
}
Exemple #13
0
void save(struct virtscreen *vscr)
{
    sem_acquire(vscr->lock);
    if(vscr->data != vscr->back) {
        memcpy(vscr->back,vscr->data,vscr->num_bytes);
        vscr->data = vscr->back;
    }
    sem_release(vscr->lock);
}
Exemple #14
0
void producer(void* arg)
{
	int id;
	id = *(int *)arg;
	printf("Producer %d\n", id);

	while(1)
	{
		sem_acquire(shared.empty);
		sem_acquire(shared.mutex);
		shared.buf[shared.in] = item++;
		shared.in = (shared.in + 1) % SH_SIZE;
		printf("Producer %d produced item no : %d\n", id, item);
		sem_release(shared.mutex);
		sem_release(shared.full);
		sleep(rand() % 3);
	}
}
Exemple #15
0
void vputs(struct virtscreen *vscr, char *s)
{
    sem_acquire(vscr->lock);
	while(*s) {
		char_to_virtscreen(vscr, *s);
        if(*s == '\n') char_to_virtscreen(vscr, '\r');
		s++;
	}
    sem_release(vscr->lock);
}
Exemple #16
0
void mutex_unlock(mutex *m)
{
	thread_id me = thread_get_current_thread_id();

	if(me != m->holder)
		panic("mutex_unlock failure: thread 0x%x is trying to release mutex %p (current holder 0x%x)\n",
			me, m, m->holder);
	m->holder = -1;
	sem_release(m->sem, 1);
}
Exemple #17
0
void task_time() {
	printf("TIME TASK (ID %d) started.\n",CURRENT_TASK_ID);
	yield();
	while(true) {
	    sem_acquire(&lcd_sem);
		lcd_cursor(0,0);
        lcd_printf("Runtime: %d.%d    ",millis()/1000, (millis()%1000)/100);
        sem_release(&lcd_sem);
 		sleep_for(100);
    }
}
Exemple #18
0
void rhine_xmit(rhine *r, const char *ptr, ssize_t len)
{
#if 0
	PANIC_UNIMPLEMENTED();
#if 0
	int i;
#endif

//restart:
	sem_acquire(r->tx_sem, 1);
	mutex_lock(&r->lock);

#if 0
	dprintf("XMIT %d %x (%d)\n",r->txbn, ptr, len);

	dprintf("dumping packet:");
	for(i=0; i<len; i++) {
		if(i%8 == 0)
			dprintf("\n");
		dprintf("0x%02x ", ptr[i]);
	}
	dprintf("\n");
#endif

	int_disable_interrupts();
	acquire_spinlock(&r->reg_spinlock);

#if 0
	/* wait for clear-to-send */
	if(!(RTL_READ_32(r, RT_TXSTATUS0 + r->txbn*4) & RT_TX_HOST_OWNS)) {
		dprintf("rhine_xmit: no txbuf free\n");
		rhine_dumptxstate(r);
		release_spinlock(&r->reg_spinlock);
		int_restore_interrupts();
		mutex_unlock(&r->lock);
		sem_release(r->tx_sem, 1);
		goto restart;
	}
#endif

	memcpy((void*)(r->txbuf + r->txbn * 0x800), ptr, len);
	if(len < ETHERNET_MIN_SIZE)
		len = ETHERNET_MIN_SIZE;

	RTL_WRITE_32(r, RT_TXSTATUS0 + r->txbn*4, len | 0x80000);
	if(++r->txbn >= 4)
		r->txbn = 0;

	release_spinlock(&r->reg_spinlock);
	int_restore_interrupts();

	mutex_unlock(&r->lock);
#endif
}
Exemple #19
0
float measures_acceleration(Mma845xAxis axis)
{
	sem_obtain(&i2c_sem);
	int acc = mma845x_read(&i2c_bus, 0, axis);
	sem_release(&i2c_sem);

	if (acc == MMA_ERROR)
		return -6.66;
	else
		return (acc * 9.81 * 4.0) / 512;
}
Exemple #20
0
void push_cdp_cb_event(cdp_cb_event_t* event) {
    lock_get(cdp_event_list->lock);
    if (cdp_event_list->head == 0) { //empty list
        cdp_event_list->head = cdp_event_list->tail = event;
    } else {
        cdp_event_list->tail->next = event;
        cdp_event_list->tail = event;
    }
    sem_release(cdp_event_list->empty);
    lock_release(cdp_event_list->lock);
}
Exemple #21
0
void keypress(int key)
{
	char c;
	
	sem_acquire(active->lock);
	char_to_virtscreen(active, key);
	sem_release(active->lock);	
	if(remote_port > 0) {
		c = key;
		port_send(send_port, remote_port, &c, 1, 0);
	}
}
Exemple #22
0
void load(struct virtscreen *vscr)
{
    sem_acquire(vscr->lock);
    if(vscr->data == vscr->back) {
        vscr->data = screen;
        memcpy(vscr->data,vscr->back,vscr->num_bytes);
    }
    active = vscr;
    movecursor(vscr->xpos,vscr->ypos);
    sem_release(vscr->lock);
    status(vscr - con);
}
void push_cdp_cb_event(cdp_cb_event_t* event) {
    lock_get(cdp_event_list->lock);
    if (cdp_event_list->head == 0) { //empty list
        cdp_event_list->head = cdp_event_list->tail = event;
    } else {
        cdp_event_list->tail->next = event;
        cdp_event_list->tail = event;
    }
    cdp_event_list->size++;
    if(cdp_event_list_size_threshold > 0 && cdp_event_list->size > cdp_event_list_size_threshold) {
	    LM_WARN("cdp_event_list is size [%d] and has exceed cdp_event_list_size_threshold of [%d]", cdp_event_list->size, cdp_event_list_size_threshold);
    }
    sem_release(cdp_event_list->empty);
    lock_release(cdp_event_list->lock);
}
Exemple #24
0
bool recursive_lock_unlock(recursive_lock *lock)
{
	thread_id thid = thread_get_current_thread_id();
	bool retval = false;

	if(thid != lock->holder)
		panic("recursive_lock %p unlocked by non-holder thread!\n", lock);

	if(--lock->recursion == 0) {
		lock->holder = -1;
		sem_release(lock->sem, 1);
		retval = true;
	}
	return retval;
}
Exemple #25
0
void task_scroller() {
	printf("SCROLLER TASK (ID %d) started.\n",CURRENT_TASK_ID);
	yield();

    uint8_t mode = 0;
	while(true) {
	    mode = !mode;
	    for(uint8_t i = 0; i < 16; i++) {
		    sem_acquire(&lcd_sem);
		    lcd_cursor(i,1);
            lcd_data(mode?0xFF:' ');
		    sem_release(&lcd_sem);
 		    sleep_for(20);
		}
	}
}
Exemple #26
0
//
//	Test malloc()
//
int malloc_thread(void*)
{
	for (int i = 0; i < 50000; i++){
#if LOOK_ITS_A_RACE
		sem_acquire(malloc_sem);
#endif
		free(malloc(10000));

#if LOOK_ITS_A_RACE
		sem_release(malloc_sem);
#endif
	}

	printf("malloc thread finished\n");		
	os_terminate(0);
	return 0;
}
Exemple #27
0
void push_reginfo_event(reginfo_event_t* event)
{
	lock_get(reginfo_event_list->lock);
	if (reginfo_event_list->head == 0) { //empty list
		reginfo_event_list->head = reginfo_event_list->tail = event;
	} else {
		reginfo_event_list->tail->next = event;
		reginfo_event_list->tail = event;
	}
	reginfo_event_list->size++;
	
	if(reginfo_queue_size_threshold > 0 && reginfo_event_list->size > reginfo_queue_size_threshold) {
	    LM_WARN("Reginfo queue is size [%d] and has exceed reginfo_queue_size_threshold of [%d]", reginfo_event_list->size, reginfo_queue_size_threshold);
	}
	
	sem_release(reginfo_event_list->empty);
	lock_release(reginfo_event_list->lock);
}
Exemple #28
0
static void NORETURN acc_process(void)
{
	ticks_t start = timer_clock();
	mtime_t delay = 0;
	while (1)
	{
		sem_obtain(&i2c_sem);
		bool r = mma845x_rawAcc(&i2c_bus, 0, acc_buf[acc_idx].acc);
		sem_release(&i2c_sem);
		if (!r)
			kprintf("ACC error!\n");
		if (++acc_idx >= countof(acc_buf))
		{
			acc_idx = 0;
			logging_acc(acc_buf, sizeof(acc_buf));
		}

		/* Wait for the next sample adjusting for time spent above */
		delay += (1000 / ACC_SAMPLE_RATE);
		timer_delay(delay - ticks_to_ms(timer_clock() - start));
	}
}
Exemple #29
0
ssize_t rhine_rx(rhine *r, char *buf, ssize_t buf_len)
{
	PANIC_UNIMPLEMENTED();
#if 0
	rx_entry *entry;
	uint32 tail;
	uint16 len;
	int rc;
	bool release_sem = false;

//	dprintf("rhine_rx: entry\n");

	if(buf_len < 1500)
		return -1;

restart:
	sem_acquire(r->rx_sem, 1);
	mutex_lock(&r->lock);

	int_disable_interrupts();
	acquire_spinlock(&r->reg_spinlock);

	tail = TAILREG_TO_TAIL(RTL_READ_16(r, RT_RXBUFTAIL));
//	dprintf("tailreg = 0x%x, actual tail 0x%x\n", RTL_READ_16(r, RT_RXBUFTAIL), tail);
	if(tail == RTL_READ_16(r, RT_RXBUFHEAD)) {
		release_spinlock(&r->reg_spinlock);
		int_restore_interrupts();
		mutex_unlock(&r->lock);
		goto restart;
	}

	if(RTL_READ_8(r, RT_CHIPCMD) & RT_CMD_RX_BUF_EMPTY) {
		release_spinlock(&r->reg_spinlock);
		int_restore_interrupts();
		mutex_unlock(&r->lock);
		goto restart;
	}

	// grab another buffer
	entry = (rx_entry *)((uint8 *)r->rxbuf + tail);
//	dprintf("entry->status = 0x%x\n", entry->status);
//	dprintf("entry->len = 0x%x\n", entry->len);

	// see if it's an unfinished buffer
	if(entry->len == 0xfff0) {
		release_spinlock(&r->reg_spinlock);
		int_restore_interrupts();
		mutex_unlock(&r->lock);
		goto restart;
	}

	// figure the len that we need to copy
	len = entry->len - 4; // minus the crc

	// see if we got an error
	if((entry->status & RT_RX_STATUS_OK) == 0 || len > ETHERNET_MAX_SIZE) {
		// error, lets reset the card
		rhine_resetrx(r);
		release_spinlock(&r->reg_spinlock);
		int_restore_interrupts();
		mutex_unlock(&r->lock);
		goto restart;
	}

	// copy the buffer
	if(len > buf_len) {
		dprintf("rhine_rx: packet too large for buffer (len %d, buf_len %ld)\n", len, (long)buf_len);
		RTL_WRITE_16(r, RT_RXBUFTAIL, TAILREG_TO_TAIL(RTL_READ_16(r, RT_RXBUFHEAD)));
		rc = ERR_TOO_BIG;
		release_sem = true;
		goto out;
	}
	if(tail + len > 0xffff) {
//		dprintf("packet wraps around\n");
		memcpy(buf, (const void *)&entry->data[0], 0x10000 - (tail + 4));
		memcpy((uint8 *)buf + 0x10000 - (tail + 4), (const void *)r->rxbuf, len - (0x10000 - (tail + 4)));
	} else {
		memcpy(buf, (const void *)&entry->data[0], len);
	}
	rc = len;

	// calculate the new tail
	tail = ((tail + entry->len + 4 + 3) & ~3) % 0x10000;
//	dprintf("new tail at 0x%x, tailreg will say 0x%x\n", tail, TAIL_TO_TAILREG(tail));
	RTL_WRITE_16(r, RT_RXBUFTAIL, TAIL_TO_TAILREG(tail));

	if(tail != RTL_READ_16(r, RT_RXBUFHEAD)) {
		// we're at last one more packet behind
		release_sem = true;
	}

out:
	release_spinlock(&r->reg_spinlock);
	int_restore_interrupts();

	if(release_sem)
		sem_release(r->rx_sem, 1);
	mutex_unlock(&r->lock);

#if 0
{
	int i;
	dprintf("RX %x (%d)\n", buf, len);

	dprintf("dumping packet:");
	for(i=0; i<len; i++) {
		if(i%8 == 0)
			dprintf("\n");
		dprintf("0x%02x ", buf[i]);
	}
	dprintf("\n");
}
#endif

	return rc;
#endif
}
Exemple #30
0
ssize_t rtl8169_rx(rtl8169 *r, char *buf, ssize_t buf_len)
{
	uint32 tail;
	size_t len;
	int rc;
	bool release_sem = false;

	SHOW_FLOW0(3, "rtl8169_rx: entry\n");

	if(buf_len < 1500)
		return -1;

restart:
	sem_acquire(r->rx_sem, 1);
	mutex_lock(&r->lock);

	int_disable_interrupts();
	acquire_spinlock(&r->reg_spinlock);

	/* look at the descriptor pointed to by rx_idx_free */
	if (r->rxdesc[r->rx_idx_free].flags & RTL_DESC_OWN) {
		/* for some reason it's owned by the card, wait for more packets */
		release_spinlock(&r->reg_spinlock);
		int_restore_interrupts();
		mutex_unlock(&r->lock);
		goto restart;
	}

	/* process this packet */
	len =  r->rxdesc[r->rx_idx_free].frame_len & 0x3fff;
	SHOW_FLOW(3, "rtl8169_rx: desc idx %d: len %d\n", r->rx_idx_free, len);

	if (len > buf_len) {
		rc = ERR_TOO_BIG;
		release_sem = true;
		goto out;
	}

	memcpy(buf, RXBUF(r, r->rx_idx_free), len);
	rc = len;

#if debug_level_flow >= 3
	hexdump(RXBUF(r, r->rx_idx_free), len);
#endif

	/* stick it back in the free list */
	r->rxdesc[r->rx_idx_free].buffer_size = BUFSIZE_PER_FRAME;
	r->rxdesc[r->rx_idx_free].flags = (r->rxdesc[r->rx_idx_free].flags & RTL_DESC_EOR) | RTL_DESC_OWN;
	inc_rx_idx_free(r);

	/* see if there are more packets pending */
	if ((r->rxdesc[r->rx_idx_free].flags & RTL_DESC_OWN) == 0)
		release_sem = true; // if so, release the rx sem so the next reader gets a shot

out:
	release_spinlock(&r->reg_spinlock);
	int_restore_interrupts();

	if(release_sem)
		sem_release(r->rx_sem, 1);
	mutex_unlock(&r->lock);

	return rc;
}