About Queue library (SDK 17.1.0)

RE: About Queue library (SDK 17.1.0)

Jared — Thu, 17 Mar 2022 10:11:45 GMT

OK. I'll close this then, since the original issue has been resolved.

best regards

Jared

RE: About Queue library (SDK 17.1.0)

June6 — Thu, 17 Mar 2022 01:59:37 GMT

In the future, if I have any questions, I'll send another ticket to ask your official staff. Thank you for your patience

RE: About Queue library (SDK 17.1.0)

June6 — Thu, 17 Mar 2022 01:57:43 GMT

Hello, it's strange that after I upgraded the version of SES this week, there was no crash under the same code conditions.

RE: About Queue library (SDK 17.1.0)

June6 — Fri, 11 Mar 2022 14:00:37 GMT

I'll reply tomorrow after confirmation. I don't have my computer with me now.

RE: About Queue library (SDK 17.1.0)

Jared — Fri, 11 Mar 2022 13:30:07 GMT

Hi,

What will sizeof(test_data) return in this case? Will it return 7? I'm asking because I'm not entirely sure that it equals the element count as the compiler might be increasing the size due to padding.

regards

Jared

RE: About Queue library (SDK 17.1.0)

June6 — Wed, 09 Mar 2022 00:46:42 GMT

In addition, I still don't understand why def uses its own data structure, and its member size can't exceed 6. You can also try the following code snippet in the routine.

typedef struct {
 uint8_t data[7];
} data_t;

NRF_QUEUE_DEF(data_t, m_data_queue, 255*sizeof(data_t), NRF_QUEUE_MODE_NO_OVERFLOW);

int main (void) {
    data_t test_data;
    
    test_data.data[0] = 0x01;
    test_data.data[1] = 0x01;
    test_data.data[2] = 0xAA
    test_data.data[3] = 0xBB;
    test_data.data[4] = 0xCC;
    test_data.data[5] = 0x03;
    test_data.data[6] = 0x04;
    
    ret = nrf_queue_write(&m_data_queue, &test_data.data, sizeof(test_data));
    APP_ERROR_CHECK(ret);
    
    data_t data_read;
    
    ret = nrf_queue_read(&m_data_queue, &data_read.data, sizeof(data_read));
    APP_ERROR_CHECK(ret);
}

When running to nrf_queue_write, the system will crash 100%. The phenomenon is like using a wild pointer to cause memory overflow. No error code will be reported

RE: About Queue library (SDK 17.1.0)

June6 — Wed, 09 Mar 2022 00:40:06 GMT

It is only used to temporarily store fixed length data, and finally it will be written to flash. However, data storage and reading will be a little frequent, so first use the queue to cache these data.

RE: About Queue library (SDK 17.1.0)

June6 — Wed, 09 Mar 2022 00:38:08 GMT

Well, maybe my usage scenario is so special that I don't care about the standard of the queue and complain

RE: About Queue library (SDK 17.1.0)

Jared — Tue, 08 Mar 2022 12:37:54 GMT

Yes, that is correct. I believe the queue implementation in the SDK follows the normal definition of a queue. Is there a specific reason for why you're using a queue?

RE: About Queue library (SDK 17.1.0)

June6 — Mon, 07 Mar 2022 14:41:56 GMT

I have finished reading and writing, but now I have a new problem to confirm.

Every time I finish reading, does it mean that I have taken out the data in the queue, and the data I have read no longer exists in the queue? In other words, for the purpose of query, I need to write back the read data again. Is this logic correct?

By the way, the queue library is really difficult to use. Peek can only read the first byte of data. Pop and read will automatically clear the data out of the queue after reading the data.

RE: About Queue library (SDK 17.1.0)

Jared — Mon, 07 Mar 2022 14:26:02 GMT

Hi there,

It seems that the wrong parameter is passed to nrf_queue_write() and nrf_queue_read() in the first case. The third parameter should be the element count, not the size of the struct. Try replacing it with 1.

regards

Jared

RE: About Queue library (SDK 17.1.0)

June6 — Sat, 05 Mar 2022 08:52:48 GMT

No, it hasn't improved.

Moreover, I found that as long as the data type parameters filled in NRF_QUEUE_DEF are user-defined structures, the number of members of that structure cannot be too many.

Specifically, I tested in the second test segment. If the array in data_t is defined as data [7] or larger, there will be a problem.

On the contrary, if the data type filled in NRF_QUEUE_DEF is uint8_ t. Then no matter how many members of the structure are, there is no problem.

This phenomenon is very strange. It is reasonable to say that although the parameter passed into the actual operation function is a pointer, the space occupied by my structure members is a fixed size, so I don't need to apply for additional memory. I can't figure it out

RE: About Queue library (SDK 17.1.0)

Jared — Fri, 04 Mar 2022 14:55:21 GMT

Hi there,

Is the issue mitigated If you set data2 type to uint8_t instead of uint32_t?

regards

Jared

RE: About Queue library (SDK 17.1.0)

June6 — Thu, 03 Mar 2022 16:30:09 GMT

Besides, my mother tongue is not English. Please forgive me for any strange expression.

RE: About Queue library (SDK 17.1.0)

June6 — Thu, 03 Mar 2022 16:27:41 GMT

In addition, I have seen in another ticket that it is recommended to use push instead of write in overwrite mode. This ticket will not tangle with this problem.