acltdtDequeueData

Applicable Products

Product

Supported

Ascend 950PR/Ascend 950DT

√

Atlas A3 training products/Atlas A3 inference products

√

Atlas A2 training products/Atlas A2 inference products

√

Atlas 200I/500 A2 inference products

√

Atlas inference products

√

Atlas training products

√

Function

Obtains data from a queue.

Prototype

1
aclError acltdtDequeueData(uint32_t qid, void *data, size_t dataSize, size_t *retDataSize, void *userData, size_t userDataSize, int32_t timeout)

Parameters

Parameter

Input/Output

Description

qid

Input

Queue from which data is obtained.

You must call acltdtCreateQueue to create a queue in advance.

data

Input/Output

Pointer to the buffer data.

dataSize

Input

Size of buffer data, in bytes.

retDataSize

Output

Actual data size, in bytes.

userData

Input/Output

Pointer to the user-defined data.

If no user-defined data is available, set this parameter to nullptr.

userDataSize

Input

Size of the user-defined data (≤ 96 bytes).

If no user-defined data is available, set this parameter to 0.

timeout

Input

Wait timeout interval. If data is obtained from an empty queue, the system determines how to process the data based on the configured wait timeout interval.

The options are as follows:
  • -1: blocking mode. The system waits until the queue is not empty.
  • 0: non-blocking mode (for device only). When the queue is empty, an error message indicating that the queue is empty is returned. In this case, the retry interval can be set by the user.
  • > 0: specified timeout interval, in ms. When the queue is empty, an error is returned after the timeout interval has elapsed.

    The timeout interval varies with the operating system. The deviation is generally within a time slice of an operating system. For example, if the time slice of an operating system is 4 ms and the timeout interval is set to 1 ms, the actual timeout interval ranges from 1 ms to 5 ms. When the CPU load is high, the timeout interval may fluctuate.

Returns

0 on success; otherwise, failure. For details, see aclError.