acltdtDequeueData

Description

Obtains data from a queue.

Prototype

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	Pointer to buffer data. The host buffer or device buffer is supported.
dataSize	Input	Size of buffer data, in bytes.
retDataSize	Input/Output	Actual data size, in bytes.
userData	Input	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 value of wait 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

The value 0 indicates success, and other values indicate failure. For details, see aclError.

Parent topic: Shared Queue Management