Why are queues available for re-use in RTOS?
Because the data contained in the variable was copied into the queue the variable itself is available for re-use. There is no requirement for the task that sends the message and the task that receives the message to agree which task owns the message, and which task is responsible for freeing the message when it is no longer required.
How are queues used in the FreeRTOS system?
FreeRTOS Queues [See also Blocking on Multiple RTOS Objects ] Queues are the primary form of intertask communications. They can be used to send messages between tasks, and between interrupts and tasks.
How to flush a receive queue in a QP?
In order to flush a Receive Queue in a QP that isn’t associated with an SRQ, one should call ibv_modify_qp () and move the QP to the Error state. This action will flush all of the Work Requests in the Receive Queue that weren’t completed and for each of them a Work Completion with the “Flushed in Error” status will be generated.
When to flush the receive queue in RDMA?
The Receive Queue may be flushed if the QP, from any transport type, will be transferred by the RDMA device to the Error state. The Work Requests in the Receive Queue specify to which memory buffers the incoming messages to any QP, which is associated with the SRQ, that consume a Receive Request will be written.
What is queue in real time operating system?
A queue in a real-time operating system (RTOS) is a kernel object that is capable of passing information between tasks without incurring overwrites from other tasks or entering into a race condition. A queue is a first in, first out (FIFO) system where items are removed from the queue once read.
How does a queue work in a FIFO system?
A queue is a simple FIFO system with atomic reads and writes. “Atomic operations” are those that cannot be interrupted by other tasks during their execution. This ensures that another task cannot overwrite our data before it is read by the intended target. In this example, Task A writes some data to a queue.