Svc::DpManager (Active Component)

1. Introduction

Svc::DpManager is an active component for managing data products. It does the following:

1. Receive requests for buffers to hold data products.

   1. When a client component synchronously requests a data product buffer, request an Fw::Buffer from a buffer manager. Return the buffer to the client component so the component can fill it.

   2. When a client component asynchronously requests a data product buffer, request an Fw::Buffer from a buffer manager. Send the buffer to the client component so the component can fill it.

2. Receive buffers filled with data products by client components. Upon receiving a buffer, send the buffer out on a port. Another component such as Svc::BufferAccumulator or Svc::DpWriter will process the buffer and then send it back to the buffer manager for deallocation.

2. Requirements

3. Design

3.1. Component Diagram

The diagram below shows the DpManager component.

3.2. Ports

DpManager has the following ports:

3.3. State

DpManager maintains the following state:

1. numSuccessfulAllocations (U32): The number of successful buffer allocations.

2. numFailedAllocations (U32): The number of failed buffer allocations.

3. numDataProducts (U32): The number of data products handled.

4. numBytes (U64): The number of bytes handled.

3.4. Compile-Time Setup

The configuration constant DpManagerNumPorts specifies the number of ports for requesting data product buffers and for sending filled data products.

3.5. Runtime Setup

No special runtime setup is required.

3.6. Port Handlers

3.6.1. schedIn

The handler for this port sends out the state variables as telemetry.

3.6.2. productGetIn

This handler receives a port number portNum, a container ID id, a requested buffer size size, and a mutable reference to a buffer B. It does the following:

1. Set status = getBuffer(portNum, id, size, B).

2. Return status.

3.6.3. productRequestIn

This handler receives a port number portNum, a container ID id and a requested buffer size size. It does the following:

1. Initialize a local variable B with an invalid buffer.

2. Set status = getBuffer(portNum id, size, B).

3. Send (id, B, status) on port portNum of productResponseOut.

3.6.4. productSendIn

This handler receives a port number portNum, a data product ID I and a buffer B. It does the following:

1. Update numDataProducts and numBytes.

2. Send B on port portNum of productSendOut.

3.7. Helper Methods

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3.7.1. getBuffer

This function receives a port number portNum, a container ID id, a requested buffer size size, and a mutable reference to a buffer B. It does the following:

1. Set status = FAILURE.

2. Set B = bufferGetOut_out(portNum, size).

3. If B is valid, then atomically increment numSuccessfulAllocations and set status = SUCCESS.

4. Otherwise atomically increment numFailedAllocations and emit a warning event.

5. Return status.

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4. Ground Interface

4.1. Commands

4.2. Telemetry

4.3. Events

5. Example Uses

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5.1. Topology Diagrams

The following topology diagrams show how to connect Svc::DpManager to a client component, a buffer manager, and a data product writer. The diagrams use the following instances:

• bufferManager: An instance of Svc::BufferManager.

• dpManager: An instance of Svc::DpManager.

• dpWriter: An instance of Svc::DpWriter.

• producer: A client component that produces data products. productRequestOut is the special product request port. productRecvIn is the special product recv port.

The connections shown use port zero for requesting, receiving, and sending data product buffers. If DpManagerNumPorts is greater than one, then you can also use other ports, e.g., port one or port two. That way you can use one DpManager instance to support multiple sets of connections.

5.1.1. Synchronously Getting Data Product Buffers

5.1.2. Asynchronously Requesting Data Product Buffers

5.1.3. Sending Data Products

5.2. Sequence Diagrams

5.2.1. Synchronously Getting a Data Product Buffer

sequenceDiagram
    activate producer
    producer->>dpManager: Request buffer [productGetIn]
    dpManager->>bufferManager: Request buffer B [bufferGetOut]
    bufferManager-->>dpManager: Return B
    dpManager->>dpManager: Store B into producer
    dpManager-->>producer: Return SUCCESS
    deactivate producer

5.2.2. Asynchronously Requesting a Data Product Buffer

sequenceDiagram
    activate producer
    activate dpManager
    producer-)dpManager: Request buffer [productRequestIn]
    dpManager->>bufferManager: Request buffer B [bufferGetOut]
    bufferManager-->>dpManager: Return B
    dpManager-)producer: Send B [productResponseOut]
    deactivate dpManager
    deactivate producer

5.2.3. Sending a Data Product

sequenceDiagram
    activate producer
    activate dpManager
    activate dpWriter
    producer-)dpManager: Send buffer B [productSendIn]
    dpManager-)dpWriter: Send B [productSendOut]
    dpWriter->>bufferManager: Deallocate B
    bufferManager-->>dpWriter: Return
    deactivate dpWriter
    deactivate dpManager
    deactivate producer