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Intranode Messages

This set of messages is defined for intercommunication between resource managers operating on different processing nodes. These messages are used to request data and instruction objects (or information about them,) as well as clearing a remote dependency or posting a task for evaluation remotely.

Two different levels of message transport are provided: reliable, and unreliable, allowing the use of one (reliable) for essential or time insensitive messages (such as initialization, and debugging information), and the other (unreliable) when a higher level of software is providing error recovery (e.g. requesting data objects.)

The <TT>SEND-MESSAGE</TT> primitive is used to transmit a message unreliably. It utilizes the process environment, which contains information about which processor nodes to query.

GET-OBJECT

This message request the transmittal of a data or instruction object, referred to by a tag.

GET-STREAM-OBJECT

This message requests that the specified context of a stream object, referred to by a tag, be transferred into local memory.

BKOFF-STREAM-OBJECT

This message indicates that a particular context of a stream object referred to by a tag is no longer needed right away. This serves to propagate a buffer full situation.

ACK

This message acknowledges receipt of a request. It may either indicate that additional time is required before returning the requested data, or that the requested data is not present on the acknowledging processing node.

GET-STREAM-INFO

This message fetches a information about a stream object referred to by a tag into local memory.

PUT-OBJECT

This message is used to send a data object to another node (usually in response to a GET-OBJECT request.) It may also be used to preload an object onto a processing node to speed time critical processing.

PUT-STREAM-OBJECT

This message is used to send a stream fragment to another node (usually in response to a GET-STREAM-OBJECT request.) It may also be used to preload a stream onto a processing node to speed time critical processing.

PUT-STREAM-INFO

This message is used to send information about a stream to another node (usually in response to a GET-STREAM-INFO request.) It may also be used to preload an object onto a processing node to speed time critical processing.

POST-TASK

This message posts a list of task tokens for evaluation on a remote node. Note that the remote node may decide to further subdivide the task.

CLEAR-TASK-DEP

This message explicitly clears a dependency on a particular task token.


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