AcqContext

Synopsis

typedef struct AcqContext {
 Item creatorTask;
 uint32 creatorSignal;
 int32 creatorStatus;
 char* fileName;
 ItemPoolPtr ioReqItemPoolPtr;
 Item threadItem;
 void* threadStackBlock;
 Item requestPort;
 uint32 requestPortSignal;
 Item ioDoneReplyPort;
 uint32 ioDoneReplyPortSignal;
 DataAcqMsgPtr requestQueue;
 DataAcqMsgPtr abortQueue;
 DataAcqMsgPtr dataQueueHead;
 DataAcqMsgPtr dataQueueTail;
 Boolean fEOFWasSent;
 long offset;
 BlockFile blockFile;
 Item dsReqReplyPort;
 uint32 dsReqReplyPortSignal;
 uint32 subscriberPortSignal;
 Item subscriberPort;
 DSStreamCBPtr streamCBPtr;
 MarkerChunkPtr markerChunk;
} AcqContext, *AcqContextPtr

Description

Fields

creatorTask

Item of the task that created the acquisition thread, usually the task to signal that the acquisition thread has been initialized.

creatorSignal

Signal to send for synchronous completion.

creatorStatus

Initialization status code of acquisition thread, usually returned to the creator task for error checking.

fileName

Pointer to the character string that is the name of the file from which the task acquires data.

ioReqItemPoolPtr

Pointer to the pool of ioReqItem items allocated by the data buffers for the thread. See DSDataBuf{} for more details.

threadItem

Item of the acquisition thread.

threadStackBlock

Pointer to the stack memory block allocated to the acquisition thread.

requestPort

DataStreamer message port through which the thread receives acquisition requests.

requestPortSignal

Signal associated with requestPort.

ioDoneReplyPort

Message port for I/O completion messages.

ioDoneReplyPortSignal

Signal associated with ioDoneReplyPort.

requestQueue

List of outstanding I/O request messages.

abortQueue

List of outstanding I/O request messages that are considered `aborted'.

dataQueueHead

Head of requests waiting for ioreqitems.

dataQueueTail

Tail of requests waiting for ioreqitems.

fEOFWasSent

Indicates whether an end of file character (EOF) has been sent to the acquisition thread: TRUE if one has been sent, FALSE if not.

offset

Location in the block file at which the acquisition thread is currently reading blocks of data. The offset is calculated, in blocks, as an offset from the beginning of the file.

blockFile

Block file from which the acquisition thread acquires blocks of data.

dsReqReplyPort

Reply port for requests to streamer.

dsReqReplyPortSignal

Signal for replies to streamer requests

subscriberPortSignal

Signal for receipt of subscriber messages.

subscriberPort

Message port for our data type.

streamCBPtr

Stream control block of connected stream.

markerChunk

Pointer to copy of most recent translation table.

Associated Files

See Also