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altering read() system call behavior

heymanj
Occasional Contributor

altering read() system call behavior

Hi.

 

I've been tasked with porting existing Linux functionality to our HP-UX client.  A previous question, passthru devices, was answered quickly so I thought I'd ask another.

 

I've been pouring over the web and HP-UX documentation, but have been unable to determine if what the Linux client is doing is possible on HP-UX.  Scenario:

 

Multiple scsi commands can be issued to read from the SCSI attached device, and I need to guarantee that the read order of the packets returned is sequential, regardless of order returned.

 

On Linux, there is an ioctl() call

 

ioctl(fd, SG_SET_FORCE_PACK_ID, &one)

 

that according to /usr/include/scsi/sg.h file does:

 

"When SG_SET_FORCE_PACK_ID set to 1, pack_id is input to read() which tries to fetch a packet with a matching

 pack_id, waits, or returns EAGAIN.  If pack_id is -1 then read oldest waiting.  When ...FORCE_PACK_ID set to 0 then

 pack_id ignored by read() and oldest readable fetched."

 

Is there something similar within HP-UX?

 

jerry