OSMMsgSetInboundFrameSize(D3i2o)
OSMMsgSetInboundFrameSize --
request change in message frame size of inbound FIFO of an IOP
Synopsis
#include <sys/types.h>
#include <i2o/common.h>
int OSMMsgSetInboundFrameSize(int IopNum, int size, uint_t flags)
Description
OSMMsgSetInboundFrameSize
requests a change in the message frame size of the
inbound FIFO of IOP IopNum at the next reboot.
Arguments
IopNum-
Global number of the the IOP.
size-
Size in bytes of message frame requested.
This must be a power of 2.
flags-
The flag I2O_FRAMESIZE_FORCE forces the change.
All other bits of the flag are reserved and should be
set to zero.
Return values
SUCCESS-
Message successfully sent to the IOP to change the size of
the inbound message frame after the next reboot.
EINVAL-
IOPNum is invalid, or size is not a power of 2.
Usage
The system keeps an internal variable which represents
the message frame size that the IOP will use at the
next reboot.
Requests to lower the value of this variable are silently ignored
and SUCCESS is returned
unless the I2O_FRAME_FORCE flag is set.
For example, if the system will use 128-byte message frames, it sets the
variable to 128 bytes. If OSM ``A''
sends OSMMsgSetInboundFrameSize(
n, 512, 0)
,
then the a message is sent to IOP n
requesting the message frame size be 512
bytes on the next reboot. If the message is successful, the variable is set to
512 and SUCCESS is returned to the caller.
If OSM ``B'' now sends
OSMMsgSetInboundFrameSize(
n, 256, 0)
,
the system will simply return SUCCESS to the caller.
OSM ``B'' can quite easily use the 512-byte
message frame. If for some reason OSM ``B'' really
does need to lower the size at the next reboot to 256 bytes, it must
set the I2O_FRAME_FORCE flag.
The system will then send the message. If the
message is successful, the variable is updated and
SUCCESS is returned.
Context and synchronization constraints
User or blockable context
Hardware applicability
All
Version applicability
i2omsg: in HDK Technical Reference
2
Differences between versions
None
References
Intro(D3i2o),
OSMMsgGetInboundFrameSize(D3i2o),
OSMMsgGetOutboundFrameSize(D3i2o)
19 June 2005
© 2005 The SCO Group, Inc. All rights reserved.
OpenServer 6 and UnixWare (SVR5) HDK - June 2005