PKMESG(3PVM) PVM Version 3.4 PKMESG(3PVM)NAME
pvm_pkmesg, pvm_pkmesgbody, pvm_upkmesg - Pack messages into other mes‐
sages.
SYNOPSIS
C int info = pvm_pkmesg( int bufid )
int info = pvm_pkmesgbody( int bufid )
int newbufid = pvm_upkmesg( )
Fortran call pvmfpkmesg( bufid, info )
call pvmfpkmesgbody( bufid, info )
call pvmfupkmesg( bufid, newbufid )
PARAMETERS
bufid Message buffer to pack.
newbufid New message buffer unpacked or result code.
info Result code.
DESCRIPTION
These functions are used to include messages in other messages, as data
elements.
pvm_pkmesg packs the specified message into the current send buffer.
The entire body of the message is packed, along with header attributes:
length
context tag
message tag
wait identifier
encoding
checksum
source and destination addresses
The buffer specified must not be the same as the current send buffer.
Multiple messages can be packed into a single message, and packed mes‐
sages can be mixed with any other data types.
pvm_upkmesg unpacks a message from the current receive buffer, allocat‐
ing a new message buffer for it. The body of the newly created mes‐
sage, and header attributes listed above, match the one originally
packed using pvm_pkmesg.
pvm_pkmesgbody is similar to pvm_pkmesg, but packs only the body of the
specified message, omitting the header fields. In other words, it
splices the messages together (the included message is left unaltered).
When calling pvm_pkmesgbody, the encoding types of the two messages
must match because the included message body is simply appended to the
send buffer. Calls to pvm_pkmesgbody can be mixed with calls to pack
any other data types.
Note: pvm_upkmesgbody doesn't exist, because PVM doesn't keep track of
the boundary between the two messages.
EXAMPLES
pvm_recv(-1, -1);
pvm_initsend(PvmDataDefault);
pvm_pkstr("here is the message I received...");
pvm_pkmesg(pvm_getrbuf());
ERRORS
The following error conditions can be returned by pvm_pkmesg,
pvm_pkmesgbody or pvm_upkmesg:
PvmBadParam
An invalid value was specified for bufid argument, or bufid is
the current send buffer.
PvmNoSuchBuf
Message buffer bufid doesn't exist.
PvmNoMem
Libpvm is unable to allocate memory to pack data.
PvmNoData
The end of the message has been reached, perhaps because pack
and unpack calls were mismatched.
PvmNoBuf
There is no current send (or receive) buffer.
PvmMismatch
pvm_pkmesgbody was called and the encoding types of bufid and
the current send buffer don't match.
SEE ALSOpvm_getrbuf(3PVM), pvm_getsbuf(3PVM), pvm_pack(3PVM),
10 February, 1995 PKMESG(3PVM)
