|tid||Integer task identifier of sending process supplied by the user.|
|msgtag||Integer message tag supplied by the user. msgtag should be >= 0.|
Integer returning the value of the new active receive buffer
identifier. Values less than zero indicate an error.
The routine pvm_probe checks to see if a message with label msgtag has arrived from tid. If a matching message has arrived pvm_probe returns a buffer identifier in bufid. This bufid can be used with pvm_bufinfo to determine information about the message such as its source and length.
If the requested message has not arrived, then pvm_probe returns with a 0 in bufid. If some error occurs bufid will be < 0.
A -1 in msgtag or tid matches anything. This allows the user the following options. If tid = -1 and msgtag is defined by the user, then pvm_probe will accept a message from any process which has a matching msgtag. If msgtag = -1 and tid is defined by the user, then pvm_probe will accept any message that is sent from process tid. If tid = -1 and msgtag = -1, then pvm_probe will accept any message from any process.
pvm_probe can be called multiple times to check if a given message has arrived yet. After the message has arrived, pvm_recv must be called before the message can be unpacked into the users memory using the unpack routines.
C: tid = pvm_parent(); msgtag = 4 ; arrived = pvm_probe( tid, msgtag ); if ( arrived ) info = pvm_bufinfo( arrived, &len, &tag, &tid ); else /* go do other computing */
Fortran: CALL PVMFPROBE( -1, 4, ARRIVED ) IF ( ARRIVED .GT. 0 ) THEN CALL PVMFBUFINFO( ARRIVED, LEN, TAG, TID, INFO ) ELSE * GO DO USEFUL WORK ENDIF
These error conditions can be returned by pvm_probe.
PvmBadParam giving an invalid tid value or msgtag. PvmSysErr pvmd not responding.
|PROBE (3PVM)||30 August, 1993|