BARRIER(3PVM) PVM Version 3.4 BARRIER(3PVM)NAMEpvm_barrier - Blocks the calling process until all processes in a group
have called it.
SYNOPSIS
C int info = pvm_barrier( char *group, int count )
Fortran call pvmfbarrier( group, count, info )
PARAMETERS
group Character string group name. The group must exist and the call‐
ing process must be a member of the group.
count Integer specifying the number of group members that must call
pvm_barrier before they are all released. Though not required,
count is expected to be the total number of members of the
specified group.
info Integer status code returned by the routine. Values less than
zero indicate an error.
DESCRIPTION
The routine pvm_barrier blocks the calling process until count members
of the group have called pvm_barrier. The count argument is required
because processes could be joining the given group after other pro‐
cesses have called pvm_barrier. Thus PVM doesn't know how many group
members to wait for at any given instant. Although count can be set
less, it is typically the total number of members of the group. So the
logical function of the pvm_barrier call is to provide a group synchro‐
nization. During any given barrier call all participating group mem‐
bers must call barrier with the same count value. Once a given barrier
has been successfully passed, pvm_barrier can be called again by the
same group using the same group name.
If pvm_barrier is successful, info will be 0. If some error occurs then
info will be < 0.
EXAMPLES
C:
inum = pvm_joingroup( "worker" );
.
.
info = pvm_barrier( "worker", 5 );
Fortran:
CALL PVMFJOINGROUP( "shakers", INUM )
COUNT = 10
CALL PVMFBARRIER( "shakers", COUNT, INFO )
ERRORS
These error conditions can be returned by pvm_barrier
PvmSysErr
pvmd was not started or has crashed.
PvmBadParam
giving a count < 1.
PvmNoGroup
giving a non-existent group name.
PvmNotInGroup
calling process is not in specified group.
SEE ALSOpvm_joingroup(3PVM)
30 August, 1993 BARRIER(3PVM)
