Section: PVM Version 3.4 (3PVM)
Updated: 30 August, 1993
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pvm_barrier - Blocks the calling process until all processes
in a group have called it.
C int info = pvm_barrier( char *group, int count )
Fortran call pvmfbarrier( group, count, info )
Character string group name. The group must exist and the
calling process must be a member of the group.
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
Integer status code returned by the routine.
Values less than zero indicate an error.
blocks the calling process until
members of the
have called pvm_barrier.
The count argument is required because processes could be
joining the given group after other processes 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 synchronization.
During any given barrier call all participating group members
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
If pvm_barrier is successful,
will be 0. If some error occurs then
will be < 0.
inum = pvm_joingroup( "worker" );
info = pvm_barrier( "worker", 5 );
CALL PVMFJOINGROUP( "shakers", INUM )
COUNT = 10
CALL PVMFBARRIER( "shakers", COUNT, INFO )
These error conditions can be returned by
pvmd was not started or has crashed.
giving a count < 1.
giving a non-existent group name.
calling process is not in specified group.
- SEE ALSO
linux.jgfs.net manual pages