SETTMASK(3PVM) PVM Version 3.4 SETTMASK(3PVM)NAME
pvm_gettmask, pvm_settmask - Get or set trace mask of a task or its
children.
SYNOPSIS
C #include <pvm3.h>
#include <pvmtev.h>
int info = pvm_gettmask( int who, Pvmtmask mask )
int info = pvm_settmask( int who, Pvmtmask mask )
Fortran Not Available
PARAMETERS
who Specifies which trace mask to get or set:
PvmTaskSelf The current task
PvmTaskChild Children tasks to be spawned
mask Trace mask (owned by caller), which is filled in with the cur‐
rent trace vector on calling pvm_gettmask or used to set the
current trace vector on calling pvm_settmask.
info Status code returned. Values less than zero indicate an error.
DESCRIPTION
Each task has a trace mask, which can be used to individually enable
tracing of each libpvm function. The mask is inherited from its parent
task (or initially all cleared if the task has no parent). When calls
are made to functions in libpvm, the parameters and results are sent in
messages to the trace sink of the task (variable PvmTraceTid set by
calling pvm_setopt - see man page).
The PVM console and XPVM use this system to get trace data from appli‐
cation programs.
A task can get or set either its own trace mask, or the mask passed to
children it spawns. Note the mask must be set before the spawn call;
setting the child trace mask has no effect on already-running children.
The trace mask can be kept in a temporary variable, declared as:
Pvmtmask mymask;
Right now, this is a character array with approximately 80 bits.
There are four macros defined to manipulate trace masks. Along with
the functions, these allow a program to get the current trace mask,
modify or save it, and put it back:
TEV_INIT_MASK(mask)
TEV_SET_MASK(mask, kind)
TEV_UNSET_MASK(mask, kind)
TEV_CHECK_MASK(mask, kind)
TEV_INIT_MASK initializes a mask to all bits cleared and must be used
to initialize a trace mask (unless that is done by setting it from
pvm_gettmask). TEV_SET_MASK sets a bit in a mask. Bit values are
defined in <pvmtev.h>. Likewise, TEV_UNSET_MASK clears a single bit
and TEV_CHECK_MASK checks to see if a bit is set, returning nonzero if
true.
Note: Most events in the trace mask come in pairs, the first (ending in
...0) is generated on entry to a function and the second (...1) on
exit. The trace mask has only half as many bits as there are events;
events are enabled in pairs. In other words, if you select TEV_SEND0,
you'll also get TEV_SEND1.
The trace mask is deliberately kept as a printable (and null-termi‐
nated) string, for two reasons. First, it is passed through the envi‐
ronment between tasks, in the form:
PVMTMASK=@@AAOG@@NO@L@@@@@@@@
so the pvmd doesn't have to explicitly manage it. Second, the mask
variables can be passed between tasks using pvm_pkstr() or otherwise
manipulated as strings.
pvm_gettmask and pvm_settmask return PvmOk on success, else a negative
value.
EXAMPLES
C:
#include <pvm3.h>
#include <pvmtev.h>
Pvmtmask m;
pvm_gettmask( PvmTaskChild, m );
TEV_SET_MASK(m, TEV_ADDHOSTS0 );
pvm_settmask( PvmTaskChild, m );
pvm_spawn( "worker", (char **)0, PvmTaskDefault, "", 1, (int *)0);
ERRORS
The following error condition can be returned by pvm_gettmask or
pvm_settmask:
PvmBadParam
invalid value for who argument.
SEE ALSOpvm(1PVM), pvm_getopt(3PVM), pvm_setopt(3PVM)
16 March, 1994 SETTMASK(3PVM)
