SETOPT(3PVM)

NAME
pvm_setopt - Sets libpvm options.

SYNOPSIS
C	int oldval = pvm_setopt( int what, int val )
Fortran	call pvmfsetopt( what, val, oldval )

PARAMETERS

what
    Integer defining what to set. One of:
    PvmRoute              1    Message routing policy
    PvmDebugMask          2    Libpvm debug mask
    PvmAutoErr            3    Auto error reporting
    PvmOutputTid          4    Stdout destination for children
    PvmOutputCode         5    Output message tag for children
    PvmTraceTid           6    Trace data destination for children
    PvmTraceCode          7    Trace message tag for children
    PvmTraceBuffer        8    Trace buffer size for children
    PvmTraceOptions       9    Trace collection options for children
    PvmFragSize          10    Message fragment size
    PvmResvTids          11    Allow messages to reserved tags and TIDs
    PvmSelfOutputTid     12    Stdout destination
    PvmSelfOutputCode    13    Output message tag
    PvmSelfTraceTid      14    Trace data destination
    PvmSelfTraceCode     15    Trace message tag
    PvmSelfTraceBuffer   16    Trace buffer size
    PvmSelfTraceOptions  17    Trace collection options
    PvmShowTids          18    pvm_catchout prints task ids with output
    PvmPollType          19    Message wait policy (shared memory)
    PvmPollTime          20    Message spinwait duration
    PvmOutputContext     21    Output message context for children
    PvmTraceContext      22    Trace message context for children
    PvmSelfOutputContext 23    Output message context
    PvmSelfTraceContext  24    Trace message context
    PvmNoReset           25    Do not kill task on reset

val Integer specifying new setting of option.

    Predefined values for PvmRoute are:
    PvmDontRoute      1    Don't request or grant connections
    PvmAllowDirect    2    (Default) Don't request but allow
    PvmRouteDirect    3    Request and allow connections

    Predefined values for PvmTraceOptions are:
    PvmTraceFull      1    (Default) Do full trace events
    PvmTraceTime      2    Only do PVM routine timings
    PvmTraceCount     3    Only do PVM routine profiling (call counts)

    Predefined values for PvmPollType are:
    PvmPollConstant   1    Spin on its message queue
    PvmPollSleep      2    Poll the message queue PvmPollTime times

oldval
    Integer returning the previous setting of the option.

DESCRIPTION
The routine pvm_setopt is a general purpose function used to set miscellaneous options in the PVM library. What is one of:

PvmRoute
    Advises PVM on whether to set up direct task-to-task links PvmRouteDirect (using TCP) for all subsequent communication. Once a link is established it persists until the application finishes. If a direct link can not be established because one of the two tasks has requested PvmDontRoute or because adequate resources aren't available, then the default route through the PVM daemons is used. On multiprocessors such as Intel Paragon this option is ignored because the communication between tasks on these machines always uses the native protocol for direct communication. pvm_setopt can be called multiple times to selectively establish direct links, but is typically set only once near the beginning of each task. PvmAllowDirect is the default route setting. This setting on task A allows other tasks to set up direct links to A. Once a direct link is established between tasks both tasks will use it for sending messages.

PvmDebugMask
    When debugging is turned on, PVM will log detailed information about its operations and progress on its stderr stream. val is the debugging level. Default is not to print any debug information.

PvmAutoErr
    When an error results from a libpvm function call and PvmAutoErr is set to 1 (the default), an error message is automatically printed on stderr. A setting of 0 disables this. A setting of 2 causes the library to terminate the task by calling exit() after printing the error message. A setting of 3 causes the library to abort after printing the error message.

PvmOutputTid
    Sets the stdout destination for children tasks (spawned after the call to pvm_setopt). Everything printed on the standard output of tasks spawned by the calling task is packed into messages and sent to the destination. val is the TID of a PVM task. Setting PvmOutputTid to 0 redirects stdout to the master pvmd, which writes to the log file /tmp/pvml.<uid> The default setting is inherited from the parent task, else is 0.

PvmOutputCode
    Sets the message tag for standard output messages. Should only be set when a task has PvmOutputTid set to itself.

PvmTraceTid
    Sets the trace data message destination for children tasks (spawned after the call to pvm_setopt). Libpvm trace data is sent as messages to the destination. val is the TID of a PVM task. Setting PvmTraceTid to 0 discards trace data. The default setting is inherited from the parent task, else is 0.

PvmTraceCode
    Sets the message tag for trace data messages. Should only be set when a task has PvmTraceTid set to itself.

PvmTraceBuffer
    Sets the trace buffer size for trace event collection (in bytes). Rather than send a separate message for each trace event, the events are written to a message buffer until the buffer reaches PvmTraceBuffer bytes. Then a single large trace message is sent. This can greatly reduce tracing intrusion. Make sure you call pvm_exit() in your tasks to flush the trace buffer!

PvmTraceOptions
    Sets the PVM built-in tracing options. This is useful for custom trace collection tools to allow analysis of library routine execution times and invocation counts. By default, tracing with PvmTraceFull produces full trace events with calling arguments and return values. Using PvmTraceTime produces total time spent executing each library routine. The PvmTraceCount option keep only a count of the number of times each routine was called.

PvmFragSize
    Val specifies the message fragment size in bytes. Default value varies with host architecture.

PvmResvTids
    A val of 1 enables the task to send messages with reserved tags and to non-task destinations. The default (0) causes libpvm to generate a PvmBadParam error when a reserved identifier is specified.

PvmSelfOutputTid
    Sets the stdout destination for the calling task. Everything printed on stdout is packed into messages and sent to the destination. Note: this only works for spawned tasks, because the pvmd doesn't get the output from tasks started by other means. val is the TID of a PVM task. Setting PvmSelfOutputTid to 0 redirects stdout to the master pvmd, which writes to the log file /tmp/pvml.<uid>. The default setting is inherited from the parent task, else is 0. Setting either PvmSelfOutputTid or PvmSelfOutputCode also causes both PvmOutputTid and PvmOutputCode to take on the values of PvmSelfOutputTid and PvmSelfOutputCode, respectively.

PvmSelfOutputCode
    Sets the message tag for standard output messages.

PvmSelfTraceTid
    Sets the trace data message destination for the calling task. Libpvm trace data is sent as messages to the destination. val is the TID of a PVM task. Setting PvmSelfTraceTid to 0 discards trace data. The default setting is inherited from the parent task, else is 0. Setting either PvmSelfTraceTid or PvmSelfTraceCode also causes both PvmTraceTid and PvmTraceCode to take on the values of PvmSelfTraceTid and PvmSelfTraceCode, respectively.

PvmSelfTraceCode
    Sets the message tag for trace data messages.

PvmSelfTraceBuffer
    Sets the trace buffer size for trace event collection (in bytes).

PvmSelfTraceOptions
    Sets the PVM built-in tracing options for the calling task (see PvmTraceOptions).

PvmShowTids
    If true (nonzero), pvm_catchout tags each line of output printed by a child task with the task id. Otherwise, output is exactly as printed.

PvmPollType
    Sets the message wait policy when using shared-memory message transport. Setting PvmPollType to PvmPollConstant causes the application to spin on its message queue waiting for a message. Setting PvmPollType to PvmPollSleep causes the application to poll the message queue for messages PvmPollTime times before pending on the semaphore.

PvmPollTime
    Sets the poll count for applications checking their message queue before they pend on the semaphore. This option is ignored if PvmPollType is set to PvmPollConstant.

PvmOutputContext
    Sets the message context for output collection messages from children.

PvmTraceContext
    Sets the message context for trace data messages from children.

PvmSelfOutputContext
    Sets the message context for output collection from the calling task.

PvmSelfTraceContext
    Sets the message context for trace data messages from the calling task.

PvmNoReset
    When set true (non-zero integer value) informs PVM *not* to kill off the calling task when performing a "reset" command, such as issued by the "pvm" console.

pvm_setopt returns the previous value of the option. If an error occurs, the PVM error code is returned in place of the option value.

EXAMPLES
C:
	oldval = pvm_setopt( PvmRoute, PvmRouteDirect );
Fortran:
	CALL PVMFSETOPT( PVMAUTOERR, 1, OLDVAL )

ERRORS
This error condition can be returned

PvmBadParam
    giving an invalid value.

SEE ALSO
pvm_getopt(3PVM)