---
name: "pvm_notify"
section: "3"
platform: "linux"
package: "pvm-dev"
version: "3.4.2-8"
release: "Debian 3.0 (Woody)"
platforms: ["linux"]
url: "https://new.carta.tech/pvm_notify"
---

# pvm\_notify(3)

Request notification of PVM event such as host failure.

## NAME

pvm\_notify - Request notification of PVM event such as host failure.

## SYNOPSIS

```
C	int info = pvm_notify( int what, int msgtag, int cnt, int *tids )
Fortran	call pvmfnotify( what, msgtag, cnt, tids, info )
```

## PARAMETERS

- what

  **Type of event to trigger the notification.** **Presently one of:**

  ```
  	Value	Meaning
  	PvmTaskExit	Task exits or is killed
  	PvmHostDelete	Host is deleted or crashes
  	PvmHostAdd	New host is added
  ```

- msgtag

  **Message tag to be used in notification.**\

- cnt

  **For** *PvmTaskExit* and *PvmHostDelete*, specifies the length of the *tids* array. For *PvmHostAdd*, specifies the number of times to notify.\

- tids

  For *PvmTaskExit* and *PvmHostDelete*, an array of length *cnt* of task or pvmd TIDs to be notified about. The array is not used with the *PvmHostAdd* option.\

- info

  Integer status code returned by the routine. Values less than zero indicate an error.

## DESCRIPTION

The routine *pvm\_notify* requests PVM to notify the caller on detecting certain events. One or more notify messages (see below) are sent by PVM back to the calling task. The messages have tag *msgtag* supplied to notify.

The notification messages have the following format:

- PvmTaskExit

  One notify message for each TID requested. The message body contains a single TID of exited task.

- PvmHostDelete

  One notify message for each TID requested. The message body contains a single pvmd-TID of exited pvmd.

- PvmHostAdd

  *cnt* notify messages are sent, one each time the local pvmd's host table is updated. The message body contains an integer length followed by a list of pvmd-TIDs of new pvmds. The counter of *PvmHostAdd* messages yet to be sent is replaced by successive calls to *pvm\_notify*. Specifying a *cnt* of -1 turns on *PvmHostAdd* messages until a future notify; a count of zero disables them.

TIDs in the notify messages are packed as integers.

The calling task is responsible for receiving messages with the specified tag and taking appropriate action.

Future versions of PVM may expand the list of available notification events.

## EXAMPLES

```
C:
	info = pvm_notify( PvmTaskExit, 9999, ntask, tids )

Fortran:
	CALL PVMFNOTIFY( PVMHOSTDELETE, 1111, NUMHOSTS, DTIDS, INFO )
```

## ERRORS

- PvmSysErr

  pvmd not responding.

- PvmBadParam

  giving an invalid argument value.

## SEE ALSO

pvm\_tasks(3PVM), pvm\_config(3PVM)