---
name: "pvm_hostsync"
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_hostsync"
---

# pvm\_hostsync(3)

Get time-of-day clock from PVM host.

## NAME

pvm\_hostsync - Get time-of-day clock from PVM host.

## SYNOPSIS

```
C	#include <sys/time.h>
	int info = pvm_hostsync( int host, struct timeval *clk,
		struct timeval *delta )
Fortran	call pvmfhostsync( host, clksec, clkusec, deltasec, deltausec, info )
```

## PARAMETERS

- host

  **TID of host.**\

- clk

  **(or** *clksec* and *clkusec*) Returns time-of-day clock sample from host.\

- delta

  (or *deltasec* and *deltausec*) Returns difference between local clock and remote host clock.

## DESCRIPTION

*pvm\_hostsync* samples the time-of day clock of a host in the virtual machine and returns both the clock value and the difference between local and remote clocks.

To reduce the delta error due to message transit time, local clock samples are taken before and after reading the remote clock. Delta is the difference between the mean local clocks and remote clock.

Note that the delta time can be negative. The microseconds field is always normalized to 0..999999, while the sign of the seconds field gives the sign of the delta. For example:\
\
 	3\.25 Sec =  3,250000\
\
 	0        =  0,0\
\
 	\-1 uSec  = -1,999999\
\
 	\-1 Sec   = -1,000000\
\
 	\-1.1 Sec = -2,999000

In C, if *clk* or *delta* is a null pointer, that parameter is not returned.

## ERRORS

If pvm\_hostsync is successful, it returns PvmOk. These error conditions can be returned by *pvm\_hostsync*

- PvmSysErr

  pvmd not responding.

- PvmNoHost

  specified host not in virtual machine.

- PvmHostFail

  host is unreachable (and thus possibly failed)

## SEE ALSO

pvm\_config(3PVM)