ffiolock

Date:: 10-20-2011

NAME

ffiolock, ffiounlock - Provides locking for FFIO functions

SYNOPSIS

#include <ffio.h>
int ffiolock (int fd, struct ffsw *status);
int ffiounlock (int fd, struct ffsw *status);

IMPLEMENTATION

Cray Linux Environment (CLE)

DESCRIPTION

The ffiolock and ffiounlock functions provide a way of locking a group of Flexible File I/O (FFIO) function calls that use the same fd. The ffiolock function sets a lock; any other task that issues an FFIO call with the same fd will wait until the lock is released. Function ffiounlock releases the lock.

Arguments to ffiolock are as follows:

fd: Value returned from an ffopen or ffopens call.
status: Pointer to the ffsw status return structure, described in detail in ffread(3c).

The description of handling asynchronous FFIO is given under ffread(3c).

RETURN VALUES

In case of error, both functions return -1 and the ffsw.sw_error field contains the error value. Otherwise, 0 is returned. If status is NULL, the error value is returned in errn0.