tis_read_trylock(3)					     Library Functions Manual					       tis_read_trylock(3)

NAME

       tis_read_trylock - Attempts to acquire a read-write lock for read access.  Does not wait if the lock cannot be immediately granted.

LIBRARY

       Standard C Library (libc.so, libc.a)

SYNOPSIS

       #include <tis.h>

       int   tis_read_trylock(
			      tis_rwlock_t   *lock);

STANDARDS

       None

PARAMETERS

       Address of the read-write lock to be acquired.

DESCRIPTION

       This routine attempts to acquire a read-write lock for read access.  If the lock cannot be granted, the routine returns without waiting.

       When a thread calls this routine, an attempt is made to immediately acquire the lock for read access.  If the lock is acquired, zero (0) is
       returned.  If a holder of the lock for write access exists, [EBUSY] is returned.

       If the lock cannot be acquired for read access immediately, the calling program does not wait for the lock to be released.

RETURN VALUES

       If an error condition occurs, this routine returns an integer value indicating the type of error.  Possible return values are  as  follows:
       Successful completion; the lock was acquired.  The lock is being held for write access.	The lock for read access was not acquired.

ERRORS

       None

RELATED INFORMATION

       Functions:   tis_read_lock(3),  tis_read_unlock(3),  tis_rwlock_destroy(3),  tis_rwlock_init(3),  tis_write_lock(3),  tis_write_trylock(3),
       tis_write_unlock(3)

       Manuals: Guide to DECthreads and Programmer's Guide delim off

															       tis_read_trylock(3)