lock(9s) [osf1 man page]

lock(9s)																  lock(9s)

NAME

       lock - General: Contains complex lock-specific information

SYNOPSIS

       The lock data structure is an opaque data structure; that is, its associated members are referenced and manipulated by the operating system
       and not by the user of the complex lock mechanism. Therefore, this reference page omits a description of the lock data structure's  associ-
       ated members.

DESCRIPTION

       The  lock  data	structure  is the complex lock structure that contains complex lock-specific information. A kernel module writer using the
       complex lock method declares a pointer to a lock data structure and passes its address to the associated lock routines.

NOTES

       The header file <lock.h> shows typedef statements that assign the alternate name lock_data_t for the complex lock structure and lock_t  for
       a pointer to the complex lock structure.

FILES

SEE ALSO

       Routines: lock_done(9r), lock_init(9r), lock_read(9r), lock_terminate(9r), lock_try_read(9r), lock_try_write(9r), lock_write(9r)

       Data Structures: slock(9s)

																	  lock(9s)

lock_try_read(9r)														 lock_try_read(9r)

NAME

       lock_try_read - General: Tries to assert a complex lock with read-only access

SYNOPSIS

       #include <kern/lock.h>

       boolean_t lock_try_read(
	       lock_t lock_structptr );

ARGUMENTS

       Specifies  a  pointer to the complex lock structure, lock. This is the lock structure associated with the resource on which you want to try
       to assert a complex lock with read-only access. The lock structure is an opaque data structure; that is, its associated members are  refer-
       enced and manipulated by the operating system and not by the user of the complex lock mechanism.

DESCRIPTION

       The  lock_try_read  routine  tries  to  assert a complex lock (without blocking) with read-only access for the resource associated with the
       specified lock structure pointer. To release a complex lock  with  read-only  access  successfully  asserted  by  lock_try_read,  call  the
       lock_done routine.

NOTES

       You  must call lock_init (once only) prior to calling lock_try_read to initialize the lock structure pointer for the resource.  A resource,
       from the kernel module's standpoint, is data that more than one kernel thread can manipulate. You can store the resource  in  global  vari-
       ables and in data structure members.

RETURN VALUES

       The  lock_try_read  routine  returns  one  of  the following values: The attempt to acquire the read-only complex lock was successful.  The
       attempt to acquire the read-only complex lock was unsuccessful.

FILES

SEE ALSO

       Routines: lock_done(9r), lock_terminate(9r), lock_try_write(9r), lock_write(9r)

       Data Structures: lock(9s)

																 lock_try_read(9r)