lock_write(9r) lock_write(9r)
NAME
lock_write - Asserts a complex lock with write access
SYNOPSIS
#include <kern/lock.h>
void lock_write(
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
assert a complex lock with write access. The lock 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.
DESCRIPTION
The lock_write routine asserts a lock with exclusive write access for the resource associated with the specified lock structure pointer.
This means that once a write lock is asserted, no other kernel thread can gain read or write access to the resource until it is released.
To release a complex write lock successfully asserted by lock_write, call the lock_done routine.
NOTES
You must call lock_init (once only) prior to calling lock_write 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
None
FILES
SEE ALSO
Routines: lock_done(9r), lock_read(9r), lock_terminate(9r), lock_try_read(9r), lock_try_write(9r)
Data Structures: lock(9s)
lock_write(9r)
