lock_write(9r)lock_write(9r)NAMElock_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 manipu‐
lated 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 ini‐
tialize 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 variables
and in data structure members.
RETURN VALUES
None
FILESSEE 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)
