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)
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lock_init(9r)lock_init(9r)NAME
lock_init - General: Initializes a complex lock
SYNOPSIS
#include <kern/lock.h>
void lock_init(
lock_t lock_structptr,
boolean_t can_sleep );
ARGUMENTS
Specifies a pointer to the complex lock structure, lock. 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. Specifies a Boolean value that
indicates whether to allow kernel threads to block (sleep) if the complex lock is asserted. You can pass to this argument only the value
TRUE (allow kernel threads to block if the lock is asserted).
DESCRIPTION
The lock_init routine initializes a complex lock. You identify this lock by declaring a pointer to a complex lock structure and passing it
as the first argument. The complex lock structure pointer must be initialized before you can assert read and write operations on the com-
plex lock.
RETURN VALUES
None
FILES SEE ALSO
Routines: lock_done(9r), lock_read(9r), lock_terminate(9r), lock_try_read(9r), lock_try_write(9r), lock_write(9r)
Data Structures: lock(9s)lock_init(9r)
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Hi Everybody..
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