|
|
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)