VM_MAP_LOCK(9)						   BSD Kernel Developer's Manual					    VM_MAP_LOCK(9)

NAME

     vm_map_lock, vm_map_unlock, vm_map_lock_read, vm_map_unlock_read, vm_map_trylock, vm_map_trylock_read, vm_map_lock_upgrade,
     vm_map_lock_downgrade -- vm_map locking macros

SYNOPSIS

     #include <sys/param.h>
     #include <vm/vm.h>
     #include <vm/vm_map.h>

     void
     vm_map_lock(vm_map_t map);

     void
     vm_map_unlock(vm_map_t map);

     void
     vm_map_lock_read(vm_map_t map);

     void
     vm_map_unlock_read(vm_map_t map);

     int
     vm_map_trylock(vm_map_t map);

     int
     vm_map_trylock_read(vm_map_t map);

     int
     vm_map_lock_upgrade(vm_map_t map);

     int
     vm_map_lock_downgrade(vm_map_t map);

DESCRIPTION

     The vm_map_lock() macro obtains an exclusive lock on map.

     The vm_map_unlock() macro releases an exclusive lock on map.

     The vm_map_lock_read() macro obtains a read-lock on map.

     The vm_map_unlock_read() macro releases a read-lock on map.

     The vm_map_trylock() macro attempts to obtain an exclusive lock on map.  It returns FALSE if the lock cannot be immediately acquired; other-
     wise return TRUE with the lock acquired.

     The vm_map_trylock_read() macro attempts to obtain a read-lock on map.  It returns FALSE if the lock cannot be immediately acquired; other-
     wise return TRUE with the lock acquired.

     The vm_map_lock_upgrade() macro attempts to atomically upgrade a read-lock on map to an exclusive lock.

     The vm_map_lock_downgrade() macro attempts to downgrade an exclusive lock on map to a read-lock.

IMPLEMENTATION NOTES

     Currently, all of the locking macros implement their locks as sleep locks.

SEE ALSO

     vm_map(9)

AUTHORS

     This manual page was written by Bruce M Simpson <bms@spc.org>.

BSD
								   July 19, 2003							       BSD