FreeBSD manual

download PDF document: vm_map_lock_downgrade.9.pdf

VM_MAP_LOCK(9) FreeBSD 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; otherwise 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; otherwise 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. AUTHORS This manual page was written by Bruce M Simpson <bms@spc.org>. FreeBSD 14.0-RELEASE-p11 July 19, 2003 FreeBSD 14.0-RELEASE-p11