2 .\" Copyright (c) 2003 Bruce M Simpson <bms@spc.org>
3 .\" All rights reserved.
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6 .\" modification, are permitted provided that the following conditions
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34 .Nm vm_map_lock_read ,
35 .Nm vm_map_unlock_read ,
37 .Nm vm_map_trylock_read ,
38 .Nm vm_map_lock_upgrade ,
39 .Nm vm_map_lock_downgrade
40 .Nd vm_map locking macros
46 .Fn vm_map_lock "vm_map_t map"
48 .Fn vm_map_unlock "vm_map_t map"
50 .Fn vm_map_lock_read "vm_map_t map"
52 .Fn vm_map_unlock_read "vm_map_t map"
54 .Fn vm_map_trylock "vm_map_t map"
56 .Fn vm_map_trylock_read "vm_map_t map"
58 .Fn vm_map_lock_upgrade "vm_map_t map"
60 .Fn vm_map_lock_downgrade "vm_map_t map"
64 macro obtains an exclusive lock on
69 macro releases an exclusive lock on
74 macro obtains a read-lock on
76 Currently this is implemented as an exclusive lock.
79 .Fn vm_map_unlock_read
80 macro releases a read-lock on
85 macro attempts to obtain an exclusive lock on
87 It returns FALSE if the lock cannot be immediately acquired;
88 otherwise return TRUE with the lock acquired.
91 .Fn vm_map_trylock_read
92 macro attempts to obtain a read-lock on
94 It returns FALSE if the lock cannot be immediately acquired;
95 otherwise return TRUE with the lock acquired.
96 Currently this is implemented as an exclusive lock.
99 .Fn vm_map_lock_upgrade
100 macro attempts to atomically upgrade a read-lock on
102 to an exclusive lock.
103 As read-locks are currently implemented as exclusive locks,
104 this macro is a no-op.
107 .Fn vm_map_lock_downgrade
108 macro attempts to downgrade an exclusive lock on
111 As read-locks are currently implemented as exclusive locks,
112 this macro is a no-op.
113 .Sh IMPLEMENTATION NOTES
114 Currently, all of the locking macros implement their locks as sleep locks.
118 This manual page was written by
119 .An Bruce M Simpson Aq bms@spc.org .