diff options
Diffstat (limited to 'share/man/man9/locking.9')
| -rw-r--r-- | share/man/man9/locking.9 | 23 |
1 files changed, 9 insertions, 14 deletions
diff --git a/share/man/man9/locking.9 b/share/man/man9/locking.9 index 4a54800..00478bf 100644 --- a/share/man/man9/locking.9 +++ b/share/man/man9/locking.9 @@ -82,7 +82,7 @@ since it may modify protected data. Reader/writer locks can be treated as mutexes (see above and .Xr mutex 9 ) with shared/exclusive semantics. -More specifically, regular mutexes can be +More specifically, regular mutexes can be considered to be equivalent to a write-lock on an .Em rw_lock. The @@ -94,7 +94,7 @@ are anonymous. Another important property is that shared holders of .Em rw_lock can recurse, but exclusive locks are not allowed to recurse. -This ability should not be used lightly and +This ability should not be used lightly and .Em may go away. .Pp See @@ -122,7 +122,7 @@ and read-mostly locks. They don't support priority propagation. They should be considered to be closely related to .Xr sleep 9 . -In fact it could in some cases be +In fact it could in some cases be considered a conditional sleep. .Pp See @@ -235,7 +235,6 @@ mutex before the function returns. See .Xr sleep 9 for details. -.Pp .Ss Lockmanager locks Shared/exclusive locks, used mostly in .Xr VFS 9 , @@ -294,9 +293,7 @@ running inside an interrupt thread. The following table shows what you can and can not do while holding one of the synchronization primitives discussed: .Bl -column ".Ic xxxxxxxxxxxxxxxxxxx" ".Xr XXXXXXXXX" ".Xr XXXXXXX" ".Xr XXXXXXX" ".Xr XXXXXXX" ".Xr XXXXXX" -offset indent -.It Xo -.Em "You have: You want:" Ta spin mtx Ta mutex Ta sx Ta rwlock Ta rmlock Ta sleep -.Xc +.It Em "You have: You want:" Ta spin mtx Ta mutex Ta sx Ta rwlock Ta rmlock Ta sleep .It spin mtx Ta \&ok-1 Ta \&no Ta \&no Ta \&no Ta \&no Ta \&no-3 .It mutex Ta \&ok Ta \&ok-1 Ta \&no Ta \&ok Ta \&ok Ta \&no-3 .It sx Ta \&ok Ta \&ok Ta \&ok-2 Ta \&ok Ta \&ok Ta \&ok-4 @@ -337,13 +334,11 @@ for details. The next table shows what can be used in different contexts. At this time this is a rather easy to remember table. .Bl -column ".Ic Xxxxxxxxxxxxxxxxxxx" ".Xr XXXXXXXXX" ".Xr XXXXXXX" ".Xr XXXXXXX" ".Xr XXXXXXX" ".Xr XXXXXX" -offset indent -.It Xo -.Em "Context:" Ta spin mtx Ta mutex Ta sx Ta rwlock Ta rmlock Ta sleep -.Xc -.It interrupt filter: Ta \&ok Ta \&no Ta \&no Ta \&no Ta \&no Ta \&no -.It interrupt thread: Ta \&ok Ta \&ok Ta \&no Ta \&ok Ta \&ok Ta \&no -.It callout: Ta \&ok Ta \&ok Ta \&no Ta \&ok Ta \&no Ta \&no -.It syscall: Ta \&ok Ta \&ok Ta \&ok Ta \&ok Ta \&ok Ta \&ok +.It Em "Context:" Ta spin mtx Ta mutex Ta sx Ta rwlock Ta rmlock Ta sleep +.It interrupt filter: Ta \&ok Ta \&no Ta \&no Ta \&no Ta \&no Ta \&no +.It interrupt thread: Ta \&ok Ta \&ok Ta \&no Ta \&ok Ta \&ok Ta \&no +.It callout: Ta \&ok Ta \&ok Ta \&no Ta \&ok Ta \&no Ta \&no +.It syscall: Ta \&ok Ta \&ok Ta \&ok Ta \&ok Ta \&ok Ta \&ok .El .Sh SEE ALSO .Xr witness 4 , |
