diff options
| -rw-r--r-- | share/man/man9/rwlock.9 | 35 |
1 files changed, 33 insertions, 2 deletions
diff --git a/share/man/man9/rwlock.9 b/share/man/man9/rwlock.9 index a06c056..6116634 100644 --- a/share/man/man9/rwlock.9 +++ b/share/man/man9/rwlock.9 @@ -30,6 +30,7 @@ .Sh NAME .Nm rwlock , .Nm rw_init , +.Nm rw_init_flags, .Nm rw_destroy , .Nm rw_rlock , .Nm rw_wlock , @@ -50,6 +51,8 @@ .Ft void .Fn rw_init "struct rwlock *rw" "const char *name" .Ft void +.Fn rw_init_flags "struct rwlock *rw" "const char *name" "int opts" +.Ft void .Fn rw_destroy "struct rwlock *rw" .Ft void .Fn rw_rlock "struct rwlock *rw" @@ -108,7 +111,7 @@ are anonymous. Another important property is that shared holders of .Nm can recurse, -but exclusive locks are not allowed to recurse. +and exclusive locks can be made recursive selectively. .Ss Macros and Functions .Bl -tag -width indent .It Fn rw_init "struct rwlock *rw" "const char *name" @@ -119,6 +122,30 @@ as reader/writer lock, described by name The description is used solely for debugging purposes. This function must be called before any other operations on the lock. +.It Fn rw_init_flags "struct rwlock *rw" "const char *name" "int opts" +Initialize the rw lock just like +.Fn rw_init +function, but specifing a set of optional flags to alter the +behaviour of +.Fa rw , +through the +.Fa opts +argument. It contains one or more of the following flags: +.Bl -tag -width ".Dv RW_NOPROFILE" +.It Dv RW_DUPOK +Witness should not log messages about duplicate locks being acquired. +.It Dv RW_NOPROFILE +Do not profile this lock. +.It Dv RW_NOWITNESS +Instruct +.Xr witness 4 +to ignore this lock. +.It Dv RW_QUIET +Do not log any operations for this lock via +.Xr ktr 4 . +.It Dv RW_RECURSE +Allow threads to recursively acquire exclusive locks for +.Fa rw . .It Fn rw_rlock "struct rwlock *rw" Lock .Fa rw @@ -139,7 +166,11 @@ as a writer. If there are any shared owners of the lock, the current thread blocks. The .Fn rw_wlock -function cannot be called recursively. +function can be called recursively only if +.Fa rw +has been initialized with the +.Dv RW_RECURSE +option enabled. .It Fn rw_runlock "struct rwlock *rw" This function releases a shared lock previously acquired by .Fn rw_rlock . |
