Document sx_xholder().

1 files changed, 12 insertions, 0 deletions

diff --git a/share/man/man9/sx.9 b/share/man/man9/sx.9
index 8c82f13..68267b6 100644
--- a/share/man/man9/sx.9
+++ b/share/man/man9/sx.9
@@ -44,6 +44,7 @@
 .Nm sx_try_upgrade ,
 .Nm sx_downgrade ,
 .Nm sx_sleep ,
+.Nm sx_xholder ,
 .Nm sx_xlocked ,
 .Nm sx_assert ,
 .Nm SX_SYSINIT
@@ -78,6 +79,8 @@
 .Fn sx_downgrade "struct sx *sx"
 .Ft int
 .Fn sx_sleep "void *chan" "struct sx *sx" "int priority" "const char *wmesg" "int timo"
+.Ft "struct thread *"
+.Fn sx_xholder "struct sx *sx"
 .Ft int
 .Fn sx_xlocked "struct sx *sx"
 .Pp
@@ -235,6 +238,15 @@ Assert that the current thread does not have a recursed lock on
 .Fa sx .
 .El
 .Pp
+.Fn sx_xholder
+will return a pointer to the thread which currently holds an exclusive lock on
+.Fa sx .
+If no thread holds an exclusive lock on
+.Fa sx ,
+then
+.Dv NULL
+is returned instead.
+.Pp
 .Fn sx_xlocked
 will return non-zero if the current thread holds the exclusive lock;
 otherwise, it will return zero.