Better docs for leaving guile mode.

diff --git a/doc/ref/api-scheduling.texi b/doc/ref/api-scheduling.texi
index be3fd64..4eda18a 100644 (file)
--- a/doc/ref/api-scheduling.texi
+++ b/doc/ref/api-scheduling.texi
@@ -310,23 +310,30 @@ guile mode.  The following functions can be used to temporily leave
 guile mode or to perform some common blocking operations in a supported
 way.
 
-@deftypefn {C Function} scm_t_guile_ticket scm_leave_guile ()
-Leave guile mode and return a ticket that can be used with
-@code{scm_enter_guile} to enter it again.
+@deftypefn  {C Function} scm_t_guile_ticket scm_leave_guile ()
+@deftypefnx {C Function} void scm_enter_guile (scm_t_guile_ticket ticket)
+These two functions must be called as a pair and can be used to leave
+guile mode temporarily.  The call to @code{scm_leave_guile} returns a
+ticket that must be used with @code{scm_enter_guile} to match up the two
+calls.
 
 While a thread has left guile mode, it must not call any libguile
-functions except @code{scm_enter_guile} and must not use any libguile
-macros.  Also, local variables of type @code{SCM} that are allocated
-while not in guile mode are not protected from the garbage collector.
-@end deftypefn
-
-@deftypefn {C Function} void scm_enter_guile (scm_t_guile_ticket ticket)
-Enter guile mode again.
+functions except @code{scm_enter_guile}, @code{scm_with_guile},
+@code{scm_without_guile} or @code{scm_leave_guile} and must not use any
+libguile macros.  Also, local variables of type @code{SCM} that are
+allocated while not in guile mode are not protected from the garbage
+collector.
+
+When used from non-guile mode, a pair of calls to @code{scm_leave_guile}
+and @code{scm_enter_guile} do nothing.  In that way, you can leave guile
+mode without having to know whether the current thread is in guile mode
+or not.
 @end deftypefn
 
 @deftypefn {C Function} void *scm_without_guile (void *(*func) (void *), void *data)
-Leave guile mode, call @var{func} on @var{data}, enter guile mode and
-return the result of calling @var{func}.
+Leave guile mode as with @code{scm_leave_guile}, call @var{func} on
+@var{data}, enter guile mode as with @code{scm_enter_guile} and return
+the result of calling @var{func}.
 @end deftypefn
 
 @deftypefn {C Function} int scm_pthread_mutex_lock (pthread_mutex_t *mutex)