Test the return value of CONDITION-NOTIFY and CONDITION-BROADCAST

apiv2/api-condition-variables.lisp

@@ -83,17 +83,16 @@
   It is unspecified which thread gets a wakeup and does not
   necessarily relate to the order that the threads went to sleep in.
 
-  CONDITION-NOTIFY returns T if a thread was woken up, otherwise NIL."
+  CONDITION-NOTIFY returns always NIL."
   (%condition-notify condition-variable)
-  t)
+  nil)
 
 (defun condition-broadcast (condition-variable)
   "Notify all threads waiting for CONDITION-VARIABLE.
   
   The order of wakeup is unspecified and does not necessarily relate
   to the order that the threads went to sleep in.
 
-  CONDITION-BROADCAST returns T if at least one thread was woken up,
-  otherwise NIL."
+  CONDITION-BROADCAST returns always NIL."
   (%condition-broadcast condition-variable)
-  t)
+  nil)

docs/content/condition-variables/condition-broadcast.md

@@ -19,9 +19,7 @@ boolean](http://www.lispworks.com/documentation/HyperSpec/Body/26_glo_g.htm#gene
 
 Notify all the threads waiting for `condition-variable`.
 
-Returns
-[true](http://www.lispworks.com/documentation/HyperSpec/Body/26_glo_t.htm#true)
-if at least one thread was woken up, otherwise
+Returns always
 [false](http://www.lispworks.com/documentation/HyperSpec/Body/26_glo_f.htm#false).
 
 #### Exceptional situations:
@@ -40,3 +38,8 @@ if `condition-variable` is not a
 
 The order of wakeup is unspecified and does not necessarily relate to
 the order in which the threads went to sleep.
+
+**condition-broadcast** always returns
+[false](http://www.lispworks.com/documentation/HyperSpec/Body/26_glo_f.htm#false)
+because not all implementations' primitives can tell whether or not
+some threads were indeed woken up.

docs/content/condition-variables/condition-notify.md

@@ -19,9 +19,7 @@ boolean](http://www.lispworks.com/documentation/HyperSpec/Body/26_glo_g.htm#gene
 
 Notify one of the threads waiting for `condition-variable`.
 
-Returns
-[true](http://www.lispworks.com/documentation/HyperSpec/Body/26_glo_t.htm#true)
-if a thread was woken up, otherwise
+Returns always
 [false](http://www.lispworks.com/documentation/HyperSpec/Body/26_glo_f.htm#false).
 
 #### Exceptional situations:
@@ -40,3 +38,8 @@ if `condition-variable` is not a
 
 It is unspecified which thread gets a wakeup and does not necessarily
 relate to the order in which the threads went to sleep.
+
+**condition-notify** always returns
+[false](http://www.lispworks.com/documentation/HyperSpec/Body/26_glo_f.htm#false)
+because not all implementations' primitives can tell whether or not
+some threads were indeed woken up.

test/tests-v2.lisp

@@ -430,6 +430,35 @@ lock."
           (with-lock-held (res-lock)
             (condition-wait res-cv res-lock)
             (is-false lock-was-acquired-p)))))))
+
+#+#.(bt2::implemented-p* 'bt2:make-condition-variable)
+(test condition-notify.no-waiting-threads
+  "Test that `CONDITION-NOTIFY` returns NIL whether or not there are
+threads waiting."
+  (let ((lock (make-lock :name "Test lock"))
+        (cv (make-condition-variable :name "Test condition variable")))
+    (is-false (condition-notify cv))
+    (make-thread (lambda ()
+                   (with-lock-held (lock)
+                     (condition-wait cv lock))))
+    (is-false (condition-notify cv))))
+
+#+#.(bt2::implemented-p* 'bt2:make-condition-variable)
+(test condition-broadcast.return-value
+  "Test that `CONDITION-BROADCAST` returns NIL whether or not there
+are threads waiting."
+  (let ((lock (make-lock :name "Test lock"))
+        (cv (make-condition-variable :name "Test condition variable")))
+    (is-false (condition-notify cv))
+    (make-thread (lambda ()
+                   (with-lock-held (lock)
+                     (condition-wait cv lock)))
+                 :name "Waiting thread 1")
+    (make-thread (lambda ()
+                   (with-lock-held (lock)
+                     (condition-wait cv lock)))
+                 :name "Waiting thread 2")
+    (is-false (condition-broadcast cv))))
 
 
 ;;;