1.0.37.8: add ATOMIC-DECF, fix WAIT-ON-SEMAPHORE-BUGLET
[sbcl.git] / tests / threads.impure.lisp
index 11b39cf..3937dad 100644 (file)
     (wait-on-semaphore sem)
     (assert signalled-p)))
 
-(with-test (:name (:semaphore :multiple-signals))
+(defun test-semaphore-multiple-signals (wait-on-semaphore)
   (let* ((sem (make-semaphore :count 5))
-         (threads (loop repeat 20
-                        collect (make-thread (lambda ()
-                                               (wait-on-semaphore sem))))))
+         (threads (loop repeat 20 collecting
+                        (make-thread (lambda ()
+                                       (funcall wait-on-semaphore sem))))))
     (flet ((count-live-threads ()
              (count-if #'thread-alive-p threads)))
       (sleep 0.5)
       (sleep 0.5)
       (assert (= 0 (count-live-threads))))))
 
+(with-test (:name (:semaphore :multiple-signals))
+  (test-semaphore-multiple-signals #'wait-on-semaphore))
+
+(with-test (:name (:try-semaphore :trivial-fail))
+  (assert (eq (try-semaphore (make-semaphore :count 0)) 'nil)))
+
+(with-test (:name (:try-semaphore :trivial-success))
+  (let ((sem (make-semaphore :count 1)))
+    (assert (try-semaphore sem))
+    (assert (zerop (semaphore-count sem)))))
+
+(with-test (:name (:try-semaphore :emulate-wait-on-semaphore))
+  (flet ((busy-wait-on-semaphore (sem)
+           (loop until (try-semaphore sem) do (sleep 0.001))))
+    (test-semaphore-multiple-signals #'busy-wait-on-semaphore)))
+
+;;; Here we test that interrupting TRY-SEMAPHORE does not leave a
+;;; semaphore in a bad state.
+(with-test (:name (:try-semaphore :interrupt-safe))
+  (flet ((make-threads (count fn)
+           (loop repeat count collect (make-thread fn)))
+         (kill-thread (thread)
+           (when (thread-alive-p thread)
+             (ignore-errors (terminate-thread thread))))
+         (count-live-threads (threads)
+           (count-if #'thread-alive-p threads)))
+    ;; WAITERS will already be waiting on the semaphore while
+    ;; threads-being-interrupted will perform TRY-SEMAPHORE on that
+    ;; semaphore, and MORE-WAITERS are new threads trying to wait on
+    ;; the semaphore during the interruption-fire.
+    (let* ((sem (make-semaphore :count 50))
+           (waiters (make-threads 20 #'(lambda ()
+                                         (wait-on-semaphore sem))))
+           (triers  (make-threads 40 #'(lambda ()
+                                         (sleep (random 0.01))
+                                         (try-semaphore sem))))
+           (more-waiters
+            (loop repeat 10
+                  do (kill-thread (nth (random 40) triers))
+                  collect (make-thread #'(lambda () (wait-on-semaphore sem)))
+                  do (kill-thread (nth (random 40) triers)))))
+      (sleep 0.5)
+      ;; Now ensure that the waiting threads will all be waked up,
+      ;; i.e. that the semaphore is still working.
+      (loop repeat (+ (count-live-threads waiters)
+                      (count-live-threads more-waiters))
+            do (signal-semaphore sem))
+      (sleep 0.5)
+      (assert (zerop (count-live-threads triers)))
+      (assert (zerop (count-live-threads waiters)))
+      (assert (zerop (count-live-threads more-waiters))))))
+
+
+
 (format t "~&semaphore tests done~%")
 
 (defun test-interrupt (function-to-interrupt &optional quit-p)
 
 (format t "~&interrupt test done~%")
 
-(defparameter *interrupt-count* 0)
+(defstruct counter (n 0 :type sb-vm:word))
+(defvar *interrupt-counter* (make-counter))
 
 (declaim (notinline check-interrupt-count))
 (defun check-interrupt-count (i)
                                       (princ cond)
                                       (sb-debug:backtrace
                                        most-positive-fixnum))))
-              (loop (check-interrupt-count *interrupt-count*)))))))
+              (loop (check-interrupt-count (counter-n *interrupt-counter*))))))))
   (let ((func (lambda ()
                 (princ ".")
                 (force-output)
-                (sb-impl::atomic-incf/symbol *interrupt-count*))))
-    (setq *interrupt-count* 0)
+                (sb-ext:atomic-incf (counter-n *interrupt-counter*)))))
+    (setf (counter-n *interrupt-counter*) 0)
     (dotimes (i 100)
       (sleep (random 0.1d0))
       (interrupt-thread c func))
-    (loop until (= *interrupt-count* 100) do (sleep 0.1))
+    (loop until (= (counter-n *interrupt-counter*) 100) do (sleep 0.1))
     (terminate-thread c)
     (wait-for-threads (list c))))
 
 
 (format t "waitqueue wakeup tests done~%")
 
+;;; Make sure that a deadline handler is not invoked twice in a row in
+;;; CONDITION-WAIT. See LP #512914 for a detailed explanation.
+;;;
+#-sb-lutex    ; See KLUDGE above: no deadlines for condition-wait+lutexes.
+(with-test (:name (:condition-wait :deadlines :LP-512914))
+  (let ((n 2) ; was empirically enough to trigger the bug
+        (mutex (sb-thread:make-mutex))
+        (waitq (sb-thread:make-waitqueue))
+        (threads nil)
+        (deadline-handler-run-twice? nil))
+    (dotimes (i n)
+      (let ((child
+             (sb-thread:make-thread
+              #'(lambda ()
+                  (handler-bind
+                      ((sb-sys:deadline-timeout
+                        (let ((already? nil))
+                          #'(lambda (c)
+                              (when already?
+                                (setq deadline-handler-run-twice? t))
+                              (setq already? t)
+                              (sleep 0.2)
+                              (sb-thread:condition-broadcast waitq)
+                              (sb-sys:defer-deadline 10.0 c)))))
+                    (sb-sys:with-deadline (:seconds 0.1)
+                      (sb-thread:with-mutex (mutex)
+                        (sb-thread:condition-wait waitq mutex))))))))
+        (push child threads)))
+    (mapc #'sb-thread:join-thread threads)
+    (assert (not deadline-handler-run-twice?))))
+
+(with-test (:name (:condition-wait :signal-deadline-with-interrupts-enabled))
+  (let ((mutex (sb-thread:make-mutex))
+        (waitq (sb-thread:make-waitqueue))
+        (A-holds? :unknown)
+        (B-holds? :unknown)
+        (A-interrupts-enabled? :unknown)
+        (B-interrupts-enabled? :unknown)
+        (A)
+        (B))
+    ;; W.L.O.G., we assume that A is executed first...
+    (setq A (sb-thread:make-thread
+             #'(lambda ()
+                 (handler-bind
+                     ((sb-sys:deadline-timeout
+                       #'(lambda (c)
+                           ;; We came here through the call to DECODE-TIMEOUT
+                           ;; in CONDITION-WAIT; hence both here are supposed
+                           ;; to evaluate to T.
+                           (setq A-holds? (sb-thread:holding-mutex-p mutex))
+                           (setq A-interrupts-enabled?
+                                 sb-sys:*interrupts-enabled*)
+                           (sleep 0.2)
+                           (sb-thread:condition-broadcast waitq)
+                           (sb-sys:defer-deadline 10.0 c))))
+                   (sb-sys:with-deadline (:seconds 0.1)
+                     (sb-thread:with-mutex (mutex)
+                       (sb-thread:condition-wait waitq mutex)))))))
+    (setq B (sb-thread:make-thread
+             #'(lambda ()
+                 (thread-yield)
+                 (handler-bind
+                     ((sb-sys:deadline-timeout
+                       #'(lambda (c)
+                           ;; We came here through the call to GET-MUTEX
+                           ;; in CONDITION-WAIT (contended case of
+                           ;; reaquiring the mutex) - so the former will
+                           ;; be NIL, but interrupts should still be enabled.
+                           (setq B-holds? (sb-thread:holding-mutex-p mutex))
+                           (setq B-interrupts-enabled?
+                                 sb-sys:*interrupts-enabled*)
+                           (sleep 0.2)
+                           (sb-thread:condition-broadcast waitq)
+                           (sb-sys:defer-deadline 10.0 c))))
+                   (sb-sys:with-deadline (:seconds 0.1)
+                     (sb-thread:with-mutex (mutex)
+                       (sb-thread:condition-wait waitq mutex)))))))
+    (sb-thread:join-thread A)
+    (sb-thread:join-thread B)
+    (let ((A-result (list A-holds? A-interrupts-enabled?))
+          (B-result (list B-holds? B-interrupts-enabled?)))
+      ;; We also check some subtle behaviour w.r.t. whether a deadline
+      ;; handler in CONDITION-WAIT got the mutex, or not. This is most
+      ;; probably very internal behaviour (so user should not depend
+      ;; on it) -- I added the testing here just to manifest current
+      ;; behaviour.
+      (cond ((equal A-result '(t t)) (assert (equal B-result '(nil t))))
+            ((equal B-result '(t t)) (assert (equal A-result '(nil t))))
+            (t (error "Failure: fall through."))))))
+
 (with-test (:name (:mutex :finalization))
   (let ((a nil))
     (dotimes (i 500000)