Changeset 95

Timestamp:

02/23/07 00:18:57 (18 years ago)

Author:

psmith

Message:

Fixed problem with NIL being read from queue and then waiting when we should have returned

File:

• branches/home/psmith/restructure/src/utils/concurrent-queue.lisp (modified) (4 diffs)

branches/home/psmith/restructure/src/utils/concurrent-queue.lisp ¶

@@ -48 +48 @@
 
 
-
-(defmacro pop-elt(a-buffer loc)
-  `(if ,a-buffer 
-       (let ((head (car ,a-buffer)))
-         (setf ,a-buffer (cdr ,a-buffer))
-#+nio-debug (format-threadsafe t "concurent-queue:take - (~A,~A) read ~A at ~A~%" sb-thread:*current-thread* (length (buffer queue)) head ,loc)
-         head)
-       nil))
-
-
 ;Do an (optionally blocking) remove of the element at the head of this queue
 (defmethod take ((queue concurrent-queue) &key (blocking-call t))
-#+nio-debug (format-threadsafe t "concurent-queue:take - (~A) attempting to obtain mutex ~A~%" sb-thread:*current-thread* (buffer-lock queue))
+#+nio-debug (format-log t "concurent-queue:take - (~A) attempting to obtain mutex ~A~%" sb-thread:*current-thread* (buffer-lock queue))
   (sb-thread:with-mutex ((buffer-lock queue))
-#+nio-debug (format-threadsafe t "concurent-queue:take - (~A) aquired mutex mutex ~A~%" sb-thread:*current-thread* (buffer-lock queue))
+#+nio-debug (format-log t "concurent-queue:take - (~A) aquired mutex mutex ~A~%" sb-thread:*current-thread* (buffer-lock queue))
     ;if its there, pop it
-    (let ((ret (pop-elt (buffer queue) "1sttry")))
-      (if (or ret (not blocking-call))
-          ret
-          (progn
-#+nio-debug (format-threadsafe t "concurent-queue:take - (~A) about to wait on queue~%" sb-thread:*current-thread*)
-            (sb-thread:condition-wait (buffer-queue queue) (buffer-lock queue))
-#+nio-debug (format-threadsafe t "concurent-queue:take - (~A) notified on queue~%" sb-thread:*current-thread*)
-            (pop-elt (buffer queue) "2ndtry"))))))
+      (if (> (length (buffer queue)) 0)
+          (pop (buffer queue))
+          (when blocking-call
+            (loop
+#+nio-debug (format-log t "concurent-queue:take - (~A) about to wait on queue~%" sb-thread:*current-thread*)
+               (sb-thread:condition-wait (buffer-queue queue) (buffer-lock queue))
+#+nio-debug (format-log t "concurent-queue:take - (~A) notified on queue~%" sb-thread:*current-thread*)
+               (if (> (length (buffer queue)) 0)
+                 (return-from take (pop (buffer queue)))))))))
 
 ;Append the element to the tail of this queue
 (defmethod add ((queue concurrent-queue) elt)
-#+nio-debug (format-threadsafe t "concurent-queue:add - (~A) adding ~A~%" sb-thread:*current-thread* elt)
+#+nio-debug (format-log t "concurent-queue:add - (~A) adding ~A~%" sb-thread:*current-thread* elt)
   (sb-thread:with-mutex ((buffer-lock queue))
     (setf (buffer queue) (append (buffer queue) (list elt)) )
-    (sb-thread:condition-broadcast (buffer-queue queue))))
+    (sb-thread:condition-notify (buffer-queue queue))))
 
 
@@ -84 +75 @@
   (loop for i from 0 to 100 do
 ;       (sleep (random 0.1))
-       (format-threadsafe t "Adding ~A~%" i)
+       (format-log t "Adding ~A~%" i)
        (add queue i)))
        
 (defun test-reader(queue results)
-  (format-threadsafe t "Started reader ~A~%" sb-thread:*current-thread*)
+  (format-log t "Started reader ~A~%" sb-thread:*current-thread*)
   (loop
      (let ((elt (take queue)))
        (push elt results)
-       (format-threadsafe t "reader on ~A got elt ~A~%" 
+       (format-log t "reader on ~A got elt ~A~%" 
                sb-thread:*current-thread* 
                results))))
@@ -106 +97 @@
           ;(t2 (sb-thread:make-thread #'(lambda()(test-reader queue *results2*)))))
       (sleep 5) ;;wait for it to probably complete
-      (format-threadsafe t "t1 got: ~A~%" *results1*)
-      (format-threadsafe t "t2 got: ~A~%" *results2*)
+      (format-log t "t1 got: ~A~%" *results1*)
+      (format-log t "t2 got: ~A~%" *results2*)
       (sb-thread:destroy-thread t1)
 ;      (sb-thread:destroy-thread t2)
@@ -121 +112 @@
     (sb-thread:make-thread #'(lambda()(test-writer queue)))
     (sleep 10)
-    (format-threadsafe t "running asserts")
+    (format-log t "running asserts")
     (sb-thread:with-mutex ((buffer-lock queue))
       (assert (eql (length (buffer queue)) 0)))))