refs #5351 fix a test deadlock

git-svn-id: file:///svn/toku/tokudb@48720 c7de825b-a66e-492c-adef-691d508d4ae1

portability/circular_buffer.h

@@ -23,11 +23,13 @@ class circular_buffer {
 
     void push(const T &);
 
+    __attribute__((warn_unused_result))
     bool trypush(const T &);
 
+    __attribute__((warn_unused_result))
     T pop(void);
 
-    __attribute__((nonnull))
+    __attribute__((nonnull, warn_unused_result))
     bool trypop(T * const);
 
 private:

portability/tests/test-circular-buffer.cc

@@ -88,6 +88,10 @@ static void test_with_threads(void) {
     swapped = __sync_bool_compare_and_swap(&producers_joined, false, true);
     invariant(swapped);
 
+    // kick it in case it's still waiting
+    bool pushed = buf.trypush(1);
+    (void) pushed;  // yes, really ignore it
+
     r = toku_pthread_join(consumer_thd, nullptr);
     invariant_zero(r);