Pauser to warn only if trying to use busy pauser, but using sleepy du…

…e to not enough cores. closes OpenHFT#22

src/main/java/net/openhft/chronicle/threads/Pauser.java

@@ -33,11 +33,12 @@ public interface Pauser {
 
     static boolean getSleepy() {
         int procs = Runtime.getRuntime().availableProcessors();
-        if (procs < MIN_PROCESSORS) {
-            Jvm.warn().on(Pauser.class, "Using Pauser.sleepy() as not enough processors, have " + procs + ", needs " + MIN_PROCESSORS + "+");
-            return true;
-        }
-        return false;
+        return procs < MIN_PROCESSORS;
+    }
+
+    static Pauser yielding(int minBusy) {
+        SleepyWarning.warnSleepy();
+        return SLEEPY ? sleepy() : new YieldingPauser(minBusy);
     }
 
     static TimingPauser sleepy() {
@@ -91,20 +92,32 @@ static Pauser yielding() {
         return yielding(2);
     }
 
-    static Pauser yielding(int minBusy) {
-        return SLEEPY ? sleepy() : new YieldingPauser(minBusy);
-    }
-
     /**
      * A busy pauser which never waits
      *
      * @return a busy/non pauser
      */
     @NotNull
     static Pauser busy() {
+        SleepyWarning.warnSleepy();
         return SLEEPY ? sleepy() : BusyPauser.INSTANCE;
     }
 
+
+    enum SleepyWarning {
+        ;
+
+        static {
+            if (SLEEPY) {
+                int procs = Runtime.getRuntime().availableProcessors();
+                Jvm.warn().on(Pauser.class, "Using Pauser.sleepy() as not enough processors, have " + procs + ", needs " + MIN_PROCESSORS + "+");
+            }
+        }
+
+        static void warnSleepy() {
+        }
+    }
+
     @NotNull
     static TimingPauser timedBusy() {
         return SLEEPY ? sleepy() : new BusyTimedPauser();

src/test/java/net/openhft/chronicle/threads/PauserTest.java

@@ -0,0 +1,21 @@
+package net.openhft.chronicle.threads;
+
+import org.junit.Test;
+
+public class PauserTest {
+
+    @Test
+    public void sleepy() {
+        Pauser.sleepy();
+    }
+
+    @Test
+    public void yielding() {
+        Pauser.yielding();
+    }
+
+    @Test
+    public void busy() {
+        Pauser.busy();
+    }
+}