net.openhft.chronicle.core.util

Class AssertUtil

java.lang.Object

net.openhft.chronicle.core.util.AssertUtil

public final class AssertUtil
extends Object

Field Summary

Fields

Modifier and Type	Field and Description
static boolean	SKIP_ASSERTIONS Setting SKIP_ASSERTIONS to true will disable assertions in this package and will almost certainly remove the assertion byte code from the target jar(s).

Method Summary

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

SKIP_ASSERTIONS

public static final boolean SKIP_ASSERTIONS

Setting SKIP_ASSERTIONS to true will disable assertions in this package and will almost certainly remove the assertion byte code from the target jar(s).

Here is an original class:

 import static net.openhft.chronicle.core.util.AssertUtil.SKIP_ASSERTIONS;
 import static net.openhft.chronicle.core.util.Ints.*;

 public final class AssertTest {

     public static void testWithAssertDirectly(int x) {
         assert SKIP_ASSERTIONS || x >= 0 ;
     }

     public static void testWithAssertDirectlyWithText(int x) {
         assert SKIP_ASSERTIONS || assertIfEnabled(nonNegative(), x);
     }

     public static void testWithAssertMethod(int x) {
         assertIfEnabled(nonNegative(), x);
     }

 }
 

It has the following byte code with SKIP_ASSERTIONS = false:

 % javap -c  target/test-classes/net/openhft/chronicle/core/util/AssertTest.class
 Compiled from "AssertTest.java"
 public final class net.openhft.chronicle.core.util.AssertTest {
   static final boolean $assertionsDisabled;

   public net.openhft.chronicle.core.util.AssertTest();
     Code:
        0: aload_0
        1: invokespecial #2                  // Method java/lang/Object."":()V
        4: return

   public static void testWithAssertDirectly(int);
     Code:
        0: getstatic     #3                  // Field $assertionsDisabled:Z
        3: ifne          18
        6: iload_0
        7: ifge          18
       10: new           #4                  // class java/lang/AssertionError
       13: dup
       14: invokespecial #5                  // Method java/lang/AssertionError."":()V
       17: athrow
       18: return

   public static void testWithAssertDirectlyWithText(int);
     Code:
        0: getstatic     #3                  // Field $assertionsDisabled:Z
        3: ifne          24
        6: invokestatic  #6                  // Method net/openhft/chronicle/core/util/Ints.nonNegative:()Ljava/util/function/IntPredicate;
        9: iload_0
       10: invokestatic  #7                  // Method net/openhft/chronicle/core/util/Ints.assertIfEnabled:(Ljava/util/function/IntPredicate;I)Z
       13: ifne          24
       16: new           #4                  // class java/lang/AssertionError
       19: dup
       20: invokespecial #5                  // Method java/lang/AssertionError."":()V
       23: athrow
       24: return

   public static void testWithAssertMethod(int);
     Code:
        0: invokestatic  #6                  // Method net/openhft/chronicle/core/util/Ints.nonNegative:()Ljava/util/function/IntPredicate;
        3: iload_0
        4: invokestatic  #7                  // Method net/openhft/chronicle/core/util/Ints.assertIfEnabled:(Ljava/util/function/IntPredicate;I)Z
        7: pop
        8: return

   static {};
     Code:
        0: ldc           #8                  // class net/openhft/chronicle/core/util/AssertTest
        2: invokevirtual #9                  // Method java/lang/Class.desiredAssertionStatus:()Z
        5: ifne          12
        8: iconst_1
        9: goto          13
       12: iconst_0
       13: putstatic     #3                  // Field $assertionsDisabled:Z
       16: return
 }
 

But it has the following byte code with SKIP_ASSERTIONS = true:

 javap -c  target/test-classes/net/openhft/chronicle/core/util/AssertTest.class
 Compiled from "AssertTest.java"
 public final class net.openhft.chronicle.core.util.AssertTest {
   public net.openhft.chronicle.core.util.AssertTest();
     Code:
        0: aload_0
        1: invokespecial #2                  // Method java/lang/Object."":()V
        4: return

   public static void testWithAssertDirectly(int);
     Code:
        0: return

   public static void testWithAssertDirectlyWithText(int);
     Code:
        0: return

   public static void testWithAssertMethod(int);
     Code:
        0: invokestatic  #3                  // Method net/openhft/chronicle/core/util/Ints.nonNegative:()Ljava/util/function/IntPredicate;
        3: iload_0
        4: invokestatic  #4                  // Method net/openhft/chronicle/core/util/Ints.assertIfEnabled:(Ljava/util/function/IntPredicate;I)Z
        7: pop
        8: return
 }
 

As can be seen, the cost is zero when SKIP_ASSERTIONS = true in the first two cases.

Performance critical code should use one of the first two schemes devised above to assert invariants. The third, more convenient form, can be used for non-performance critical code.

See Also:

Constant Field Values