https://github.com/peter-lawrey/Java-Thread-Affinity/issues/4

peter-lawrey · peter-lawrey · commit cac12b8eb668 · 2011-12-30T08:11:03.000Z
Improved errno handling
diff --git a/src/main/java/vanilla/java/affinity/JNAAffinity.java b/src/main/java/vanilla/java/affinity/JNAAffinity.java
@@ -26,18 +26,19 @@
 public enum JNAAffinity implements AffinitySupport.IAffinity {
     INSTANCE;
     public static final Boolean LOADED;
-    public static final String LIBRARY_NAME = Platform.isWindows() ? "msvcrt" : "c";
+    private static final String LIBRARY_NAME = Platform.isWindows() ? "msvcrt" : "c";
 
     /**
      * @author BegemoT
+     * @author jbellis
      */
     private interface CLibrary extends Library {
         public static final CLibrary INSTANCE = (CLibrary)
                 Native.loadLibrary(LIBRARY_NAME, CLibrary.class);
 
-        public int sched_setaffinity(final int pid, final int cpusetsize, final PointerType cpuset);
+        public int sched_setaffinity(final int pid, final int cpusetsize, final PointerType cpuset) throws LastErrorException;
 
-        public int sched_getaffinity(final int pid, final int cpusetsize, final PointerType cpuset);
+        public int sched_getaffinity(final int pid, final int cpusetsize, final PointerType cpuset) throws LastErrorException;
 
 //        public int sched_getcpu();
     }
@@ -58,27 +59,15 @@ public long getAffinity() {
         final CLibrary lib = CLibrary.INSTANCE;
         final LongByReference cpuset = new LongByReference(0L);
         final int ret = lib.sched_getaffinity(0, Long.SIZE / 8, cpuset);
-        if (ret < 0) {
-            final int errNo = getErrorNo();
-            throw new IllegalStateException("sched_getaffinity((" + Long.SIZE / 8 + ") , &(" + cpuset + ") ) return " + ret + ", errno() = " + errNo);
-        }
+        assert ret == 0;
         return cpuset.getValue();
     }
 
     @Override
     public void setAffinity(long affinity) {
         final CLibrary lib = CLibrary.INSTANCE;
         final int ret = lib.sched_setaffinity(0, Long.SIZE / 8, new LongByReference(affinity));
-        if (ret < 0) {
-            final int errNo = getErrorNo();
-            throw new IllegalStateException("sched_setaffinity((" + Long.SIZE / 8 + ") , &(" + affinity + ") ) return " + ret + ", errno() = " + errNo);
-        }
-    }
-
-    private static int getErrorNo() {
-        final NativeLibrary nativeLib = NativeLibrary.getInstance(LIBRARY_NAME);
-        final Pointer pErrNo = nativeLib.getFunction("errno");
-        return pErrNo.getInt(0);
+        assert ret == 0;
     }
 
     @Override
diff --git a/src/test/java/vanilla/java/affinity/JNAAffinityTest.java b/src/test/java/vanilla/java/affinity/JNAAffinityTest.java
@@ -16,10 +16,14 @@
 
 package vanilla.java.affinity;
 
+import com.sun.jna.LastErrorException;
 import org.junit.Assume;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
+import static junit.framework.Assert.assertEquals;
+import static junit.framework.Assert.fail;
+
 /**
  * @author peter.lawrey
  */
@@ -29,6 +33,23 @@ public static void checkJniLibraryPresent() {
         Assume.assumeTrue(JNAAffinity.LOADED);
     }
 
+    @Test
+    public void getSetAffinity() {
+        long init = JNAAffinity.INSTANCE.getAffinity();
+        JNAAffinity.INSTANCE.setAffinity(0x01);
+        assertEquals(0x01, JNAAffinity.INSTANCE.getAffinity());
+
+        try {
+            JNAAffinity.INSTANCE.setAffinity(0x00);
+            fail("This should fail");
+        } catch (LastErrorException expected) {
+            assertEquals("errno was " + expected.getErrorCode(), expected.getMessage());
+        }
+
+        JNAAffinity.INSTANCE.setAffinity(init);
+        assertEquals(init, JNAAffinity.INSTANCE.getAffinity());
+    }
+
     @Test
     public void testNanoTimePerf() {
         final int runs = 10 * 1000 * 1000;
