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UnsafeDetectUtil also checks that the Unsafe class has the field theUnsafe to make it work on Android platform.

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This commit is contained in:
Johan Rask 2012-01-19 16:14:00 +01:00
parent 59e5f2f262
commit fbb1432e8e
1 changed files with 22 additions and 4 deletions
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26
common/src/main/java/io/netty/util/UnsafeDetectUtil.java
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@ -15,26 +15,44 @@
*/ */
package io.netty.util; package io.netty.util;
import java.security.AccessController;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.concurrent.atomic.AtomicInteger; import java.util.concurrent.atomic.AtomicInteger;
/** /**
* Utility which checks if {@value #UNSAFE} class can be found in the classpath * Utility which checks if {@value #UNSAFE} class can be found in the classpath
* and that it can be accessed using "theUnsafe" field which is not true for all platforms, i.e Android
* where it is called "THE_ONE".
*/ */
public final class UnsafeDetectUtil { public final class UnsafeDetectUtil {
private static final String THE_UNSAFE = "theUnsafe";
private static final String UNSAFE = "sun.misc.Unsafe"; private static final String UNSAFE = "sun.misc.Unsafe";
private static final boolean UNSAFE_FOUND = isUnsafeFound(AtomicInteger.class.getClassLoader()); private static final boolean UNSAFE_FOUND = isUnsafeFound(AtomicInteger.class.getClassLoader());
public static boolean isUnsafeFound(ClassLoader loader) { public static boolean isUnsafeFound(ClassLoader loader) {
try { try {
Class.forName(UNSAFE, true, loader); Class<?> unsafeClazz = Class.forName(UNSAFE, true, loader);
return true; return hasUnsafeField(unsafeClazz);
} catch (ClassNotFoundException e) { } catch (ClassNotFoundException e) {
return false; return false;
} } catch (SecurityException e) {
return false;
} catch (PrivilegedActionException e) {
return false;
}
} }
private static boolean hasUnsafeField(final Class<?> unsafeClass) throws PrivilegedActionException {
return AccessController.doPrivileged (new PrivilegedExceptionAction<Boolean>() {
public Boolean run() throws Exception {
unsafeClass.getDeclaredField(THE_UNSAFE);
return true;
}});
}
public static boolean isUnsafeFound() { public static boolean isUnsafeFound() {
return UNSAFE_FOUND; return UNSAFE_FOUND;
} }