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[Jython-checkins] SF.net SVN: jython:[6973] trunk/jython/src/org/python/core
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From: <le...@us...> - 2010-01-31 06:16:27
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Revision: 6973
http://jython.svn.sourceforge.net/jython/?rev=6973&view=rev
Author: leosoto
Date: 2010-01-31 06:16:21 +0000 (Sun, 31 Jan 2010)
Log Message:
-----------
Fixed problems introduced with the recent class loading refactor.
Note that we still do not have a stable/consistent classloading hierarchy in place. But we are closer.
Modified Paths:
--------------
trunk/jython/src/org/python/core/Py.java
trunk/jython/src/org/python/core/imp.java
Modified: trunk/jython/src/org/python/core/Py.java
===================================================================
--- trunk/jython/src/org/python/core/Py.java 2010-01-30 16:36:46 UTC (rev 6972)
+++ trunk/jython/src/org/python/core/Py.java 2010-01-31 06:16:21 UTC (rev 6973)
@@ -787,7 +787,7 @@
* @param name Name of the Java class to load and initialize
* @param reason Reason for loading it, used for debugging. No debug output
* is generated if it is null
- * @return the loaded class, or null if no class loader is accessible
+ * @return the loaded class
* @throws ClassNotFoundException if the class wasn't found by the class loader
*/
private static Class<?> findClassInternal(String name, String reason) throws ClassNotFoundException {
@@ -799,39 +799,42 @@
}
return loadAndInitClass(name, classLoader);
}
-
if (!syspathJavaLoaderRestricted) {
try {
classLoader = imp.getSyspathJavaLoader();
+ if (classLoader != null && reason != null) {
+ writeDebug("import", "trying " + name + " as " + reason +
+ " in SysPathJavaLoader");
+ }
} catch (SecurityException e) {
syspathJavaLoaderRestricted = true;
}
- if (classLoader != null) {
- if (reason != null) {
- writeDebug("import", "trying " + name + " as " + reason +
- " in SysPathJavaLoader");
- }
- try {
- return loadAndInitClass(name, classLoader);
- } catch (ClassNotFoundException cnfe) {
- // let the default classloader try
- }
+ }
+ if (syspathJavaLoaderRestricted) {
+ classLoader = imp.getParentClassLoader();
+ if (classLoader != null && reason != null) {
+ writeDebug("import", "trying " + name + " as " + reason +
+ " in Jython's parent class loader");
}
+ }
+ if (classLoader != null) {
+ try {
+ return loadAndInitClass(name, classLoader);
+ } catch (ClassNotFoundException cnfe) {
+ // let the default classloader try
+ // XXX: by trying another classloader that may not be on a
+ // parent/child relationship with the Jython's parent
+ // classsloader we are risking some nasty class loading
+ // problems (such as having two incompatible copies for
+ // the same class that is itself a dependency of two
+ // classes loaded from these two different class loaders)
+ }
}
if (reason != null) {
writeDebug("import", "trying " + name + " as " + reason +
- " in Jython's parent class loader");
+ " in context class loader, for backwards compatibility");
}
- classLoader = imp.getParentClassLoader();
- if (classLoader != null) {
- return loadAndInitClass(name, classLoader);
- }
-
- if (reason != null) {
- writeDebug("import", "trying " + name + " as " + reason +
- " in Class.forName");
- }
- return Class.forName(name);
+ return loadAndInitClass(name, Thread.currentThread().getContextClassLoader());
}
/**
Modified: trunk/jython/src/org/python/core/imp.java
===================================================================
--- trunk/jython/src/org/python/core/imp.java 2010-01-30 16:36:46 UTC (rev 6972)
+++ trunk/jython/src/org/python/core/imp.java 2010-01-31 06:16:21 UTC (rev 6973)
@@ -48,36 +48,63 @@
}
/**
- * Returns the parent class loader for Jython. In most environments
- * is just the class loader that loaded this class (imp.class). However,
- * when that class loader is null (e.g., when Jython has been
- * loaded using the boot loader) we return the Thread's context class
- * loader (which can also be null, but in such case we return null anyway).
+ * <p>
+ * Selects the parent class loader for Jython, used for dinamically load classes and resources
*
- * @return the parent class loader for Jython
+ * <p>
+ * The current implementation chooses between the current and context
+ * classloader based on the following criteria:<ul>
+ *
+ * <li>If both are the same, that one is returned.
+ * <li>If either is null, the non-null one is selected.
+ * <li>If both are not null, and a parent/child relationship can be determined,
+ * the child is selected.
+ * <li>If both are not null and not on a parent/child relationship, the
+ * current class loader is returned (since it is likely for the
+ * context class loader to <b>not</b> see the Jython classes)
+ *
+ * @return the parent class loader for Jython or null if both the current and context classloaders are null;
*/
public static ClassLoader getParentClassLoader() {
- ClassLoader parent = null;
- // XXX: While trying the current class loader before using the context class
- // loader seems like the saner approach, there may be legacy code
- // expecting Jython to use the context class loader,
- //
- // Se we should uncomment the following line when we feel like
- // doing backwards-incompatible changes (3.0?)
- //
- // parent = imp.class.getClassLoader();
- if (parent == null) {
- // Try the context class loader
- try {
- parent = Thread.currentThread().getContextClassLoader();
- } catch (SecurityException e) {
- // We just give up
- }
- }
- return parent;
- }
+ ClassLoader current = imp.class.getClassLoader();
+ ClassLoader context = Thread.currentThread().getContextClassLoader();
+ if (context == current) {
+ return current;
+ }
+ if (context == null) {
+ return current;
+ }
+ if (current == null) {
+ return context;
+ }
+ if (isParentClassLoader(context, current)) {
+ return current;
+ }
+ if (isParentClassLoader(current, context)) {
+ return context;
+ }
+ return current;
+ }
- private imp() {
+ private static boolean isParentClassLoader(
+ ClassLoader suspectedParent, ClassLoader child) {
+ try {
+ ClassLoader parent = child.getParent();
+ if (suspectedParent == parent) {
+ return true;
+ }
+ if (parent == null || parent == child) {
+ // We reached the boot class loader
+ return false;
+ }
+ return isParentClassLoader(suspectedParent, parent);
+
+ } catch (SecurityException e) {
+ return false;
+ }
+ }
+
+ private imp() {
}
/**
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