hg: jdk7/tl/jdk: 6935563: (dc) Improve connection reset/port unreachable handling [win]
Changeset: af68ad345389 Author:alanb Date: 2010-06-09 18:51 +0100 URL: http://hg.openjdk.java.net/jdk7/tl/jdk/rev/af68ad345389 6935563: (dc) Improve connection reset/port unreachable handling [win] Reviewed-by: chegar ! src/windows/native/sun/nio/ch/DatagramChannelImpl.c ! src/windows/native/sun/nio/ch/Net.c + test/java/nio/channels/DatagramChannel/SelectWhenRefused.java
Re: Must call RegisterNatives after getMethodID, else get UnsatisfiedLinkError
David, Thanks for the bug archaeology. Judging by the other
commenters, this bug is a regression from jdk5, and has cost many
other users hours of frustrating debugging time, so I think an
increase to P2 is in order. Since it used to work, it shouldn't be
too hard to fix - all you need to do is to properly track registered
native methods.
Sorry for not doing this kind of research myself - it's just too
painful without my beloved jbugs script :-(
Here's an improved version of our test case, with
-XX:+PrintJNIResolving output added,
that you might add to the bug report.
$ cat Test.java; echo -; cat jvm.cc; echo
--; JDK=`jver 1.7.0-b96`; g++ -I$JDK/include
-I$JDK/include/linux -ldl -DJDK=\"$JDK\" jvm.cc && ./a.out
public class Test {
public Test() {
System.out.println("My class loader is " + getClass().getClassLoader());
testNative();
System.out.println("back to Java");
}
public static native void testNative();
}
-
#include
#include
#include
#include
JavaVM* jvm;
JNIEnv* env;
const char* libjvm = JDK "/jre/lib/amd64/server/libjvm.so";
const char* loader_url = "file://./";
const char* class_name = "Test";
#define countof(array) (sizeof(array)/sizeof(array[0]))
void InitializeJVM() {
JavaVMOption options[] = {
{ (char*)"-Djava.class.path=.", NULL },
{ (char*)"-XX:+PrintJNIResolving", NULL },
//{ (char*)"-verbose:jni", NULL },
};
JavaVMInitArgs vm_args;
vm_args.version = JNI_VERSION_1_2;
vm_args.options = options;
vm_args.nOptions = countof(options);
vm_args.ignoreUnrecognized = JNI_TRUE;
void* handle = dlopen(libjvm, RTLD_LAZY);
if (!handle) { fprintf(stderr, "%s\n", dlerror()); exit(1); }
jint JNICALL (*func_create_java_vm)(JavaVM**, void**, void*) =
reinterpret_cast
(dlsym(handle, "JNI_CreateJavaVM"));
if (!func_create_java_vm) { fprintf(stderr, "%s\n", dlerror()); exit(1); }
jint result = (*func_create_java_vm)(&jvm, (void**)(&env), &vm_args);
}
void TestNative(JNIEnv* env, jclass cls) {
printf("Successfully called registered native method\n");
}
void RegisterNativeMethod(jclass cls) {
static const JNINativeMethod jni_method =
{ (char*)"testNative",
(char*)"()V",
(void*)&TestNative };
env->RegisterNatives(cls, &jni_method, 1);
if (env->ExceptionCheck()) env->ExceptionDescribe();
}
void Test() {
// URL[] urls = {new URL(url)}
jclass cls = env->FindClass("java/net/URL");
jmethodID method = env->GetMethodID(cls, "", "(Ljava/lang/String;)V");
jstring jurl_str = env->NewStringUTF(loader_url);
jobject jurl = env->NewObject(cls, method, jurl_str);
jobjectArray jurls = env->NewObjectArray(1, cls, jurl);
// URLClassLoader loader = new URLClassLoaer(urls)
cls = env->FindClass("java/net/URLClassLoader");
method = env->GetMethodID(cls, "", "([Ljava/net/URL;)V");
jobject jloader = env->NewObject(cls, method, jurls);
// Class cls = loader.loadClass(name)
method = env->GetMethodID(
cls, "loadClass", "(Ljava/lang/String;Z)Ljava/lang/Class;");
jstring jname = env->NewStringUTF(class_name);
cls = (jclass)env->CallObjectMethod(jloader, method, jname, (jboolean) true);
// RegisterNatives must be called after GetMethodID.
// If the order is reversed, we get UnsatisfiedLinkError,
// which seems like a bug.
RegisterNativeMethod(cls);
method = env->GetMethodID(cls, "", "()V");
if (env->ExceptionCheck()) env->ExceptionDescribe();
env->NewObject(cls, method);
if (env->ExceptionCheck()) env->ExceptionDescribe();
}
int main(int argc, char** argv) {
InitializeJVM();
Test();
return 0;
}
--
[Dynamic-linking native method java.lang.Object.registerNatives ... JNI]
[Registering JNI native method java.lang.Object.hashCode]
[Registering JNI native method java.lang.Object.wait]
[Registering JNI native method java.lang.Object.notify]
[Registering JNI native method java.lang.Object.notifyAll]
[Registering JNI native method java.lang.Object.clone]
[Dynamic-linking native method java.lang.System.registerNatives ... JNI]
[Registering JNI native method java.lang.System.currentTimeMillis]
[Registering JNI native method java.lang.System.nanoTime]
[Registering JNI native method java.lang.System.arraycopy]
[Dynamic-linking native method java.lang.Thread.registerNatives ... JNI]
[Registering JNI native method java.lang.Thread.start0]
[Registering JNI native method java.lang.Thread.stop0]
[Registering JNI native method java.lang.Thread.isAlive]
[Registering JNI native method java.lang.Thread.suspend0]
[Registering JNI native method java.lang.Thread.resume0]
[Registering JNI native method java.lang.Thread.setPriority0]
[Registering JNI native method java.lang.Thread.yield]
[Registering JNI native method java.lang.Thread.sleep]
[Registering JNI native method java.lang.Thread.currentThread]
[Registering JNI native method java.lang.Thread.countStackFrames]
[Registering JNI native method java.lang.
Re: Must call RegisterNatives after getMethodID, else get UnsatisfiedLinkError
It's been a while since I worked with this stuff, but I would have
done a:
jclass cls = env->FindClass("Test");
Which, if I recall, FindClass actually initializes the class.
Just a stab in the dark.
-kto
On Jun 9, 2010, at 12:39 PM, Martin Buchholz wrote:
David, Thanks for the bug archaeology. Judging by the other
commenters, this bug is a regression from jdk5, and has cost many
other users hours of frustrating debugging time, so I think an
increase to P2 is in order. Since it used to work, it shouldn't be
too hard to fix - all you need to do is to properly track registered
native methods.
Sorry for not doing this kind of research myself - it's just too
painful without my beloved jbugs script :-(
Here's an improved version of our test case, with
-XX:+PrintJNIResolving output added,
that you might add to the bug report.
$ cat Test.java; echo -; cat jvm.cc; echo
--; JDK=`jver 1.7.0-b96`; g++ -I$JDK/include
-I$JDK/include/linux -ldl -DJDK=\"$JDK\" jvm.cc && ./a.out
public class Test {
public Test() {
System.out.println("My class loader is " +
getClass().getClassLoader());
testNative();
System.out.println("back to Java");
}
public static native void testNative();
}
-
#include
#include
#include
#include
JavaVM* jvm;
JNIEnv* env;
const char* libjvm = JDK "/jre/lib/amd64/server/libjvm.so";
const char* loader_url = "file://./";
const char* class_name = "Test";
#define countof(array) (sizeof(array)/sizeof(array[0]))
void InitializeJVM() {
JavaVMOption options[] = {
{ (char*)"-Djava.class.path=.", NULL },
{ (char*)"-XX:+PrintJNIResolving", NULL },
//{ (char*)"-verbose:jni", NULL },
};
JavaVMInitArgs vm_args;
vm_args.version = JNI_VERSION_1_2;
vm_args.options = options;
vm_args.nOptions = countof(options);
vm_args.ignoreUnrecognized = JNI_TRUE;
void* handle = dlopen(libjvm, RTLD_LAZY);
if (!handle) { fprintf(stderr, "%s\n", dlerror()); exit(1); }
jint JNICALL (*func_create_java_vm)(JavaVM**, void**, void*) =
reinterpret_cast
(dlsym(handle, "JNI_CreateJavaVM"));
if (!func_create_java_vm) { fprintf(stderr, "%s\n", dlerror());
exit(1); }
jint result = (*func_create_java_vm)(&jvm, (void**)(&env), &vm_args);
}
void TestNative(JNIEnv* env, jclass cls) {
printf("Successfully called registered native method\n");
}
void RegisterNativeMethod(jclass cls) {
static const JNINativeMethod jni_method =
{ (char*)"testNative",
(char*)"()V",
(void*)&TestNative };
env->RegisterNatives(cls, &jni_method, 1);
if (env->ExceptionCheck()) env->ExceptionDescribe();
}
void Test() {
// URL[] urls = {new URL(url)}
jclass cls = env->FindClass("java/net/URL");
jmethodID method = env->GetMethodID(cls, "", "(Ljava/lang/
String;)V");
jstring jurl_str = env->NewStringUTF(loader_url);
jobject jurl = env->NewObject(cls, method, jurl_str);
jobjectArray jurls = env->NewObjectArray(1, cls, jurl);
// URLClassLoader loader = new URLClassLoaer(urls)
cls = env->FindClass("java/net/URLClassLoader");
method = env->GetMethodID(cls, "", "([Ljava/net/URL;)V");
jobject jloader = env->NewObject(cls, method, jurls);
// Class cls = loader.loadClass(name)
method = env->GetMethodID(
cls, "loadClass", "(Ljava/lang/String;Z)Ljava/lang/Class;");
jstring jname = env->NewStringUTF(class_name);
cls = (jclass)env->CallObjectMethod(jloader, method, jname,
(jboolean) true);
// RegisterNatives must be called after GetMethodID.
// If the order is reversed, we get UnsatisfiedLinkError,
// which seems like a bug.
RegisterNativeMethod(cls);
method = env->GetMethodID(cls, "", "()V");
if (env->ExceptionCheck()) env->ExceptionDescribe();
env->NewObject(cls, method);
if (env->ExceptionCheck()) env->ExceptionDescribe();
}
int main(int argc, char** argv) {
InitializeJVM();
Test();
return 0;
}
--
[Dynamic-linking native method java.lang.Object.registerNatives ...
JNI]
[Registering JNI native method java.lang.Object.hashCode]
[Registering JNI native method java.lang.Object.wait]
[Registering JNI native method java.lang.Object.notify]
[Registering JNI native method java.lang.Object.notifyAll]
[Registering JNI native method java.lang.Object.clone]
[Dynamic-linking native method java.lang.System.registerNatives ...
JNI]
[Registering JNI native method java.lang.System.currentTimeMillis]
[Registering JNI native method java.lang.System.nanoTime]
[Registering JNI native method java.lang.System.arraycopy]
[Dynamic-linking native method java.lang.Thread.registerNatives ...
JNI]
[Registering JNI native method java.lang.Thread.start0]
[Registering JNI native method java.lang.Thread.stop0]
[Registering JNI native method java.lang.Thread.isAlive]
[Registering JNI native method java.lang.Thread.suspend0]
[Registering JNI native method java.lang.Thread.resume0]
[Registering JNI native method java.lang.Thread.setPriority0]
[Registering JNI native method java.lang.Threa
