我是Java初学者。我的问题是:我从C++调用Java类的方法。为此,我使用JNI。逝去的工作是正确的,但我在C++程序的过程中的一些内存泄漏...C++进程中的Java JNI泄漏
所以..我做了简单的例子..
1)我创建一个Java机(jint RES = JNI_CreateJavaVM(& JVM,(无效**)&的env,& vm_args);)
2)然后我需要一个指针上java类(JCLASS CLS = env-> findClass的( “test_jni”));
3)之后,我创建一个Java类对象的对象,通过调用构造(testJavaObject = env-> NewObject的(CLS,testConstruct);)
AT在C的过程此时此刻++程序被分配10 MB的内存
4)接下来,我删除了类,对象,和Java机..
在这个非常时刻的10 MB的内存是不是免费的 ........ ......... 所以下面我有几行代码
C++程序
void main()
{
{
//Env
JNIEnv *env;
// java virtual machine
JavaVM *jvm;
JavaVMOption* options = new JavaVMOption[1];
//class paths
options[0].optionString = "-Djava.class.path=C:/Sun/SDK/jdk/lib;D:/jms_test/java_jni_leak;";
// other options
JavaVMInitArgs vm_args;
vm_args.version = JNI_VERSION_1_6;
vm_args.options = options;
vm_args.nOptions = 1;
vm_args.ignoreUnrecognized = false;
// alloc part of memory (for test) before CreateJavaVM
char* testMem0 = new char[1000];
for(int i = 0; i < 1000; ++i)
testMem0[i] = 'a';
// create java VM
jint res = JNI_CreateJavaVM(&jvm, (void**)&env, &vm_args);
// alloc part of memory (for test) after CreateJavaVM
char* testMem1 = new char[1000];
for(int i = 0; i < 1000; ++i)
testMem1[i] = 'b';
//Creating java virtual machine
jclass cls = env->FindClass("test_jni");
// Id of a class constructor
jmethodID testConstruct = env->GetMethodID(cls, "<init>", "()V");
// The Java Object
// Calling the constructor, is allocated 10 MB of memory in c++ process
jobject testJavaObject = env->NewObject(cls, testConstruct);
// function DeleteLocalRef,
// In this very moment memory not free
env->DeleteLocalRef(testJavaObject);
env->DeleteLocalRef(cls);
// 1!!!!!!!!!!!!!
res = jvm->DestroyJavaVM();
delete[] testMem0;
delete[] testMem1;
// In this very moment memory not free. TO ///
}
int gg = 0;
}
java类(它只是allocs一些存储器)
import java.util.*;
public class test_jni
{
ArrayList<String> testStringList;
test_jni()
{
System.out.println("start constructor");
testStringList = new ArrayList<String>();
for(int i = 0; i < 1000000; ++i)
{
// засераю память
testStringList.add("TEEEEEEEEEEEEEEEEST");
}
}
}
进程内存视图,板条箱的JavaVM和Java对象后: testMem0和testMem1 - 测试存储器,这是被C分配++ 。
**************
testMem0
**************
JNI_CreateJavaVM
**************
testMem1
**************
// create java object
jobject testJavaObject = env->NewObject(cls, testConstruct);
**************
进程内存视图,后破坏JAVAVM和删除Java对象的参照: testMem0和testMem1被删除到;
**************
JNI_CreateJavaVM
**************
// create java object
jobject testJavaObject = env->NewObject(cls, testConstruct);
**************
所以testMem0和testMem1被删除,但JavaVM的和 Java对象不是....
母猪我做错了...以及如何我可以释放在C++程序的程序存储器的内容。
SOME EDIT ....
如果我ALLOC新存储器(字符* TEST3 =新的char [1000]),破坏JVM,C的堆之后++过程看起来喜欢这样:
和存储器过程正在成长!...
**************
JNI_CreateJavaVM (memory after JVM)
**************
jobject testJavaObject = env->NewObject(cls, testConstruct);
memory after Java object
**************
char* test3 (memory is allocated by char* test3 = new char[1000])
**************
只是好奇:你如何检查空闲内存? – bestsss 2011-03-16 08:14:04
我在任务管理器中查看内存大小,然后在heapviewer – DimShust 2011-03-16 12:31:12
的内存中查看该情况,我认为这是正常行为;它会发生在您添加的任何其他库上。除了堆之外,还有代码要加载。只是B/C没有实例,并不意味着整个代码都在吹。如果内存对于虚拟机的每个alloc/dealloc都保持上升,则会发生泄漏。 – bestsss 2011-03-16 12:45:58