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我已經用JNI寫了一個Hello,world程序。 Java使用字符串調用c程序,c程序打印該字符串。這裏是java程序JNI內存泄漏
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
public class JNISample {
public native void leakMem(String str);
static {
System.loadLibrary("sample");
}
public static void main(String args[]) throws IOException {
JNISample sample = new JNISample();
sample.leakMem("Hello world!");
}
}
相應的C程序
#include <stdlib.h>
#include <jni.h>
#include "JNISample.h"
JNIEXPORT void JNICALL Java_JNISample_leakMem(JNIEnv *env, jobject jobj, jstring givenStr) {
const char *javaStr = env->GetStringUTFChars (givenStr, 0);
printf("Received String: %s\n", javaStr);
env->ReleaseStringUTFChars (givenStr, javaStr);
}
當我執行此程序的valgrind,用下面的命令
valgrind --trace-children=yes --show-reachable=yes --leak-check=full java -Djava.library.path=. JNISample 10 2> log
我已經在日誌中觀察到的肯定失去了字節,這裏是valgrind的記憶總結
LEAK SUMMARY:
==5385== definitely lost: 5,246 bytes in 36 blocks
==5385== indirectly lost: 5,072 bytes in 23 blocks
==5385== possibly lost: 154,317 bytes in 131 blocks
==5385== still reachable: 6,164,933 bytes in 831 blocks
==5385== suppressed: 0 bytes in 0 blocks
爲什麼在沒有任何內存分配的情況下,這樣的小程序肯定會丟失字節? JNI用法或JNI泄漏內存有問題嗎?我在Ubuntu 11.10 64位機器上使用了JDK6。