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ReferenceTable overflow 問題彙總

JNI層coding經常會遇到ReferenceTable overflow問題,特別是當jni函式被反覆呼叫上千上萬次的時候,現彙總如下,未完待續,並歡迎補充,(*^__^*) 嘻嘻……

總體原則:釋放所有對object的引用

1.FindClass 

例如,

jclass ref= (env)->FindClass("java/lang/String");

env->DeleteLocalRef(ref); 

2.NewString/ NewStringUTF/NewObject/NewByteArray

例如,

jstring     (*NewString)(JNIEnv*, const
jchar*, jsize); const jchar* (*GetStringChars)(JNIEnv*, jstring, jboolean*); void (*ReleaseStringChars)(JNIEnv*, jstring, const jchar*);
jstring     (*NewStringUTF)(JNIEnv*, const char*);    

const char* (*GetStringUTFChars)(JNIEnv*, jstring, jboolean*);     

void        (*ReleaseStringUTFChars)(JNIEnv*, jstring, const
char*);
env->DeleteLocalRef(ref);

3.GetObjectField/GetObjectClass/GetObjectArrayElement

jclass ref = env->GetObjectClass(robj);

env->DeleteLocalRef(ref); 

4.GetByteArrayElements

jbyte* array= (*env)->GetByteArrayElements(env,jarray,&isCopy);

(*env)->ReleaseByteArrayElements(env,jarray,array,0
);

4.const char* input =(*env)->GetStringUTFChars(env,jinput, &isCopy);

(*env)->ReleaseStringUTFChars(env,jinput,input);

5.NewGlobalRef/DeleteGlobalRef

 jobject     (*NewGlobalRef)(JNIEnv*, jobject);     

void        (*DeleteGlobalRef)(JNIEnv*, jobject);

例如,

jobject ref= env->NewGlobalRef(customObj);

env->DeleteGlobalRef(customObj);