C++ C++;jobjectarray返回方法的NDK库内存管理
//******新问题***** 当结构被传递到线程时,下面有一个内存泄漏。无法理解原因,因为线程内的代码如果在主线程中直接调用,不会泄漏内存C++ C++;jobjectarray返回方法的NDK库内存管理,c++,memory-management,memory-leaks,android-ndk,java-native-interface,C++,Memory Management,Memory Leaks,Android Ndk,Java Native Interface,//******新问题***** 当结构被传递到线程时,下面有一个内存泄漏。无法理解原因,因为线程内的代码如果在主线程中直接调用,不会泄漏内存 class PeopleCounting{ // Class variables Ptr<cv::BackgroundSubtractorMOG2> pMOG2 = cv::createBackgroundSubtractorMOG2(500, 16); Mat maskBackgroundSubtracted = Mat(re
class PeopleCounting{
// Class variables
Ptr<cv::BackgroundSubtractorMOG2> pMOG2 = cv::createBackgroundSubtractorMOG2(500, 16);
Mat maskBackgroundSubtracted = Mat(resizeDimension.height, resizeDimension.width, CV_8UC1);
// Thread creation code below, code called from main.
//Create thread
pthread_t threads;
pthread_attr_t attr;
void *status;
// Initialize and set thread joinable
pthread_attr_init(&attr);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
// Creating thread data and initializing it
BackgroundSubstractionThreadData threadData = {CamImage, maskBackgroundSubtracted, pMOG2};
int rc;
rc = pthread_create(&threads, NULL, performBackgroundSubstraction, (void *)&threadData);
if (rc)
{
__android_log_print(ANDROID_LOG_ERROR, APPNAME, "Error: peopleCountingMainMono unable to create thread - %d",rc);
}
// free attribute and wait for the other threads
pthread_attr_destroy(&attr);
// ************** Do something else in main thread **************
// Join thread i.e. wait till completion of thread
rc = pthread_join(threads, &status);
if (rc)
{
__android_log_print(ANDROID_LOG_ERROR, APPNAME, "Error: peopleCountingMainMono unable to join - %d",rc);
}
// Using class variable **maskBackgroundSubtracted** and **pMOG2** for later use. **CamImage** (opencv mat) usually gets released automatically in general due to smart pointer implementation, not sure if it is the source of leak
}
// Note: Outside class
void *performBackgroundSubstraction(void *threadarg)
{
struct BackgroundSubstractionThreadData *my_data;
my_data = (struct BackgroundSubstractionThreadData *)threadarg;
Mat fgMask;
my_data->pMOG2F->apply(my_data->leftCamImage, fgMask, 0.002);
morphologyEx(fgMask, fgMask, MORPH_OPEN, getStructuringElement(MORPH_RECT, Size(3, 3)),Point(-1,-1),1);
morphologyEx(fgMask, fgMask, MORPH_CLOSE, getStructuringElement(MORPH_RECT, Size(11, 11)),Point(-1,-1),1);
threshold(fgMask, my_data->dst, 128, 255, THRESH_BINARY);
pthread_exit(NULL);
};
class人员计数{
//类变量
Ptr pMOG2=cv::createBackgroundSubtractorMOG2(500,16);
Mat MaskBackground减去=Mat(resizeDimension.height,resizeDimension.width,CV_8UC1);
//下面是线程创建代码,代码从main调用。
//创建线程
pthread_t线程;
pthread_attr_t attr;
无效*状态;
//初始化并设置线程可连接
pthread_attr_init(&attr);
pthread_attr_setdetachstate(&attr,pthread_CREATE_JOINABLE);
//创建线程数据并初始化它
BackgroundSubstrationReadData threadData={CamImage,maskBackgroundSubtracted,pMOG2};
int rc;
rc=pthread_创建(&threads,NULL,performbackgroundsubstration,(void*)&threadData);
if(rc)
{
__android_日志_打印(android_日志_错误,APPNAME,“错误:peopleCountingMainMono无法创建线程-%d”,rc);
}
//释放属性并等待其他线程
pthread_attr_destroy(&attr);
//*************在主线程中执行其他操作**************
//连接线程,即等待线程完成
rc=pthread_join(线程和状态);
if(rc)
{
__android_日志_打印(android_日志_错误,APPNAME,“错误:peopleCountingMainMono无法加入-%d”,rc);
}
//使用类变量**maskBackgroundSubtracted**和**pMOG2**供以后使用。**CamImage**(opencv mat)通常会由于智能指针实现而自动释放,不确定它是否是泄漏源
}
//注:课外
void*performbackgroundsubstration(void*threadarg)
{
struct BackgroundSubstrationReadData*my_数据;
my_data=(结构背景SubstrationReadData*)线程arg;
Mat-FG面罩;
my_data->pMOG2F->apply(my_data->leftCamImage,fgMask,0.002);
morphologyEx(fgMask,fgMask,MORPH_OPEN,getStructuringElement(MORPH_RECT,Size(3,3)),点(-1,-1),1);
morphologyEx(fgMask,fgMask,MORPH_CLOSE,getStructuringElement(MORPH_RECT,Size(11,11)),点(-1,-1),1);
阈值(fgMask,我的数据->dst,128,255,阈值二进制);
pthread_exit(NULL);
};
//******问题结束****
我有一个NDK库,它有一个JNI函数,返回jobjectArray
在下面的代码中,我使用的是一个静态全局jPeopleCountArray,它通过一个循环填充jobject并返回给Java调用方法。这个JNI函数通过Java代码中的循环一次又一次地调用,但一次只调用一个实例,因此允许全局返回对象。在库使用结束时,我通过循环jobject数组并删除jobject的本地ref,最后删除jPeopleCountArray的全局ref来执行内存清理。内存清理只在最后执行,因为迭代使用(但只有单个实例)允许重用返回对象
问题是何时通过NewObjectArray分配全局jobjectArray。由于上一次调用而保留在jobjectArray中的所有jobjects是否从内存中释放
class PeopleCounting{
public:
static inline jobjectArray jPeopleCountArray = NULL;
static inline JNI_PEOPLECOUNT * jniPeopleCount = NULL;
// .... Rest of Code ...
}
// JNI function
PeopleCounting *obj = (PeopleCounting *) hEngineHandle;
obj->LoadJniPeopleCount(env);
Mat *pMatCGray = (Mat *) addrCamGray;
vector<PeopleSegment> peopleCountingFromContourRes = obj->peopleCountingMainMono(
*pMatCGray);
// ******** IMPORTANT BELOW *********
obj->jPeopleCountArray = env->NewObjectArray(peopleCountingFromContourRes.size(),
obj->jniPeopleCount->cls, NULL);
for (size_t i = 0; i < peopleCountingFromContourRes.size(); i++) {
jobject jPeopleCount = env->NewObject(obj->jniPeopleCount->cls,
obj->jniPeopleCount->constructortorID);
obj->FillPeopleCountValuesToJni(env, jPeopleCount, peopleCountingFromContourRes[i]);
env->SetObjectArrayElement(obj->jPeopleCountArray, i, jPeopleCount);
}
return obj->jPeopleCountArray;
// Memory cleanup at the end of library use.
PeopleCounting *obj = (PeopleCounting *) hEngineHandle;
if (obj->jPeopleCountArray != NULL){
__android_log_print(ANDROID_LOG_VERBOSE, APPNAME,
"Freeing memory of jobject array");
//https://www.ibm.com/developerworks/library/j-jni/index.html
int size = env->GetArrayLength(obj->jPeopleCountArray);
for(int i = 0; i < size; i++)
{
jobject row = env->GetObjectArrayElement(obj->jPeopleCountArray, i);
if(env->ExceptionOccurred()) {
break;
}
env->DeleteLocalRef(row);
}
env->DeleteGlobalRef(obj->jPeopleCountArray);
}
delete (PeopleCounting *)(hEngineHandle);
class人员计数{
公众:
静态内联jobjectArray JPeopCountArray=NULL;
静态内联JNI_PEOPLECOUNT*jniPeopleCount=NULL;
//…代码的其余部分。。。
}
//JNI函数
PeopleCounting*obj=(PeopleCounting*)hEngineHandle;
obj->LoadJniPeopleCount(环境);
Mat*pMatCGray=(Mat*)addrCamGray;
向量peopleCountingFromContourRes=obj->peopleCountingMainMono(
*pMatCGray);
//*******重要信息如下**********
obj->jPeopleCountArray=env->NewObjectArray(peopleCountingFromContourRes.size(),
obj->jniPeopleCount->cls,空);
对于(size_t i=0;iNewObject(obj->jniPeopleCount->cls,
obj->jniPeopleCount->constructortorID);
obj->将PeopleCountValues填入JNI(env,jpePeopleCount,peopleCountingFromContourRes[i]);
env->SetObjectArrayElement(obj->jpeopCountArray,i,jpeopCount);
}
返回obj->jpeopecountarray;
//库使用结束时的内存清理。
PeopleCounting*obj=(PeopleCounting*)hEngineHandle;
if(obj->jPeopleCountArray!=NULL){
__android_日志_打印(android_日志_详细,APPNAME,
“释放jobject数组的内存”);
//https://www.ibm.com/developerworks/library/j-jni/index.html
int size=env->GetArrayLength(obj->jpeopCountArray);
对于(int i=0;iGetObjectArrayElement(obj->jPeopleCountArray,i);
如果(环境->例外发生()){
打破
}
env->DeleteLocalRef(行);
}
env->DeleteGlobalRef(obj->jPeopleCountArray);
}
删除(PeopleCounting*)(hEngineHandle);
您的代码可能会耗尽非常有限的本地引用表(其大小取决于实现,但可能低至256)
您可以在创建的循环中删除对jpeopecount的本地引用,就在SetObjectArrayElement(…,jpeopeCount)
之后。另一方面,所有这些本地引用将在JNI函数返回obj->jPeopleCountArray后自动释放
类似地,删除对obj->jPeopleCountArray元素的本地引用的循环是冗余的。在使用GetObjectArrayElement()创建这些引用之前,不存在要处理的本地引用
这说明了本地引用和全局引用之间的行为差异。您不需要创建对的全局引用