heap-memory

I'm developing form submission service with Jersey 2.0. The form includes several text fields and one file field. I need to extract file , file name , file media type and file content type and save them in object store. @Path("upload") @Consumes({MediaType.MULTIPART_FORM_DATA}) @Produces({MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON}) public class UploadService { @POST public BlobDo uploadFile(FormDataMultiPart uploadedBody) { String accountSid = uploadedBody.getField("account-sid").getValue(); String apiToken = uploadedBody.getField("api-token").getValue(); String checksum =

I'm aware you can use MemoryLayout<T>.size to get the size of a type T . For example: MemoryLayout<Int32>.size // 4 However, for class instances (objects), MemoryLayout<T>.size returns the size of the reference to the object (8 bytes on 64 bit machines), not the size of the actual objects on the heap. class ClassA { // Objects should be at least 8 bytes let x: Int64 = 0 } class ClassB {// Objects should be at least 16 bytes let x: Int64 = 0 let y: Int64 = 0 } MemoryLayout<ClassA>.size // 8 MemoryLayout<ClassB>.size // 8, as well :( How can I get the size of the objects themselves? For those

The following code is causing a OutOfMemmoryError: heap space for some 3 million rows. Memory allocated to JVM is 4 GB, using 64 bit installation. while (rs.next()) { ArrayList<String> arrayList = new ArrayList<String>(); for (int i = 1; i <= columnCount; i++) { arrayList.add(rs.getString(i)); } objOS.writeObject(arrayList); } The memory referenced by the ArrayList is eligible for garbage collection in each iteration of the while loop, and internally JVM calls garbage collection ( System.gc() ) before throwing an OutOfMemory Error because of heap space. So why is the exception occurring? Is

When you add -Xmx????m to the command line, the JVM gives you a heap which is close to this value but can be out by up to 14%. The JVM can give you a figure much closer to what you want, but only through trial and error. System.out.println(Runtime.getRuntime().maxMemory()); prints -Xmx1000m -> 932184064 -Xmx1024m -Xmx1g -> 954728448 -Xmx1072m -> 999292928 -Xmx1073m -> 1001390080 I am running HotSpot Java 8 update 5. Clearly, the heap can be something just above 1000000000 but why is this -Xmx1073m instead of say -Xmx1000m ? BTW 1g == 1024m which suggests that 1g should be 1024^3 which is 7%

Is an instance variable of an object in Java stored on the stack or method area of the JVM? Also, do we have different instance variable for multiple threads? If it is stored in method area how is instance variable different from static variable storage? Matej Špilár Stack and heap are the memories allocated by the OS to the JVM that runs in the system. Stack is a memory place where the methods and the local variables are stored. (variable references either primitive or object references are also stored in the stack). Heap is a memory place where the objects and its instance variable are

How will I free the nodes allocated in another function? struct node { int data; struct node* next; }; struct node* buildList() { struct node* head = NULL; struct node* second = NULL; struct node* third = NULL; head = malloc(sizeof(struct node)); second = malloc(sizeof(struct node)); third = malloc(sizeof(struct node)); head->data = 1; head->next = second; second->data = 2; second->next = third; third->data = 3; third->next = NULL; return head; } I call the buildList function in the main() int main() { struct node* h = buildList(); printf("The second element is %d\n", h->next->data); return 0;

I am developing an music player app. All works fine except the app dies suddenly. Sometimes this happens when the app starts, and sometimes after running for long time. Sometimes all goes well without app getting died. I observed the log to get to know what is the causing the app to die and found this: 11-02 16:39:39.293: A/libc(3556): @@@ ABORTING: INVALID HEAP ADDRESS IN dlfree 11-02 16:39:39.293: A/libc(3556): Fatal signal 11 (SIGSEGV) at 0xdeadbaad (code=1) The full log is given below, what I found in logcat when the app died: 11-02 16:39:39.293: A/libc(3556): @@@ ABORTING: INVALID HEAP

I have set the heap size of tomcat 7 by adding the following line in catalina.sh export CATALINA_OPTS="-Xms512m -Xmx1024m" then stopped and started the tomcat. but when tried to get the heap size using the command jmap -heap , i can notice that the memory doesn't change: Heap Configuration: MinHeapFreeRatio = 40 MaxHeapFreeRatio = 70 MaxHeapSize = 526385152 (502.0MB) NewSize = 1048576 (1.0MB) MaxNewSize = 4294901760 (4095.9375MB) OldSize = 4194304 (4.0MB) NewRatio = 2 SurvivorRatio = 8 PermSize = 16777216 (16.0MB) MaxPermSize = 67108864 (64.0MB) Heap Usage: PS Young Generation Eden Space: