heap-memory Archives

[Solved] best Java code to control big heap memeory used (like 1G) [closed]

February 1, 2023 by Kirat

Quickly allocate 1 GB of memory: byte[][] memoryWaster = new byte[1024][1_048_576]; See last test run below for successful allocation of 16 GB of memory. Test program Runtime runtime = Runtime.getRuntime(); System.out.printf(“total: %11d max: %d%n”, runtime.totalMemory(), runtime.maxMemory()); System.out.printf(“used: %11d%n”, runtime.totalMemory() – runtime.freeMemory()); System.gc(); System.out.printf(“gc: %11d%n”, runtime.totalMemory() – runtime.freeMemory()); byte[][] memoryWaster = new byte[1024][1_048_576]; memoryWaster[0][0] = 2; … Read more

[Solved] How to find the PID of a C code during compilation time? [closed]

January 30, 2023 by Kirat

Why not the getpid() method defined in unistd.h? #include <unistd.h> int main(){ int pid = getpid(); int parentsPID = getppid(); return 0; } 1 solved How to find the PID of a C code during compilation time? [closed]

[Solved] How to specify more than 64 mb memory for an application?

January 21, 2023 by Kirat

largeHeap = “true” does not increase the heap size to or by 64 MB: Most apps should not need this and should instead focus on reducing their overall memory usage for improved performance. Enabling this also does not guarantee a fixed increase in available memory, because some devices are constrained by their total available memory. … Read more

[Solved] Is it possible to force c++ class instantiation on the heap?

January 1, 2023 by Kirat

Just make ctor private/protected and provide a static method(s) to create an instance: class HeapOnly { HeapOnly(); HeapOnly( int i ); public: static HeapOnly *create() { return new HeapOnly; } static HeapOnly *create( int i ) { return new HeapOnly( i ); } }; You may consider to return a std::unique_ptr in general case, but … Read more

[Solved] How new Java.util.Date() works while other classes return just reference?

December 10, 2022 by Kirat

java.util.Date, like a lot of other classes in the JDK, overrides toString(), which allows you to control the string representation of your objects. You can, of course, do this for your own classes too. 1 solved How new Java.util.Date() works while other classes return just reference?

[Solved] About struct and pointer in C++ [duplicate]

October 26, 2022 by Kirat

Okay to explain it in a more complete way. The most other guys had already wrote that you have to use ‘->’ when ever you have a pointer. But you could also do this with ‘.’, to do this you must respect the priority of the operators. We need the ‘*’ to get the content … Read more

[Solved] How does string works in c#? [closed]

October 23, 2022 by Kirat

review String Interning or .Net String Intern table or CLR Intern Pool. Basically, the Common Language Runtime (CLR) maintains a table of [unique] string values, and whenever you manipulate a string in your code, the CLR examines this intern table to see if the new value you are trying to create is already in there … Read more

[Solved] Why the heap is changing in java

October 8, 2022 by Kirat

I understand the question to be why the heap size drops from 1500m (1472000K) to something less (1258752K) even though initial size is set to 1500m. As it turns out, this is well known behavior in long running JVMs, and is related to the PS MarkSweep / Full GC mechanism – See this article for … Read more

[Solved] How to debug why my C code causes a segmentation fault? [closed]

September 29, 2022 by Kirat

1) You check feof() first, then do a fscanf(), and then don’t check its return value (or re-check feof() at the very least. (You might have been right at the end of the file prior to the fscanf() call, or the configuration file might be malformed, but you wouldn’t detect this with your code.) 2) … Read more

[Solved] Variable arguments in C functions

September 28, 2022 by Kirat

c itself doesn’t specify things like “heap” or “stack”, so programming standard and portable c, you should better think in categories of the c standard: static, automatic and dynamic storage. Nevertheless, in a typical implementation, “automatic storage” translates to “the stack is used for it”. This is the case for function arguments and variadic functions … Read more

[Solved] java.lang.OutOfMemoryError: Java heap space [duplicate]

August 23, 2022 by Kirat

Yes it is. The heap is being over-allocated. The only way to solve other then increasing the heap space is to see what is using all the heap space and then trying to make sure objects can be collected that stay around longer then they are needed. If it is a file or something that … Read more

(Solved) What and where are the stack and heap?

August 20, 2022 by Kirat

The stack is the memory set aside as scratch space for a thread of execution. When a function is called, a block is reserved on the top of the stack for local variables and some bookkeeping data. When that function returns, the block becomes unused and can be used the next time a function is … Read more