With a Little Bit of Help From the JVM… WARNING: This solution is now obsolete in newer Java SE versions. See other ad-hoc solutions further below. If you use an HotSpot JVM, since Java 6 update 21, you can use this command-line option: -XX:+UseCompressedStrings The JVM Options page reads: Use a byte[] for Strings which … Read more
Unfortunately this is not possible, but there are a number of ways of approximating the answer: for very simple objects (e.g. ints, strings, floats, doubles) which are represented more or less as simple C-language types you can simply calculate the number of bytes as with John Mulder’s solution. For more complex objects a good approximation … Read more
The configuration for the memory_limit of PHP running as an Apache module to server webpages has to take into consideration how many Apache process you can have at the same time on the machine — see the MaxClients configuration option for Apache. If MaxClients is 100 and you have 2,000 MB of RAM, a very … Read more
I think you can find a lot of documentation about the kmalloc + mmap part. However, I am not sure that you can kmalloc so much memory in a contiguous way, and have it always at the same place. Sure, if everything is always the same, then you might get a constant address. However, each … Read more
See this topic: are-javascript-arrays-sparse In most implementations of Javascript (probably all modern ones) arrays are sparse. That means no, it’s not going to allocate memory up to the maximum index. If it’s anything like a Lua implementation there is actually an internal array and dictionary. Densely populated parts from the starting index will be stored … Read more
From IEEE 1003.1: The mmap() function shall establish a mapping between a process’ address space and a file, shared memory object, or [TYM] typed memory object. It needs all the virtual address space because that’s exactly what mmap() does. The fact that it isn’t really running out of memory doesn’t matter – you can’t map … Read more
In the etc directory under your Netbeans-Home, edit the file netbeans.conf file. -Xms and -Xmx should be increased to the values that allow your program to compile. Here are the instructions in netbeans.conf: # Note that default -Xmx and -XX:MaxPermSize are selected for you automatically. # You can find these values in var/log/messages.log file in … Read more
Like this: void * p = (void *)0x28ff44; Or if you want it as a char *: char * p = (char *)0x28ff44; …etc. If you’re pointing to something you really, really aren’t meant to change, add a const: const void * p = (const void *)0x28ff44; const char * p = (const char *)0x28ff44; … Read more
I did a lot of research, and couldn’t find a solution to fix the problem per se. But there is a decent work around that prevents the memory blowout for a small cost, worth especially on server side long running code. The solution essentially was to restart individual worker processes after a fixed number of … Read more
A quick definition of the “permanent generation”: “The permanent generation is used to hold reflective data of the VM itself such as class objects and method objects. These reflective objects are allocated directly into the permanent generation, and it is sized independently from the other generations.” [ref] In other words, this is where class definitions … Read more