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I know this is a weird question to ask in Java, but is there a way to let Java dynamic memory allocation be aligned with some alignment constraints? For example, is it possible to dynamically allocate objects that are aligned with the page size?
The reason I want to do this is because I'm going to access the Java object from native code through JNI interface, and the native code library requires the object to be aligned.
Thanks.
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You might assume that reducing the size of a struct or class saves the same amount of memory. However due to memory alignment in memory allocators it can make no difference, or perhaps more difference than you might expect. This is because the the amount of memory reserved is usually a multiple of the memory alignment.
The Java Virtual Machine divides the memory into Stack and Heap Memory. For Java Virtual Machine, executing an application in its maximum potential can happen from stack and heap memory. Every time a new variable or object is declared, the memory allocates memory dedicated to such operations.
For instance, in a 32-bit architecture, the data may be aligned if the data is stored in four consecutive bytes and the first byte lies on a 4-byte boundary. Data alignment is the aligning of elements according to their natural alignment.
What is alignment? Alignment refers to the arrangement of data in memory, and specifically deals with the issue of accessing data as proper units of information from main memory. First we must conceptualize main memory as a contiguous block of consecutive memory locations. Each location contains a fixed number of bits.
No it is not possible. Keep in mind that objects on the heap in Java can move around during garbage collection. You have some options:
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