146. Shaping C-like structs into memory segments Let’s consider the C-like struct from the following figure: Figure 7.12 – A C-like structure So, in Figure 7.12, we have a C-like ... Read MoreRead More
144. Understanding addresses (pointers) A memory segment has a memory address (pointer) expressed as a long number. An off-heap memory segment has a physical address that points out the memory ... Read MoreRead More
Hooking size, alignment, stride, and padding Before continuing working with padding, we need to cover some notions which are closely related to each other and work hand in hand with ... Read MoreRead More
155. Introducing memory segment view VarHandle Let’s consider the following simple memory segment for storing an int (arena is an instance of Arena): MemorySegment segment = arena.allocate(ValueLayout.JAVA_INT); We know that ... Read MoreRead More
Adding explicit extra space (explicit padding) to validate alignment Let’s consider the following C-like struct (let’s denote this as Case 1): StructLayout product = MemoryLayout.structLayout( ValueLayout.JAVA_INT.withName(“sku”), ValueLayout.JAVA_CHAR.withName(“energy”), ValueLayout.JAVA_BYTE.withName(“weight”)); The product ... Read MoreRead More
157. Tackling mapped memory segments We know that a computer has limited physical memory referred to as RAM memory. Common sense though tells us that we cannot allocate a memory ... Read MoreRead More
158. Introducing Foreign Linker API The main goal of Foreign Linker API is to provide a robust and easy-to-use API (no need to write C/C++ code) for sustaining interoperability between ... Read MoreRead More
159. Calling the sumTwoInt() foreign function Do you remember the sumTwoInt() function? We have defined this C function in a native shared library named math.dll (check Problems 137, 138, and ... Read MoreRead More
150. Tackling the slicing allocator Let’s consider the following three Java regular int arrays: int[] arr1 = new int[]{1, 2, 3, 4, 5, 6};int[] arr2 = new int[]{7, 8, 9};int[] ... Read MoreRead More
161. Calling the strcat() foreign function The strcat() foreign function is part of the C standard library and it has the following signature (https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/strcat-wcscat-mbscat): char *strcat(char *strDestination, const char *strSource); ... Read MoreRead More