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
145. Introducing sequence layout In Problem X, we already covered the ValueLayout for basic data types. Next, let’s talk about the sequence layout (java.lang.foreign.SequenceLayout).But, before introducing the sequence layout, let’s ... Read MoreRead More
151. Introducing slice handle Let’s suppose that we have the following nested model (10 sequences of 5 double values each): SequenceLayout innerSeq = MemoryLayout.sequenceLayout(5, ValueLayout.JAVA_DOUBLE);SequenceLayout outerSeq = MemoryLayout.sequenceLayout(10, innerSeq); Next, ... 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
Hooking stride The minimum byte-distance between two member layouts is called stride. The stride can be greater than or equal to the size. When we don’t face any alignment issues ... Read MoreRead More
149. Copying and slicing memory segments Let’s consider the following memory segment (arena is an instance of Arena): MemorySegment srcSegment = arena.allocateArray( ValueLayout.JAVA_INT, 1, 2, 3, 4, -1, -1, -1, ... 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
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
165. Creating an electrical panel (hierarchy of classes) Let’s assume that we want to model in code lines an electrical panel. Of course, we are not electricians, so in a ... Read MoreRead More
Declaring classes/interfaces as non-public Going further, we can declare interfaces/classes as non-public (by skipping the public keyword from the class/interface definition it becomes non-public and is set by default in ... Read MoreRead More