Are Array read/writes atomic in nature?
int[] arr = new int[10];
int[8] = 4; // This is what I'm interested in
In the above code, the second line should generate two Machine Instructions like
reg1 = reg_containing_arr_address + 32
Memcopy reg1 4
Some posts on stack overflow saw that these are atomic. Can anyone explain me how they are?
The components (elements) of arrays are variables.
The result of an array access expression is a variable of type
T, namely the variable within the array selected by the value of the index expression.
According to this answer, writes and reads of int variables are atomic. Since your array is of type int, reads and writes to it are atomic.
int variables are atomic, and read/writes to that variable are atomic (i.e. the second instruction in my generated machine code). But there is one more instruction of generating the variable's address in setting the array's value. I really don't think this explains how and what atomic instruction is generated when setting the array value.
reg1 is effectively a constant/immutable. It will never change. So it's basically just memcopy <addr> 4.reg1 can be different between the first and second instructions.