OpenGL Programming Guide: The Official Guide to Learning OpenGL, Version 4.3, Eighth Edition

Atomic Operations and Synchronization

Now that you have seen how shaders may read and write arbitrary locations in textures (through built-in functions) and buffers (through direct memory access), it is important to understand how these accesses can be controlled such that simultaneous operations to the same memory location do not destroy each other’s effects. In this section, you will be introduced to a number of atomic operations that may be performed safely by many shader invocations simultaneously on the same memory location. Also, we will cover functionality that allows your application to provide ordering information to OpenGL. This to ensure that reads observe the results of any previous writes and that writes occur in desired order, ...