Atomic Memory Update Unit & Methods

An apparatus for concurrent computation, comprising:

• an update unit;
• a memory;
• and
• a plurality of computation cores coupled to the update unit through an interconnect, each computation core capable of
• executing a sequence of instructions, and which are operable to output update requests to the update unit under control of the sequence of instructions,
• the update requests outputted to change data stored in portions of the memory to which the sequence of instructions has write permissions, each update request including a first value to be used to update a specified location in the memory and a condition to be satisfied in order for the first value to be used to update the specified location in the memory, the condition comprising a reference to a second location in the memory, and a criteria to be satisfied by a value in the second location in the memory,
• wherein the update unit is configured to initiate and complete each update request atomically, comprising that the value in the second location in the memory is not changed between when the update unit accesses the value in the second location in the memory and when the update unit updates the first value to the specified location in the memory.