Information processing apparatus and context switching method

An information processing apparatus which, when executing a plurality of predetermined units of processing, executes the predetermined units of processing in parallel by switching between contexts associated with the respective predetermined units, the processing apparatus comprising:

• a plurality of register banks that respectively store the contexts associated with the respective predetermined units of processing;
• a processor that, in the context switching, grants a right of execution to a context stored in one of the plurality of register banks and executes a unit of processing associated with the context having the right of execution granted;
• a save controller that performs saving in which to read out a context having handed over the right of execution from one of the other register banks than the one register bank storing the context having the right of execution granted and write into a memory that is distinct from the plurality of register banks, and that is accessible by the processor;
• and
• a restore controller that performs restoring in which to read out a context to be granted the right of execution the next time from the memory and write into the one of the other register banks,
• the save controller and the restore controller performing the saving and/or the restoring in parallel with the processor executing the unit of processing associated with the context having the right of execution granted.

A method for an information processing apparatus of switching between contexts associated with a respective plurality of predetermined units of processing so as to execute the predetermined units of processing in parallel, the method comprising:

• storing the contexts associated with the respective plurality of predetermined units of processing in a plurality of register banks respectively;
• in the context switching, granting a right of execution to a context stored in one of the plurality of register banks and executing, by a processor, a unit of processing associated with the context having the right of execution granted;
• and
• by a save/restore controller, in parallel with executing by the processor the unit of processing associated with the context having the right of execution granted, performing saving and restoring wherein the saving executes to read out a context having handed over the right of execution from one of the other register banks than the one register bank storing the context having the right of execution granted and write into a memory that is distinct from the plurality of register banks, and that is accessible by the processor, and the restoring executes to read out a context to be granted the right of execution the next time from the memory and write into the one of the other register banks.