Data processing systems

A method of operating a data processing system that comprises:

• one or more processors that each execute one or more operating systems, each operating system including one or more applications;
• an accelerator that provides a shared resource for a plurality of the applications;
• one or more sets of physical register input/output interfaces for the submission of tasks to the accelerator;
• and
• an interface mapping unit that exposes a plurality of virtual accelerator input/output interfaces to the applications, the virtual input/output interfaces being mapped to respective applications, and configured to dynamically map the virtual input/output interfaces to the physical register input/output interfaces for the accelerator;
• the method comprising:
• an application when it wishes the accelerator to perform a task, accessing a virtual input/output interface to which the application has been mapped:
• the interface mapping unit in response to the application accessing the virtual input/output interface, determining if a physical register input/output interface for the submission of a task to the accelerator is available, and if a physical register input/output interface is available, mapping the virtual input/output interface to the physical register input/output interface to thereby allow the application to dispatch its task to the accelerator.

A data processing system comprising:

• one or more processors that each execute one or more operating systems, each operating system including one or more applications, each application when executing, executing one or more application threads;
• and
• an event timeout register to which application threads can write an event timeout period value when they are waiting for an event to occur before they can continue their operation, the event timeout period value indicating a time period after which the application thread will request to be de-scheduled if the event that the application thread is waiting for has not happened yet;
• wherein:
• the event timeout register is shared between plural applications, such that threads from plural applications each write their event timeout values to the same, shared event timeout register.

A computer readable storage medium storing computer software code which when executing on a processor performs a method of operating a data processing system that comprises:

• one or more processors that each execute one or more operating systems, each operating system including one or more applications;
• an accelerator that provides a shared resource for a plurality of the applications;
• one or more sets of physical register input/output interfaces for the submission of tasks to the accelerator;
• and
• an interface mapping unit that exposes a plurality of virtual accelerator input/output interfaces to the applications, the virtual input/output interfaces being mapped to respective applications, and configured to dynamically map the virtual input/output interfaces to the physical register input/output interfaces for the accelerator;
• the method comprising:
• an application when it wishes the accelerator to perform a task, accessing a virtual input/output interface to which the application has been mapped:
• the interface mapping unit in response to the application accessing the virtual input/output interface, determining if a physical register input/output interface for the submission of a task to the accelerator is available, and if a physical register input/output interface is available, mapping the virtual input/output interface to the physical register input/output interface to thereby allow the application to dispatch its task to the accelerator.