Data structure and management techniques for local user-level thread data

An article of manufacture comprising a tangible machine-readable storage medium having a plurality of machine-readable instructions, wherein, when the instructions are executed by a processor of a data processing system, the instructions enable the data processing system to perform operations comprising:

• after an operating system (“OS”) has generated a thread to execute under management of the OS, generating, by an application-managed thread unit, a user-level thread (“shred”) to execute under management of the application-managed thread unit wherein:
• the operation of generating the thread comprises providing a thread environment block (TEB) for the thread,
• the application-managed thread unit comprises a user-level application, and
• the operation of generating the shred comprises providing a shred environment block (SEB) for the shred, wherein the SEB is organized according to an organizational structure of the TEB;
• maintaining state data for the shred across a context switch from the application-managed thread unit to a thread unit that is managed by the OS;
• using the TEB to register an exception handler for the thread;
• using the SEB to register an exception handler for the shred;
• and
• in response to an exception thrown to the OS from the shred, automatically transferring control from the OS to the exception handler for the shred.

A data processing system comprising:

• a processor;
• a storage medium responsive to the processor;
• and
• instructions in the storage medium which, when executed by the processor, enable the data processing system to perform operations comprising:
• after an operating system (“OS”) has generated a thread to execute under management of the OS, generating, by an application-managed thread unit, a user-level thread (“shred”) to execute under management of the application-managed thread unit wherein:
• the operation of generating the thread comprises providing a thread environment block (TEB) for the thread,
• the application-managed thread unit comprises a user-level application,
• the operation of generating the shred comprises providing a shred environment block (SEB) for the shred, and
• the SEB is organized according to an organizational structure of the TEB;
• maintaining state data for the shred across a context switch from the application-managed thread unit to a thread unit that is managed by the OS;
• using the TEB to register an exception handler for the thread;
• using the SEB to register an exception handler for the shred;
• and
• in response to an exception thrown to the OS from the shred, automatically transferring control from the OS to the exception handler for the shred.