US 8,276,147 B2Granted

Low synchronization means of scheduler finalization

AssigneeMicrosoft Corporation

InventorsWilliam Robert Messmer, Paul F. Ringseth, Genevieve Fernandes

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Abstract

Shutting down a computer work scheduler. The work scheduler includes a number of virtual processors, each of which is either active or inactive. An active processor executes work, searches for work, or is idle. An inactive has no context running atop it. The method includes determining that all processors controlled by the scheduler are idle. As a result of determining that all controlled by the scheduler are idle, the method proceeds to a first phase of a shutdown operation, which when successful, includes: performing a sweep of all collections searching for any work in the scheduler and determining that no work is found in the scheduler. As a result of determining that no work is found in the scheduler, the method proceeds to a second phase of a shutdown operation, which when successful includes messaging all contexts in the scheduler and telling them to exit.

Claims20

Dependent claims

In a computing system, a method of shutting down a computer work scheduler, the work scheduler comprising a number of virtual processors, each representing the ability to execute a single thread, wherein each virtual processor is either active in that it has a context running atop it performing at least one of executing work, searching for work, or idle after not finding work after a predetermined amount of searching for work, or inactive in that it has no context running atop it, the method comprising:

determining that all processors in a given set of active virtual processors controlled by the scheduler are idle;
as a result of determining that all processors in the given set of active virtual processors controlled by the scheduler are idle, proceeding to a first phase of a shutdown operation, which when successful, includes:
performing a sweep of all collections searching for any work in the scheduler;
and
determining that no work is found in the scheduler;
and
as a result of determining that no work is found in the scheduler proceeding to a second phase of the shutdown operation, which when successful includes messaging all contexts in the scheduler and telling them to exit the scheduler.

4 more elements

A computing system including functionality for shutting down a computer work scheduler, the work scheduler comprising a number of virtual processors, each representing the ability to execute a single thread, wherein each virtual processor is either active in that it has a context running atop it performing at least one of executing work, searching for work, or idle after not finding work after a predetermined amount of searching for work, or inactive in that it has no context running atop it, the system comprising:

a computer module that determines that virtual processors in a given set of active virtual processors controlled by the scheduler are idle;
a computer module that as a result of determining that all processors in the given set of active virtual processors controlled by the scheduler are idle,:
performs a sweep of all collections searching for any work in the scheduler;
and
determines that no work is found in the scheduler;
and
a computer module that, as a result of determining that no work is found in the scheduler messages all contexts in the scheduler and tells them to exit the scheduler.

4 more elements

In a computing environment, a method of shutting down a computer work scheduler, the work scheduler comprising a number of virtual processors, each representing the ability to execute a single thread, wherein each virtual processor is either active in that it has a context running atop it performing at least one of executing work, searching for work, or idle after not finding work after a predetermined amount of searching for work, or inactive in that it has no context running atop it, the method comprising:

determining that all processors in a given set of active virtual processors controlled by the scheduler are idle;
as a result of determining that all processors in the given set of active virtual processors controlled by the scheduler are idle, atomically setting a shutdown initiated flag;
determining that at the time atomically setting the shutdown initiated flag succeeds that all processors in the given set of active virtual processors controlled by the scheduler are idle;
as a result of determining that at the time atomically setting the shutdown initiated flag succeeds that all processors in the given set of active virtual processors controlled by the scheduler are idle, proceeding to a first phase of a shutdown operation, which when successful, includes:
atomically setting a active suspend state flag;
performing a sweep of all collections searching for any work in the scheduler;
and
determining that no work is found in the scheduler;
as a result of determining that no work is found in the scheduler proceeding to a second phase of the shutdown operation, which when successful includes:
messaging all contexts and telling them to exit the scheduler;
atomically setting a shutdown completed flag;
and
atomically clearing the active suspend state flag.

10 more elements

Dependencies are inferred from the claim text.