Application compatible leap second support

Patent metadata

Field	Value
Publication number	US-11061433-B2
Application number	US-202017023787-A
Country	US
Kind code	B2
Filing date	Sep 17, 2020
Priority date	Sep 4, 2018
Publication date	Jul 13, 2021
Grant date	Jul 13, 2021

Abstract

Exposing a leap second to a plurality of applications includes identifying that a positive leap second should be added to the end of a chosen date. Based on the occurrence of the positive leap second, a first conversion component is exposed to a first application. The first conversion component presents, over a period of two seconds of actual time, a last second of the chosen date as if it is one second of system time. Based on the occurrence of the positive leap second, and based on a second application opting in to leap seconds, a second conversion component is exposed to the second application. The second conversion component presents an extra 61st second of system time at the end of a last minute of the chosen date.

First claim

What is claimed:

1. A method, implemented at a computer system that includes one or more processors, for exposing a leap second to a plurality of applications executing at the computer system, the method comprising:
identifying that a positive leap second should be added to an end of a chosen date;
based on an occurrence of the positive leap second, exposing to a first application a first conversion component that presents, over a period of two seconds of actual time, a last second of the chosen date as if it is one second of system time; and
based on the occurrence of the positive leap second, and based on a second application opting in to leap seconds, exposing to the second application a second conversion component that presents an extra 61st second of system time at an end of a last minute of the chosen date.

2. The method as recited in claim 1 , wherein the second application opts in to leap seconds based on the second application making an application programming interface (API) call.

3. The method as recited in claim 2 , wherein the API call is available to the second application based on a system setting enabling leap second support having been set.

4. The method as recited in claim 1 , wherein the second application opts in to leap seconds based on the second application expressing an application-specific configuration setting preference.

5. The method as recited in claim 1 , wherein an indication of the occurrence of the positive leap second is received from a remote computer system.

6. The method as recited in claim 1 , wherein an indication of the occurrence of the positive leap second is retrieved from durable storage at the computer system.

7. The method as recited in claim 1 , wherein presenting the last second of the chosen date as if it is one second of system time comprises presenting each exposed unit of system time making up the last second of the chosen date over a period of two corresponding units of actual time.

8. The method as recited in claim 1 , further comprising:
maintaining a counter used by the first and second conversion components.

9. The method as recited in claim 8 , wherein the first and second conversion components provide different interpretations of the counter.

10. A computer system, comprising:
one or more processors; and
one or more computer-readable media having stored thereon computer-executable instructions that are executable by the one or more processors to expose a leap second to a plurality of applications executing at the computer system, the computer-executable instructions including instructions that are executable by the one or more processors to at least:
identify that a positive leap second should be added to an end of a chosen date;
based on an occurrence of the positive leap second, expose to a first application a first conversion component that presents, over a period of two seconds of actual time, a last second of the chosen date as if it is one second of system time; and
based on the occurrence of the positive leap second, and based on a second application opting in to leap seconds, expose to the second application a second conversion component that presents an extra 61st second of system time at an end of a last minute of the chosen date.

11. The computer system as recited in claim 10 , wherein the second application opts in to leap seconds based on the second application making an application programming interface (API) call.

12. The computer system as recited in claim 11 , wherein the API call is available to the second application based on a system setting enabling leap second support having been set.

13. The computer system as recited in claim 10 , wherein the second application opts in to leap seconds based on the second application expressing an application-specific configuration setting preference.

14. The computer system as recited in claim 10 , wherein an indication of the occurrence of the positive leap second is received from a remote computer system and stored in durable storage at the computer system.

15. The computer system as recited in claim 10 , wherein presenting the last second of the chosen date as if it is one second of system time comprises presenting each exposed unit of system time making up the last second of the chosen date over a period of two corresponding units of actual time.

16. The computer system as recited in claim 10 , the computer-executable instructions also including instructions that are executable by the one or more processors to maintain a counter used by the first and second conversion components.

17. The computer system as recited in claim 16 , wherein the first and second conversion components provide different interpretations of the counter.

18. A computer program product comprising one or more hardware storage devices having stored thereon computer-executable instructions that are executable by one or more processors to expose a leap second to a plurality of applications executing at a computer system, the computer-executable instructions including instructions that are executable by the one or more processors to perform at last the following to at least:
identify that a positive leap second should be added to an end of a chosen date;
based on an occurrence of the positive leap second, expose to a first application a first conversion component that presents, over a period of two seconds of actual time, a last second of the chosen date as if it is one second of system time; and
based on the occurrence of the positive leap second, expose to a second application a second conversion component that presents an extra 61st second of system time at an end of a last minute of the chosen date.

19. The computer program product as recited in claim 18 , wherein the second application opts in to leap seconds based on the second application making an application programming interface (API) call.

20. The computer program product as recited in claim 18 , wherein presenting the last second of the chosen date as if it is one second of system time comprises presenting each exposed unit of system time making up the last second of the chosen date over a period of two corresponding units of actual time.

Assignees

• Microsoft Technology Licensing Llc

Inventors

• Lin Jason
• Iyigun Mehmet
• Cuomo Jr Daniel F
• Mange Keith Loren
• Madakasira Sarath
• Luke Travis

Classifications

• G06F1/14

  Time supervision arrangements, e.g. real time clock · CPC title

• G06F1/12 Primary

  Synchronisation of different clock signals {provided by a plurality of clock generators} · CPC title

• H04N21/8547

  involving timestamps for synchronizing content · CPC title