Method and mechanism for providing computer programs with computer system events

• US 6,859,829 B1
• Filed: 02/23/1999
• Issued: 02/22/2005
• Est. Priority Date: 02/23/1999
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Parupudi, Gopal, Goertzel, Mario C., Srinivas, Murthy
• Primary Examiner(s): Dinh, Dung C.
• Application Number:
  US09/256,624
• Time in Patent Office: 2,191 Days
• Field of Search: 709/224, 709/303, 709/205, 709/223, 709/203, 709/201, 709/237, 719/318, 713/323
• US Class Current: 709/224
• CPC Class Codes: G06F 2209/544 Remote
• CPC Class Codes: G06F 9/542 Event management; Broadcasting; Multicasting; Notifications
• CPC Class Codes: H04L 41/0604 using filtering, e.g. reduction of information by using priority, element types, position or time
• CPC Class Codes: H04L 43/0811 by checking connectivity

Abstract

A method and system for providing system event notifications to clients such as applications. Clients register for notification of one or more types of events with a registration mechanism, and a System Event Notification Service, (SENS), receives system event information and fires event notifications in response thereto. A distribution mechanism selectively communicates the fired event to each client registered for notification thereof based on the type of event. Events include network events, for which the service monitors the connectivity state of the machine, including whether a connection is established or lost, the type of connection (LAN/WAN) and bandwidth information. To monitor a LAN state, the service caches outgoing and incoming network information including errors and packet counts and statistically evaluates this cached information against current information to determine whether the connection is established or lost. The service also determines if a destination (IP address or name) is reachable, by periodically polling destinations. Other system event notifications may be fired, including logon or logoff operations and power management events.

Claims

1. A system for providing notifications of computer system events to clients, comprising:

a registration mechanism for clients to register for notification of one or more types of events, including at least one client registered for network connectivity event notification;

a central service configured to monitor for system events including at least one system event corresponding to whether network connectivity has changed state and to fire at least one event notification in response thereto, including at least one event notification when a network connection is established, the central service including a plurality of time-based caches for caching network information and a mechanism for evaluating differences between at least two of the caches to determine a connectivity state of a network; and

a distribution mechanism that communicates the at least one fired event notification to each client registered for notification thereof based on the type of event.

2. The system of claim 1 wherein the time-based caches maintain counts corresponding to network activity.

3. The system of claim 2 wherein the counts corresponding to network activity include counts of incoming packets, outgoing packets, incoming errors and outgoing errors.

4. The system of claim 3 wherein the mechanism for evaluating the caches determines that the connectivity state of the network is true if the incoming packet counts have increased based on at least one difference in the packet counts between at least two of the caches.

5. A system for providing notifications of computer system events to clients, comprising:

a registration mechanism for clients to register for notification of one or more types of events;

a central service configured to monitor for system events and to fire at least one event notification in response thereto, the central service including a plurality of time-based caches for caching network information and a mechanism for evaluating differences been at least two of the caches to determine a connectivity state of a network; and

a distribution mechanism that communicates the at least one fired event notification to each client registered for notification thereof based on the type of event.

6. The system of claim 5, wherein at least one client registers for notification of changes in network connectivity and wherein the central service fires an event notification notifying the at least one client when the connectivity state of the network changes.

7. A computer-readable medium having computer-executable instructions, comprising:

receiving system information at a central service;

generating an event notification based on the information when a specified destination is reachable within specified Quality of Connection parameters;

determining a client to send the event notification to based on a filter, the client having previously subscribed to the event notification, the client indicating further conditions other than the filter for receiving the event notification, the filter matching events to subscribers; and

if the filter matches the event notification to the client, sending the event to the client only if the further conditions have also been met.

8. The computer-readable medium of claim 7, wherein the event notification relates to battery charge, and wherein the further conditions indicate that the client is only notified if the battery charge decreases below a selected percentage.

9. The computer-readable medium of claim 7, wherein the further conditions comprise that the client be currently executing to receive the event notification.

10. The computer-readable medium of claim 7, wherein the further conditions comprise that the client be activated when the event notification is generated.