Methods, apparatus, and product for distributed garbage collection

• US 6,704,756 B2
• Filed: 05/14/2001
• Issued: 03/09/2004
• Est. Priority Date: 10/11/1996
• Status: Expired due to Term

• Current Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Waldo, James H., Wollrath, Ann M., Riggs, Roger
• Primary Examiner(s): Breene, John
• Assistant Examiner(s): LEWIS, CHERYL RENEA
• Application Number:
  US09/853,644
• Publication Number:
  US 20020002576A1
• Time in Patent Office: 1,030 Days
• Field of Search: 707/206, 707/10, 707/103.Y, 707/201, 709/104, 709/201, 711/167
• US Class Current: 1/1
• CPC Class Codes: G06F 12/023 Free address space management
• CPC Class Codes: G06F 12/0253 Garbage collection, i.e. reclamation of unreferenced memory
• CPC Class Codes: G06F 12/0261 using reference counting
• CPC Class Codes: G06F 16/289 Object oriented databases
• CPC Class Codes: G06F 9/4411 Configuring for operating with peripheral devices; Loading of device drivers
• CPC Class Codes: G06F 9/465 Distributed object oriented systems remote method invocation [RMI] G06F9/548
• CPC Class Codes: G06F 9/5011 the resources being hardware resources other than CPUs, Servers and Terminals
• CPC Class Codes: G06F 9/5016 the resource being the memory
• CPC Class Codes: G06F 9/5022 Mechanisms to release resources
• CPC Class Codes: G06F 9/5055 considering software capabilities, i.e. software resources associated or available to the machine
• CPC Class Codes: G06F 9/5061 Partitioning or combining of resources
• CPC Class Codes: G06F 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores
• CPC Class Codes: G06F 9/547 Remote procedure calls [RPC]; Web services
• CPC Class Codes: H04L 12/417 with deterministic access, e.g. token passing
• CPC Class Codes: H04L 12/433 with asynchronous transmission, e.g. token ring, register insertion
• CPC Class Codes: H04L 69/24 Negotiation of communication capabilities
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 : Recoverability
• CPC Class Codes: Y10S 707/99957 : Garbage collection

Abstract

In accordance with the present invention a process is provided for allocating and deallocating resources in a distributed processing system having a requester platform and a server platform. The process involves receiving a request from the requester platform referring to a system resource and specifying a requested lease period, permitting shared access to the system resource for a lease period, sending a return call to the requester platform advising of the lease period, and deallocating the system resource when the lease period expires.

Claims

1. A method for managing objects distributed among a plurality of platforms within a distributed processing system, the method comprising:

sending, from a first platform to a second platform remotely located from the first platform, a first request to access an object managed by the second platform, wherein the request indicates a period of time the first platform requests access to the object;

sending, from the second platform to the first platform, a lease indicating a period of time for which access to the object is permitted by the first platform; and

sending, by the first platform to the second platform, a second request to renew the lease, wherein the second request includes an indication of an additional period of time the first platform requests access to the object and wherein the additional period of time includes a time factor associated with a transmission time for the second request to be received by the second platform.

2. The method of claim 1, wherein sending the lease from the second platform to the first platform includes:

incrementing a count corresponding to the object.

3. The method of claim 2, further including:

collecting resources corresponding to the object when the second platform determines that the access period for the object indicated in the lease has expired or the count corresponding to the object indicates that access to the object is no longer requested.

4. The method of claim 2, further including:

sending, from the first platform to the second platform, a notification indicating that access to the object is no longer needed; and

decrementing, by the second platform, the count corresponding to the object.

5. A method for managing resources distributed among a plurality of platforms within a distributed processing system, the method performed by a first platform comprising:

sending to a second platform a first dirty call associated with a resource managed by the second platform and including a requested lease period;

receiving a return call including a granted lease period during which access to the resource is permitted by the first platform;

determining a transmission time for the dirty call to be received by the second platform;

determining that the lease period is about to expire;

generating a second dirty call associated with the resource managed by the second platform and including a new requested lease period, wherein the new requested lease period includes a time factor associated with the transmission time; and

sending the second dirty call to the second platform.

6. The method of claim 5, further including:

determining that access to the resource is no longer needed; and

sending to the second platform a notification indicating that access to the resource managed by the second platform is no longer needed.

7. A method for managing resources within a distributed processing system including a first platform and a second platform, the method performed by the second platform comprising:

receiving a first dirty call from the first platform associated with a resource managed by the second platform and including a requested lease period;

sending a first return call to the first platform including a granted lease period during which access to the resource is permitted by the first platform;

receiving a second dirty call from the first platform associated with the resource managed by the second platform and including a new requested lease period, wherein the new requested lease period includes a time factor associated with a transmission time for the second dirty call to be received by the second platform; and

sending a second return call to the first platform including a second granted lease period during which additional access to the resource is permitted by the first platform.

8. The method of claim 7, wherein sending the first return call includes:

incrementing a count corresponding to the resource.

9. The method of claim 8, further including:

collecting the resource when the second platform determines that the granted lease period for the resource has expired or the count corresponding to the resource indicates that access to the resource is no longer requested.

10. The method of claim 8, further including:

receiving a notification from the first platform indicating that access to the resource is no longer needed; and

decrementing the count corresponding to the resource.

11. A computer-readable medium including instructions for performing a method when executed by a processor, for managing objects distributed among a plurality of platforms within a distributed processing system, the method comprising:

sending, from a first platform to a second platform remotely located from the first platform, a first request to access an object managed by the second platform, wherein the request indicates a period of time the first platform requests access to the object;

sending, from the second platform to the first platform, a lease indicating a period of time for which access to the object is permitted by the first platform; and

sending, by the first platform to the second platform, a second request to renew the lease, wherein the second request includes an indication of an additional period of time the first platform requests access to the object and wherein the additional period of time includes a time factor associated with a transmission time for the second request to be received by the second platform.

12. The computer-readable medium of claim 11, wherein sending the lease from the second platform to the first platform includes:

incrementing a count corresponding to the object.

13. The computer-readable medium of claim 12, further including:

collecting resources corresponding to the object when the second platform determines that the access period for the object indicated in the lease has expired or the count corresponding to the object indicates that access to the object is no longer requested.

14. The computer-readable medium of claim 12, further including:

sending, from the first platform to the second platform, a notification indicating that access to the object is no longer needed; and

decrementing, by the second platform, the count corresponding to the object.

15. A computer-readable medium including instructions for performing a method, when executed by a processor, for managing resources distributed among a plurality of platforms within a distributed processing system, the method performed by a first platform comprising:

sending to a second platform a first dirty call associated with a resource managed by the second platform and including a requested lease period;

receiving a return call including a granted lease period during which access to the resource is permitted by the first platform;

determining a transmission time for the dirty call to be received at the second platform;

determining that the lease period is about to expire;

generating a second dirty call associated with the resource managed by the second platform and including a new requested lease period, wherein the new requested lease period includes a time factor associated with the transmission time;

sending the second dirty call to the second platform.

16. The computer-readable medium of claim 15, further including:

determining that access to the resource is no longer needed; and

sending to the second platform a notification indicating that access to the resource managed by the second platform is no longer needed.

17. A computer-readable medium including instructions for performing a method, when executed by a processor, for managing resources within a distributed processing system including a first platform and a second platform, the method performed by the second platform comprising:

receiving a first dirty call from the first platform associated with a resource managed by the second platform and including a requested lease period;

sending a first return call to the first platform including a granted lease period during which access to the resource is permitted by the first platform;

receiving a second dirty call from the first platform associated with the resource managed by the second platform and including a new requested lease period, wherein the new requested lease period includes a time factor associated with a transmission time for the second dirty call to be received by the second platform; and

sending a second return call to the first platform including a second granted lease period during which additional access to the resource is permitted by the first platform.

18. The computer-readable medium of claim 17, wherein sending the first return call includes:

incrementing a count corresponding to the resource.

19. The computer-readable medium of claim 18, wherein the method further includes:

collecting the resource when the second platform determines that the granted lease period for the resource has expired or the count corresponding to the resource indicates that access to the resource is no longer requested.

20. The computer-readable medium of claim 18, wherein the method further includes:

receiving a notification from the first platform indicating that access to the resource is no longer needed; and

decrementing the count corresponding to the resource.

21. A method for managing objects in a distributed system, comprising:

receiving a response to a request for a lease to a reference to an object located on a remote platform for a requested lease period;

holding the lease;

determining when the lease is about to expire based on a granted lease period corresponding to the requested lease period; and

sending a request to renew the lease based on the determination.

22. The method of claim 21, further comprising:

receiving a renewed lease to the reference with an associated renewed lease period.

23. The method of claim 21, wherein prior to holding the lease, the method further includes:

receiving an indication of a grant of the lease for the granted lease period.

24. The method of claim 21, wherein the determining and sending steps are repeated until the object is no longer needed.

25. A method for managing objects in a distributed system including a first entity and a second entity, the method performed by the first entity, comprising:

holding a lease to a reference to an object, wherein associated with the lease is a requested lease period designated by the first entity, and wherein the lease was granted by the second entity for a granted lease period corresponding to the requested lease period;

determining when the lease is about to expire based on the lease period; and

sending a request to the second entity to renew the lease based on the determination.

26. The method of claim 25, wherein the determining and sending steps are repeated until the object is no longer needed.

27. A method for managing resources, comprising:

holding a lease associated with an object, and

receiving a response to a request to renew the lease for a requested renewed lease period shortly before the lease is to expire based on a determination that a need exists to continue to have access to the object.

28. A method for managing resources, comprising:

holding a lease to a reference to an object, wherein associated with the lease is a lease period;

determining when the object is no longer needed; and

sending an indication that the object is no longer needed, based on the determination.

29. The method of claim 28, wherein the lease is revoked and resources corresponding to the object are reclaimed by a process that manages the object in response to the indication being sent.

30. A method for managing objects in a system including a first process and a second process, wherein the second process manages references to objects, the method performed by the first process, comprising:

holding a lease to a reference to a first object, wherein associated with the lease is a lease period;

determining when the first object is no longer needed; and

sending an indication to the second process that the object is no longer needed, based on the determination.

31. A method for managing resources, comprising:

granting a lease for a lease period to a resource in response to a request for the lease, wherein the lease period is determined based on a requested lease period included in the request for the lease;

receiving a request to renew the lease before the lease period expires; and

granting the request for a new lease period.

32. A method for managing resources, comprising:

granting a lease to a reference to a resource in response to a request for the lease, wherein the lease is associated with a lease period;

receiving an indication that the resource is no longer needed; and

reclaiming the resource in response to the indication.

33. A computer-readable medium including instructions for performing a method, when executed by a processor, for managing objects in a distributed system, the method comprising:

receiving a response to a request for a lease to a reference to an object located on a remote platform for a requested lease period;

holding the lease;

determining when the lease is about to expire based on a granted lease period corresponding to the requested lease period; and

sending a request to renew the lease based on the determination.

34. The computer-readable medium of claim 33, further comprising:

receiving a renewed lease to the reference with an associated renew lease period.

35. The computer-readable medium of claim 33, wherein prior to holding the lease, the method further includes:

receiving an indication of a grant of the lease for the granted lease period.

36. The computer-readable medium of claim 33, wherein the determining and sending steps are repeated until the resource is no longer needed.

37. A computer-readable medium including instructions for performing a method, when executed by a processor, for managing objects in a distributed system including a first entity and a second entity, the method performed by the first entity, comprising:

holding a lease to a reference to an object, wherein associated with the lease is a requested lease period designated by the first entity, and wherein the lease was granted by the second entity for a granted lease period corresponding to the requested lease period;

determining when the lease is about to expire based on the lease period; and

sending a request to the second entity to renew the lease based on the determination.

38. The computer-readable medium of claim 37, wherein the determining and sending steps are repeated until the object is no longer needed.

39. A computer-readable medium including instructions for performing a method, when executed by a processor, for managing resources, the method comprising:

holding a lease associated with an object, and

receiving a response to a request to renew the lease for a requested renewed lease period shortly before the lease is to expire based on a determination that a need exists to continue to have access to the object.

40. A computer-readable medium including instructions for performing a method, when executed by a processor, for managing resources, comprising:

holding a lease to a reference to an object, wherein associated with the lease is a lease period;

determining when the object is no longer needed; and

sending an indication that the object is no longer needed, based on the determination.

41. The computer-readable medium of claim 40, wherein the lease is revoked and resources corresponding to the object are reclaimed by a process that manages the object in response to the indication being sent.

42. A computer-readable medium including instructions for performing a method, when executed by a processor, for managing objects in a distributed system including a first process and a second process, wherein the second process manages references to objects, the method performed by the first process, comprising:

holding a lease to a reference to a first object, wherein associated with the lease is a lease period;

determining when the first object is no longer needed; and

sending an indication to the second process that the object is no longer needed, based on the determination.

43. A computer-readable medium including instructions for performing a method, when executed by a processor, for managing resources, the method comprising:

granting a lease for a lease period to a resource in response to a request for the lease, wherein the lease period is determined based on a requested lease period included in the request for the lease;

receiving a request to renew the lease before the lease period expires; and

granting the request for a new lease period.

44. A computer-readable medium including instructions for performing a method, when executed by a processor, for managing resources, the method comprising:

granting a lease to a reference to a resource in response to a request for the lease, wherein the lease is associated with a lease period;

receiving an indication that the resource is no longer needed; and

reclaiming the resource in response to the indication.

45. A system for managing objects distributed among a plurality of platforms within a distributed processing system, the system comprising:

means for sending, from a first platform to a second platform remotely located from the first platform, a first request to access an object managed by the second platform, wherein the request indicates a period of time the first platform requests access to the object;

means for sending, from the second platform to the first platform, a lease indicating a period of time for which access to the object is permitted by the first platform; and

means for sending, by the first platform to the second platform, a second request to renew the lease, wherein the second request includes an indication of an additional period of time the first platform requests access to the object and wherein the additional period of time includes a time factor associated with a transmission time for the second request to be received by the second platform.

46. The system of claim 45, wherein the means for sending the lease from the second platform to the first platform includes:

means for incrementing a count corresponding to the object.

47. The system of claim 46, further including:

means for collecting resources corresponding to the object when the second platform determines that the access period for the object indicated in the lease has expired or the count corresponding to the object indicates that access to the object is no longer requested.

48. The system of claim 46, further including:

means for sending, from the first platform to the second platform, a notification indicating that access to the object is no longer needed; and

means for decrementing, by the second platform, the count corresponding to the object.

49. A system for managing resources distributed among a plurality of platforms within a distributed processing system, including a first and second platform, the first platform comprising:

means for sending to the second platform a first dirty call associated with a resource managed by the second platform and including a requested lease period;

means for receiving a return call including a granted lease period during which access to the resource is permitted by the first platform;

means for determining a transmission time for the dirty call to be received by the second platform;

means for determining that the lease period is about to expire;

means for generating a second dirty call associated with the resource managed by the second platform and including a new requested lease period, wherein the new requested lease period includes a time factor associated with the transmission time; and

means for sending the second dirty call to the second platform.

50. The system of claim 49, wherein the first platform further includes:

means for determining that access to the resource is no longer needed; and

means for sending to the second platform a notification indicating that access to the resource managed by the second platform is no longer needed.

51. A system for managing resources within a distributed processing system including a first platform and a second platform, the second platform comprising:

means for receiving a first dirty call from the first platform associated with a resource managed by the second platform and including a requested lease period;

means for sending a first return call to the first platform including a granted lease period during which access to the resource is permitted by the first platform;

means for receiving a second dirty call from the first platform associated with the resource managed by the second platform and including a new requested lease period, wherein the new requested lease period includes a time factor associated with a transmission time for the second dirty call to be received by the second platform; and

means for sending a second return call to the first platform including a second granted lease period during which additional access to the resource is permitted by the first platform.

52. The system of claim 51, wherein the means for sending the first return call includes:

means for incrementing a count corresponding to the resource.

53. The system of claim 52, wherein the second platform further includes:

means for collecting the resource when the second platform determines that the granted lease period for the resource has expired or the count corresponding to the resource indicates that access to the resource is no longer requested.

54. The system of claim 52, further including:

receiving a notification from the first platform indicating that access to the resource is no longer needed; and

decrementing the count corresponding to the resource.

55. A system for managing objects in a distributed system, comprising:

means for receiving a response to a request for a lease to a reference to an object located on a remote platform for a requested lease period;

means for holding the lease;

means for determining when the lease is about to expire based on a granted lease period corresponding to the requested lease period; and

means for sending a request to renew the lease based on the determination.

56. The system of claim 55, further comprising:

means for receiving a renewed lease to the reference with an associated renewed lease period.

57. The system of claim 55, wherein the means for holding the lease further includes:

means for receiving an indication of a grant of the lease for the granted lease period.

58. A system for managing objects in a distributed system including a first entity and a second entity, the first entity comprising:

means for holding a lease to a reference to an object, wherein associated with the lease is a requested lease period designated by the first entity, and wherein the lease was granted by the second entity for a granted lease period corresponding to the requested lease period;

means for determining when the lease is about to expire based on the lease period; and

means for sending a request to the second entity to renew the lease based on the determination.

59. A system for managing resources, comprising:

means for holding a lease associated with an object, and

means for receiving a response to a request to renew the lease for a requested renewed lease period shortly before the lease is to expire based on a determination that a need exists to continue to have access to the object.

60. A system for managing resources, comprising:

means for holding a lease to a reference to an object, wherein associated with the lease is a lease period;

means for determining when the object is no longer needed; and

means for sending an indication that the object is no longer needed, based on the determination.

61. The system of claim 60, wherein the lease is revoked and resources corresponding to the object are reclaimed by a process that manages the object in response to the indication being sent.

62. A system for managing objects in a system including a first process and a second process, wherein the second process manages references to objects, the first process comprising:

means for holding a lease to a reference to a first object, wherein associated with the lease is a lease period;

means for determining when the first object is no longer needed; and

means for sending an indication to the second process that the object is no longer needed, based on the determination.

63. A system for managing resources, comprising:

means for granting a lease for a lease period to a resource in response to a request for the lease, wherein the lease period is determined based on a requested lease period included in the request for the lease;

means for receiving a request to renew the lease before the lease period expires, and

means for granting the request for a new lease period.

64. A system for managing resources, comprising:

means for granting a lease to a reference to a resource in response to a request for the lease, wherein the lease is associated with a lease period;

means for receiving an indication that the resource is no longer needed; and

means for reclaiming the resource in response to the indication.

65. A memory for storing data for access by a process being executed by a processor, the memory comprising:

a structure for maintaining (i) a reference count corresponding to a resource and reflecting a number of processes having references to the resource, and (ii) a time interval during which it is guaranteed that the resource will be accessible for at least one process, wherein a reclamation process may reclaim the resource after the time interval.

66. The memory of claim 65, wherein a renew process extends the time interval during which the resource is accessible.

67. A memory for storing data for access by a process being executed by a processor, the memory comprising:

a structure for maintaining (i) a reference count corresponding to an object and reflecting a number of other objects having references to the object, and (ii) a time interval during which it is guaranteed that the object will be accessible for at least one of the other objects, wherein a reclamation process determines to reclaim the object upon expiration of the time interval regardless of the number of other objects having references to the object reflected by the reference count.

70. The memory of any one of claims 67-69, wherein a renew process extends the time interval during which the object is accessible.

68. A memory for storing data for access by a process being executed by a processor, the memory comprising:

a structure for maintaining a time interval during which it is guaranteed that an object will be accessible for at least one process, wherein a reclamation process determines to reclaim the object upon expiration of the time interval regardless of whether any other processes maintain references to the object.

69. A memory for storing data for access by a process being executed by a processor, the memory comprising:

a structure for maintaining a time interval during which it is guaranteed that an object will be accessible to at least one other object, wherein a reclamation process determines to reclaim the object based on expiration of the time interval regardless of whether any other objects maintain references to the object.

71. A memory for storing data for access by a process being executed by a processor, the memory comprising:

a structure for maintaining a time interval during which it is guaranteed that a first object will be accessible for at least one other object, wherein a reclamation process determines to reclaim the first object upon expiration of the time interval regardless of whether a reference count corresponding to the first object indicates that the at least one other object has a reference to the object.

73. The memory of any one of claims 71 and 72, wherein a renew process extends the time interval during which the first object is accessible.

72. A memory for storing data for access by a process being executed by a processor, the memory comprising:

a structure for maintaining a time interval during which it is guaranteed that a first object will be accessible for at least one other process, wherein a reclamation process determines to reclaim the first object upon expiration of the time interval regardless of whether a reference count corresponding to the first object indicates that other processes hold references to the object.

74. A method for managing objects performed by at least one processor comprising:

sending a request to access an object;

receiving a response to the request indicating a period of time for which access to the object on a nonexclusive basis is permitted;

determining whether the period for which access to the object has been permitted is about to expire; and

providing a notification that the period for which access to the object has been permitted is about to expire.

75. The method of claim 74, further comprising:

renewing the request to access the object based upon a determination that access to the object is required.

76. The method of claim 74, wherein the receiving step includes:

incrementing a counter corresponding to the object reflecting the response.

77. The method of claim 74, further comprising:

sending a notification indicating that access to the object is no longer required.

78. The method of claim 77, wherein sending a notification indicating that access to the object is no longer required, includes:

decrementing a counter corresponding to the object reflecting the notification.

79. The method of claim 78, wherein decrementing a counter corresponding to the object reflecting the notification, includes:

invoking a process to collect resources corresponding to the object upon a determination that the counter corresponding to the object indicates that access to this object is no longer required.

80. The method of any one of claims 74 to 79, wherein the request includes a reference corresponding to the object and indicating a period of time for which access to the object is requested.

81. A method for managing objects performed by at least one processor comprising:

receiving a response to a request to access an object, wherein access to the object is permitted for a time interval associated with the object;

determining whether the period for which access to the object has been permitted is about to expire; and

providing a notification that the period for which access to the object has been permitted is about to expire.

82. A method for managing objects performed by at least one processor comprising:

receiving a response to a request to access an object, wherein access to the object on a nonexclusive basis is permitted for a time interval associated with the object;

determining whether the period for which access to the object has been permitted is about to expire; and

providing a notification that the period for which access to the object has been permitted is about to expire.

83. A method for managing objects comprising the steps, performed by at least one processor, of:

receiving a request for access to an object for a requested lease period; and

permitting access to the object for a granted lease period determined based on the requested lease period.

84. The method of claim 83, wherein the request includes an application for a lease to the object.

85. The method of claim 83, further including:

releasing any resources associated with the object when or after the lease period expires.

86. The method of claim 83, wherein the request includes a reference to the object.

87. The method of claim 83, further including:

sending a response to the request.

88. The method of claim 87, wherein the response includes a reference to the object.

89. The method of claim 87, wherein the response includes an indication of the lease period.

90. The method of any one of claims 83 to 88, wherein access to the object is permitted on a nonexclusive basis for the lease period.

91. The method of any one of claims 83 to 88, further including:

providing a notification that the time interval is about to expire.

92. The method of claim 83, further including:

receiving a request for lease renewal.

93. A method for managing objects performed by at least one processor comprising:

receiving a response to a request for access to an object for a requested lease period, wherein access to the object is permitted for a granted lease period determined based on the requested lease period; and

sending a request for renewed access to the object.

94. The method of claim 93, wherein sending includes:

determining whether the lease period for which access to the object has been permitted is about to expire.

95. A system for managing objects, comprising:

means for sending a request to access an object;

means for receiving a response to the request indicating a period of time for which access to the object on a nonexclusive basis is permitted;

means for determining whether the period for which access to the object has been permitted is about to expire; and

means for providing a notification that the period for which access to the object has been permitted is about to expire.

96. The system of claim 95, further comprising:

means for renewing the request to access the object based upon a determination that access to the object is required.

97. The system of claim 95, wherein the means for receiving includes:

means for incrementing a counter corresponding to the object reflecting the response.

98. The system of claim 95, further comprising:

means for sending a notification indicating that access to the object is no longer required.

99. The system of claim 98, wherein the means for sending a notification indicating that access to the object is no longer required, includes:

means for decrementing a counter corresponding to the object reflecting the notification.

100. The system of claim 99, wherein the means for decrementing a counter corresponding to the object reflecting the notification, includes:

means for invoking a process to collect resources corresponding to the object upon a determination that the counter corresponding to the object indicates that access to this object is no longer required.

101. The system of any one of claims 95 to 100, wherein the request includes a reference corresponding to the object and indicating a period of time for which access to the object is requested.

102. A system for managing objects, comprising:

means for receiving a response to a request to access an object, wherein access to the object is permitted for a time interval associated with the object;

means for determining whether the period for which access to the object has been permitted is about to expire; and

means for providing a notification that the period for which access to the object has been permitted is about to expire.

103. A system for managing objects, comprising:

means for receiving a response to a request to access an object, wherein access to the object on a nonexclusive basis is permitted for a time interval associated with the object;

means for determining whether the period for which access to the object has been permitted is about to expire; and

means for providing a notification that the period for which access to the object has been permitted is about to expire.

104. A system for managing objects, comprising:

means for receiving a request for access to an object for a requested lease period; and

means for permitting access to the object for a granted lease period determined based on the requested lease period.

105. The system of claim 104, wherein the request includes an application for a lease to the object.

106. The system of claim 104, further including:

means for releasing any resources associated with the object when or after the lease period expires.

107. The system of claim 104, wherein the request includes a reference to the object.

108. The system of claim 104, further including:

means for sending a response to the request.

109. The system of claim 108, wherein the response includes a reference to the object.

110. The system of claim 108, wherein the response includes an indication of the lease period.

111. The system of anyone of claims 104 to 110, wherein access to the object is permitted on a nonexclusive basis for the lease period.

112. The system of any one of claims 104 to 110, further including:

means for providing a notification that the time interval is about to expire.

113. The system of claim 104, further including:

means for receiving a request for lease renewal.

114. A system for managing objects, comprising:

means for receiving a response to a request for access to an object for a requested lease period, wherein access to the object is permitted for a granted lease period determined based on the requested lease period; and

means for sending a request for renewed access to the object.

115. The system of claim 114, wherein the means for sending includes:

means for determining whether the lease period for which access to the object has been permitted is about to expire.

116. A computer-readable medium including instructions for performing a method, when executed by at least one processor, for managing objects, the method comprising:

sending a request to access an object;

receiving a response to the request indicating a period of time for which access to the object on a nonexclusive basis is permitted;

determining whether the period for which access to the object has been permitted is about to expire; and

providing a notification that the period for which access to the object has been permitted is about to expire.

117. The computer-readable medium of claim 116, the method further comprising:

renewing the request to access the object based upon a determination that access to the object is required.

118. The computer-readable medium of claim 116, wherein the receiving step includes:

incrementing a counter corresponding to the object reflecting the response.

119. The computer-readable medium of claim 116, the method further comprising:

sending a notification indicating that access to the object is no longer required.

120. The computer-readable medium of claim 119, wherein sending a notification indicating that access to the object is no longer required, includes:

decrementing a counter corresponding to the object reflecting the notification.

121. The computer-readable medium of claim 120, wherein decrementing a counter corresponding to the object reflecting the notification, includes:

invoking a process to collect resources corresponding to the object upon a determination that the counter corresponding to the object indicates that access to this object is no longer required.

122. The computer-readable medium of any one of claims 116 to 121, wherein the request includes a reference corresponding to the object and indicating a period of time for which access to the object is requested.

123. A computer-readable medium including instructions for performing a method, when executed by at least one processor, for managing objects, the method comprising:

receiving a response to a request to access an object, wherein access to the object is permitted for a time interval associated with the object;

determining whether the period for which access to the object has been permitted is about to expire; and

providing a notification that the period for which access to the object has been permitted is about to expire.

124. A computer-readable medium including instructions for performing a method, when executed by at least one processor, for managing objects, the method comprising:

receiving a response to a request to access an object, wherein access to the object on a nonexclusive basis is permitted for a time interval associated with the object;

determining whether the period for which access to the object has been permitted is about to expire; and

providing a notification that the period for which access to the object has been permitted is about to expire.

125. A computer-readable medium including instructions for performing a method, when executed by at least one processor, for managing objects, the method comprising:

receiving a request for access to an object for a requested lease period; and

permitting access to the object for a granted lease period determined based on the requested lease period.

126. The computer-readable medium of claim 125, wherein the request includes an application for a lease to the object.

127. The computer-readable medium of claim 125, the method further including:

releasing any resources associated with the object when or after the lease period expires.

128. The computer-readable medium of claim 125, wherein the request includes a reference to the object.

129. The computer-readable medium of claim 125, the method further including:

sending a response to the request.

130. The computer-readable medium of claim 129, wherein the response includes a reference to the object.

131. The computer-readable medium of claim 129, wherein the response includes an indication of the lease period.

132. The computer-readable medium of any one of claims 125 to 131, wherein access to the object is permitted on a nonexclusive basis for the lease period.

133. The computer-readable medium of any one of claims 125 to 131, the method further including:

providing a notification that the time interval is about to expire.

134. The computer-readable medium of claim 125, the method further including:

receiving a request for lease renewal.

135. A computer-readable medium including instructions for performing a method, when executed by at least one processor, for managing objects, the method comprising:

receiving a response to a request for access to an object for a requested lease period, wherein access to the object is permitted for a granted lease period determined based on the requested lease period; and

sending a request for renewed access to the object.

136. The computer-readable medium of claim 135, wherein sending includes:

determining whether the lease period for which access to the object has been permitted is about to expire.

137. An apparatus for managing objects, comprising:

a component configured to send a request to access an object, receive a response to the request indicating a period of time for which access to the object on a nonexclusive basis is permitted, determine whether the period for which access to the object has been permitted is about to expire, and provide a notification that the period for which access to the object has been permitted is about to expire; and

a component configured to provide the response based on the request to access an object.

138. An apparatus for managing objects, comprising:

a module configured to receive a response to a request to access an object, wherein access to the object is permitted for a time interval associated with the object;

a module configured to determine whether the period for which access to the object has been permitted is about to expire; and

a module configured to provide a notification that the period for which access to the object has been permitted is about to expire.

139. An apparatus for managing objects, comprising:

a memory that contains at least one set of program instructions that receive a response to a request to access an object, wherein access to the object on a nonexclusive basis is permitted for a time interval associated with the object, determine whether the period for which access to the object has been permitted is about to expire, and provide a notification that the period for which access to the object has been permitted is about to expire; and

a processor that executes the at least one set of program instructions.

140. An apparatus for managing objects, comprising:

a processing module that receives a request for access to an object for a requested lease period; and

a processing module that permits access to the object for a granted lease period determined based on the requested lease period.

141. The apparatus of claim 140, wherein the request includes an application for a lease to the object.

142. The apparatus of claim 140, further including:

a processing module that releases any resources associated with the object when or after the lease period expires.

143. The apparatus of claim 140, wherein the request includes a reference to the object.

144. The apparatus of claim 140, further including:

a processing module that sends a response to the request.

145. The apparatus of claim 144, wherein the response includes a reference to the object.

146. The apparatus of claim 144, wherein the response includes an indication of the lease period.

147. The apparatus of any one of claims 140 to 146, wherein access to the object is permitted on a nonexclusive basis for the lease period.

148. The apparatus of any one of claims 140 to 146, further including:

a processing module that provides a notification that the time interval is about to expire.

149. The apparatus of claim 140, further including:

a processing module that receives a request for lease renewal.