-
公开(公告)号：DE69733305T2
公开(公告)日：2006-01-19
申请号：DE69733305
申请日：1997-11-28
Applicant: IBM
Inventor： MCNABB DANIEL LLOYD , WYLLIE JAMES CHRISTOPHER , PORTER SCOTT LYNN
Abstract: A general purpose interface is provided to a file system of a multimedia server for improving datastream throughput by avoiding data copying and context switching. The file system includes an export registration service providing function pointers to the file system's implementation of a predefined set of zero copy interfaces. These interfaces include an initialization service to set up necessary data structures and to place use counts on objects to prevent them from being removed while zero copy operations are in progress. A termination service in the zero copy interfaces cleans up data structures and removes use counts. Additional services validate that a specified file is suitable for zero copy operations, find and record file attributes needed to later acquire buffers at interrupt level. A data structure is defined to hold these attributes for subsequent calls. Another service locks a buffer at an interrupt level and returns the amount of data present, and provides addressability to the buffer in another address space context. A data structure holds these buffer attributes for subsequent calls. A service is additionally provided to unlock the buffer at interrupt level. Finally, a service provides information on changes to the access pattern of the file such as would be needed to support VCR functions. A hash chain emplyoing a singly linked list updated atomically allows for safe buffer lookups at interrupt level. Compare-and-swap locking faciliates this. A mailbox interface useful at interrupt leve provides prefetch and release information to the daemon. In case of a lock collision or where the buffer is not available, the buffer is acquired in a process context.
-
公开(公告)号：AT296011T
公开(公告)日：2005-06-15
申请号：AT97480083
申请日：1997-11-28
Applicant: IBM
Inventor： MCNABB DANIEL LLOYD , WYLLIE JAMES CHRISTOPHER , PORTER SCOTT LYNN
Abstract: A general purpose interface is provided to a file system of a multimedia server for improving datastream throughput by avoiding data copying and context switching. The file system includes an export registration service providing function pointers to the file system's implementation of a predefined set of zero copy interfaces. These interfaces include an initialization service to set up necessary data structures and to place use counts on objects to prevent them from being removed while zero copy operations are in progress. A termination service in the zero copy interfaces cleans up data structures and removes use counts. Additional services validate that a specified file is suitable for zero copy operations, find and record file attributes needed to later acquire buffers at interrupt level. A data structure is defined to hold these attributes for subsequent calls. Another service locks a buffer at an interrupt level and returns the amount of data present, and provides addressability to the buffer in another address space context. A data structure holds these buffer attributes for subsequent calls. A service is additionally provided to unlock the buffer at interrupt level. Finally, a service provides information on changes to the access pattern of the file such as would be needed to support VCR functions. A hash chain emplyoing a singly linked list updated atomically allows for safe buffer lookups at interrupt level. Compare-and-swap locking faciliates this. A mailbox interface useful at interrupt leve provides prefetch and release information to the daemon. In case of a lock collision or where the buffer is not available, the buffer is acquired in a process context.
-
公开(公告)号：SG54076A1
公开(公告)日：1998-11-16
申请号：SG1995000386
申请日：1995-05-03
Applicant: IBM
Inventor： SEKENA ASHOK RAJ , WYLLIE JAMES CHRISTOPHER , HENLEY MARTHA R
IPC: G06F3/06 , H04N5/93 , G06F12/00 , H04L29/06 , H04N5/765 , H04N7/16 , H04N7/173 , H04N21/2183 , H04N21/238 , H04N21/262 , G06F15/00
Abstract: A media streamer (10) includes at least one storage node (16, 17) comprising mass storage for storing a digital representation of at least one video presentation; and a plurality of communication nodes (14) each having at least one input port that is coupled to an output of the at least one storage node for receiving a digital representation of a video presentation therefrom. Each of the plurality of communication nodes further includes a plurality of output ports, individual ones of the plurality of output ports being operable for transmitting a digital representation as a data stream to a consumer of the digital representation. Individual ones of the output ports also have an associated data buffer for buffering a portion of a digital representation prior to a transmission of the digital representation. Each of the plurality of communication nodes further includes a scheduler for scheduling, for individual ones of the data buffers, a read request to the at least one storage node for a next sequential portion of the digital representation for storage within individual ones of the data buffers. Each read request for a particular individual one of the data buffers is scheduled at a predetermined time such that a requested next sequential portion of the digital representation is available to a requesting communications node prior to a time that the requested next sequential portion is required to be transmitted from the output port that is associated with the data buffer for which the read request was scheduled. The at least one storage node further includes a scheduler for scheduling a read request to the mass storage such that a next sequential portion of a digital representation is available for outputting, prior to the at least one storage node receiving a read request for the next sequential portion from one of the communication nodes.
-
-
Search Results
13
records
(took 0.017 seconds)
