High speed buffer management of share memory using linked lists and plural buffer managers for processing multiple requests concurrently

Claim 1

A storage system consisting of a shared memory (10) subdivided into a plurality of buffers, a buffer-control memory (11) subdivided into as many sections for buffer control records (BCRs) as buffers exist, and a buffer manager (12), comprising: a free-buffer manager (21; 83) controlling and organizing all of said buffers being free by keeping the corresponding BCRs in at least one free-buffer linked list (23.1), an allocated-buffer manager (22; 90) controlling and organizing all of said buffers being already allocated by keeping the corresponding BCRs in allocated-buffer linked lists (23.2-23.n), employing an allocated-buffer linked list (23.2-23.n) for each user, and a request manager (20) for granting or not granting a request of a user, based on a plurality of rules implemented in said request manager (20), involving a plurality of user-defined variables and system status variables, said request manager (20) comprising a storage (41) in which said plurality of user-defined and system status variables are stored, a work register (42) linked to said storage (41) such that the stored plurality of used user-defined and system status variables are made accessible, a server (43) determining whether a request is to be granted by employing said plurality of rules and plurality of variables which are made accessible by means of said work register (42), said user-defined variables being used for granting buffer allocation requests and said system status variables being controlled and updated by said request manager (20), said free-buffer manager (21; 83), said allocated-buffer manager (22; 90), and said request manager (20) being implemented as separate concurrently operating hardware units which are arranged such that different users can put/get data to/from buffers of said shared memory (10), and such that said free-buffer linked list (23.1) and said allocated-buffer linked lists (23.2-23.n) are concentrated in an interlaced list of BCRs in said buffer-control memory (11).

Claim 11

A method managing access of different users to a shared memory (10), said shared memory being subdivided into a plurality of buffers and being part of a storage system which further comprises a buffer-control memory (11), subdivided into as many sections for buffer-control records (BCRs) as buffers exist, and a buffer manager (12), said method comprising the steps of: a. organizing all free buffers of said shared memory as at least one chained queue of free buffers by keeping the corresponding BCRs in at least one free-buffer linked list (23.1); b. organizing all allocated buffers of said shared memory (10) as chained queues of allocated buffers, one queue for each of said users, by keeping the corresponding BCRs in as many allocated-buffer linked lists (23.2-23.n) as queues exist; c. allocating a free buffer to a user by removing the newly allocated buffer from said chained queue of free buffers and linking it to the queue of said user if still existing; otherwise, linking said newly allocated-buffer to a new queue by taking its BCR from said free-buffer linked list (23.1) and adding it to the allocated-buffer linked list (23.2-23.n) of said queue; d. releasing a buffer from the queue of a user by adding said released buffer to said chained queue of free buffers by taking its BCR from the allocated-buffer linked list (23.2-23.n) of said user and adding it to said free-buffer linked list (23.1); e. granting or not granting a request by said buffer manager for allocating a buffer to a user depending on (e.1) a plurality of rules implemented in said buffer manager (12), (e.2) a plurality of user-defined variables, and (e.3) system status variables, wherein all said variables are stored in a storage (41) linked to a work register (42) such that the stored plurality of user-defined and system status variables are made accessible, said user-defined variables being used for granting buffer allocation requests and said system status variables being controlled and updated by said buffer manager; wherein said queues are controlled and organized by said buffer manager (12) such that requests for allocation of buffers from different users are dealt with in a parallel manner.

Claim 12

A method managing access of different users to a shared memory (10), said shared memory being subdivided into a plurality of buffers and being part of a storage system which further comprises a buffer-control memory (11), subdivided into as many sections for buffer-control records (BCRs) as buffers exist, and a buffer manager (12), said method comprising the steps of: a. organizing all free buffers of said shared memory as at least one chained queue of free buffers by keeping the corresponding BCRs in at least one free-buffer linked list (23.1); b. organizing all allocated buffers of said shared memory (10) as chained queues of allocated buffers, one queue for each of said users, by keeping the corresponding BCRs in as many allocated-buffer linked lists (23.2-23.n) as queues exist; c. allocating a free buffer to a user by removing the newly allocated buffer from said chained queue of free buffers and linking it to the queue of said user if still existing; otherwise, linking said newly allocated-buffer to a new queue by taking its BCR from said free-buffer linked list (23.1) and adding it to the allocated-buffer linked list (23.2-23.n) of said queue; d. releasing a buffer from the queue of a user by adding said released buffer to said chained queue of free buffers by taking its BCR from the allocated-buffer linked list (23.2-23.n) of said user and adding it to said free-buffer linked list (23.1); e. granting or not granting a request by said buffer manager for allocating a buffer to a user depending on (e.1) a plurality of rules implemented in said buffer manager (12), (e.2) a plurality of user-defined variables, and (e.3) system status variables, wherein all said variables are stored in a storage (41) linked to a work register (42) such that the stored plurality of user-defined and system status variables are made accessible, said user-defined variables being used for granting buffer allocation requests and said system status variables being controlled and updated by said buffer manager; wherein said queues are controlled and organized by said buffer manager (12) such that requests for allocation of buffers from different users are dealt with in a parallel manner.