EP0682312A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Hardware implemented locking mechanism for parallel/distributed computer system
Assignee: International Business Machines Corp
•
Filing: 1995-05-03
•
Granted: —
•
Expires: 2015-05-03
Abstract
Abstract A parallel computing system includes multiple nodes, each node including a processor with software control. According to the invention, the parallel computing system includes a distributed lock mechanism that controls access to system resources, the lock mechanism being distributed among the multiple nodes, with each node including hardware-based lock processing apparatus. Such apparatus comprises a communication interface for receiving and transmitting control and data messages and a table arrangement for storing plural lock words. A hardware logic circuitry such as a state machine is present in each node and is connected to the table arrangement and to the communications interface and is responsive to a received lock request to perform hardware-controlled lock processing functions. In preferred embodiments, those functions include: reading a stored lock word from the table arrangement; comparing the stored lock word with a compare lock word in the received lock request; compiling a message which grants the lock request if the comparison indicates a match, or a message denying the lock request if the comparison indicates a non-match, or a message indicating completion of a specified operation. The state machine performs the function without invoking the processor and/or its software control, thereby enabling lock grant/denial/information messages to be handled independently of software controlled processor procedures.
Inventors
- 👤 James T. Brady
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 11:46
CPC Classifications
G; G06; G06F; G06F9/00; G06F9/06; G06F9/46; G06F9/52
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
209 words
A lock system for controlling access to system resources within a parallel computing system including multiple nodes, each node including a processor with software control, said lock system being distributed among said multiple nodes, each node including hardware-based processing apparatus comprising: a communication interface (14) for receiving and transmitting control messages that contain at least one lock request, each lock request identifying a lock word (46) which the node issuing the control message desires to acquire possession of; a table (30, 32) for storing a plurality of lock words (46), each lock word being associated with a system resource; hardware logic circuitry (40) connected to said table (30, 32) and to said communication interface (14) and responsive to receipt of a control message to perform hardware-controlled, software independent, functions including: determining if a desired lock word (46) from said table (30, 32) is available in response to said received control message, compiling a message which grants said lock request if said desired lock word is available or a message denying said lock request if said desired lock word is not available, said hardware logic circuitry (40) performing said functions without invoking operation of software which controls said processor, whereby lock grant/denial messages are handled independently of software-controlled processor procedures.
Claim 2
Dependent Claim
82 words
A lock system as claimed in claim 1 wherein a control message contains a number of lock requests, said hardware logic circuitry (40) iteratively performing said determining function for each of said number of lock requests by accessing the lock word referred to by each lock request and determining availability of that lock word, said hardware logic circuitry (40) compiling a locking message response indicating results of said determining function and transmitting said message to the node which issued said control message.
Claim 3
Dependent Claim
39 words
A lock system as claimed in claim 2 wherein said hardware logic circuitry (40), in said locking message response, grants a request for a lock word only if all lock requests in said received control message can be granted.
Claim 4
Dependent Claim
41 words
A lock system as claimed in claim 2 wherein said hardware logic circuitry (40), in said locking message response, grants a request for a lock word if at least one lock word requested in said number of lock requests is available.
Claim 5
Dependent Claim
39 words
A lock system as claimed in claim 2 wherein said hardware logic circuitry (40), in said locking message response, grants a request for all lock words determined to be available that are requested in said number of lock requests.
Claim 6
Dependent Claim
69 words
A lock system as claimed in any preceding claim, wherein the functions performed by the hardware logic circuitry (40) comprise: reading a stored lock word from said table, comparing said stored lock word with a compare word in said received lock request, compiling a message which grants said lock request if the comparison indicates a match, or a message denying said lock request if the comparison indicates a non-match.
Claim 7
Dependent Claim
108 words
A lock system as claimed in any preceding claim, wherein a lock request includes an input port table (30) address which indicates where a lock table (32) address is stored that identifies where a lock word is stored, said table comprising: a lock table (32) for storing plural lock words at lock table addresses; and an input port table (30) for storing entries at a plurality of input port table addresses, each entry indicating a lock table address where at least an associated lock word is stored; whereby said hardware logic circuitry (40) employs said lock request to access a lock word stored at a lock table address.
Claim 8
Dependent Claim
70 words
A lock system as claimed in claim 7, wherein said hardware logic circuitry (40) sets a control to said lock table (32) to prevent access to said lock table address while said hardware logic circuitry (40) determines whether or not to compile a message granting said lock request, whereby said lock word at said lock table address is prevented from modification until said hardware logic circuitry (40) resets said control.
Claim 9
Dependent Claim
47 words
A lock system as claimed in any preceding claim, wherein said lock request includes compare and swap words, and said hardware logic circuitry (40), in determining whether to grant or deny said lock request, determines if said compare word matches the lock word accessed from said table.
Claim 10
Dependent Claim
46 words
A lock system as claimed in claim 9, wherein said hardware logic circuitry (40), upon finding a match between said compare word and the lock word accessed from said table, replaces said lock word with said swap word and compiles a message granting said lock request.
Claim 11
Dependent Claim
89 words
A lock system as claimed in any of claims 7 to 10 wherein said lock request includes plural compare words, each compare word matching a desired lock word, and plural input port table addresses where lock table addresses are stored for said desired lock words, said hardware logic circuitry (40) comparing said plural compare words with lock words at said lock table addresses in a single atomic procedure to determine a match or a non-match between said plural compare words and said lock words at said lock table addresses.
Claim 12
Dependent Claim
72 words
A lock system as claimed in any of claims 9, 10 or 11, wherein if said hardware logic circuitry (40) compiles a message granting said received lock request in response to a compare word matching a lock word from a lock table address, said hardware logic circuitry (40) further provides in said message data from at least one further lock table address which contain data pertaining to said lock word that matches.
Claim 13
Dependent Claim
66 words
A lock system as claimed in any of claims 9, 10 or 11, wherein if said hardware logic circuitry (40) compiles a message granting said received lock request in response to a compare word matching a lock word from a lock table address, said hardware logic circuitry (40) stores in at least a further lock table address, data received as part of said received lock request.
Claim 14
Dependent Claim
78 words
A lock system as claimed in any of claims 9 to 13, wherein a received lock request includes a compare mask and a swap mask, said hardware logic circuitry (40) selecting bits from a compare word and swap word contained in said received lock request in accordance with said compare mask and swap mask and employing said bits for comparison purposes with bits in a lock word or a swap word to be stored in said lock table.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.