System and method for implementing operating system message queues with recoverable shared virtual storage

A system for insuring reliability of system-wide data structures in a data processing system having a plurality of processors interconnected by a communications link, comprising:

• means for sharing virtual storage by each of the plurality of processors during operation of said system;
• means for accessing each one of a plurality of virtual storage segments of said virtual storage by a same virtual address from any one of said processors during operation of said system;
• means for keeping at least two copies of a virtual page, wherein each of said copies is stored in a different processor;
• means for updating each of said copies for each of said pages when modified by a completed transaction;
• a message queue table stored in a first virtual storage segment having information about a plurality of message queues in the data processing system;
• means for issuing a message get system call from a process in any one of said plurality of processors;
• means for scanning the message queue table for an entry for said called message queue;
• means for creating a new message queue in a second virtual storage is no entry is found;
• means for designating ownership of the new message queue by the processor of the process issuing the message get system call;
• and
• means for adding an entry to said message table for said new message queue.

A system for insuring reliability of system-wide data structures in a data processing system having a plurality of processors interconnected by a communications link, comprising:

• means for sharing virtual storage by each of said plurality of processors during operation of said system;
• means for accessing each one of a plurality of virtual storage segments of said virtual storage by a same virtual address from any one of said processors during operation of said system;
• means for keeping at least two copies of a virtual page, wherein each of said copies is stored in a different processor;
• means for updating each of said copies for each of said pages when modified by a completed transaction;
• a message table stored in a first virtual storage segment having information about a plurality of message queues in the data processing system;
• means for issuing a message control system call from a process in any one of said plurality of processors to remove a message queue;
• means for deleting the message queue from a second virtual storage segment containing the queue;
• and
• means for deleting the entry for the deleted queue in the message table stored int eh first virtual storage segment.

A system for insuring reliability of system-wide data structures in a data processing system having a plurality of processors interconnected by a communications link, comprising:

• means for sharing virtual storage by each of said plurality of processors during operation of said system;
• means for accessing each one of a plurality of virtual storage segments by a same virtual address from any one of said processors during operation of said system;
• means for keeping at least two copies of a virtual page, wherein each of said copies is stored in a different processor;
• means for updating each of said copies for each of said pages when modified by a completed transaction;
• a message queue table stored in a first virtual storage segment having information about a plurality of message queues in the data processing system;
• means for issuing a message control system call from a process in any one of said processors to update the control information associated with a queue;
• and
• means for updating the control information for the queue in response to a message control system call.

A system for insuring reliability of system-wide data structures in a data processing system having a plurality of processors interconnected by a communications link, comprising:

• means for sharing virtual storage by each of said plurality of processors during operation of said system;
• means for accessing each one of a plurality of virtual storage segments of said virtual storage by same virtual address from any one of said processors during operation of said system;
• means for keeping at least two copies of a virtual page, wherein each of said copies is stored in a different processor;
• means for updating each of said copies for each of said pages when modified by a completed transaction;
• a message queue table stored in a first virtual storage segment having information about a plurality of message queues int eh data processing system;
• means for issuing a message send system call from a process in any one of said processors to send a message to a queue;
• means for scanning said message queue table to locate the queue;
• means for determining if the queue to which the message is to be sent is full;
• means for putting the process originating the message call to sleep if the queue is full;
• means for periodically waking up the process to complete the system call;
• and
• means for transferring the message to the queue of the queue is not full.

A method for insuring reliability for system-wide data structures in a data processing system having a plurality of processors interconnected by a communications link, said method comprising:

• sharing virtual storage by each of said plurality of processors during operation of said system;
• accessing each one of a plurality of virtual storage segments having a plurality of pages of said virtual storage by a same virtual address from any one of said processors during operation of said system;
• keeping at least two copies of each virtual page in a virtual segment, wherein each of said copies is stored in a different processor;
• storing information about a plurality of message queues in the data processing system in a message queue table in a first virtual storage segment;
• issuing a message get system call from a process of one of said plurality of processors;
• scanning the message queue table for an entry for said message queue;
• creating a new message queue if no entry is found;
• designating the ownership of the new message queue by said processor issuing the system call;
• adding an entry to said message queue table for said new message queue;
• and
• updating each of the copies for each of said virtual pages when modified by a completed transaction.

A method for insuring reliability of system-wide data structures in a data processing system having a plurality of processors interconnected by a communications link comprising:

• sharing virtual storage by each of said plurality of processors during operation of said system;
• accessing each one of a plurality of virtual storage segments of said virtual storage by a same virtual address from any one of said processors during operation of said system;
• keeping at least two copies of a virtual page, wherein each of said copies is stored in a different processor;
• storing information about the identity and location of a plurality of message queues in the data processing system in a message queue table stored in a first virtual storage segment;
• storing status information about a plurality of message queues in a message header table stored in a second virtual segment;
• storing text information associated with each header in a third virtual segment;
• issuing a message control system call from a process in any one of said plurality of processors to remove a message queue;
• deleting the message queue from a second virtual storage segment;
• and
• deleting the entry for the deleted queue in the message queue table stored in the first virtual segment.

A method for insuring reliability of system-wide data structures in data processing system having a plurality of processors interconnected by a communications link, comprising:

• sharing virtual storage by each of said plurality of processors during operation of said system;
• accessing each one of a plurality of virtual storage segments of said virtual storage by a same virtual address for any one of said processors during operation of said system;
• keeping at least two copies of each virtual page of a virtual segment, wherein each of said copies is stored in a different processor;
• storing information about a plurality of message queues in the data processing system in a message queue table stored in a first virtual storage segment;
• issuing a message send system call from a process in any one of said processors to send a message to a queue;
• determining if the queue to which the message is to be sent is full;
• putting the process originating the message call to sleep if the queue is full;
• periodically waking up the process to complete the system call;
• transferring the message to the queue if the queue is not full;
• and
• updating each of said copies for each of said pages modified.

A system for insuring reliability in a data processing system having a plurality of processors interconnected by a communications link, comprising:

• means for producing a message from a requesting process in one of said plurality of processors;
• means for placing the message from the requesting process in a virtual storage segment accessible by each of said plurality for processors during operation of said system;
• means for passing the message to a receiving process;
• means for updating in the segment of said virtual storage originally containing the data structure;
• and
• means for keeping at least two copies of the virtual storage containing the data, wherein each of the copies is stored in a different processor.

A system for insuring reliability of system-wide data structures in a data processing system having a plurality of processors interconnected by a communications link, comprising:

• means for sharing virtual storage among the plurality of processors during operation of said system;
• means for accessing each one of a plurality of virtual storage segments of said virtual storage by a same address form each of said processors during operation of said system;
• means for placing a message in a virtual storage segment by a requesting process;
• and
• means for examining said virtual storage segment periodically by a receiving processor for said placed message.

A system for insuring reliability of system-wide data structure sin a data processing system having a plurality of processors interconnected by a communications link, said system comprising:

• means for sharing virtual storage among the plurality of processors during operation of said system;
• means for accessing each one of a plurality of virtual storage segments of said virtual storage by a same address form each one of said processors during operation of said system;
• means for storing, in one of said virtual storage segments owned by one of said processors as an owning site, a table for a plurality of data structures;
• means for designating another processor to b a back-up processor of the processor owning the table;
• and
• means for storing a copy of said table in said back-up processor.

A method for insuring reliability of system-wide data structures in a data processing system having a plurality of

• processors interconnected by a communications link, comprising:
• storing identifying information about a plurality of data structures in a segment of virtual storage shareable and addressable by each of said processors during operation of said system, wherein a copy of said identifying information is stored in one of a the plurality of processors;
• assigning a back-up processor for said processor containing a copy of the identifying information, wherein another copy of said identifying information is also stored in said back-up processor;
• issuing a system call, which uses the identifying information to execute an atomic transaction on a data structure store din a virtual storage segment by a process on one of the plurality of processors;
• attaching the segment containing the identifying information to each of the processors upon the issuance of the first system call which uses the identifying information;
• and
• updating all copies of said identifying information upon the successful completion of the transaction.

A system for insuring reliability of system-side data structures in a data processing system having a plurality of processors interconnected by a communication link, wherein each processor shares virtual storage segments, each accessible by a same virtual address from any one of said processors during operation of said system, comprising:

• storing identifying information about a plurality of data structures in a segment of virtual storage shareable and addressable by each of said processors, wherein a copy of said identifying information is stored in one of the plurality of processors;
• assigning a back-up processor for said processor containing a copy of the identifying information, wherein another copy of said identifying information is also stored in said back-up processor;
• issuing a system call, which uses the identifying information to execute an atomic transaction on a data structure stored in a virtual storage segment by a process on one of the plurality of processors;
• attaching said segment containing the identifying information to each of said processors upon the issuance of the first system call which uses the identifying information;
• and
• maintaining the previous copies of identifying information in the event the transaction is aborted.

A system for insuring reliability of system-wide data structures in a data processing system having a plurality of processors interconnected by a communication link, wherein each processor shares virtual storage segments, each accessible by a same virtual address from any one of said processors during operation of said system, comprising:

• a table stored in a virtual storage segment having identifying information about a plurality of system-wide data structures, wherein the table is created by one of the processors during the start-up of the system;
• means for assigning a back-up processor of the processor owning the virtual storage segment containing the table and storing a copy of said table in said back-up processor;
• means for attaching said virtual storage segment containing the table to each of the plurality of processors upon the issuance of a first system call by such processor which uses the identifying information;
• and
• means for updating all copies of said table stored in the virtual segment upon the successful completion of the system call.

A system for insuring reliability of system-wide data structures in a data processing system having a plurality of processors interconnected by a communications link, comprising:

• means for sharing virtual storage by each of the plurality of processors during operation of said system;
• means for accessing each one of a plurality of virtual storage segments of said virtual storage by a virtual address form any one of said processors during operation of said system;
• a table created by a first processor for storing in a first virtual storage segment identifying information about a plurality of data structures;
• means for assigning at least one back-up processor to said first processor;
• means for copying said table int he first processor to said back-up processor;
• means for issuing a system call to execute an atomic transaction on a data structure owned by a processor form a process in any one of said plurality of processors;
• means for assigning a back-up processor to said processor owning said data structure;
• and
• means for updating all copies of the data structure upon the successful completion of the transaction.