Patent application number | Description | Published |
20090094430 | PROVIDING A PROCESS EXCLUSIVE ACCESS TO A PAGE INCLUDING A MEMORY ADDRESS TO WHICH A LOCK IS GRANTED TO THE PROCESS - Provided are a method, system, and article of manufacture for providing a process exclusive access to a page including a memory address to which a lock is granted to the process. A request is received for a memory address in a memory device from a requesting process. A lock is granted to the requested memory address to the requesting process. The requesting process is provided exclusive access to a page including the requested memory address for a page access time period. The exclusive access to the page provided to the requesting process is released in response to an expiration of the page access time period. | 04-09-2009 |
20090144742 | METHOD, SYSTEM AND COMPUTER PROGRAM TO OPTIMIZE DETERMINISTIC EVENT RECORD AND REPLAY - A method, system and computer-usable medium for managing task events during the scheduling period of a task executing on one of the CPUs of a multi-processor computer. Only events of specific portions of scheduling period are logged, wherein a first shared resource access has been granted for the task, this portion of scheduling period gathering all the non-deterministic events which cannot be replayed by simple task re-execution. Other independent non-deterministic event records are still logged as usual when they occur out of the portion of scheduling period for which a record has been created. This limits the number of logged events during recording session of an application and the frequency of events to transmit from the production machine to the replay machine. | 06-04-2009 |
20090254724 | METHOD AND SYSTEM TO MANAGE MEMORY ACCESSES FROM MULTITHREAD PROGRAMS ON MULTIPROCESSOR SYSTEMS - A method, computer program and system for controlling accesses to memory by threads created by a process executing on a multiprocessor computer. A page table structure is allocated for each new thread and copied from the existing threads. The page access is controlled by a present bit and a writable bit. Upon a page fault the access is provided to one thread. The kernel handles the new page entry creation process and set the page present bits to zero which creates page faults. In a second embodiment, two page table structures are created, one for one thread having access to the address space and the other page table structure shared by all the other threads not having access to the address space. | 10-08-2009 |
20090328044 | Transfer of Event Logs for Replication of Executing Programs - A mechanism for replicating programs executing on a computer system having a first storage means is provided. The mechanism identifies the events corresponding to requests from one executing program, which may be different from the executing program to be replicated, which are non-deterministic and identifies the ‘Non Abortable Events’ (NAE's), which change irremediably the state of the external world that need to be reproduced in the replay of the programs. These events are immediately transferred for replay and the executing program is blocked until the transfer is acknowledged. For the other non-deterministic events, they are logged and sent to the executing program, the executing programs remaining blocked only if the log is full and/or if a timer between two NAEs expires, in this case a log transfer to the standby machine is performed to prepare replication before unblocking of the executing program. | 12-31-2009 |
20100275260 | Deterministic Serialization of Access to Shared Resource in a Multi-Processor System for code Instructions Accessing Resources in a Non-Deterministic Order - Managing access to resources shared among multiple processes within a computer system. Multiple program instances of an application are almost simultaneously executed on multiple processors for fault tolerance. The replication solution supports the recording and subsequent replay of reservation events granting the shared resources exclusive access rights to the processes, when one program code instruction may request access to a set of shared resources in a non-deterministic order. | 10-28-2010 |
20130254877 | Deterministic Serialization of Access to Shared Resources In A Multi-processor System For Code Instructions Accessing Resources In a Non-Deterministic Order - Managing access to resources shared among multiple processes within a computer system. Multiple program instances of an application are almost simultaneously executed on multiple processors for fault tolerance. The replication solution supports the recording and subsequent replay of reservation events granting the shared resources exclusive access rights to the processes, when one program code instruction may request access to a set of shared resources in a non-deterministic order. | 09-26-2013 |
20140149977 | Assigning a Virtual Processor Architecture for the Lifetime of a Software Application - A method, system and computer-usable medium are disclosed for managing virtual processor operations. A dynamic loader receives a request to initiate the creation of a new process, followed by a virtual processor being assigned to an isolated execution environment. The dynamic loader then initiates the creation of the new process by mapping kernel data associated with the virtual processor into the address space of the process. The dynamic loader completes the creation of the new process, and its execution is initiated within the isolated execution environment. | 05-29-2014 |