4129results about "Program synchronisation" patented technology

Methods for operating a network as a clustered file system is disclosed. The methods involve client load rebalancing, distributed Input and Output (I/O) and resource load rebalancing. Client load rebalancing refers to the ability of a client enabled with processes in accordance with the current invention to remap a path through a plurality of nodes to a resource. Distributed I/O refers to the methods on the network which provide concurrent input/output through a plurality of nodes to resources. Resource rebalancing includes remapping of pathways between nodes, e.g. servers, and resources, e.g. volumes/file systems. The network includes client nodes, server nodes and resources. Each of the resources couples to at least two of the server nodes. The method for operating comprising the acts of: redirecting an I/O request for a resource from a first server node coupled to the resource to a second server node coupled to the resource; and splitting the I/O request at the second server node into an access portion and a data transfer portion and passing the access portion to a corresponding administrative server node for the resource, and completing at the second server nodes subsequent to receipt of an access grant from the corresponding administrative server node a data transfer for the resource. In an alternate embodiment of the invention the methods may additionally include the acts of: detecting a change in an availability of the server nodes; and rebalancing the network by applying a load balancing function to the network to re-assign each of the available resources to a corresponding available administrative server node responsive to the detecting act.

Methods for load rebalancing by clients in a network are disclosed. Client load rebalancing allows the clients to optimize throughput between themselves and the resources accessed by the nodes. A network which implements this embodiment of the invention can dynamically rebalance itself to optimize throughput by migrating client I/O requests from overutilized pathways to underutilized pathways. Client load rebalancing refers to the ability of a client enabled with processes in accordance with the current invention to remap a path through a plurality of nodes to a resource. The remapping may take place in response to a redirection command emanating from an overloaded node, e.g. server. These embodiments disclosed allow more efficient, robust communication between a plurality of clients and a plurality of resources via a plurality of nodes. In an embodiment of the invention a method for load balancing on a network is disclosed. The network includes at least one client node coupled to a plurality of server nodes, and at least one resource coupled to at least a first and a second server node of the plurality of server nodes. The method comprises the acts of: receiving at a first server node among the plurality of server nodes a request for the at least one resource; determining a utilization condition of the first server node; and re-directing subsequent requests for the at least one resource to a second server node among the plurality of server nodes in response to the determining act. In another embodiment of the invention the method comprises the acts of: sending an I/O request from the at least one client to the first server node for the at least one resource; determining an I/O failure of the first server node; and re-directing subsequent requests from the at least one client for the at least one resource to an other among the plurality of server nodes in response to the determining act.

An apparatus, system, and method are disclosed for data block usage information synchronization for a non-volatile storage volume. The method includes referencing first data block usage information for data blocks of a non-volatile storage volume managed by a storage manager. The first data block usage information is maintained by the storage manager. The method also includes synchronizing second data block usage information managed by a storage controller with the first data block usage information maintained by the storage manager. The storage manager maintains the first data block usage information separate from second data block usage information managed by the storage controller.

An apparatus, system, and method are disclosed for storage space recovery after reaching a read count limit. A read module reads data in a storage division of solid-state storage. A read counter module then increments a read counter corresponding to the storage division. A read counter limit module determines if the read count exceeds a maximum read threshold, and if so, a storage division selection module selects the corresponding storage division for recovery. A data recovery module reads valid data packets from the selected storage division, stores the valid data packets in another storage division of the solid-state storage, and updates a logical index with a new physical address of the valid data.

An apparatus, system, and method are disclosed for redundant write caching. The apparatus, system, and method are provided with a plurality of modules including a write request module, a first cache write module, a second cache write module, and a trim module. The write request module detects a write request to store data on a storage device. The first cache write module writes data of the write request to a first cache. The second cache write module writes the data to a second cache. The trim module trims the data from one of the first cache and the second cache in response to an indicator that the storage device stores the data. The data remains available in the other of the first cache and the second cache to service read requests.

An apparatus, system, and method are disclosed for managing data in a solid-state storage device. A solid-state storage and solid-state controller are included. The solid-state storage controller includes a write data pipeline and a read data pipeline The write data pipeline includes a packetizer and an ECC generator. The packetizer receives a data segment and creates one or more data packets sized for the solid-state storage. The ECC generator generates one or more error-correcting codes (“ECC”) for the data packets received from the packetizer. The read data pipeline includes an ECC correction module, a depacketizer, and an alignment module. The ECC correction module reads a data packet from solid-state storage, determines if a data error exists using corresponding ECC and corrects errors. The depacketizer checks and removes one or more packet headers. The alignment module removes unwanted data, and re-formats the data as data segments of an object.

According to some embodiments, a multithreaded microcontroller includes a thread control unit comprising thread control hardware (logic) configured to perform a number of multithreading system calls essentially in real time, e.g. in one or a few clock cycles. System calls can include mutex lock, wait condition, and signal instructions. The thread controller includes a number of thread state, mutex, and condition variable registers used for executing the multithreading system calls. Threads can transition between several states including free, run, ready and wait. The wait state includes interrupt, condition, mutex, I-cache, and memory substates. A thread state transition controller controls thread states, while a thread instructions execution unit executes multithreading system calls and manages thread priorities to avoid priority inversion. A thread scheduler schedules threads according to their priorities. A hardware thread profiler including global, run and wait profiler registers is used to monitor thread performance to facilitate software development.

A method for isolating access by application programs to native resources provided by an operating system redirects a request for a native resource made by an application program executing on behalf of a user to an isolation environment. The isolation environment includes a user isolation scope and an application isolation scope. An instance of the requested native resource is located in the user isolation scope corresponding to the user. The request for the native resource is fulfilled using the version of the resource located in the user isolation scope. If an instance of the requested native resource is not located in the user isolation scope, the request is redirected to an application isolation scope. The request for the native resource is fulfilled using the version of the resource located in the application isolation scope. If an instance of the requested native resource is not located in the application isolation scope, the request is redirected to a system scope.

An apparatus, system, and method are disclosed for converting a storage request to an append data storage command. A storage request receiver module receives a storage request from a requesting device. The storage request is to store a data segment onto a data storage device. The storage request includes source parameters for the data segment. The source parameters include a virtual address. A translation module translates the storage request to storage commands. At least one storage command includes an append data storage command that directs the data storage device to store data of the data segment and the one or more source parameters with the data, including a virtual address, at one or more append points. A mapping module maps source parameters of the data segment to locations where the data storage device appended the data packets of the data segment and source parameters.

An apparatus, system, and method are disclosed for efficiently mapping virtual and physical addresses. A forward mapping module uses a forward map to identify physical addresses of data of a data segment from a virtual address. The data segment is identified in a storage request. The virtual addresses include discrete addresses within a virtual address space where the virtual addresses sparsely populate the virtual address space. A reverse mapping module uses a reverse map to determine a virtual address of a data segment from a physical address. The reverse map maps the data storage device into erase regions such that a portion of the reverse map spans an erase region of the data storage device erased together during a storage space recovery operation. A storage space recovery module uses the reverse map to identify valid data in an erase region prior to an operation to recover the erase region.

A system includes a communication module to communicate with at least one client; and a server to process a task identified by the client, the task associated with an account, the server including a plurality of account-centric pipelines, one or more account-centric pipelines each configured to process the task.

The invention comprises (i) a compilation method for automatically converting a single-threaded software program into an application-specific supercomputer, and (ii) the supercomputer system structure generated as a result of applying this method. The compilation method comprises: (a) Converting an arbitrary code fragment from the application into customized hardware whose execution is functionally equivalent to the software execution of the code fragment; and (b) Generating interfaces on the hardware and software parts of the application, which (i) Perform a software-to-hardware program state transfer at the entries of the code fragment; (ii) Perform a hardware-to-software program state transfer at the exits of the code fragment; and (iii) Maintain memory coherence between the software and hardware memories. If the resulting hardware design is large, it is divided into partitions such that each partition can fit into a single chip. Then, a single union chip is created which can realize any of the partitions.

One embodiment entails delivering a software payload to guest software in a virtual machine so that the software payload is part of a file system accessible by the guest software, wherein delivery avoids a data path involving a network stack of the virtual machine.

An editing apparatus efficiently performs cooperative editing of a document. Multiple users can edit a document in parallel using the editing apparatus which includes a screen output section, an editing screen, a section for receiving, a selection input section for inputting, and an update section for reflecting the edited content selected by a selection instruction, and updating the document.

A system for using a lease to detect a failure and to perform failure recovery is provided. In using this system, a client requests a lease from a server to utilize a resource managed by the server for a period of time. Responsive to the request, the server grants the lease, and the client continually requests renewal of the lease. If the client fails to renew the lease, the server detects that an error has occurred to the client. Similarly, if the server fails to respond to a renew request, the client detects that an error has occurred to the server. As part of the lease establishment, the client and server exchange failure-recovery routines that each invokes if the other experiences a failure.

A method and several variants for using information about the scope of access of objects acted upon by mutual exclusion, or mutex, locks to transform a computer program by eliminating locking operations from the program or simplifying the locking operations, while strictly performing the semantics of the original program. In particular, if it can be determined by a compiler that the object locked can only be accessed by a single thread it is not necessary to perform the "acquire" or "release" part of the locking operation, and only its side effects must be performed. Likewise, if it can be determined that the side effects of a locking operation acting on a variable which is locked in multiple threads are not needed, then only the locking operation, and not the side effects, needs to be performed. This simplifies the locking operation, and leads to faster programs which use fewer computer processor resources to execute; and programs which perform fewer shared memory accesses, which in turn not only causes the optimized program, but also other programs executing on the same computing machine to execute faster. The method also describes how information about the semantics of the locking operation side effects and the information about the scope of access can also be used to eliminate performing the side effect parts of the locking operation, thereby completely eliminating the locking operation. The method also describes how to analyze the program to compute the necessary information about the scope of access. Variants of the method show how one or several of the features of the method may be performed.

Memory allocator combines private (per thread) sets of fixed-size free blocks lists, a global, common for all threads, set of fixed-sized free block lists, and a general-purpose external coalescing allocator. Blocks of size bigger than the maximal fixed size are managed directly by the external allocator. The lengths of fixed-size lists are changed dynamically in accordance with the allocation and disallocation workload. A service thread performs updates of all the lists and collects memory associated with terminated user threads. A mutex-free serialization method, utilizing thread suspension, is used in the process.

A method for managing a mutex in a data processing system is presented. For each mutex, a count is maintained of the number of threads that are spinning while waiting to acquire a mutex. If a thread attempts to acquire a locked mutex, then the thread enters a spin state or a sleep state based on restrictive conditions and the number of threads that are spinning during the attempted acquisition. In addition, the relative length of time that is required by a thread to spin on a mutex after already sleeping on the mutex may be used to regulate the number of threads that are allowed to spin on the mutex.

A method and system for interconnecting peripherals, processor nodes, and hardware devices to a data network to produce a network bus providing OS functionality for managing hardware devices connected to the network bus involves defining a network bus driver at each of the processor nodes that couples hardware device drivers to a network hardware abstraction layer of the processor node. The network bus can be constructed to account for the hot-swappable nature of the hardware devices using a device monitoring function, and plug and play functionality for adding and, removing device driver instances. The network bus can be used to provide a distributed processing system by defining a shared memory space at each processor node. Distributed memory pages are provided with bus-network-wide unique memory addresses, and a distributed memory manager is added to ensure consistency of the distributed memory pages, and to provide a library of functions for user mode applications.