Qnx Software Systems Limited

Qnx Software Systems Gmbh & Co. Kg

Apple Inc.

2236008 Ontario Limited

Blackberry Corporation

Peter H Van Der Veen

Dan T Dodge

Colin Burgess

Brian John Stecher

Sebastien Marineau-Mes

Thomas Fletcher

Stephen J McPolin

Attilla Danko

Shawn R Woodtke

Thomas O P Fletcher

Joseph A Sarlo

Attila Danko

Danny Thomas Dodge

Denis J Palmans

Steve Tomkins

Xiaodan Tang

Andrew C Boyd

Gilberto Gemin

Stephane Couture

David Paul Yach

Pradeep Kumar Kathail

David Donohoe

Robert David Turner

Dan Cardamore

Tim Jenkins

Elad Lahav

Michael Kisel

Aleksandar Ristovski

Brian Edmond

Sheridan Ethier

Garry Turcotte

Giles Roy

Gianluca Guida

Hao Zhou

Steve Belair

Sunil Kittur

Gilles Roy

In an embodiment, an operating system includes a device manager that is a central repository of device information. Device drivers may communicate with the device manager over respective channels, and may request channel identifiers (Cids) to communicate with resources related to the respective devices. The device manager may provide values for resource access (or handles that the resources may use to access values). In an embodiment, the device drivers do not have the ability to allocate resources for a peripheral device. Accordingly, the security of the system may be increased. Furthermore, the resource allocation may be centrally located, simplifying the process of updating resource allocation when needed. Additionally, the device manager may delay response to requests from a given device driver until its dependencies are clear (e.g., other device drivers and hardware initializations). Thus, startup scripts may be avoided in some embodiments.

Device manager providing resource control and synchronization

In an embodiment, a central repository of rights may be implemented, and accessing entities (e.g. clients) and entities for which access is controlled (e.g. files, servers, etc.) may rely on the central repository. The rights may vary on a client-by-client basis. In an embodiment, the rights may be managed as a value that is interpreted by the access-controlled entity. Accordingly, the definition of access rights may vary based on the entity. In an embodiment, visibility to the access rights may be limited. For example, the central repository may provide a handle that is associated with the access rights, but the access rights themselves may not be provided. When an accessing entity attempts to access the access-controlled entity, the handle may be used to identify the access rights. The handle may be presented to the central repository by the access-controlled entity to confirm access rights.

Entitlement system

In an embodiment, an operating system for a computer system includes a kernel that assigns code sequences to execute on various processors. The kernel itself may execute on a processor as well. Specifically, in one embodiment, the kernel may execute on a processor with a relatively low instructions per clock (IPC) design. At least a portion of other processors in the system may have higher IPC designs, and processors with higher IPC designs may be used to execute some of the code sequences. A given code sequence executing on a processor may queue multiple messages to other code sequences, which the kernel may asynchronously read and schedule the targeted code sequences for execution in response to the messages. Rather than synchronously preparing a message and making a call to send the message, the executing code sequences may continue executing and queuing messages until the code has completed or is in need of a result from one of the messages.

Asynchronous kernel

In an embodiment, an operating system is defined in terms of a set of actors, each of which implements one or more capabilities built into the system. The actors may establish channels between them for communication of messages between the actors. Some actors may interpose between other actors. These other actors may, in some cases, interpose on channels used by the base actor. In some embodiments, some channels may be interposed while others may be monitored by the interposing actor but may still communicate directly with the underlying actor. Some channels may not be affected by the interposition (e.g. the channels may not be interposed or monitored), in an embodiment. Other examples of interposition may include debugging, simulation, and sandboxing.

Interposition

In an embodiment, an operating system includes a device manager that is a central repository of device information. Device drivers may communicate with the device manager over respective channels, and may request channel identifiers (Cids) to communicate with resources related to the respective devices. The device manager may provide values for resource access (or handles that the resources may use to access values). In an embodiment, the device drivers do not have the ability to allocate resources for a peripheral device. Accordingly, the security of the system may be increased. Furthermore, the resource allocation may be centrally located, simplifying the process of updating resource allocation when needed. Additionally, the device manager may delay response to requests from a given device driver until its dependencies are clear (e.g. other device drivers and hardware initializations). Thus, startup scripts may be avoided in some embodiments.

In an embodiment, an operating system for a computer system assigns each independently-schedulable code sequence to an activity. An activity may thus be associated with a group of related code sequences, such as threads that communicate with each other (whether or not they are part of the same program). When a code sequence is ready to be scheduled and it is not part of the current activity, it may preempt the current activity if the activity for the code sequence is not enabled and is not masked by the enabled activities. Each activity may define which other activities it masks. A flexible scheduling scheme may be devised based on the mask assignments for each activity.

Scheduling threads based on mask assignments for activities

A system and method enforce file system path-based access controls in a message-based operating system. The system and method enforce a list of rules that provide a grant and an access restriction to file system paths to server applications. A path manager receives client messages marked by a kernel to indicate that the client is subject to the path-based access controls. The path manager control access to the file systems served by the server applications in response to the rules that provide grants and access restrictions. The path manager exercises that control by transmitting messages to the client that establishes privileges to systems paths through an authentication protocol.

Path-based access control for message-based operating systems

In an embodiment, an operating system for a computer system is built on a set of capabilities. Each capability includes at least one pointer to a function that implements the capability. One or more actors are defined which use one or more of the capabilities, and which may be connected to other actors for communication through channels. The channels may be created and maintained by a channel actor. In an embodiment, one or more actors may be assembled to create a composed actor. The actors within the composed actor still communicate over the channels defined between the internal actors, but may pass channel identifiers for actors outside the composed actor, so that the actors within the composed actor communicate with the outside actors as if they were one single actor. Arbitrarily complex actors may be formed in this fashion, while still maintaining the stability and safety of the initial actors.

Composable system

A system includes a processor and memory storage units storing software code. The software code comprises code for a scheduling system and for generating a plurality of adaptive partitions that are each associated with one or more process threads and that each have a corresponding processor budget. The code also is executable to, when the system is under a normal load, allocate the processor to one of the threads that is in a ready state and has the highest priority among the process threads that are in a ready state. The code is also executable to, when the system is in overload, allocate the processor to one of the process threads that is in a ready state and has the highest priority among the process threads that are in a ready state and for which the adaptive partition that the process thread is associated with has available guaranteed processor budget.

Process scheduler employing adaptive partitioning of process threads

An adaptive partition scheduler is a priority-based scheduler that also provides execution time guarantees (fair-share). Execution time guarantees apply to threads or groups of threads when the system is overloaded. When the system is not overloaded, threads are scheduled based strictly on priority, maintaining strict real-time behavior. When the system is overloaded, threads are scheduled based priority of threads that are in a ready state and based on the available guaranteed processor time budget of the adaptive partition associated with each thread.

Adaptive partitioning for operating system

Mobile devices enable users to access data and documents in a convenient portable format. The disclosed method and system enables documents to be transferred/moved onto a mobile device for review or reference by making the transfer simple and straight forward so that it is easy for non-technically literate users (e.g. administrative assistant putting documents on their executive's mobile device). From a sender perspective the transfer mechanism can work whether the mobile device is on a local network (relative to the sender) or on a remote network when the sender does not know the actual location of the mobile device.

System and method for transferring documents

A system includes a processor, one or more memory storage units, and software code stored in the one or more memory storage units. The software code is executable by the processor to generate a plurality of adaptive partitions that are each associated with one or more process threads. The software code further includes a scheduling system that is executable by the processor for selectively allocating the processor to run the process threads based on a comparison between ordering function values for each adaptive partition. The ordering function value for each adaptive partition is calculated using one or more weighted variables for each adaptive partition. The variables include, for example, 1) the process budget, such as a guaranteed time budget, of the adaptive partition, 2) the critical budget, if any, of the adaptive partition, 3) the rate at which the process threads of an adaptive partition consume processor time.

Process scheduler employing ordering function to schedule threads running in multiple adaptive partitions

The present invention relates generally to computer operating systems, and more specifically, to operating system calls in a symmetric multiprocessing (SMP) environment. Existing SMP strategies either use a single lock or multiple locks to limit access to critical areas of the operating system to one thread at a time. These strategies suffer from a number of performance problems including slow execution, large software and execution overheads and deadlocking problems. The invention applies a single lock strategy to a micro kernel operating system design which delegates functionality to external processes. The micro kernel has a single critical area, the micro kernel itself, which executes very quickly, while the external processes are protected by proper thread management. As a result, a single lock may be used, overcoming the performance problems of the existing strategies.

Symmetric multi-processor system

A multimedia system comprising at least two multimedia devices having differing filesystems and/or no filesystem(s), one or more applications, and a media filesystem adapted to communicate with the at least two multimedia devices and the one or more applications is disclosed. The one or more applications are adapted to issue filesystem commands and/or receive filesystem responses in a common filesystem representation with respect to files of the at least two multimedia devices. The media filesystem may accept the filesystem commands from the one or more applications and may provide responses to filesystem commands to the one or more applications using the common filesystem representation.

Multimedia filesystem having unified representation of content on diverse multimedia devices

A system is set forth that includes a processor, one or more memory storage units, and software code stored in the one or more memory storage units. The software code is executable by the processor to generate a plurality of adaptive partitions that are each associated with one or more process threads. Each of the plurality of adaptive partitions has a corresponding processor budget that is assigned to it. The process threads include a mutex holding thread and a mutex waiting thread. The mutex holding thread is associated with a first adaptive partition and may gain exclusive access to a mutex object. The mutex waiting thread is associated with a second adaptive partition and must wait for access to the mutex object while the mutex object is held by the mutex holding thread. The software code further includes a scheduling system that selectively allocates the processor to run the process threads based, at least in part, on the processor budget of the associated adaptive partitions. The scheduling system bills processor allocation used to run the mutex holding thread to the processor budget of the second adaptive partition when the processor budget of the first adaptive partition has been exhausted.

Growing community of inventors

Ottawa, Canada

Peter H Van Der Veen