Abstract: Unsuspended co-routines are handled by the machine call stack mechanism in which the stack grows and shrinks as recursive calls are made and returned from. When a co-routine is suspended, however, additional call stack processing is performed. A suspension message is issued, and the entire resume-able part of the call stack is removed, and is copied to the heap. A frame that returns control to a driver method (a resumer) is copied to the call stack so that resumption of the co-routine does not recursively reactivate the whole call stack. Instead the resumer reactivates only the topmost or most current frame called the leaf frame. When a co-routine is suspended, it does not return to its caller, but instead returns to the resumer that has reactivated it.

Abstract: Multiple types of executable agents operating within a domain. The domain includes mutable shared state and immutable shared state, with agents internal to the domain only operating on the shared state. Writer agents are defined to be agents that have read access and write access to mutable shared state and read access only to immutable shared state. General reader agents have read access to both mutable shared state and immutable shared state and have no write access. Immutable reader agents have read access to only immutable shared state and have no write access. By appropriate scheduling of the different types of agents, data races may be reduced or eliminated.

Abstract: A compiler that enforces, at compile time, domain data access permissions and/or agent data access permissions on at least one agent to be created within a domain. The compiler identifies domain data of a domain to be created, and an agent to be created within the domain at runtime. The domain access permissions of the agent are also identified. As part of compilation of an expression of an agent, a reference to the domain data is identified. Then, the compiler evaluates an operation that the reference to the domain data would impose on the domain data upon evaluating the expression at runtime. The compiler then determines whether or not the operation is in violation of the domain access permissions of the agent with respect to the identified domain data. Agent data access may also be evaluated depending on whether the access occurs by a function or a method.

Abstract: The scheduling of dataflow components in a dataflow network. A number, if not all, of the dataflow components are created using a domain/agent model. A scheduler identifies, for a number of the components, a creation source for the given component. The scheduler also identifies an appropriate domain-level access permission (and potentially also an appropriate agent-level access permission) for the given component based on the creation source of the given component. Tokens may be used at the domain or agent level to control access.

Abstract: Systems and methods that integrate data type conversion(s) into a programming language, and describe external formats within a syntax thereof. A mapping component defines a declarative mapping from an external data format to one or more of its internal data types (e.g., expressing external data types in terms of source languages.) Moreover, a rule establishing component can define value-based rules, such as invariants to the external data format, wherein the schema declaration further defines data fields that make up the schema. Accordingly, by expressing rules in form of predicate logic (instead of imperative program logic) the subject innovation increase a likelihood that compilers can reason about the data.

Abstract: An interface between a resource manager and schedulers in a process executing on a computer system allows the resource manager to manage the resources of the schedulers. The resource manager communicates with the schedulers using the interface to access statistical information from the schedulers. The statistical information describes the amount of use of the resources by the schedulers. The resource manager also communicates with the schedulers to dynamically allocate and reallocate resources among the schedulers in the same or different processes or computer systems in accordance with the statistical information.

Abstract: A scheduler in a process of a computer system schedules tasks of a task group for concurrent execution by multiple execution contexts. The scheduler provides a mechanism that allows the task group to be cancelled by an arbitrary execution context or an asynchronous error state. When a task group is cancelled, the scheduler sets a cancel indicator in each execution context that is executing tasks corresponding to the cancelled task group and performs a cancellation process on each of the execution contexts where a cancel indicator is set. The scheduler also creates local aliases to allow task groups to be used without synchronization by execution contexts that are not directly bound to the task groups.

Abstract: A method and/or computer program that incorporates isolation principles of separate address spaces and enforces the principles with a compiler and supporting runtime through a language-based model is disclosed. This approach significantly lowers the required overhead and retains the beneficial qualities of the scalable, isolated model. The model is implemented in a programming language where memory-based state is partitioned into a plurality of domains where the variables inside of a domain are isolated from external components. Agents are introduced inside of the domain and act on behalf of clients outside of the domain. The agents communicate with their clients via message-passing to enforce the isolation of the domain state. The domain-based isolation addresses the partitioning of memory-based state without the introduction of separate processes. Domains can also be used in conjunction with a distributed model either within a single computing device or between computing devices.

Abstract: A language-based model to support asynchronous operations set forth in a synchronous syntax is provided. The asynchronous operations are transformed in a compiler into an asynchronous pattern, such as an APM-based pattern (or asynchronous programming model based pattern). The ability to compose asynchronous operations comes from the ability to efficiently call asynchronous methods from other asynchronous methods, pause them and later resume them, and effectively implementing a single-linked stack. One example includes support for ordered and unordered compositions of asynchronous operations. In an ordered composition, each asynchronous operation is started and finished before another operation in the composition is started. In an unordered composition, each asynchronous operation is started and completed independently of the operations in the unordered composition.

Abstract: Each processing resource in a scheduler of a process executing on a computer system maintains counts of the number of tasks that arrive at the processing resource and the number of tasks that complete on the processing resource. The counts are maintained in storage that is only writeable by the corresponding processing resource. The scheduler collects and sums the counts from each processing resource and provides statistics based on the summed counts and previous summed counts to a resource manager in response to a request from the resource manager. The scheduler does not reset the counts when the counts are collected and stores copies of the summed counts for use with the next request from the resource manager. The counts may be maintained without synchronization and with thread safety to minimize the impact of gathering statistics on the application.

Abstract: Fine-grained parallelism within isolated object graphs is used to provide safe concurrent operations within the isolated object graphs. One example provides an abstraction labeled IsolatedObjectGraph that encapsulates at least one object graph, but often two or more object graphs, rooted by an instance of a type member. By encapsulating the object graph, no references from outside of the object graph are allowed to objects inside of the object graph. Also, the encapsulated object graph does not contain references to objects outside of the graphs. The isolated object graphs provide for safe data parallel operations, including safe data parallel mutations such as for each loops. In an example, the ability to isolate the object graph is provided through type permissions.

Abstract: Local storage may be allocated for each processing resource in a process of a computer system. Each processing resource may be virtualized and may have a one-to-one or a many-to-one correspondence with with physical processors. The contents of each local storage persist across various execution contexts that are executed by a corresponding processing resource. Each local storage may be accessed without synchronization (e.g., locks) by each execution context that is executed on a corresponding processing resource. The local storages provide the ability to segment data and store and access the data without synchronization. The local storages may be used to implement lock-free techniques such as a generalized reduction where a set of values is combined through an associative operator.

Abstract: A process in a computer system creates and uses a meta-scheduler with meta-contexts that execute on meta-virtual processors. The meta-scheduler includes a set of schedulers with scheduler-contexts that execute on virtual processors. The meta-scheduler schedules the scheduler-contexts on the meta-contexts and schedules the meta-contexts on the meta-virtual processors which execute on execution contexts associated with hardware threads.

Abstract: The present invention adds support for concurrency to a mainstream object-oriented language. Language extensions are provided that can enable programs to be developed that can either be run in one address space, distributed across several process on a single computer, or distributed across a local-area or wide-area network, without recoding the program. Central to this aspect is the notion of a service, which can execute its own algorithmic (logical) thread. Services do not share memory or synchronize using explicit synchronization primitives. Rather, both data sharing and synchronization is accomplished via message-passing, e.g., a set of explicitly declared messages are sent between services. Messages can contain data that is shared, and the pattern of message exchange provide the necessary synchronization.

Abstract: A compositional model referred to as a source-target pattern for connecting processes into process networks in a general, flexible, and extensible manner is provided. The model allows common process algebra constructs to be combined with data flow networks to form process networks. Process algebraic operations may be expressed in terms of the compositional model to form data flow networks that provide fully interoperable process algebraic operations between processes.

Abstract: A runtime environment of a computer system is provided that creates first and second scheduler instances in a process. Each scheduler instance includes allocated processing resources and is assigned a set of tasks for execution. Each scheduler instance schedules tasks for execution using the allocated processing resources to perform the work of the process.

Abstract: A memory allocator is provided for each processor resource in a process of a computer system. Each memory allocator includes a set of pages, a locally freed list of objects, and a remotely freed list of objects. Each memory allocator requests the pages from an operating system and allocates objects to all execution contexts executing on a corresponding processing resource. Each memory allocator attempts to allocate an object from the locally freed list before allocating an object from the remotely freed list or an allocated page.

Abstract: A scheduler in a process of a computer system includes a local collection of tasks for each processing resource allocated to the scheduler and at least one general collection of tasks. The scheduler assigns each task that becomes unblocked to the local collection corresponding to the processing resource that caused the task to become unblocked. When a processing resource becomes available, the processing resource attempts to execute the most recently added task in the corresponding local collection. If there are no tasks in the corresponding local collection, the available processing resource attempts to execute a task from the general collection.

Abstract: A scheduler in a process of a computer system includes a respective scheduling collection for each scheduling node in the scheduler. The scheduling collections are mapped into at least a partial search order based on one or more execution metrics. When a processing resource in a scheduling node becomes available, the processing resource first attempts to locate a task to execute in a scheduling collection corresponding to the scheduling node before searching other scheduling collections in an order specified by the search order.

Abstract: Protection entries and techniques for providing fine granularity computer memory protection. A method of protecting a computer memory may include separating or parsing the computer memory, containing data or code, into blocks and creating protection entries for each block. The protection entries optionally include a reference field for identifying a block of memory, and a protection field for specifying one or more levels of access to the identified block of memory. The protection entries may then be used to pass messages between various system entities, the messages specifying one or more levels of access to the one or more blocks of memory or code.