Abstract: A scheduler in a process of a computer system allows an external execution context to execute on a processing resource allocated to the scheduler. The scheduler provides control of the processing resource to the external execution context. The scheduler registers for a notification of an exit event associated with the external execution context. In response to receiving the notification that the exit event has occurred, the scheduler regains control of the processing resource and causes a task associated with an execution context controlled by the scheduler to be executed by the processing resource.

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 runtime environment allows a scheduler in a process of a computer system to be finalized prior to the process completing. The runtime environment causes execution contexts that are inducted into the scheduler and execution contexts created by the scheduler to be tracked. The runtime environment finalizes the scheduler subsequent to each inducted execution context exiting the scheduler and each created execution context being retired by the scheduler.

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: 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 detects a task with an associated execution context that has not been previously invoked by the scheduler. The scheduler executes the task on a processing resource without performing a context switch if the processing resource executed a previous task to completion. The scheduler stores the execution context originally associated with the task for later use.

Abstract: Sharing access to resources using an inter-process communication (“IPC”) provides a connection in which references to resources may be passed from a sender to a receiver in a trusted third party environment. A sender in possession of a reference to a resource, such as a handle to an object, may initiate the connection with the receiver. In turn, the receiver may accept or refuse the connection, and may further specify the types of resources in which the receiver is interested when accepting through the connection. Sharing access to resources in this manner advantageously insures that only a process that already has access to a resource is able to share that access with another process, and further that only processes that wish to do so will accept such access.

Abstract: The number of copies of a message to be transferred from one process to another process in a computer where each process has a differing address space may be reduced through the use of a message-passing data structure. The sending process generates an operating system service call to copy the message to be transferred into the message-passing data structure. The receiving process need not generate a system service request to the kernel in order to retrieve the sent message and also does not require an additional copy of the transferred message to be made by the kernel, in order to read the message content. The data structure permits a mapping of the message into the address space of the receiving process as well as the address space of the kernel. The inter-process mechanism for exchanging messages provides proper flow control, synchronization, and security when two processes exchange data.

Abstract: A system and method for identity decisions and invalidation. Modified objects (e.g., files, executables, etc.) are flagged for reevaluation. Privileges associated with the object are only persisted if the modifications are determined to be authorized (e.g., updates and patches). In one embodiment, a tagging system registers to be notified of all writes, renames, truncations, moves, deletions, or any other relevant modifications to objects. If the tagging system detects a modification operation targeting the object, it invalidates all identity decisions cached with the object. The next time the object runs, the system does not recognize the object and it is forced to reevaluate its identity. Thus, patching and other write operations are still permitted, but the system detects the changed object and reevaluates the identity.

Abstract: Granting an executable object (e.g., an application program, thread, or process) access to a namespace object (e.g., a named object, resource, file, or folder). A request by the executable object for the namespace object is intercepted and processed to determine whether a local namespace associated with the executable object, user, or session stores a copy of the requested namespace object. If the copy exists in one of the local namespaces, the request is granted and allowed to operate on that local namespace. If the requested namespace object exists only in a global namespace, the namespace object is copied to a local namespace. The request is then granted and allowed to operate on the copy of the namespace object in the local namespace. Protecting the namespace objects stored in the global namespace from modification improves the stability of the application program and operating system.

Abstract: Granting an application program access to a resource as a function of a privilege associated with the application program. An embodiment of the invention employs a persistent, individual identity associated with the components of an application program or a group of application programs to allow an operating system to identify and differentiate between different application programs or groups of application programs installed on a computing system. The identity associated with each component of an application program enables the identification and removal or uninstallation of the application program. The identity also enables isolation of resources of the application program and protection of operating system resources.