Apple Inc.

Jainam Ashokkumar Shah

Daniel Andreas Steffen

James Michael Magee

Jeremy C Andrus

Vishal Patel

Russell Alexader Blaine

Daniel Allen Chimene

Damien Pascal Sorresso

Kushal Dalmia

Eric Russell Clements

Marina Sadini

Kevin James Van Vechten

Jacques Anthony Vidrine

Kelly B Yancey

Pierre Habouzit

A turnstile OS primitive is provided that enables support for owner tracking and waiting. The turnstile primitive enables a common framework that can be adopted across multiple different types of synchronization primitives to provide a common service for priority boosting and wait queuing. A turnstile can also provide a mechanism to enable a turnstile to block on another turnstile, allowing multi-hop priority boosting within a chain of multiple blocking turnstiles.

Turnstile API for runtime priority boosting

One embodiment provides for a computer-implemented method comprising instantiating a synchronization primitive to control access to a resource, acquiring the synchronization primitive at a first thread, the first thread having a first priority, associating a turnstile with the synchronization primitive, setting an inheritor of the turnstile to the first thread, attempting to acquire the synchronization primitive at a second thread while the synchronization primitive is held by the first thread, the second thread having a second priority, adding the second thread to a wait queue of the turnstile; and in response to determining that the second priority is higher than the first priority, increasing the priority of the first thread to the second priority.

Techniques are disclosed relating to inter-process communication. In some embodiments, a kernel receives a notification of a communication to be sent from a first thread of a first application to a second thread of a second application. The kernel provides a reply port to the first thread for receiving a reply to the communication from the second thread. The kernel facilitates sending the communication from the first thread to the second thread. The kernel increases an execution priority of the second thread in response to the kernel determining that the reply port and a destination port associated with the second thread are identified in the communication. In some embodiments, the kernel creates the reply port in response to receiving the notification and, in response to detecting the reply has been communicated to the reply port, decreases the execution priority of the second thread and removes the reply port.

Execution priority management for inter-process communication

A method and an apparatus to dynamically distribute privileges among a plurality of processes are described. Each process may have attributes including a privilege to control access to processing resources. A first process may be running with a first privilege prohibited from access to a processing resource. A second process may be running with a second privilege allowed to access the processing resource. The first process may receive a request from the second process to perform a data processing task for the second process. In response, the second privilege may be dynamically transferred to the first process to allow the first process to access the processing resource. The first process may perform operations for the data processing task with the second privilege transferred from the second process.

Method and apparatus for inter process privilige transfer

Systems and methods are disclosed for logging encoded diagnostic information from a sequence of processing operations, the processing operations generated by an activity in a computing environment. Diagnostic information is tracked by activity, across process boundaries where the processes can be in computationally isolated, or 'sandboxed'. Within each process, diagnostic information for an activity is stored in an activity-specific buffer registered with a kernel in the computing environment. For each activity in the computing system, the kernel keeps a list of all processes that have performed, or are performing, a processing task of the activity. The kernel also keeps a reference to the activity-specific log buffers for the activity for each process associated with the activity. If a processing operation for an activity fails, all activity-specific logs from all processes that are associated with the activity can be collected. A report can be generated from the collected logs for the activity.

Activity tracing diagnostic systems and methods

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San Jose, CA, United States of America

Jainam Ashokkumar Shah