Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.