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: Techniques are disclosed relating to efficiently handling execution of multiple threads to perform various actions. In some embodiments, an application instantiates a queue and a synchronization primitive. The queue maintains a set of work items to be operated on by a thread pool maintained by a kernel. The synchronization primitive controls access to the queue by a plurality of threads including threads of the thread pool. In such an embodiment, a first thread of the application enqueues a work item in the queue and issues a system call to the kernel to request that the kernel dispatch a thread of the thread pool to operate on the first work item. In various embodiments, the dispatched thread is executable to acquire the synchronization primitive, dequeue the work item, and operate on it.

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: 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: Systems and methods are disclosed for synchronizing one or more user data sets on one or more client devices of a user, using a synchronization system. Each client device can have two independent and asynchronously-operating synchronization engines. The synchronization system can include a synchronization system manager that can resolve conflicts in data that arise from different versions of software being used generate a data set. Each client can maintain two separate databases: a first database that can contain a snapshot of the state of the user data sets across client devices, as known to the synchronization system. The second database can contain a snapshot of the local file system and information about the state of synchronization of the local file system with the synchronization system.

Abstract: Systems and methods are disclosed that track a document within a file system using document identifier (DOCID) that is preserved during safe save operations. The DOCID can be a universally unique identifier (UUID). The DOCID can be generated on a local file system or generated during a synchronization process with a remote synchronization service. Applications can opt in to document tracking. The kernel of the operating system can monitor file system operations on a per-application and per-thread basis and determine when a processing thread is about to perform a safe save. When a sequence of file system operations indicates that a safe save is to be performed, the kernel can generate and store a tombstone record that includes the DOCID and other metadata of the tracked document and pass the DOCID and metadata to the newly saved document.

Abstract: Techniques are disclosed relating to efficiently handling execution of multiple threads to perform various actions. In some embodiments, an application instantiates a queue and a synchronization primitive. The queue maintains a set of work items to be operated on by a thread pool maintained by a kernel. The synchronization primitive controls access to the queue by a plurality of threads including threads of the thread pool. In such an embodiment, a first thread of the application enqueues a work item in the queue and issues a system call to the kernel to request that the kernel dispatch a thread of the thread pool to operate on the first work item. In various embodiments, the dispatched thread is executable to acquire the synchronization primitive, dequeue the work item, and operate on it.

Abstract: Systems and methods are disclosed for synchronizing one or more user data sets on one or more client devices of a user, using a synchronization system. Each client device can have two independent and asynchronously-operating synchronization engines. The synchronization system can include a synchronization system manager that can resolve conflicts in data that arise from different versions of software being used generate a data set. Each client can maintain two separate databases: a first database that can contain a snapshot of the state of the user data sets across client devices, as known to the synchronization system. The second database can contain a snapshot of the local file system and information about the state of synchronization of the local file system with the synchronization system.

Abstract: Systems and methods are disclosed that track a document within a file system using document identifier (DOCID) that is preserved during safe save operations. The DOCID can be a universally unique identifier (UUID). The DOCID can be generated on a local file system or generated during a synchronization process with a remote synchronization service. Applications can opt in to document tracking. The kernel of the operating system can monitor file system operations on a per-application and per-thread basis and determine when a processing thread is about to perform a safe save. When a sequence of file system operations indicates that a safe save is to be performed, the kernel can generate and store a tombstone record that includes the DOCID and other metadata of the tracked document and pass the DOCID and metadata to the newly saved document.