公开(公告)号：US20140258645A1

公开(公告)日：2014-09-11

申请号：US13784965

申请日：2013-03-05

Applicant: ORACLE INTERNATIONAL CORPORATION

Inventor： David Dice ,  Yosef Lev ,  Yujie Liu ,  Victor M. Luchangco ,  Mark S. Moir

IPC: G06F12/14

CPC classification number: G06F9/467 ,  G06F9/5027 ,  G06F9/528 ,  G06F2209/523

Abstract: Transactional reader-writer locks may leverage available hardware transactional memory (HTM) to simplify the procedures of the reader-writer lock algorithm and to eliminate a requirement for type stable memory An HTM-based reader-writer lock may include an ordered list of client-provided nodes, each of which represents a thread that holds (or desires to acquire) the lock, and a tail pointer. The locking and unlocking procedures invoked by readers and writers may access the tail pointer or particular ones of the nodes in the list using various combinations of transactions and non-transactional accesses to insert nodes into the list or to remove nodes from the list. A reader or writer that owns a node at the head of the list (or a reader whose node is preceded in the list only by other readers' nodes) may access a critical section of code or shared resource.

Abstract translation: 事务读写器锁可以利用可用的硬件事务存储器（HTM）来简化读写器锁定算法的过程，并消除对类型稳定存储器的要求基于HTM的读写器锁可以包括客户端 - 提供的节点，每个节点表示一个保存（或希望获取）锁的线程和一个尾部指针。 读者和作者调用的锁定和解锁过程可以使用事务和非事务性访问的各种组合来访问列表中的尾部指针或特定节点，以将节点插入到列表中或从列表中删除节点。 在列表头部拥有一个节点的阅读器或写入器（或者只有其他读取器节点在其列表中的节点之前的读取器）可以访问代码或共享资源的关键部分。

公开(公告)号：US20140181827A1

公开(公告)日：2014-06-26

申请号：US13722811

申请日：2012-12-20

Applicant: ORACLE INTERNATIONAL CORPORATION

Inventor： David Dice ,  Yosef Lev ,  Mark S. Moir

IPC: G06F9/48

CPC classification number: G06F9/4881 ,  G06F9/52 ,  G06F9/526

Abstract: The systems and methods described herein may implement scalable statistics counters that are adaptive to the amount of contention for the counters. The counters may be accessible within transactions. Methods for determining whether or when to increment the counters in response to initiation of an increment operation and/or methods for updating the counters may be selected dependent on current, recent, or historical amounts of contention. Various contention management policies or retry conditions may be applied to select between multiple methods. One counter may include a precise counter portion that is incremented under low contention and a probabilistic counter portion that is updated under high contention. Amounts by which probabilistic counters are incremented may be contention-dependent. Another counter may include a node identifier portion that encourages consecutive increments by threads on a single node only when under contention. Another counter may be inflated in response to contention for the counter.

Abstract translation: 本文描述的系统和方法可以实现可自适应于计数器的争用量的可伸缩统计计数器。 柜台可能在交易中可访问。 可以根据当前，最近或历史的争用量来选择用于响应于增量操作的启动来确定是否或何时增加计数器的方法和/或用于更新计数器的方法。 可以应用各种争用管理策略或重试条件来在多种方法之间进行选择。 一个计数器可以包括在低争用下递增的精确计数器部分和在高争用下更新的概率计数器部分。 概率计数器增加的金额可能是争用依赖的。 另一个计数器可以包括节点标识符部分，其仅在竞争时才鼓励单个节点上的线程的连续增量。 响应于柜台的争用，另一个柜台可能会膨胀。

公开(公告)号：US12056540B2

公开(公告)日：2024-08-06

申请号：US18341588

申请日：2023-06-26

Applicant: Oracle International Corporation

Inventor： David Dice ,  Alex Kogan

IPC: G06F9/52 ,  G06F9/50

CPC classification number: G06F9/52 ,  G06F9/5022 ,  G06F9/524

Abstract: Generic Concurrency Restriction (GCR) may divide a set of threads waiting to acquire a lock into two sets: an active set currently able to contend for the lock, and a passive set waiting for an opportunity to join the active set and contend for the lock. The number of threads in the active set may be limited to a predefined maximum or even a single thread. Generic Concurrency Restriction may be implemented as a wrapper around an existing lock implementation. Generic Concurrency Restriction may, in some embodiments, be unfair (e.g., to some threads) over the short term, but may improve the overall throughput of the underlying multithreaded application via passivation of a portion of the waiting threads.

公开(公告)号：US20240064016A1

公开(公告)日：2024-02-22

申请号：US18366586

申请日：2023-08-07

Applicant: Oracle International Corporation

Inventor： Hamid Mozaffari ,  Virendra J. Marathe ,  David Dice

IPC: H04L9/30 ,  H04L9/14 ,  G06N20/00

CPC classification number: H04L9/30 ,  H04L9/14 ,  G06N20/00

Abstract: Parameter permutation is performed for federated learning to train a machine learning model. Parameter permutation is performed by client systems of a federated machine learning system on updated parameters of a machine learning model that have been updated as part of training using local training data. An intra-model shuffling technique is performed at the client systems according to a shuffling pattern. Then, the encoded parameters are provided to an aggregation server using Private Information Retrieval (PIR) queries generated according to the shuffling pattern.

公开(公告)号：US11762711B2

公开(公告)日：2023-09-19

申请号：US17547956

申请日：2021-12-10

Applicant: Oracle International Corporation

Inventor： David Dice ,  Virendra J. Marathe

IPC: G06F9/52 ,  G06F9/46 ,  G06F16/176 ,  G06F16/23 ,  G06F13/16 ,  G06F9/50

CPC classification number: G06F9/526 ,  G06F9/468 ,  G06F9/52 ,  G06F16/176 ,  G06F16/1767 ,  G06F16/1774 ,  G06F16/2343 ,  G06F9/50 ,  G06F13/1605

Abstract: NUMA-aware reader-writer locks may leverage lock cohorting techniques that introduce a synthetic level into the lock hierarchy (e.g., one whose nodes do not correspond to the system topology). The synthetic level may include a global reader lock and a global writer lock. A writer thread may acquire a node-level writer lock, then the global writer lock, and then the top-level lock, after which it may access a critical section protected by the lock. The writer may release the lock (if an upper bound on consecutive writers has been met), or may pass the lock to another writer (on the same node or a different node, according to a fairness policy). A reader may acquire the global reader lock (whether or not node-level reader locks are present), and then the top-level lock. However, readers may only hold these locks long enough to increment reader counts associated with them.

公开(公告)号：US20230206953A1

公开(公告)日：2023-06-29

申请号：US18174520

申请日：2023-02-24

Applicant: Oracle International Corporation

Inventor： David Dice ,  Alex Kogan

IPC: G11B20/10 ,  G11C16/26 ,  G06F16/23 ,  G06F9/52

CPC classification number: G11B20/10268 ,  G11B20/105 ,  G11C16/26 ,  G06F16/2343 ,  G06F16/2365 ,  G06F9/526

Abstract: A data object has a lock and a condition indicator associated with it. Based at least partly on detecting a first setting of the condition indicator, a reader stores an indication that the reader has obtained read access to the data object in an element of a readers structure and reads the data object without acquiring the lock. A writer detects the first setting and replaces it with a second setting, indicating that the lock is to be acquired by readers before reading the data object. Prior to performing a write on the data object, the writer verifies that one or more elements of the readers structure have been cleared.

公开(公告)号：US20230161641A1

公开(公告)日：2023-05-25

申请号：US18052890

申请日：2022-11-04

Applicant: Oracle International Corporation

Inventor： Alex Kogan ,  David Dice

IPC: G06F9/52

CPC classification number: G06F9/52 ,  G06F2209/521

Abstract: A computer comprising multiple processors and non-uniform memory implements multiple threads that perform a lock operation using a shared lock structure that includes a pointer to a tail of a first-in-first-out (FIFO) queue of threads waiting to acquire the lock. To acquire the lock, a thread allocates and appends a data structure to the FIFO queue. The lock is released by selecting and notifying a waiting thread to which control is transferred, with the thread selected executing on the same processor socket as the thread controlling the lock. A secondary queue of threads is managed for threads deferred during the selection process and maintained within the data structures of the waiting threads such that no memory is required within the lock structure. If no threads executing on the same processor socket are waiting for the lock, entries in the secondary queue are transferred to the FIFO queue preserving FIFO order.

公开(公告)号：US11226849B2

公开(公告)日：2022-01-18

申请号：US16812165

申请日：2020-03-06

Applicant: Oracle International Corporation

Inventor： David Dice ,  Virendra J. Marathe

IPC: G06F9/52 ,  G06F9/46 ,  G06F16/176 ,  G06F16/23 ,  G06F13/16 ,  G06F9/50

Abstract: NUMA-aware reader-writer locks may leverage lock cohorting techniques that introduce a synthetic level into the lock hierarchy (e.g., one whose nodes do not correspond to the system topology). The synthetic level may include a global reader lock and a global writer lock. A writer thread may acquire a node-level writer lock, then the global writer lock, and then the top-level lock, after which it may access a critical section protected by the lock. The writer may release the lock (if an upper bound on consecutive writers has been met), or may pass the lock to another writer (on the same node or a different node, according to a fairness policy). A reader may acquire the global reader lock (whether or not node-level reader locks are present), and then the top-level lock. However, readers may only hold these locks long enough to increment reader counts associated with them.

公开(公告)号：US10811049B2

公开(公告)日：2020-10-20

申请号：US16739851

申请日：2020-01-10

Applicant: Oracle International Corporation

Inventor： David Dice ,  Alex Kogan

IPC: G11B20/18 ,  G06F16/23 ,  G11B20/10 ,  G11C16/26 ,  G06F9/52

Abstract: A data object has a lock and a condition indicator associated with it. Based at least partly on detecting a first setting of the condition indicator, a reader stores an indication that the reader has obtained read access to the data object in an element of a readers structure and reads the data object without acquiring the lock. A writer detects the first setting and replaces it with a second setting, indicating that the lock is to be acquired by readers before reading the data object. Prior to performing a write on the data object, the writer verifies that one or more elements of the readers structure have been cleared.

公开(公告)号：US20200097455A1

公开(公告)日：2020-03-26

申请号：US16203511

申请日：2018-11-28

Applicant: Oracle International Corporation

Inventor： Alex Kogan ,  David Dice

IPC: G06F16/23 ,  G06F9/52

Abstract: A reader of a set of data accessors that includes readers and writer detects that a particular lock of a first collection of non-global locks associated with a data object of a computing environment is held by another accessor. After checking a blocking indicator, the reader uses a second lock (which is not part of the first collection) to obtain read access to the data object and implements its reads without acquiring the particular lock. Prior to implementing a write on the data object, a writer acquires at least some locks of the first collection, and sets the blocking indicator to prevent readers from using the second lock to obtain read access to the data object.