公开(公告)号：US20160246527A1

公开(公告)日：2016-08-25

申请号：US15050396

申请日：2016-02-22

Applicant: Oracle International Corporation

Inventor： Alex Kogan ,  Yosef Lev

IPC: G06F3/06 ,  G06F9/46

CPC classification number: G06F3/0604 ,  G06F3/0629 ,  G06F9/467 ,  G06F9/5016 ,  G06F9/52 ,  G06F9/524

Abstract: Threads using hardware transactions and executing instrumented critical sections that do not perform any writes may complete as long as the thread holding the lock has not yet executed its first write operation. If the thread executing the instrumented critical section performs any writes, or if the thread holding the lock performs any writes during its critical section, the hardware transaction may be aborted. A write flag may be used to determine whether the thread holding the lock performs any writes. The thread holding the lock may set the flag before performing any write operation. The thread executing the hardware transaction may subscribe to that flag and abort the transaction if the flag is set to true, indicating that the thread holding the lock performed a write operation.

Abstract translation: 只要持有锁的线程尚未执行其第一次写入操作，使用硬件事务和执行不执行任何写入的仪表化关键部分的线程就可以完成。 如果执行检测的关键部分的线程执行任何写入，或者如果持有锁的线程在其关键部分期间执行任何写操作，则可能会中止硬件事务。 可以使用写标志来确定持有锁的线程是否执行任何写入。 持有锁的线程可以在执行任何写操作之前设置该标志。 执行硬件事务的线程可以订阅该标志，并且如果标志被设置为真，则中止该事务，指示保持锁定的线程执行写入操作。

公开(公告)号：US20240338259A1

公开(公告)日：2024-10-10

申请号：US18747956

申请日：2024-06-19

Applicant: Oracle International Corporation

Inventor： David Dice ,  Alex Kogan

IPC: G06F9/52 ,  G06F9/30 ,  G06F9/50 ,  G06F9/54

CPC classification number: G06F9/526 ,  G06F9/30087 ,  G06F9/5016 ,  G06F9/541 ,  G06F9/542

Abstract: A computer including multiple processors and memory implements a managed runtime providing a synchronization application programming interface (API) for threads that perform synchronized accesses to shared objects. A standardized header of objects includes a memory word storing an object identifier. To lock the object for synchronized access, the memory word may be converted to store the tail of a linked list of a first-in-first-out synchronization structures for threads waiting to acquire the lock, with the object identifier relocated to the list structure. The list structure may further include a stack of threads waiting on events related to the object, with the synchronization API additionally providing wait, notify and related synchronization operations. Upon determining that no threads hold or desire to hold the lock for the object and that no threads are waiting on events related to the object, the memory word may be restored to contain the object identifier.

公开(公告)号：US20240160447A1

公开(公告)日：2024-05-16

申请号：US18418980

申请日：2024-01-22

Applicant: Oracle International Corporation

Inventor： David Dice ,  Alex Kogan

IPC: G06F9/30 ,  G06F9/38 ,  G06F9/52 ,  G06F12/0802 ,  G06F13/16

CPC classification number: G06F9/3009 ,  G06F9/3802 ,  G06F9/52 ,  G06F9/526 ,  G06F12/0802 ,  G06F13/1663 ,  G06F13/1689 ,  G06F2212/60

Abstract: A computer comprising one or more processors and memory may implement multiple threads that perform a lock operation using a data structure comprising an allocation field and a grant field. Upon entry to a lock operation, a thread allocates a ticket by atomically copying a ticket value contained in the allocation field and incrementing the allocation field. The thread compares the allocated ticket to the grant field. If they are unequal, the thread determines a number of waiting threads. If the number is above the threshold, the thread enters a long term wait operation comprising determining a location for long term wait value and waiting on changes to that value. If the number is below the threshold or the long term wait operation is complete, the thread waits for the grant value to equal the ticket to indicate that the lock is allocated.

公开(公告)号：US11914996B2

公开(公告)日：2024-02-27

申请号：US17817854

申请日：2022-08-05

Applicant: Oracle International Corporation

Inventor： David Dice ,  Alex Kogan

IPC: G06F12/00 ,  G06F9/30 ,  G06F12/0802 ,  G06F9/52 ,  G06F13/16 ,  G06F9/38

CPC classification number: G06F9/3009 ,  G06F9/3802 ,  G06F9/52 ,  G06F9/526 ,  G06F12/0802 ,  G06F13/1663 ,  G06F13/1689 ,  G06F2212/60

Abstract: A computer comprising one or more processors and memory may implement multiple threads that perform a lock operation using a data structure comprising an allocation field and a grant field. Upon entry to a lock operation, a thread allocates a ticket by atomically copying a ticket value contained in the allocation field and incrementing the allocation field. The thread compares the allocated ticket to the grant field. If they are unequal, the thread determines a number of waiting threads. If the number is above the threshold, the thread enters a long term wait operation comprising determining a location for long term wait value and waiting on changes to that value. If the number is below the threshold or the long term wait operation is complete, the thread waits for the grant value to equal the ticket to indicate that the lock is allocated.

公开(公告)号：US11809917B2

公开(公告)日：2023-11-07

申请号：US16723766

申请日：2019-12-20

Applicant: Oracle International Corporation

Inventor： David Dice ,  Timothy L. Harris ,  Alex Kogan ,  Yosef Lev ,  Mark S. Moir

IPC: G06F9/46 ,  G06F9/52 ,  G06F9/38 ,  G06F9/30

CPC classification number: G06F9/526 ,  G06F9/30087 ,  G06F9/3851 ,  G06F9/467

Abstract: Transactional Lock Elision allows hardware transactions to execute unmodified critical sections protected by the same lock concurrently, by subscribing to the lock and verifying that it is available before committing the transaction. A “lazy subscription” optimization, which delays lock subscription, can potentially cause behavior that cannot occur when the critical sections are executed under the lock. Hardware extensions may provide mechanisms to ensure that lazy subscriptions are safe (e.g., that they result in correct behavior). Prior to executing a critical section transactionally, its lock and subscription code may be identified (e.g., by writing their locations to special registers). Prior to committing the transaction, the thread executing the critical section may verify that the correct lock was correctly subscribed to. If not, or if locations identified by the special registers have been modified, the transaction may be aborted. Nested critical sections associated with different lock types may invoke different subscription code.

公开(公告)号：US11726838B2

公开(公告)日：2023-08-15

申请号：US17547505

申请日：2021-12-10

Applicant: Oracle International Corporation

Inventor： David Dice ,  Alex Kogan

IPC: G06F9/50 ,  G06F9/52

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：US11636152B2

公开(公告)日：2023-04-25

申请号：US16407007

申请日：2019-05-08

Applicant: Oracle International Corporation

Inventor： Alex Kogan ,  David Dice ,  Shady Alaaeldin Mohamed Abdelkader Rabie Issa

IPC: G06F16/901 ,  G06F11/30 ,  G06F16/176

Abstract: A computer comprising one or more processors and memory may implement multiple threads performing mutually exclusive lock acquisition operations on disjoint ranges of a shared resource each using atomic compare and swap (CAS) operations. A linked list of currently locked ranges is maintained and, upon entry to a lock acquisition operation, a thread waits for all locked ranges overlapping the desired range to be released then inserts a descriptor for the desired range into the linked list using a single CAS operation. To release a locked range, a thread executes a single fetch and add (FAA) operation. The operation may be extended to support simultaneous exclusive and non-exclusive access by allowing overlapping ranges to be locked for non-exclusive access and by performing an additional validation after locking to provide conflict resolution should a conflict be detected.

公开(公告)号：US20220245217A1

公开(公告)日：2022-08-04

申请号：US17586629

申请日：2022-01-27

Applicant: Oracle International Corporation

Inventor： Alex Kogan ,  David Dice

IPC: G06F17/16

Abstract: Adaptive selection of source matrix version for matrix multiply operations may be performed. Different versions of a matrix used in a matrix multiply operation, such as a transposed matrix and non-transposed matrix, may be selected and used when a matrix multiply operation is performed. The selection may be based on a performance profile that is identified for the matrix multiply operation.

公开(公告)号：US20220229691A1

公开(公告)日：2022-07-21

申请号：US17715812

申请日：2022-04-07

Applicant: Oracle International Corporation

Inventor： Virendra J. Marathe ,  Matej Pavlovic ,  Alex Kogan ,  Timothy L. Harris

IPC: G06F9/46 ,  G06F9/38 ,  G06F9/30 ,  G06F12/0815 ,  G06F9/52 ,  G06F12/0804 ,  G06F11/14 ,  G06F12/02

Abstract: A computer system including one or more processors and persistent, word-addressable memory implements a persistent atomic multi-word compare-and-swap operation. On entry, a list of persistent memory locations of words to be updated, respective expected current values contained the persistent memory locations and respective new values to write to the persistent memory locations are provided. The operation atomically performs the process of comparing the existing contents of the persistent memory locations to the respective current values and, should they match, updating the persistent memory locations with the new values and returning a successful status. Should any of the contents of the persistent memory locations not match a respective current value, the operation returns a failed status. The operation is performed such that the system can recover from any failure or interruption by restoring the list of persistent memory locations.

公开(公告)号：US20220138022A1

公开(公告)日：2022-05-05

申请号：US17245820

申请日：2021-04-30

Applicant: Oracle International Corporation

Inventor： David Dice ,  Alex Kogan

IPC: G06F9/52 ,  G06F9/30 ,  G06F9/50 ,  G06F9/54

Abstract: A computer including multiple processors and memory implements a managed runtime providing a synchronization application programming interface (API) for threads that perform synchronized accesses to shared objects. A standardized header of objects includes a memory word storing an object identifier. To lock the object for synchronized access, the memory word may be converted to store the tail of a linked list of a first-in-first-out synchronization structures for threads waiting to acquire the lock, with the object identifier relocated to the list structure. The list structure may further include a stack of threads waiting on events related to the object, with the synchronization API additionally providing wait, notify and related synchronization operations. Upon determining that no threads hold or desire to hold the lock for the object and that no threads are waiting on events related to the object, the memory word may be restored to contain the object identifier.