Changes in pthread_mutex_consistent.3

fa9896e0 - Remove $FreeBSD$: two-line nroff pattern

Wed, 16 Aug 2023 17:55:10 +0000

Remove $FreeBSD$: two-line nroff patternRemove /^\.\\"\n\.\\"\s*\$FreeBSD\$$\n/ List of files: /freebsd-14.2/share/man/man3/pthread_mutex_consistent.3

7fde0187 - Remove "All Rights Reserved" from Foundation copyrights

Thu, 30 Jun 2022 14:52:29 +0000

c5fb9d20 - More places to clarify the robustness guarantees.

Wed, 07 Aug 2019 17:51:40 +0000

More places to clarify the robustness guarantees.Wording submitted by: Martin Simmons MFC after: 3 days List of files: /freebsd-14.2/share/man/man3/pthread_mutex_consistent.3

1fdf757c - pthread_mutex_consistent: sort SEE ALSO by reference name

Mon, 27 Mar 2017 19:17:30 +0000

pthread_mutex_consistent: sort SEE ALSO by reference nameMFC after: 3 daysReported by: make manlintSponsored by: Dell EMC Isilon List of files: /freebsd-14.2/share/man/man3/pthread_mutex_consistent.3

2a339d9e - Add implementation of robust mutexes, hopefully close enough to the

Tue, 17 May 2016 09:56:22 +0000

Add implementation of robust mutexes, hopefully close enough to theintention of the POSIX IEEE Std 1003.1TM-2008/Cor 1-2013.A robust mutex is guaranteed to be cleared by the system upon eitherthread or process owner termination while the mutex is held. The nextmutex locker is then notified about inconsistent mutex state and canexecute (or abandon) corrective actions.The patch mostly consists of small changes here and there, addingneccessary checks for the inconsistent and abandoned conditions intoexisting paths. Additionally, the thread exit handler was extended toiterate over the userspace-maintained list of owned robust mutexes,unlocking and marking as terminated each of them.The list of owned robust mutexes cannot be maintained atomicallysynchronous with the mutex lock state (it is possible in kernel, butis too expensive). Instead, for the duration of lock or unlockoperation, the current mutex is remembered in a special slot that isalso checked by the kernel at thread termination.Kernel must be aware about the per-thread location of the heads ofrobust mutex lists and the current active mutex slot. When a threadtouches a robust mutex for the first time, a new umtx op syscall isissued which informs about location of lists heads.The umtx sleep queues for PP and PI mutexes are split betweennon-robust and robust.Somewhat unrelated changes in the patch:1. Style.2. The fix for proper tdfind() call use in umtxq_sleep_pi() for shared pi mutexes.3. Removal of the userspace struct pthread_mutex m_owner field.4. The sysctl kern.ipc.umtx_vnode_persistent is added, which controls the lifetime of the shared mutex associated with a vnode' page.Reviewed by: jilles (previous version, supposedly the objection was fixed)Discussed with: brooks, Martin Simmons (some aspects)Tested by: phoSponsored by: The FreeBSD Foundation List of files: /freebsd-14.2/share/man/man3/pthread_mutex_consistent.3