src-test2/include/pthread.h, branch release/11.0.0

Add implementation of robust mutexes, hopefully close enough to the

2016-05-17T09:56:22Z

intention of the POSIX IEEE Std 1003.1TM-2008/Cor 1-2013. A robust mutex is guaranteed to be cleared by the system upon either thread or process owner termination while the mutex is held. The next mutex locker is then notified about inconsistent mutex state and can execute (or abandon) corrective actions. The patch mostly consists of small changes here and there, adding neccessary checks for the inconsistent and abandoned conditions into existing paths. Additionally, the thread exit handler was extended to iterate 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 atomically synchronous with the mutex lock state (it is possible in kernel, but is too expensive). Instead, for the duration of lock or unlock operation, the current mutex is remembered in a special slot that is also checked by the kernel at thread termination. Kernel must be aware about the per-thread location of the heads of robust mutex lists and the current active mutex slot. When a thread touches a robust mutex for the first time, a new umtx op syscall is issued which informs about location of lists heads. The umtx sleep queues for PP and PI mutexes are split between non-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: pho Sponsored by: The FreeBSD Foundation

Implement process-shared locks support for libthr.so.3, without

2016-02-28T17:52:33Z

breaking the ABI. Special value is stored in the lock pointer to indicate shared lock, and offline page in the shared memory is allocated to store the actual lock. Reviewed by: vangyzen (previous version) Discussed with: deischen, emaste, jhb, rwatson, Martin Simmons Tested by: pho Sponsored by: The FreeBSD Foundation

Make use of gcc attributes in some standard include headers.

2015-04-06T01:39:16Z

The `nonnull' attribute specifies that some function parameters should be non-null pointers. This is very useful as it helps the compiler generate warnings on suspicious code and can also enable some small optimizations. Also start using 'alloc_size' attribute in the allocator functions. This is an initial step to better integrate our libc with the compiler: these attributes are fully supported by clang and they are also useful for the static analyzer. Note that due to some bogus internal procedure in the way gcc ports are built they may require updating if they were built before r280801. Relnotes: yes Hinted by: Android's bionic libc Differential Revision: https://reviews.freebsd.org/D2107

Clean some spaces vs tabs.

2015-03-29T20:20:45Z

No, this file doesn't conform with KNF at all.

Temporarily revert 280458.

2015-03-25T21:53:17Z

GCC is still carries an old version of cdefs.h which doesn't accept multiple parameters for the nonnull attribute. Since this issue probably affects many ports in the tree we will revert it for now until gcc gets fixed.

Introduce nonnull attributes in the signal and pthread headers.

2015-03-24T20:33:24Z

The `nonnull' attribute specifies that some function parameters should be non-null pointers. This is very useful as it helps the compiler generate warnings on suspicious code and can also enable some small optimizations. In clang this is also useful for the static analyzer. While we could go on defining this all over the tree, it only makes sense to annotate a subset of critical functions. Hinted by: Android's bionic libc Differential Revision: https://reviews.freebsd.org/D2101

Add lock annotations to the header files of our threading libraries.

2014-09-01T18:34:30Z

This change extends all of the functions present in the and headers to have lock annotations. This will allow Clang to warn about the following: - Locking a function twice, - Unlocking a function without a mutex being locked, - Forgetting to unlock a mutex before returning, - Destroying or reinitializing a mutex that is currenty locked, - Using an unlocked mutex in combination with a condition variable. Enabling these annotations already allowed me to catch a bug in one of our userspace tools (r270749).

Add a dummy statement to the beginning of the pthread_cleanup_pop() macro

2013-10-22T19:53:52Z

to allow a call of the macro to be labelled as in: label: pthread_cleanup_pop(); Reviewed by: imp MFC after: 3 days

Remove leftover for r214093.

2011-01-06T03:30:16Z

Add pthread_rwlockattr_setkind_np and pthread_rwlockattr_getkind_np, the

2010-10-18T05:09:22Z

functions set or get pthread_rwlock type, current supported types are: PTHREAD_RWLOCK_PREFER_READER_NP, PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP, PTHREAD_RWLOCK_PREFER_WRITER_NP, default is PTHREAD_RWLOCK_PREFER_WRITER_NONCECURSIVE_NP, this maintains binary compatible with old code.