Hi, On Thu, Jan 02, 2025 at 08:50:17PM +0100, Arkadiusz Drabczyk wrote: > Here is the minimal example for pthread_mutex_lock() with all checks: [...] Thanks! > > Arkadiusz, would you do the honours writing a patch? Should I? > > I could do that but there is one more problem here - most pthread > manpages mention EINTR only to say that they don't return it except > pthread_cond_init.3: > > $ find . -name "*pthread*" -print0 | xargs -0 grep EINTR In this repo, we respect POSIX recommendations. You can safely pass filenames to xargs(1) without needing -print0 or -0. :-) $ find man/ -type f | grep pthread | xargs grep EINTR; > ./man/man3/pthread_atfork.3:.BR EINTR . > ./man/man3/pthread_tryjoin_np.3:.BR EINTR . > ./man/man3/pthread_cond_init.3:\fBEINTR\fP > ./man/man7/pthreads.7:.BR EINTR . > > that says: > > > EINTR pthread_cond_timedwait was interrupted by a signal. > > It's hard to say if it ever really worked like that because in > man/man7/pthreads.7 it says that no EINTR has been the requirement > since 2001: > > > Most pthreads functions return 0 on success, and an error number on > > failure. The error numbers that can be returned have the same meaning > > as the error numbers returned in errno by conventional system calls > > and C library functions. Note that the pthreads functions do not set > > errno. For each of the pthreads functions that can return an error, > > POSIX.1-2001 specifies that the function can never fail with the error > > EINTR. > > Today POSIX still says that pthread_cond_timedwait() cannot return > EINTR > https://pubs.opengroup.org/onlinepubs/9799919799/functions/pthread_cond_clockwait.html > and in my experiments it really doesn't, both with glibc and musl. > > pthread_cond_init.3 has been added in 1998 under linuxthread/ > directory, maybe the behavior specified by POSIX was different than > the initial design but OTOH it's quite surprising that no one noticed > the bug for so many years, I wonder how many people still check for > EINTR in pthread_cond_timedwait even though it's not necessary (but > harmless). The history of that manual page is quite complex. $ git log --oneline --graph --abbrev --date=short --format='%h (%ad, %cd; "%s")' --follow -- man/man3/pthread_cond_init.3 | cat ... * ec557d3c5 (2024-11-13, 2024-11-13; "pthread_cond_init.3: tfix") ... * d88513fd7 (2024-06-16, 2024-06-16; "man/, share/mk/: srcfix, and remove corresponding XFAIL exceptions") ... * b841c4f3c (2024-05-19, 2024-05-19; "pthread_*.3: ffix") ... * dcde2f703 (2024-04-26, 2024-05-02; "man/, share/mk/: Move man*/ to man/") ... * ee7b1c770 (2024-02-26, 2024-02-26; "man3/: Say cancelation instead of cancellation") ... * c6d039a3a (2023-10-31, 2023-10-31; "man*/: srcfix (Use .P instead of .PP or .LP)") ... * 8a00cac75 (2023-10-04, 2023-10-04; "pthread_*.3: ffix (semantic newlines)") * 74235f157 (2023-10-03, 2023-10-04; "pthread_*.3: ffix (paragraphing)") * 13151ec52 (2023-10-03, 2023-10-04; "pthread_*.3: Remove AUTHOR section; add copyright; adapt TH") * c1c253d0e (2023-10-04, 2023-10-04; "pthread_cond_init.3, pthread_condattr_init.3, pthread_key_create.3, pthread_mutex_init.3, pthread_mutexattr_setkind_np.3, pthread_once.3: Update the glibc pages with the debian/glibc version of them") ... * a254db8b3 (2023-10-03, 2023-10-04; "pthread_cond_init.3, pthread_condattr_init.3, pthread_key_create.3, pthread_mutex_init.3, pthread_mutexattr_setkind_np.3, pthread_once.3: Import pages from glibc") * 87d09778d (2023-10-03, 2023-10-04; "Revert "linuxthreads, linuxthreads_db: Directories removed (preserved in ports repository)."") ... | * a3db24d46 (2005-07-03, 2023-10-03; "linuxthreads, linuxthreads_db: Directories removed (preserved in ports repository).") | * 2988d2724 (2004-12-22, 2023-10-03; "(CFLAGS-tst-align.c): Add -mpreferred-stack-boundary=4.") | * f7f73b1ca (2007-07-12, 2023-10-03; "2.5-18.1") ... | * 869af9b6a (1999-05-23, 2023-10-03; "Correct example.") | * 31b1e42d5 (1998-03-11, 2023-10-03; "LinuxThreads library.") |/ (There are a few commits that don't show up there, and I don't know how to show them.) Notice the difference between author dates and commit dates in the bottom 5 commits. Those pages were removed in the glibc repository as obsolete in 2005. Debian imported them into a package, but they weren't maintained for a long time. At some point, I realized about their existence, and decided to import them, with all of their git gistory, into the Linux man-pages project, to start maintaining them, and eventually de-obsolete them (which as you can see, hasn't happened yet; I need people like you reporting their problems). I imported them last year. > So I was thinking that "pthread_mutex_lock(3), pthread_cond_wait(3), > and related APIs." line could be completely removed from signal.7 > because there is no pthread API that would return EINTR and EINTR > should be removed from the list of valid error codes in > pthread_cond_init.3. Does it sound good? Sounds good. Please CC Florian and libc-help@ if you send a patch, so they can review. Have a lovely night! Alex -- <https://www.alejandro-colomar.es/>
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