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Diffstat (limited to 'upstream/archlinux/man3p/pthread_mutex_timedlock.3p')
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diff --git a/upstream/archlinux/man3p/pthread_mutex_timedlock.3p b/upstream/archlinux/man3p/pthread_mutex_timedlock.3p new file mode 100644 index 00000000..92ea85fb --- /dev/null +++ b/upstream/archlinux/man3p/pthread_mutex_timedlock.3p @@ -0,0 +1,197 @@ +'\" et +.TH PTHREAD_MUTEX_TIMEDLOCK "3P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual" +.\" +.SH PROLOG +This manual page is part of the POSIX Programmer's Manual. +The Linux implementation of this interface may differ (consult +the corresponding Linux manual page for details of Linux behavior), +or the interface may not be implemented on Linux. +.\" +.SH NAME +pthread_mutex_timedlock +\(em lock a mutex +.SH SYNOPSIS +.LP +.nf +#include <pthread.h> +#include <time.h> +.P +int pthread_mutex_timedlock(pthread_mutex_t *restrict \fImutex\fP, + const struct timespec *restrict \fIabstime\fP); +.fi +.SH DESCRIPTION +The +\fIpthread_mutex_timedlock\fR() +function shall lock the mutex object referenced by +.IR mutex . +If the mutex is already locked, the calling thread shall block +until the mutex becomes available as in the +\fIpthread_mutex_lock\fR() +function. If the mutex cannot be locked without waiting for another +thread to unlock the mutex, this wait shall be terminated when the +specified timeout expires. +.P +The timeout shall expire when the absolute time specified by +.IR abstime +passes, as measured by the clock on which timeouts are based (that is, +when the value of that clock equals or exceeds +.IR abstime ), +or if the absolute time specified by +.IR abstime +has already been passed at the time of the call. +.P +The timeout shall be based on the CLOCK_REALTIME clock. +The resolution of the timeout shall be the resolution of the clock on +which it is based. The +.BR timespec +data type is defined in the +.IR <time.h> +header. +.P +Under no circumstance shall the function fail with a timeout if the +mutex can be locked immediately. The validity of the +.IR abstime +parameter need not be checked if the mutex can be locked immediately. +.P +As a consequence of the priority inheritance rules (for mutexes +initialized with the PRIO_INHERIT protocol), if a timed mutex wait is +terminated +because its timeout expires, the priority of the owner of the mutex +shall be adjusted as necessary to reflect the fact that this thread is +no longer among the threads waiting for the mutex. +.P +If +.IR mutex +is a robust mutex and the process containing the owning thread +terminated while holding the mutex lock, a call to +\fIpthread_mutex_timedlock\fR() +shall return the error value +.BR [EOWNERDEAD] . +If +.IR mutex +is a robust mutex and the owning thread terminated while holding the +mutex lock, a call to +\fIpthread_mutex_timedlock\fR() +may return the error value +.BR [EOWNERDEAD] +even if the process in which the owning thread resides has not +terminated. In these cases, the mutex is locked by the thread but the +state it protects is marked as inconsistent. The application should +ensure that the state is made consistent for reuse and when that is +complete call +\fIpthread_mutex_consistent\fR(). +If the application is unable to recover the state, it should unlock the +mutex without a prior call to +\fIpthread_mutex_consistent\fR(), +after which the mutex is marked permanently unusable. +.P +If +.IR mutex +does not refer to an initialized mutex object, the behavior is undefined. +.SH "RETURN VALUE" +If successful, the +\fIpthread_mutex_timedlock\fR() +function shall return zero; otherwise, an error number shall be +returned to indicate the error. +.SH ERRORS +The +\fIpthread_mutex_timedlock\fR() +function shall fail if: +.TP +.BR EAGAIN +The mutex could not be acquired because the maximum number of recursive +locks for +.IR mutex +has been exceeded. +.TP +.BR EDEADLK +The mutex type is PTHREAD_MUTEX_ERRORCHECK and the current +thread already owns the mutex. +.TP +.BR EINVAL +The mutex was created with the protocol attribute having the value +PTHREAD_PRIO_PROTECT and the calling thread's priority is higher than +the mutex' current priority ceiling. +.TP +.BR EINVAL +The process or thread would have blocked, and the +.IR abstime +parameter specified a nanoseconds field value less than zero or greater +than or equal to 1\|000 million. +.TP +.BR ENOTRECOVERABLE +.br +The state protected by the mutex is not recoverable. +.TP +.BR EOWNERDEAD +.br +The mutex is a robust mutex and the process containing the previous +owning thread terminated while holding the mutex lock. The mutex lock +shall be acquired by the calling thread and it is up to the new owner +to make the state consistent. +.TP +.BR ETIMEDOUT +The mutex could not be locked before the specified timeout expired. +.P +The +\fIpthread_mutex_timedlock\fR() +function may fail if: +.TP +.BR EDEADLK +A deadlock condition was detected. +.TP +.BR EOWNERDEAD +.br +The mutex is a robust mutex and the previous owning thread terminated +while holding the mutex lock. The mutex lock shall be acquired by the +calling thread and it is up to the new owner to make the state consistent. +.P +This function shall not return an error code of +.BR [EINTR] . +.LP +.IR "The following sections are informative." +.SH EXAMPLES +None. +.SH "APPLICATION USAGE" +Applications that have assumed that non-zero return values are errors +will need updating for use with robust mutexes, since a valid return +for a thread acquiring a mutex which is protecting a currently +inconsistent state is +.BR [EOWNERDEAD] . +Applications that do not check the error returns, due to ruling out the +possibility of such errors arising, should not use robust mutexes. If +an application is supposed to work with normal and robust mutexes, it +should check all return values for error conditions and if necessary +take appropriate action. +.SH RATIONALE +Refer to +.IR "\fIpthread_mutex_lock\fR\^(\|)". +.SH "FUTURE DIRECTIONS" +None. +.SH "SEE ALSO" +.IR "\fIpthread_mutex_destroy\fR\^(\|)", +.IR "\fIpthread_mutex_lock\fR\^(\|)", +.IR "\fItime\fR\^(\|)" +.P +The Base Definitions volume of POSIX.1\(hy2017, +.IR "Section 4.12" ", " "Memory Synchronization", +.IR "\fB<pthread.h>\fP", +.IR "\fB<time.h>\fP" +.\" +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1-2017, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 7, 2018 Edition, +Copyright (C) 2018 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. +In the event of any discrepancy between this version and the original IEEE and +The Open Group Standard, the original IEEE and The Open Group Standard +is the referee document. The original Standard can be obtained online at +http://www.opengroup.org/unix/online.html . +.PP +Any typographical or formatting errors that appear +in this page are most likely +to have been introduced during the conversion of the source files to +man page format. To report such errors, see +https://www.kernel.org/doc/man-pages/reporting_bugs.html . |