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diff --git a/man-pages-posix-2013/man3p/pthread_rwlock_trywrlock.3p b/man-pages-posix-2013/man3p/pthread_rwlock_trywrlock.3p new file mode 100644 index 0000000..30313d2 --- /dev/null +++ b/man-pages-posix-2013/man3p/pthread_rwlock_trywrlock.3p @@ -0,0 +1,133 @@ +'\" et +.TH PTHREAD_RWLOCK_TRYWRLOCK "3P" 2013 "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_rwlock_trywrlock, +pthread_rwlock_wrlock +\(em lock a read-write lock object for writing +.SH SYNOPSIS +.LP +.nf +#include <pthread.h> +.P +int pthread_rwlock_trywrlock(pthread_rwlock_t *\fIrwlock\fP); +int pthread_rwlock_wrlock(pthread_rwlock_t *\fIrwlock\fP); +.fi +.SH DESCRIPTION +The +\fIpthread_rwlock_trywrlock\fR() +function shall apply a write lock like the +\fIpthread_rwlock_wrlock\fR() +function, with the exception that the function shall fail if any thread +currently holds +.IR rwlock +(for reading or writing). +.P +The +\fIpthread_rwlock_wrlock\fR() +function shall apply a write lock to the read-write lock referenced by +.IR rwlock . +The calling thread acquires the write lock if no other thread (reader +or writer) holds the read-write lock +.IR rwlock . +Otherwise, the thread shall block until it can acquire the lock. The +calling thread may deadlock if at the time the call is made it holds +the read-write lock (whether a read or write lock). +.P +Implementations may favor writers over readers to avoid +writer starvation. +.P +Results are undefined if any of these functions are called with an +uninitialized read-write lock. +.P +If a signal is delivered to a thread waiting for a read-write lock for +writing, upon return from the signal handler the thread resumes waiting +for the read-write lock for writing as if it was not interrupted. +.SH "RETURN VALUE" +The +\fIpthread_rwlock_trywrlock\fR() +function shall return zero if the lock for writing on the read-write +lock object referenced by +.IR rwlock +is acquired. Otherwise, an error number shall be returned to indicate +the error. +.P +If successful, the +\fIpthread_rwlock_wrlock\fR() +function shall return zero; otherwise, an error number shall be +returned to indicate the error. +.SH ERRORS +The +\fIpthread_rwlock_trywrlock\fR() +function shall fail if: +.TP +.BR EBUSY +The read-write lock could not be acquired for writing because it was +already locked for reading or writing. +.P +The +\fIpthread_rwlock_wrlock\fR() +function may fail if: +.TP +.BR EDEADLK +A deadlock condition was detected or the current thread already owns +the read-write lock for writing or reading. +.P +These functions shall not return an error code of +.BR [EINTR] . +.LP +.IR "The following sections are informative." +.SH EXAMPLES +None. +.SH "APPLICATION USAGE" +Applications using these functions may be subject to priority inversion, +as discussed in the Base Definitions volume of POSIX.1\(hy2008, +.IR "Section 3.287" ", " "Priority Inversion". +.SH RATIONALE +If an implementation detects that the value specified by the +.IR rwlock +argument to +\fIpthread_rwlock_trywrlock\fR() +or +\fIpthread_rwlock_wrlock\fR() +does not refer to an initialized read-write lock object, it is +recommended that the function should fail and report an +.BR [EINVAL] +error. +.SH "FUTURE DIRECTIONS" +None. +.SH "SEE ALSO" +.ad l +.IR "\fIpthread_rwlock_destroy\fR\^(\|)", +.IR "\fIpthread_rwlock_rdlock\fR\^(\|)", +.IR "\fIpthread_rwlock_timedrdlock\fR\^(\|)", +.IR "\fIpthread_rwlock_timedwrlock\fR\^(\|)", +.IR "\fIpthread_rwlock_unlock\fR\^(\|)" +.ad b +.P +The Base Definitions volume of POSIX.1\(hy2008, +.IR "Section 3.287" ", " "Priority Inversion", +.IR "Section 4.11" ", " "Memory Synchronization", +.IR "\fB<pthread.h>\fP" +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 7, Copyright (C) 2013 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. +(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/online.html . + +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 . |