SEM_CLOSE(3)               POSIX Programmer's Manual              SEM_CLOSE(3)



PPRROOLLOOGG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.

NNAAMMEE
       sem_close -- close a named semaphore

SSYYNNOOPPSSIISS
       #include <semaphore.h>

       int sem_close(sem_t *_s_e_m);

DDEESSCCRRIIPPTTIIOONN
       The _s_e_m___c_l_o_s_e() function shall indicate that the calling process is
       finished using the named semaphore indicated by _s_e_m.  The effects of
       calling _s_e_m___c_l_o_s_e() for an unnamed semaphore (one created by
       _s_e_m___i_n_i_t()) are undefined. The _s_e_m___c_l_o_s_e() function shall deallocate
       (that is, make available for reuse by a subsequent _s_e_m___o_p_e_n() by this
       process) any system resources allocated by the system for use by this
       process for this semaphore. The effect of subsequent use of the
       semaphore indicated by _s_e_m by this process is undefined. If any threads
       in the calling process are currently blocked on the semaphore, the
       behavior is undefined.  If the semaphore has not been removed with a
       successful call to _s_e_m___u_n_l_i_n_k(), then _s_e_m___c_l_o_s_e() has no effect on the
       state of the semaphore. If the _s_e_m___u_n_l_i_n_k() function has been
       successfully invoked for _n_a_m_e after the most recent call to _s_e_m___o_p_e_n()
       with O_CREAT for this semaphore, then when all processes that have
       opened the semaphore close it, the semaphore is no longer accessible.

RREETTUURRNN VVAALLUUEE
       Upon successful completion, a value of zero shall be returned.
       Otherwise, a value of -1 shall be returned and _e_r_r_n_o set to indicate
       the error.

EERRRROORRSS
       The _s_e_m___c_l_o_s_e() function may fail if:

       EEIINNVVAALL The _s_e_m argument is not a valid semaphore descriptor.

       _T_h_e _f_o_l_l_o_w_i_n_g _s_e_c_t_i_o_n_s _a_r_e _i_n_f_o_r_m_a_t_i_v_e_.

EEXXAAMMPPLLEESS
       None.

AAPPPPLLIICCAATTIIOONN UUSSAAGGEE
       None.

RRAATTIIOONNAALLEE
       None.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       None.

SSEEEE AALLSSOO
       _s_e_m_c_t_l(), _s_e_m_g_e_t(), _s_e_m_o_p(), _s_e_m___i_n_i_t(), _s_e_m___o_p_e_n(), _s_e_m___u_n_l_i_n_k()

       The Base Definitions volume of POSIX.1-2017, <<sseemmaapphhoorree..hh>>

CCOOPPYYRRIIGGHHTT
       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 .

       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 .



IEEE/The Open Group                  2017                         SEM_CLOSE(3)
