PTHREAD_MUTEXATTR_GETTYPE(3)POSIX Programmer's ManuaPlTHREAD_MUTEXATTR_GETTYPE(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
       pthread_mutexattr_gettype, pthread_mutexattr_settype -- get and set the
       mutex type attribute

SSYYNNOOPPSSIISS
       #include <pthread.h>

       int pthread_mutexattr_gettype(const pthread_mutexattr_t *restrict _a_t_t_r,
           int *restrict _t_y_p_e);
       int pthread_mutexattr_settype(pthread_mutexattr_t *_a_t_t_r, int _t_y_p_e);

DDEESSCCRRIIPPTTIIOONN
       The _p_t_h_r_e_a_d___m_u_t_e_x_a_t_t_r___g_e_t_t_y_p_e() and _p_t_h_r_e_a_d___m_u_t_e_x_a_t_t_r___s_e_t_t_y_p_e()
       functions, respectively, shall get and set the mutex _t_y_p_e attribute.
       This attribute is set in the _t_y_p_e parameter to these functions. The
       default value of the _t_y_p_e attribute is PTHREAD_MUTEX_DEFAULT.

       The type of mutex is contained in the _t_y_p_e attribute of the mutex
       attributes. Valid mutex types include:

              PTHREAD_MUTEX_NORMAL PTHREAD_MUTEX_ERRORCHECK
              PTHREAD_MUTEX_RECURSIVE PTHREAD_MUTEX_DEFAULT

       The mutex type affects the behavior of calls which lock and unlock the
       mutex. See _p_t_h_r_e_a_d___m_u_t_e_x___l_o_c_k() for details. An implementation may map
       PTHREAD_MUTEX_DEFAULT to one of the other mutex types.

       The behavior is undefined if the value specified by the _a_t_t_r argument
       to _p_t_h_r_e_a_d___m_u_t_e_x_a_t_t_r___g_e_t_t_y_p_e() or _p_t_h_r_e_a_d___m_u_t_e_x_a_t_t_r___s_e_t_t_y_p_e() does not
       refer to an initialized mutex attributes object.

RREETTUURRNN VVAALLUUEE
       Upon successful completion, the _p_t_h_r_e_a_d___m_u_t_e_x_a_t_t_r___g_e_t_t_y_p_e() function
       shall return zero and store the value of the _t_y_p_e attribute of _a_t_t_r
       into the object referenced by the _t_y_p_e parameter. Otherwise, an error
       shall be returned to indicate the error.

       If successful, the _p_t_h_r_e_a_d___m_u_t_e_x_a_t_t_r___s_e_t_t_y_p_e() function shall return
       zero; otherwise, an error number shall be returned to indicate the
       error.

EERRRROORRSS
       The _p_t_h_r_e_a_d___m_u_t_e_x_a_t_t_r___s_e_t_t_y_p_e() function shall fail if:

       EEIINNVVAALL The value _t_y_p_e is invalid.

       These functions shall not return an error code of [[EEIINNTTRR]].

       _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
       It is advised that an application should not use a
       PTHREAD_MUTEX_RECURSIVE mutex with condition variables because the
       implicit unlock performed for a _p_t_h_r_e_a_d___c_o_n_d___t_i_m_e_d_w_a_i_t() or
       _p_t_h_r_e_a_d___c_o_n_d___w_a_i_t() may not actually release the mutex (if it had been
       locked multiple times). If this happens, no other thread can satisfy
       the condition of the predicate.

RRAATTIIOONNAALLEE
       If an implementation detects that the value specified by the _a_t_t_r
       argument to _p_t_h_r_e_a_d___m_u_t_e_x_a_t_t_r___g_e_t_t_y_p_e() or _p_t_h_r_e_a_d___m_u_t_e_x_a_t_t_r___s_e_t_t_y_p_e()
       does not refer to an initialized mutex attributes object, it is
       recommended that the function should fail and report an [[EEIINNVVAALL]] error.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       None.

SSEEEE AALLSSOO
       _p_t_h_r_e_a_d___c_o_n_d___t_i_m_e_d_w_a_i_t(), _p_t_h_r_e_a_d___m_u_t_e_x___l_o_c_k()

       The Base Definitions volume of POSIX.1-2017, <<pptthhrreeaadd..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         PTHREAD_MUTEXATTR_GETTYPE(3)
