pthread_attr_setinheritsched(3)

1PTHREAD_ATTR_SETINHERITSCHEDL(i3n)ux Programmer's MaPnTuHaRlEAD_ATTR_SETINHERITSCHED(3)
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NAME

6       pthread_attr_setinheritsched,  pthread_attr_getinheritsched  -  set/get
7       inherit-scheduler attribute in thread attributes object
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SYNOPSIS

10       #include <pthread.h>
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12       int pthread_attr_setinheritsched(pthread_attr_t *attr,
13                                        int inheritsched);
14       int pthread_attr_getinheritsched(const pthread_attr_t *restrict attr,
15                                        int *restrict inheritsched);
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17       Compile and link with -pthread.
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DESCRIPTION

20       The pthread_attr_setinheritsched() function sets the  inherit-scheduler
21       attribute  of  the  thread attributes object referred to by attr to the
22       value specified in inheritsched.  The inherit-scheduler  attribute  de‐
23       termines  whether  a  thread created using the thread attributes object
24       attr will inherit its scheduling attributes from the calling thread  or
25       whether it will take them from attr.
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27       The  following scheduling attributes are affected by the inherit-sched‐
28       uler  attribute:  scheduling  policy  (pthread_attr_setschedpolicy(3)),
29       scheduling  priority  (pthread_attr_setschedparam(3)),  and  contention
30       scope (pthread_attr_setscope(3)).
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32       The following values may be specified in inheritsched:
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34       PTHREAD_INHERIT_SCHED
35              Threads that are  created  using  attr  inherit  scheduling  at‐
36              tributes  from the creating thread; the scheduling attributes in
37              attr are ignored.
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39       PTHREAD_EXPLICIT_SCHED
40              Threads that are created using attr take  their  scheduling  at‐
41              tributes from the values specified by the attributes object.
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43       The  default setting of the inherit-scheduler attribute in a newly ini‐
44       tialized thread attributes object is PTHREAD_INHERIT_SCHED.
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46       The pthread_attr_getinheritsched() returns the inherit-scheduler attri‐
47       bute  of  the thread attributes object attr in the buffer pointed to by
48       inheritsched.
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RETURN VALUE

51       On success, these functions return 0; on error, they return  a  nonzero
52       error number.
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ERRORS

55       pthread_attr_setinheritsched() can fail with the following error:
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57       EINVAL Invalid value in inheritsched.
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59       POSIX.1  also documents an optional ENOTSUP error ("attempt was made to
60       set the attribute to an unsupported value") for  pthread_attr_setinher‐
61       itsched().
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ATTRIBUTES

64       For  an  explanation  of  the  terms  used  in  this  section,  see at‐
65       tributes(7).
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67       ┌────────────────────────────────────────────┬───────────────┬─────────┐
68       │Interface                                   │ Attribute     │ Value   │
69       ├────────────────────────────────────────────┼───────────────┼─────────┤
70       │pthread_attr_setinheritsched(),             │ Thread safety │ MT-Safe │
71       │pthread_attr_getinheritsched()              │               │         │
72       └────────────────────────────────────────────┴───────────────┴─────────┘
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CONFORMING TO

75       POSIX.1-2001, POSIX.1-2008.
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BUGS

78       As  at  glibc  2.8,  if a thread attributes object is initialized using
79       pthread_attr_init(3), then the scheduling policy of the attributes  ob‐
80       ject  is  set  to  SCHED_OTHER and the scheduling priority is set to 0.
81       However, if the inherit-scheduler attribute is then set to  PTHREAD_EX‐
82       PLICIT_SCHED,  then a thread created using the attribute object wrongly
83       inherits its scheduling attributes from the creating thread.  This  bug
84       does  not  occur if either the scheduling policy or scheduling priority
85       attribute is explicitly set in  the  thread  attributes  object  before
86       calling pthread_create(3).
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EXAMPLES

89       See pthread_setschedparam(3).
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COLOPHON

98       This page is part of release 5.13 of the Linux man-pages project.  A
99       description of the project, information about reporting bugs, and the
100       latest version of this page, can be found at
101       https://www.kernel.org/doc/man-pages/.
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105Linux                             2021-03-22   PTHREAD_ATTR_SETINHERITSCHED(3)