1PTHREAD_SETSCHEDPRIO(3P) POSIX Programmer's Manual PTHREAD_SETSCHEDPRIO(3P)
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6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
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12 pthread_setschedprio - dynamic thread scheduling parameters access
13 (REALTIME THREADS)
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16 #include <pthread.h>
17 int pthread_setschedprio(pthread_t thread, int prio);
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22 The pthread_setschedprio() function shall set the scheduling priority
23 for the thread whose thread ID is given by thread to the value given by
24 prio. See Scheduling Policies for a description on how this function
25 call affects the ordering of the thread in the thread list for its new
26 priority.
27 If the pthread_setschedprio() function fails, the scheduling priority
29 of the target thread shall not be changed.
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32 If successful, the pthread_setschedprio() function shall return zero;
33 otherwise, an error number shall be returned to indicate the error.
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36 The pthread_setschedprio() function may fail if:
37 EINVAL The value of prio is invalid for the scheduling policy of the
39 specified thread.
40 ENOTSUP
42 An attempt was made to set the priority to an unsupported value.
43 EPERM The caller does not have the appropriate permission to set the
45 scheduling policy of the specified thread.
46 EPERM The implementation does not allow the application to modify the
48 priority to the value specified.
49 ESRCH The value specified by thread does not refer to an existing
51 thread.
52 The pthread_setschedprio() function shall not return an error code of
55 [EINTR].
56 The following sections are informative.
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60 None.
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63 None.
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66 The pthread_setschedprio() function provides a way for an application
67 to temporarily raise its priority and then lower it again, without hav‐
68 ing the undesired side effect of yielding to other threads of the same
69 priority. This is necessary if the application is to implement its own
70 strategies for bounding priority inversion, such as priority inheri‐
71 tance or priority ceilings. This capability is especially important if
72 the implementation does not support the Thread Priority Protection or
73 Thread Priority Inheritance options, but even if those options are sup‐
74 ported it is needed if the application is to bound priority inheritance
75 for other resources, such as semaphores.
76 The standard developers considered that while it might be preferable
78 conceptually to solve this problem by modifying the specification of
79 pthread_setschedparam(), it was too late to make such a change, as
80 there may be implementations that would need to be changed. Therefore,
81 this new function was introduced.
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84 None.
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87 Scheduling Policies, pthread_getschedparam(), the Base Definitions vol‐
88 ume of IEEE Std 1003.1-2001, <pthread.h>
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91 Portions of this text are reprinted and reproduced in electronic form
92 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
93 -- Portable Operating System Interface (POSIX), The Open Group Base
94 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
95 Electrical and Electronics Engineers, Inc and The Open Group. In the
96 event of any discrepancy between this version and the original IEEE and
97 The Open Group Standard, the original IEEE and The Open Group Standard
98 is the referee document. The original Standard can be obtained online
99 at http://www.opengroup.org/unix/online.html .
100IEEE/The Open Group 2003 PTHREAD_SETSCHEDPRIO(3P)