PTHREAD_ATTR_INIT(3) manual page

From 41f88a82b33cdb357c83b582381232733ed2d039 Mon Sep 17 00:00:00 2001 From: rpj Date: Thu, 5 May 2005 14:18:27 +0000 Subject: '' --- manual/pthread_attr_init.html | 278 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 278 insertions(+) create mode 100644 manual/pthread_attr_init.html (limited to 'manual/pthread_attr_init.html') diff --git a/manual/pthread_attr_init.html b/manual/pthread_attr_init.html new file mode 100644 index 0000000..8947cf3 --- /dev/null +++ b/manual/pthread_attr_init.html @@ -0,0 +1,278 @@ + + + + + PTHREAD_ATTR_INIT(3) manual page + + + + + + + +

Table of Contents

Name

pthread_attr_init, pthread_attr_destroy, +pthread_attr_setdetachstate, pthread_attr_getdetachstate, +pthread_attr_setschedparam, pthread_attr_getschedparam, +pthread_attr_setschedpolicy, pthread_attr_getschedpolicy, +pthread_attr_setinheritsched, pthread_attr_getinheritsched, +pthread_attr_setscope, pthread_attr_getscope - thread creation +attributes +

Synopsis

#include <pthread.h> +

int pthread_attr_init(pthread_attr_t *attr); +

int pthread_attr_destroy(pthread_attr_t *attr); +

int pthread_attr_setdetachstate(pthread_attr_t *attr, +int detachstate); +

int pthread_attr_getdetachstate(const pthread_attr_t *attr, +int *detachstate); +

int pthread_attr_setschedpolicy(pthread_attr_t *attr, +int policy); +

int pthread_attr_getschedpolicy(const pthread_attr_t *attr, +int *policy); +

int pthread_attr_setschedparam(pthread_attr_t *attr, +const struct sched_param *param); +

int pthread_attr_getschedparam(const pthread_attr_t *attr, +struct sched_param *param); +

int pthread_attr_setinheritsched(pthread_attr_t *attr, +int inherit); +

int pthread_attr_getinheritsched(const pthread_attr_t *attr, +int *inherit); +

int pthread_attr_setscope(pthread_attr_t *attr, +int scope); +

int pthread_attr_getscope(const pthread_attr_t *attr, +int *scope); +

Description

Setting attributes for threads is achieved by filling a thread +attribute object attr of type pthread_attr_t, then +passing it as second argument to pthread_create(3) +. Passing NULL is equivalent to passing a thread attribute +object with all attributes set to their default values. +

pthread_attr_init initializes the thread attribute object +attr and fills it with default values for the attributes. (The +default values are listed below for each attribute.) +

Each attribute attrname (see below for a list of all +attributes) can be individually set using the function +pthread_attr_setattrname and retrieved using the +function pthread_attr_getattrname. +

pthread_attr_destroy destroys a thread attribute object, +which must not then be reused until it is reinitialized. +

Attribute objects are consulted only when creating a new thread. +The same attribute object can be used for creating several threads. +Modifying an attribute object after a call to pthread_create +does not change the attributes of the thread previously created. +

The following thread attributes are supported: +

detachstate

Control whether the thread is created in the joinable state (value +PTHREAD_CREATE_JOINABLE) or in the detached state ( +PTHREAD_CREATE_DETACHED). +

Default value: PTHREAD_CREATE_JOINABLE. +

In the joinable state, another thread can synchronize on the +thread termination and recover its termination code using +pthread_join(3) . When a +joinable thread terminates, some of the thread resources are kept +allocated, and released only when another thread performs +pthread_join(3) on that +thread. +

In the detached state, the thread's resources are released +immediately when it terminates. pthread_join(3) +cannot be used to synchronize on the thread termination. +

A thread created in the joinable state can later be put in the +detached thread using pthread_detach(3) +. +

schedpolicy

Select the scheduling policy for the thread: one of SCHED_OTHER +(regular, non-real-time scheduling), SCHED_RR (real-time, +round-robin) or SCHED_FIFO (real-time, first-in first-out). +

Pthreads-w32 only supports SCHED_OTHER - attempting +to set one of the other policies will return an error ENOTSUP.

Default value: SCHED_OTHER. +

Pthreads-w32 only supports SCHED_OTHER - attempting +to set one of the other policies will return an error ENOTSUP.

The scheduling policy of a thread can be changed after creation +with pthread_setschedparam(3) +. +

schedparam

Contain the scheduling parameters (essentially, the scheduling +priority) for the thread.

Pthreads-w32 supports the priority levels defined by the +Windows system it is running on. Under Windows, thread priorities are +relative to the process priority class, which must be set via the +Windows W32 API.

Default value: priority is 0 (Win32 level THREAD_PRIORITY_NORMAL). +

The scheduling priority of a thread can be changed after creation +with pthread_setschedparam(3) +. +

inheritsched

Indicate whether the scheduling policy and scheduling parameters +for the newly created thread are determined by the values of the +schedpolicy and schedparam attributes (value +PTHREAD_EXPLICIT_SCHED) or are inherited from the parent +thread (value PTHREAD_INHERIT_SCHED). +

Default value: PTHREAD_EXPLICIT_SCHED. +

scope

Define the scheduling contention scope for the created thread. The +only value supported in the Pthreads-w32 implementation is +PTHREAD_SCOPE_SYSTEM, meaning that the threads contend for CPU +time with all processes running on the machine. The other value +specified by the standard, PTHREAD_SCOPE_PROCESS, means that +scheduling contention occurs only between the threads of the running +process.

Pthreads-w32 only supports PTHREAD_SCOPE_SYSTEM.

Default value: PTHREAD_SCOPE_SYSTEM. +

Return Value

All functions return 0 on success and a non-zero error code on +error. On success, the pthread_attr_getattrname +functions also store the current value of the attribute attrname +in the location pointed to by their second argument. +

Errors

The pthread_attr_setdetachstate function returns the +following error codes on error: +

EINVAL +: + the specified detachstate is not one of + PTHREAD_CREATE_JOINABLE or PTHREAD_CREATE_DETACHED. +

+ +

+The pthread_attr_setschedparam function returns the following +error codes on error: +

EINVAL +: + the priority specified in param is outside the range of + allowed priorities for the scheduling policy currently in attr + (1 to 99 for SCHED_FIFO and SCHED_RR; 0 for + SCHED_OTHER). +

+ +

+The pthread_attr_setschedpolicy function returns the following +error codes on error: +

EINVAL +: + the specified policy is not one of SCHED_OTHER, + SCHED_FIFO, or SCHED_RR. +
+ ENOTSUP +: + policy is not SCHED_OTHER, the only value supported + by Pthreads-w32.

+ +

+The pthread_attr_setinheritsched function returns the +following error codes on error: +

EINVAL +: + the specified inherit is not one of PTHREAD_INHERIT_SCHED + or PTHREAD_EXPLICIT_SCHED. +

+ +

+The pthread_attr_setscope function returns the following error +codes on error: +

EINVAL +: + the specified scope is not one of PTHREAD_SCOPE_SYSTEM + or PTHREAD_SCOPE_PROCESS. +
+ ENOTSUP +: + the specified scope is PTHREAD_SCOPE_PROCESS (not + supported by Pthreads-w32). +

+ +

+Author

Xavier Leroy <Xavier.Leroy@inria.fr> +

Modified by Ross Johnson for use with Pthreads-w32.