개요

• 솔라나라에 설명된 어플리케이션에 대해 맨 페이지를 찾아 출력한다.
• MAN 페이지에 대한 설명은 윈디하나의 솔라나라: MAN 페이지을 참고하자.
• svcadm(8)을 검색하려면 섹션에서 8 을 선택하고, 맨 페이지 이름에 svcadm을 입력하고 검색을 누른다.

pthread_getconcurrency(3c)

Standard C Library Functions
                                                    pthread_getconcurrency(3C)



NAME
       pthread_getconcurrency,  pthread_setconcurrency  -  get or set level of
       concurrency

SYNOPSIS
       #include <pthread.h>

       int pthread_getconcurrency(void);


       int pthread_setconcurrency(int new_level);

DESCRIPTION
       Unbound threads in a process may or may not be required to be  simulta‐
       neously  active.  By default, the threads implementation ensures that a
       sufficient number of threads are active so that the  process  can  con‐
       tinue  to  make progress. While this conserves system resources, it may
       not produce the most effective level of concurrency.


       The pthread_setconcurrency() function allows an application  to  inform
       the threads implementation of its desired concurrency level, new_level.
       The actual level of concurrency provided by  the  implementation  as  a
       result of this function call is unspecified.


       If new_level is 0, it causes the implementation to maintain the concur‐
       rency level at its discretion as if pthread_setconcurrency() was  never
       called.


       The pthread_getconcurrency() function returns the value set by a previ‐
       ous call to the pthread_setconcurrency() function. If the  pthread_set‐
       concurrency() function was not previously called, this function returns
       0 to indicate that the implementation is  maintaining  the  concurrency
       level.


       When  an application calls pthread_setconcurrency() it is informing the
       implementation of its desired  concurrency  level.  The  implementation
       uses this as a hint, not a requirement.


       If  an  implementation does not support multiplexing of user threads on
       top of several kernel scheduled entities, the  pthread_setconcurrency()
       and pthread_getconcurrency() functions will be provided for source code
       compatibility but they will have no effect when called. To maintain the
       function   semantics,  the  new_level  parameter  will  be  saved  when
       pthread_setconcurrency()  is  called  so  that  a  subsequent  call  to
       pthread_getconcurrency() returns the same value.

RETURN VALUES
       If  successful, the pthread_setconcurrency() function returns 0. Other‐
       wise, an error number is returned to indicate the error.


       The pthread_getconcurrency() function always  returns  the  concurrency
       level  set  by  a  previous  call  to  pthread_setconcurrency(). If the
       pthread_setconcurrency() function has never been  called,  pthread_get‐
       concurrency() returns 0.

ERRORS
       The pthread_setconcurrency() function will fail if:

       EINVAL    The value specified by new_level is negative.


       EAGAIN    The value specific by new_level would cause a system resource
                 to be exceeded.


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       tab() box; cw(2.75i) |cw(2.75i) lw(2.75i) |lw(2.75i) ATTRIBUTE  TYPEAT‐
       TRIBUTE  VALUE _ Interface StabilityCommitted _ MT-LevelMT-Safe _ Stan‐
       dardSee standards(7).


SEE ALSO
       pthread_attr_init(3C), pthread_create(3C), attributes(7), standards(7)



Oracle Solaris 11.4               16 May 2014
                                                    pthread_getconcurrency(3C)