PTHREAD_GETCONCURRENCY (3) | C library functions | Unix Manual Pages | :man▋
pthread_getconcurrency, pthread_setconcurrency - get or set level of concurrency
.In pthread.h int pthread_getconcurrency void int pthread_setconcurrency "int new_level"
The pthread_getconcurrency 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 zero, it causes the implementation to maintain the concurrency level at its discretion as if pthread_setconcurrency was never called. The pthread_getconcurrency function returns the value set by a previous call to the pthread_setconcurrency function. If the pthread_setconcurrency function was not previously called, this function returns zero 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 successful, the pthread_setconcurrency function returns zero. Otherwise, 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_getconcurrency returns zero.
The pthread_setconcurrency function will fail if:
| || The value specified by new_level is negative. |
| || The value specified by new_level would cause a system resource to be exceeded. |
Use of these functions changes the state of the underlying concurrency upon which the application depends. Library developers are advised to not use the pthread_getconcurrency and pthread_setconcurrency functions since their use may conflict with an applications use of these functions.
The pthread_getconcurrency and pthread_setconcurrency functions conform to -susv2.
shtml">manServer 1.07 from pthread_getconcurrency.3 using doc macros.
|April 11, 2003 ||PTHREAD_GETCONCURRENCY (3) || |