惠普手册页(link)说
“By default,the new thread’s scheduling policy and priority are
inherited from the creating thread—that is,by default,the
pthread_create(3) routine ignores the scheduling policy and priority
set in the specified thread attributes object. Thus,to create a
thread that is subject to the scheduling policy and priority set in
the specified thread attributes object,before calling
pthread_create(3) your program must use the
pthread_attr_setinheritsched(3) routine to set the inherit thread
attributes object’s scheduling attribute to PTHREAD_EXPLICIT_SCHED.”
这适用于Linux posix线程(NPTL pthread)吗?
如果没有,影响使用pthread_create()创建的线程的优先级和调度策略的因素是什么?
The following values may be specified in inheritsched:
PTHREAD_INHERIT_SCHED
Threads that are created using attr inherit scheduling attributes from the creating thread; the scheduling attributes in attr are ignored.PTHREAD_EXPLICIT_SCHED
Threads that are created using attr take their scheduling attributes from the values specified by the attributes object.The default setting of the inherit scheduler attribute in a newly initialized thread attributes object is PTHREAD_INHERIT_SCHED.
因此,似乎与问题中描述的行为相同.
我实际上已经认为这个默认值可以由标准定义(虽然我没有那么多经验,但我承认),但是看看Thread Scheduling Attributes部分的最后一行:
(…) The default values of other scheduling attributes are implementation-defined.