Defect in XSH pthread_cond_timedwait()

[yyyyyyyy@xxxxxx]

        Defect report from : Alexander Terekhov , IBM

(Please direct followup comments direct to yyyyyyyyyyyyyy@xxxxxxxxxxxxx)

@ page 1036 line 32668-32671 section pthread_cond_timedwait() comment 
{alt-cv.timedwait-2003-07-11}

Problem:

Edition of Specification (Year): 2003

Defect code :  3. Clarification required

The standard says:

<quote source=32668-32671>

The pthread_cond_timedwait() function shall be equivalent to 
pthread_cond_wait(), except that an error is returned if the 
absolute time specified by abstime passes (that is, system time 
equals or exceeds abstime) before the condition cond is signaled 
or broadcasted, or if the absolute time specified by abstime has 
already been passed at the time of the call.

</quote>

It isn't clear (you might want but not need to follow the link 
that can be found below) whether a thread that has been unblocked 
because its wait has been timedout while blocked in a call to 
pthread_cond_timedwait() may consume a condition signal that may 
be directed concurrently at the condition variable if there are 
other threads blocked on the condition variable.

http://google.com/groups?threadm=bej397%24ho9%241%40nntp.webmaster.com
(Subject: Strange mutex question, can a timeout satisfy a signal?)

     

Action:

add the following (or something like that) after 32671:

  A thread that has been unblocked because its wait has been 
  timedout while blocked in a call to pthread_cond_timedwait() 
  may consume a condition signal (not more than one) that may 
  be directed concurrently at the condition variable even if 
  there are other threads blocked on the condition variable.

-OR- (I really don't like it, but others disagree)

add the following (or something like that) after 32671:

  A thread that has been unblocked because its wait has been 
  timedout while blocked in a call to pthread_cond_timedwait() 
  shall not consume any condition signal that may be directed 
  concurrently at the condition variable if there are other 
  threads blocked on the condition variable.