2001-07-01 Ross Johnson <rpj@setup1.ise.canberra.edu.au>

        Contributed by  - Alexander Terekhov.

        * condvar.c: Fixed lost signal bug reported by Timur Aydin
        (taydin@snet.net).
        [RPJ (me) didn't translate the original algorithm
        correctly.]
        * semaphore.c: Added sem_post_multiple; this is a useful
        routine, but it doesn't appear to be standard. For now it's
        not an exported function.

1 files changed, 62 insertions, 9 deletions

diff --git a/ANNOUNCE b/ANNOUNCE
index 689b16d..573d15c 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -23,10 +23,8 @@ Please see the 'Acknowledgements' section at the end of this
 announcement for the list of contributors.

 

 

-Change Summary (since the last snapshot)

-----------------------------------------

-

-(See the ChangeLog file for details.)

+Changes since the last snapshot

+-------------------------------

 

 -----------------------

 Additions to Scheduling

@@ -113,11 +111,13 @@ values.
 ------------------

 Changes to Mutexes

 ------------------

+Background:

 Snapshot-2001-06-06 included Thomas Pfaff's enhancements

 to the mutex routines to improve speed. The improvements

-are most apparent on Win9x class systems where pthreads-win32

+are very large on Win9x class systems where pthreads-win32

 previously used Win32 mutexes rather than critical

-sections as the underlying mechanism. The enhancements

+sections as the underlying mechanism. On WNT systems speed

+appears to have decreased a little. On Win9x the enhancements

 also resulted in speed improvements in other primitives

 which use mutexes internally, such as condition variables

 and read-write locks. Thomas also added mutex

@@ -126,6 +126,11 @@ Specification documentation, and as provided with
 the majority of major Unix and Linux Pthreads

 implementations.

 

+Overall, the library provides far more consistent performance

+across the different Windows variants with greater compatibility.

+Future work will continue to improve on this.

+

+New changes:

 Changes have been made to further improve the speed of the

 default PTHREAD_MUTEX_NORMAL type (and therefore also

 PTHREAD_MUTEX_DEFAULT which is equivalent in pthreads-win32).

@@ -160,14 +165,62 @@ These mutex changes appear to be consistent with both
 the behaviour exhibited by other implementations and their

 documentation, including the Open Group documentation.

 

+------------

+Benchmarking

+------------

+There is a new but growing set a benchmarking programs in the

+"tests" directory. These should be runnable using the

+following command-lines corresponding to each of the possible

+library builds:

 

--------

-Bug fix

--------

+MSVC:

+nmake clean VC-bench

+nmake clean VCE-bench

+nmake clean VSE-bench

+

+Mingw32:

+make clean GC-bench

+make clean GCE-bench

+

+UWIN:

+The benchtests are run as part of the testsuite.

+

+Currently these only provide timing for various

+synchronisation senarios for the different mutex types.

+Each test does timings for each of the implemented

+mutex types and, for reference, also repeats the same

+tests using the following:

+

+Simple Critical Section

+POSIX mutex implemented using a Critical Section

+POSIX mutex implemented using a Win32 Mutex

+

+The later two represent the old implementation under

+WNT and W9x respectively.

+

+The mutex types tested are:

+PTHREAD_MUTEX_DEFAULT

+PTHREAD_MUTEX_NORMAL

+PTHREAD_MUTEX_ERRORCHECK

+PTHREAD_MUTEX_RECURSIVE

+

+These tests indicate that is may be worthwhile re-introducing

+runtime adaptation of the underlying Win32 synchronisation

+mechanism for WinNT.

+

+

+---------

+Bug fixes

+---------

 Pthread_create now sets the priority of the new thread

 from the value set in the thread attribute. 

 - from Ralf.Brese@pdb4.siemens.de.

 

+A "lost signal" bug in condition variables that I introduced

+in the last snapshot has been fixed.

+- fixed by Alexander Terekhov

+- reported by Timur Aydin taydin@snet.net

+

 

 ---------------------------

 Known bugs in this snapshot