From d14156f2c1d4a9db64cfef0370883db8930e3a6b Mon Sep 17 00:00:00 2001 From: rpj Date: Sat, 2 Mar 2002 05:00:44 +0000 Subject: Changes to documentation and makefiles. --- NEWS | 482 ++++++++++++++++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 364 insertions(+), 118 deletions(-) (limited to 'NEWS') diff --git a/NEWS b/NEWS index 0ba7e58..d4cd9c0 100644 --- a/NEWS +++ b/NEWS @@ -1,118 +1,364 @@ -SNAPSHOT 2000-08-13 -------------------- - -New: -- Renamed DLL and LIB files: - pthreadVSE.dll (MS VC++/Structured EH) - pthreadVSE.lib - pthreadVCE.dll (MS VC++/C++ EH) - pthreadVCE.lib - pthreadGCE.dll (GNU G++/C++ EH) - libpthreadw32.a - - Both your application and the pthread dll should use the - same exception handling scheme. - -Bugs fixed: -- MSVC++ C++ exception handling. - -Some new tests have been added. - - -SNAPSHOT 2000-08-10 -------------------- - -New: -- asynchronous cancelation on X86 (Jason Nye) -- Makefile compatible with MS nmake to replace - buildlib.bat -- GNUmakefile for Mingw32 -- tests/Makefile for MS nmake replaces runall.bat -- tests/GNUmakefile for Mingw32 - -Bugs fixed: -- kernel32 load/free problem -- attempt to hide internel exceptions from application - exception handlers (__try/__except and try/catch blocks) -- Win32 thread handle leakage bug - (David Baggett/Paul Redondo/Eyal Lebedinsky) - -Some new tests have been added. - - -SNAPSHOT 1999-11-02 -------------------- - -Bugs fixed: -- ctime_r macro had an incorrect argument (Erik Hensema), -- threads were not being created - PTHREAD_CANCEL_DEFERRED. This should have - had little effect as deferred is the only - supported type. (Ross Johnson). - -Some compatibility improvements added, eg. -- pthread_setcancelstate accepts NULL pointer - for the previous value argument. Ditto for - pthread_setcanceltype. This is compatible - with Solaris but should not affect - standard applications (Erik Hensema) - -Some new tests have been added. - - -SNAPSHOT 1999-10-17 -------------------- - -Bug fix - Cancelation of threads waiting on condition variables -now works properly (Lorin Hochstein and Peter Slacik) - - -SNAPSHOT 1999-08-12 -------------------- - -Fixed exception stack cleanup if calling pthread_exit() -- (Lorin Hochstein and John Bossom). - -Fixed bugs in condition variables - (Peter Slacik): - - additional contention checks - - properly adjust number of waiting threads after timed - condvar timeout. - - -SNAPSHOT 1999-05-30 -------------------- - -Some minor bugs have been fixed. See the ChangeLog file for details. - -Some more POSIX 1b functions are now included but ony return an -error (ENOSYS) if called. They are: - - sem_open - sem_close - sem_unlink - sem_getvalue - - -SNAPSHOT 1999-04-07 -------------------- - -Some POSIX 1b functions which were internally supported are now -available as exported functions: - - sem_init - sem_destroy - sem_wait - sem_trywait - sem_post - sched_yield - sched_get_priority_min - sched_get_priority_max - -Some minor bugs have been fixed. See the ChangeLog file for details. - - -SNAPSHOT 1999-03-16 -------------------- - -Initial release. - +SNAPSHOT 2002-03-02 +------------------- + +Cleanup code default style. (IMPORTANT) +---------------------------------------------------------------------- +Previously, if not defined, the cleanup style was determined automatically +from the compiler/language, and one of the following was defined accordingly: + + __CLEANUP_SEH MSVC only + __CLEANUP_CXX C++, including MSVC++, GNU G++ + __CLEANUP_C C, including GNU GCC, not MSVC + +These defines determine the style of cleanup (see pthread.h) and, +most importantly, the way that cancelation and thread exit (via +pthread_exit) is performed (see the routine ptw32_throw() in private.c). + +In short, the exceptions versions of the library throw an exception +when a thread is canceled or exits (via pthread_exit()), which is +caught by a handler in the thread startup routine, so that the +the correct stack unwinding occurs regardless of where the thread +is when it's canceled or exits via pthread_exit(). + +In this and future snapshots, unless the build explicitly defines (e.g. +via a compiler option) __CLEANUP_SEH, __CLEANUP_CXX, or __CLEANUP_C, then +the build NOW always defaults to __CLEANUP_C style cleanup. This style +uses setjmp/longjmp in the cancelation and pthread_exit implementations, +and therefore won't do stack unwinding even when linked to applications +that have it (e.g. C++ apps). This is for consistency with most +current commercial Unix POSIX threads implementations. Compaq's TRU64 +may be an exception (no pun intended) and possible future trend. + +Although it was not clearly documented before, it is still necessary to +build your application using the same __CLEANUP_* define as was +used for the version of the library that you link with, so that the +correct parts of pthread.h are included. That is, the possible +defines require the following library versions: + + __CLEANUP_SEH pthreadVSE.dll + __CLEANUP_CXX pthreadVCE.dll or pthreadGCE.dll + __CLEANUP_C pthreadVC.dll or pthreadGC.dll + +E.g. regardless of whether your app is C or C++, if you link with +pthreadVC.lib or libpthreadGC.a, then you must define __CLEANUP_C. + + +THE POINT OF ALL THIS IS: if you have not been defining one of these +explicitly, then the defaults as described at the top of this +section were being used. + +THIS NOW CHANGES, as has been explained above, but to try to make this +clearer here's an example: + +If you were building your application with MSVC++ i.e. using C++ +exceptions and not explicitly defining one of __CLEANUP_*, then +__CLEANUP_C++ was automatically defined for you in pthread.h. +You should have been linking with pthreadVCE.dll, which does +stack unwinding. + +If you now build your application as you had before, pthread.h will now +automatically set __CLEANUP_C as the default style, and you will need to +link with pthreadVC.dll. Stack unwinding will now NOT occur when a thread +is canceled, or the thread calls pthread_exit(). + +Your application will now most likely behave differently to previous +versions, and in non-obvious ways. Most likely is that locally +instantiated objects may not be destroyed or cleaned up after a thread +is canceled. + +If you want the same behaviour as before, then you must now define +__CLEANUP_C++ explicitly using a compiler option and link with +pthreadVCE.dll as you did before. + + +WHY ARE WE MAKING THE DEFAULT STYLE LESS EXCEPTION-FRIENDLY? +Because no commercial Unix POSIX threads implementation allows you to +choose to have stack unwinding. Therefore, providing it in pthread-win32 +as a default is dangerous. We still provide the choice but unless +you consciously choose to do otherwise, your pthreads applications will +now run or crash in similar ways irrespective of the threads platform +you use. Or at least this is the hope. + + +WHY NOT REMOVE THE EXCEPTIONS VERSIONS OF THE LIBRARY ALTOGETHER? +There are a few reasons: +- because there are well respected POSIX threads people who believe + that POSIX threads implementations should be exceptions aware and + do the expected thing in that context. (There are equally respected + people who believe it should not be easily accessible, if it's there + at all, for unconditional conformity to other implementations.) +- because pthreads-win32 is one of the few implementations that has + the choice, perhaps the only freely available one, and so offers + a laboratory to people who may want to explore the effects; +- although the code will always be around somewhere for anyone who + wants it, once it's removed from the current version it will not be + nearly as visible to people who may have a use for it. + + +Source module splitting +----------------------- +In order to enable smaller image sizes to be generated +for applications that link statically with the library, +most routines have been separated out into individual +source code files. + +This is being done in such a way as to be backward compatible. +The old source files are reused to congregate the individual +routine files into larger translation units (via a bunch of +# includes) so that the compiler can still optimise wherever +possible, e.g. through inlining, which can only be done +within the same translation unit. + +It is also possible to build the entire library by compiling +the single file named "pthread.c", which just #includes all +the secondary congregation source files. The compiler +may be able to use this to do more inlining of routines. + +Although the GNU compiler is able to produce libraries with +the necessary separation (the -ffunction-segments switch), +AFAIK, the MSVC and other compilers don't have this feature. + +Finally, since I use makefiles and command-line compilation, +I don't know what havoc this reorganisation may wreak amongst +IDE project file users. You should be able to continue +using your existing project files without modification. + + +New non-portable functions +-------------------------- +pthread_num_processors_np(): + Returns the number of processors in the system that are + available to the process, as determined from the processor + affinity mask. + +pthread_timechange_handler_np(): + To improve tolerance against operator or time service initiated + system clock changes. + + This routine can be called by an application when it + receives a WM_TIMECHANGE message from the system. At present + it broadcasts all condition variables so that waiting threads + can wake up and re-evaluate their conditions and restart + their timed waits if required. + - Suggested by Alexander Terekhov + + +Platform dependence +------------------- +As Win95 doesn't provide one, the library now contains +it's own InterlockedCompareExchange() routine, which is used +whenever Windows doesn't provide it. InterlockedCompareExchange() +is used to implement spinlocks and barriers, and also in mutexes. +This routine relies on the CMPXCHG machine instruction which +is not available on i386 CPUs. This library (from snapshot +20010712 onwards) is therefore no longer supported on i386 +processor platforms. + + +New standard routines +--------------------- +For source code portability only - rwlocks cannot be process shared yet. + + pthread_rwlockattr_init() + pthread_rwlockattr_destroy() + pthread_rwlockattr_setpshared() + pthread_rwlockattr_getpshared() + +As defined in the new POSIX standard, and the Single Unix Spec version 3: + + sem_timedwait() + pthread_mutex_timedlock() - Alexander Terekhov and Thomas Pfaff + pthread_rwlock_timedrdlock() - adapted from pthread_rwlock_rdlock() + pthread_rwlock_timedwrlock() - adapted from pthread_rwlock_wrlock() + + +pthread.h no longer includes windows.h +-------------------------------------- +[Not yet for G++] + +This was done to prevent conflicts. + +HANDLE, DWORD, and NULL are temporarily defined within pthread.h if +they are not already. + + +pthread.h, sched.h and semaphore.h now use dllexport/dllimport +-------------------------------------------------------------- +Not only to avoid the need for the pthread.def file, but to +improve performance. Apparently, declaring functions with dllimport +generates a direct call to the function and avoids the overhead +of a stub function call. + +Bug fixes +--------- +* Fixed potential NULL pointer dereferences in pthread_mutexattr_init, +pthread_mutexattr_getpshared, pthread_barrierattr_init, +pthread_barrierattr_getpshared, and pthread_condattr_getpshared. +- Scott McCaskill + +* Removed potential race condition in pthread_mutex_trylock and +pthread_mutex_lock; +- Alexander Terekhov + +* The behaviour of pthread_mutex_trylock in relation to +recursive mutexes was inconsistent with commercial implementations. +Trylock would return EBUSY if the lock was owned already by the +calling thread regardless of mutex type. Trylock now increments the +recursion count and returns 0 for RECURSIVE mutexes, and will +return EDEADLK rather than EBUSY for ERRORCHECK mutexes. This is +consistent with Solaris. +- Thomas Pfaff + +* Found a fix for the library and workaround for applications for +the known bug #2, i.e. where __CLEANUP_CXX or __CLEANUP_SEH is defined. +See the "Known Bugs in this snapshot" section below. + +This could be made transparent to applications by replacing the macros that +define the current C++ and SEH versions of pthread_cleanup_push/pop +with the C version, but AFAIK cleanup handlers would not then run in the +correct sequence with destructors and exception cleanup handlers when +an exception occurs. + +* Cancelation once started in a thread cannot now be inadvertantly +double canceled. That is, once a thread begins it's cancelation run, +cancelation is disabled and a subsequent cancel request will +return an error (ESRCH). + +* errno: An incorrect compiler directive caused a local version +of errno to be used instead of the Win32 errno. Both instances are +thread-safe but applications checking errno after a pthreads-win32 +call would be wrong. Fixing this also fixed a bad compiler +option in the testsuite (/MT should have been /MD) which is +needed to link with the correct library MSVCRT.LIB. + + +SNAPSHOT 2001-07-12 +------------------- + +To be added + + +SNAPSHOT 2001-07-03 +------------------- + +To be added + + +SNAPSHOT 2000-08-13 +------------------- + +New: +- Renamed DLL and LIB files: + pthreadVSE.dll (MS VC++/Structured EH) + pthreadVSE.lib + pthreadVCE.dll (MS VC++/C++ EH) + pthreadVCE.lib + pthreadGCE.dll (GNU G++/C++ EH) + libpthreadw32.a + + Both your application and the pthread dll should use the + same exception handling scheme. + +Bugs fixed: +- MSVC++ C++ exception handling. + +Some new tests have been added. + + +SNAPSHOT 2000-08-10 +------------------- + +New: +- asynchronous cancelation on X86 (Jason Nye) +- Makefile compatible with MS nmake to replace + buildlib.bat +- GNUmakefile for Mingw32 +- tests/Makefile for MS nmake replaces runall.bat +- tests/GNUmakefile for Mingw32 + +Bugs fixed: +- kernel32 load/free problem +- attempt to hide internel exceptions from application + exception handlers (__try/__except and try/catch blocks) +- Win32 thread handle leakage bug + (David Baggett/Paul Redondo/Eyal Lebedinsky) + +Some new tests have been added. + + +SNAPSHOT 1999-11-02 +------------------- + +Bugs fixed: +- ctime_r macro had an incorrect argument (Erik Hensema), +- threads were not being created + PTHREAD_CANCEL_DEFERRED. This should have + had little effect as deferred is the only + supported type. (Ross Johnson). + +Some compatibility improvements added, eg. +- pthread_setcancelstate accepts NULL pointer + for the previous value argument. Ditto for + pthread_setcanceltype. This is compatible + with Solaris but should not affect + standard applications (Erik Hensema) + +Some new tests have been added. + + +SNAPSHOT 1999-10-17 +------------------- + +Bug fix - Cancelation of threads waiting on condition variables +now works properly (Lorin Hochstein and Peter Slacik) + + +SNAPSHOT 1999-08-12 +------------------- + +Fixed exception stack cleanup if calling pthread_exit() +- (Lorin Hochstein and John Bossom). + +Fixed bugs in condition variables - (Peter Slacik): + - additional contention checks + - properly adjust number of waiting threads after timed + condvar timeout. + + +SNAPSHOT 1999-05-30 +------------------- + +Some minor bugs have been fixed. See the ChangeLog file for details. + +Some more POSIX 1b functions are now included but ony return an +error (ENOSYS) if called. They are: + + sem_open + sem_close + sem_unlink + sem_getvalue + + +SNAPSHOT 1999-04-07 +------------------- + +Some POSIX 1b functions which were internally supported are now +available as exported functions: + + sem_init + sem_destroy + sem_wait + sem_trywait + sem_post + sched_yield + sched_get_priority_min + sched_get_priority_max + +Some minor bugs have been fixed. See the ChangeLog file for details. + + +SNAPSHOT 1999-03-16 +------------------- + +Initial release. + -- cgit v1.2.3