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+PTHREADS-WIN32
+==============
+
+Pthreads-win32 is free software, distributed under the GNU Lesser
+General Public License (LGPL). See the file 'COPYING.LIB' for terms
+and conditions. Also see the file 'COPYING' for information
+specific to pthreads-win32, copyrights and the LGPL.
+
+
+What is it?
+-----------
+
+Pthreads-win32 is an Open Source Software implementation of the
+Threads component of the POSIX 1003.1c 1995 Standard (or later)
+for Microsoft's Win32 environment. Some functions from POSIX
+1003.1b are also supported including semaphores. Other related
+functions include the set of read-write lock functions. The
+library also supports some of the functionality of the Open
+Group's Single Unix specification, version 2, namely mutex types,
+plus some common and pthreads-win32 specific non-portable
+routines (see README.NONPORTABLE).
+
+See the file "ANNOUNCE" for more information including standards
+conformance details and the list of supported and unsupported
+routines.
+
+
+Prerequisites
+-------------
+MSVC or GNU C (MinGW32 MSys development kit)
+ To build from source.
+
+QueueUserAPCEx by Panagiotis E. Hadjidoukas
+ For true async cancelation of threads (including blocked threads).
+ This is a DLL and Windows driver that provides pre-emptive APC
+ by forcing threads into an alertable state when the APC is queued.
+ Both the DLL and driver are provided with the pthreads-win32.exe
+ self-unpacking ZIP, and on the pthreads-win32 FTP site (in source
+ and pre-built forms). Currently this is a separate LGPL package to
+ pthreads-win32. See the README in the QueueUserAPCEx folder for
+ installation instructions.
+
+ Pthreads-win32 will automatically detect if the QueueUserAPCEx DLL
+ QuserEx.DLL is available and whether the driver AlertDrv.sys is
+ loaded. If it is not available, pthreads-win32 will simulate async
+ cancelation, which means that it can async cancel only threads that
+ are runnable. The simulated async cancellation cannot cancel blocked
+ threads.
+
+
+Library naming
+--------------
+
+Because the library is being built using various exception
+handling schemes and compilers - and because the library
+may not work reliably if these are mixed in an application,
+each different version of the library has it's own name.
+
+Note 1: the incompatibility is really between EH implementations
+of the different compilers. It should be possible to use the
+standard C version from either compiler with C++ applications
+built with a different compiler. If you use an EH version of
+the library, then you must use the same compiler for the
+application. This is another complication and dependency that
+can be avoided by using only the standard C library version.
+
+Note 2: if you use a standard C pthread*.dll with a C++
+application, then any functions that you define that are
+intended to be called via pthread_cleanup_push() must be
+__cdecl.
+
+Note 3: the intention was to also name either the VC or GC
+version (it should be arbitrary) as pthread.dll, including
+pthread.lib and libpthread.a as appropriate. This is no longer
+likely to happen.
+
+Note 4: the compatibility number was added so that applications
+can differentiate between binary incompatible versions of the
+libs and dlls.
+
+In general:
+ pthread[VG]{SE,CE,C}c.dll
+ pthread[VG]{SE,CE,C}c.lib
+
+where:
+ [VG] indicates the compiler
+ V - MS VC, or
+ G - GNU C
+
+ {SE,CE,C} indicates the exception handling scheme
+ SE - Structured EH, or
+ CE - C++ EH, or
+ C - no exceptions - uses setjmp/longjmp
+
+ c - DLL compatibility number indicating ABI and API
+ compatibility with applications built against
+ any snapshot with the same compatibility number.
+ See 'Version numbering' below.
+
+The name may also be suffixed by a 'd' to indicate a debugging version
+of the library. E.g. pthreadVC2d.lib. Debugging versions contain
+additional information for debugging (symbols etc) and are often not
+optimised in any way (compiled with optimisation turned off).
+
+For example:
+ pthreadVSE.dll (MSVC/SEH)
+ pthreadGCE.dll (GNUC/C++ EH)
+ pthreadGC.dll (GNUC/not dependent on exceptions)
+ pthreadVC1.dll (MSVC/not dependent on exceptions - not binary
+ compatible with pthreadVC.dll)
+ pthreadVC2.dll (MSVC/not dependent on exceptions - not binary
+ compatible with pthreadVC1.dll or pthreadVC.dll)
+
+The GNU library archive file names have correspondingly changed to:
+
+ libpthreadGCEc.a
+ libpthreadGCc.a
+
+
+Versioning numbering
+--------------------
+
+Version numbering is separate from the snapshot dating system, and
+is the canonical version identification system embedded within the
+DLL using the Microsoft version resource system. The versioning
+system chosen follows the GNU Libtool system. See
+http://www.gnu.org/software/libtool/manual.html section 6.2.
+
+See the resource file 'version.rc'.
+
+Microsoft version numbers use 4 integers:
+
+ 0.0.0.0
+
+Pthreads-win32 uses the first 3 following the Libtool convention.
+The fourth is commonly used for the build number, but will be reserved
+for future use.
+
+ current.revision.age.0
+
+The numbers are changed as follows:
+
+1. If the library source code has changed at all since the last update,
+ then increment revision (`c:r:a' becomes `c:r+1:a').
+2. If any interfaces have been added, removed, or changed since the last
+ update, increment current, and set revision to 0.
+3. If any interfaces have been added since the last public release, then
+ increment age.
+4. If any interfaces have been removed or changed since the last public
+ release, then set age to 0.
+
+
+DLL compatibility numbering is an attempt to ensure that applications
+always load a compatible pthreads-win32 DLL by using a DLL naming system
+that is consistent with the version numbering system. It also allows
+older and newer DLLs to coexist in the same filesystem so that older
+applications can continue to be used. For pre .NET Windows systems,
+this inevitably requires incompatible versions of the same DLLs to have
+different names.
+
+Pthreads-win32 has adopted the Cygwin convention of appending a single
+integer number to the DLL name. The number used is based on the library
+version number and is computed as 'current' - 'age'.
+
+(See http://home.att.net/~perlspinr/libversioning.html for a nicely
+detailed explanation.)
+
+Using this method, DLL name/s will only change when the DLL's
+backwards compatibility changes. Note that the addition of new
+'interfaces' will not of itself change the DLL's compatibility for older
+applications.
+
+
+Which of the several dll versions to use?
+-----------------------------------------
+or,
+---
+What are all these pthread*.dll and pthread*.lib files?
+-------------------------------------------------------
+
+Simple, use either pthreadGCv.* if you use GCC, or pthreadVCv.* if you
+use MSVC - where 'v' is the DLL versioning (compatibility) number.
+
+Otherwise, you need to choose carefully and know WHY.
+
+The most important choice you need to make is whether to use a
+version that uses exceptions internally, or not. There are versions
+of the library that use exceptions as part of the thread
+cancelation and exit implementation. The default version uses
+setjmp/longjmp.
+
+There is some contension amongst POSIX threads experts as
+to how POSIX threads cancelation and exit should work
+with languages that use exceptions, e.g. C++ and even C
+(Microsoft's Structured Exceptions).
+
+The issue is: should cancelation of a thread in, say,
+a C++ application cause object destructors and C++ exception
+handlers to be invoked as the stack unwinds during thread
+exit, or not?
+
+There seems to be more opinion in favour of using the
+standard C version of the library (no EH) with C++ applications
+for the reason that this appears to be the assumption commercial
+pthreads implementations make. Therefore, if you use an EH version
+of pthreads-win32 then you may be under the illusion that
+your application will be portable, when in fact it is likely to
+behave differently when linked with other pthreads libraries.
+
+Now you may be asking: then why have you kept the EH versions of
+the library?
+
+There are a couple of reasons:
+- there is division amongst the experts and so the code may
+ be needed in the future. Yes, it's in the repository and we
+ can get it out anytime in the future, but it would be difficult
+ to find.
+- pthreads-win32 is one of the few implementations, and possibly
+ the only freely available one, that has EH versions. It may be
+ useful to people who want to play with or study application
+ behaviour under these conditions.
+
+Notes:
+
+[If you use either pthreadVCE or pthreadGCE]
+
+1. [See also the discussion in the FAQ file - Q2, Q4, and Q5]
+
+If your application contains catch(...) blocks in your POSIX
+threads then you will need to replace the "catch(...)" with the macro
+"PtW32Catch", eg.
+
+ #ifdef PtW32Catch
+ PtW32Catch {
+ ...
+ }
+ #else
+ catch(...) {
+ ...
+ }
+ #endif
+
+Otherwise neither pthreads cancelation nor pthread_exit() will work
+reliably when using versions of the library that use C++ exceptions
+for cancelation and thread exit.
+
+This is due to what is believed to be a C++ compliance error in VC++
+whereby you may not have multiple handlers for the same exception in
+the same try/catch block. GNU G++ doesn't have this restriction.
+
+
+Other name changes
+------------------
+
+All snapshots prior to and including snapshot 2000-08-13
+used "_pthread_" as the prefix to library internal
+functions, and "_PTHREAD_" to many library internal
+macros. These have now been changed to "ptw32_" and "PTW32_"
+respectively so as to not conflict with the ANSI standard's
+reservation of identifiers beginning with "_" and "__" for
+use by compiler implementations only.
+
+If you have written any applications and you are linking
+statically with the pthreads-win32 library then you may have
+included a call to _pthread_processInitialize. You will
+now have to change that to ptw32_processInitialize.
+
+
+Cleanup code default style
+--------------------------
+
+Previously, if not defined, the cleanup style was determined automatically
+from the compiler used, 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 short, the exceptions versions of the library throw an exception
+when a thread is canceled, or exits via pthread_exit(). This exception 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 snapshot, 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/all
+commercial Unix POSIX threads implementations.
+
+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
+
+It is recommended that you let pthread.h use it's default __CLEANUP_C
+for both library and application builds. That is, don't define any of
+the above, and then link with pthreadVC.lib (MSVC or MSVC++) and
+libpthreadGC.a (MinGW GCC or G++). The reason is explained below, but
+another reason is that the prebuilt pthreadVCE.dll is currently broken.
+Versions built with MSVC++ later than version 6 may not be broken, but I
+can't verify this yet.
+
+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 pthreads platform
+you use. Or at least this is the hope.
+
+
+Building under VC++ using C++ EH, Structured EH, or just C
+----------------------------------------------------------
+
+From the source directory run nmake without any arguments to list
+help information. E.g.
+
+$ nmake
+
+Microsoft (R) Program Maintenance Utility Version 6.00.8168.0
+Copyright (C) Microsoft Corp 1988-1998. All rights reserved.
+
+Run one of the following command lines:
+nmake clean VCE (to build the MSVC dll with C++ exception handling)
+nmake clean VSE (to build the MSVC dll with structured exception handling)
+nmake clean VC (to build the MSVC dll with C cleanup code)
+nmake clean VCE-inlined (to build the MSVC inlined dll with C++ exception handling)
+nmake clean VSE-inlined (to build the MSVC inlined dll with structured exception handling)
+nmake clean VC-inlined (to build the MSVC inlined dll with C cleanup code)
+nmake clean VC-static (to build the MSVC static lib with C cleanup code)
+nmake clean VCE-debug (to build the debug MSVC dll with C++ exception handling)
+nmake clean VSE-debug (to build the debug MSVC dll with structured exception handling)
+nmake clean VC-debug (to build the debug MSVC dll with C cleanup code)
+nmake clean VCE-inlined-debug (to build the debug MSVC inlined dll with C++ exception handling)
+nmake clean VSE-inlined-debug (to build the debug MSVC inlined dll with structured exception handling)
+nmake clean VC-inlined-debug (to build the debug MSVC inlined dll with C cleanup code)
+nmake clean VC-static-debug (to build the debug MSVC static lib with C cleanup code)
+
+
+The pre-built dlls are normally built using the *-inlined targets.
+
+You can run the testsuite by changing to the "tests" directory and
+running nmake. E.g.:
+
+$ cd tests
+$ nmake
+
+Microsoft (R) Program Maintenance Utility Version 6.00.8168.0
+Copyright (C) Microsoft Corp 1988-1998. All rights reserved.
+
+Run one of the following command lines:
+nmake clean VC (to test using VC dll with VC (no EH) applications)
+nmake clean VCX (to test using VC dll with VC++ (EH) applications)
+nmake clean VCE (to test using the VCE dll with VC++ EH applications)
+nmake clean VSE (to test using VSE dll with VC (SEH) applications)
+nmake clean VC-bench (to benchtest using VC dll with C bench app)
+nmake clean VCX-bench (to benchtest using VC dll with C++ bench app)
+nmake clean VCE-bench (to benchtest using VCE dll with C++ bench app)
+nmake clean VSE-bench (to benchtest using VSE dll with SEH bench app)
+nmake clean VC-static (to test using VC static lib with VC (no EH) applications)
+
+
+Building under Mingw32
+----------------------
+
+The dll can be built easily with recent versions of Mingw32.
+(The distributed versions are built using Mingw32 and MsysDTK
+from www.mingw32.org.)
+
+From the source directory, run make for help information. E.g.:
+
+$ make
+Run one of the following command lines:
+make clean GC (to build the GNU C dll with C cleanup code)
+make clean GCE (to build the GNU C dll with C++ exception handling)
+make clean GC-inlined (to build the GNU C inlined dll with C cleanup code)
+make clean GCE-inlined (to build the GNU C inlined dll with C++ exception handling)
+make clean GC-static (to build the GNU C inlined static lib with C cleanup code)
+make clean GC-debug (to build the GNU C debug dll with C cleanup code)
+make clean GCE-debug (to build the GNU C debug dll with C++ exception handling)
+make clean GC-inlined-debug (to build the GNU C inlined debug dll with C cleanup code)
+make clean GCE-inlined-debug (to build the GNU C inlined debug dll with C++ exception handling)
+make clean GC-static-debug (to build the GNU C inlined static debug lib with C cleanup code)
+
+
+The pre-built dlls are normally built using the *-inlined targets.
+
+You can run the testsuite by changing to the "tests" directory and
+running make for help information. E.g.:
+
+$ cd tests
+$ make
+Run one of the following command lines:
+make clean GC (to test using GC dll with C (no EH) applications)
+make clean GCX (to test using GC dll with C++ (EH) applications)
+make clean GCE (to test using GCE dll with C++ (EH) applications)
+make clean GC-bench (to benchtest using GNU C dll with C cleanup code)
+make clean GCE-bench (to benchtest using GNU C dll with C++ exception handling)
+make clean GC-static (to test using GC static lib with C (no EH) applications)
+
+
+Building under Linux using the Mingw32 cross development tools
+--------------------------------------------------------------
+
+You can build the library without leaving Linux by using the Mingw32 cross
+development toolchain. See http://www.libsdl.org/extras/win32/cross/ for
+tools and info. The GNUmakefile contains some support for this, for example:
+
+make CROSS=i386-mingw32msvc- clean GC-inlined
+
+will build pthreadGCn.dll and libpthreadGCn.a (n=version#), provided your
+cross-tools/bin directory is in your PATH (or use the cross-make.sh script
+at the URL above).
+
+
+Building the library as a statically linkable library
+-----------------------------------------------------
+
+General: PTW32_STATIC_LIB must be defined for both the library build and the
+application build. The makefiles supplied and used by the following 'make'
+command lines will define this for you.
+
+MSVC (creates pthreadVCn.lib as a static link lib):
+
+nmake clean VC-static
+
+
+MinGW32 (creates libpthreadGCn.a as a static link lib):
+
+make clean GC-static
+
+
+Define PTW32_STATIC_LIB when building your application. Also, your
+application must call a two non-portable routines to initialise the
+some state on startup and cleanup before exit. One other routine needs
+to be called to cleanup after any Win32 threads have called POSIX API
+routines. See README.NONPORTABLE or the html reference manual pages for
+details on these routines:
+
+BOOL pthread_win32_process_attach_np (void);
+BOOL pthread_win32_process_detach_np (void);
+BOOL pthread_win32_thread_attach_np (void); // Currently a no-op
+BOOL pthread_win32_thread_detach_np (void);
+
+
+The tests makefiles have the same targets but only check that the
+static library is statically linkable. They don't run the full
+testsuite. To run the full testsuite, build the dlls and run the
+dll test targets.
+
+
+Building the library under Cygwin
+---------------------------------
+
+Cygwin is implementing it's own POSIX threads routines and these
+will be the ones to use if you develop using Cygwin.
+
+
+Ready to run binaries
+---------------------
+
+For convenience, the following ready-to-run files can be downloaded
+from the FTP site (see under "Availability" below):
+
+ pthread.h
+ semaphore.h
+ sched.h
+ pthreadVC.dll - built with MSVC compiler using C setjmp/longjmp
+ pthreadVC.lib
+ pthreadVCE.dll - built with MSVC++ compiler using C++ EH
+ pthreadVCE.lib
+ pthreadVSE.dll - built with MSVC compiler using SEH
+ pthreadVSE.lib
+ pthreadGC.dll - built with Mingw32 GCC
+ libpthreadGC.a - derived from pthreadGC.dll
+ pthreadGCE.dll - built with Mingw32 G++
+ libpthreadGCE.a - derived from pthreadGCE.dll
+
+As of August 2003 pthreads-win32 pthreadG* versions are built and tested
+using the MinGW + MsysDTK environment current as of that date or later.
+The following file MAY be needed for older MinGW environments.
+
+ gcc.dll - needed to build and run applications that use
+ pthreadGCE.dll.
+
+
+Building applications with GNU compilers
+----------------------------------------
+
+If you're using pthreadGC.dll:
+
+With the three header files, pthreadGC.dll and libpthreadGC.a in the
+same directory as your application myapp.c, you could compile, link
+and run myapp.c under Mingw32 as follows:
+
+ gcc -o myapp.exe myapp.c -I. -L. -lpthreadGC
+ myapp
+
+Or put pthreadGC.dll in an appropriate directory in your PATH,
+put libpthreadGC.a in your system lib directory, and
+put the three header files in your system include directory,
+then use:
+
+ gcc -o myapp.exe myapp.c -lpthreadGC
+ myapp
+
+
+If you're using pthreadGCE.dll:
+
+With the three header files, pthreadGCE.dll, gcc.dll and libpthreadGCE.a
+in the same directory as your application myapp.c, you could compile,
+link and run myapp.c under Mingw32 as follows:
+
+ gcc -x c++ -o myapp.exe myapp.c -I. -L. -lpthreadGCE
+ myapp
+
+Or put pthreadGCE.dll and gcc.dll in an appropriate directory in
+your PATH, put libpthreadGCE.a in your system lib directory, and
+put the three header files in your system include directory,
+then use:
+
+ gcc -x c++ -o myapp.exe myapp.c -lpthreadGCE
+ myapp
+
+
+Availability
+------------
+
+The complete source code in either unbundled, self-extracting
+Zip file, or tar/gzipped format can be found at:
+
+ ftp://sources.redhat.com/pub/pthreads-win32
+
+The pre-built DLL, export libraries and matching pthread.h can
+be found at:
+
+ ftp://sources.redhat.com/pub/pthreads-win32/dll-latest
+
+Home page:
+
+ http://sources.redhat.com/pthreads-win32/
+
+
+Mailing list
+------------
+
+There is a mailing list for discussing pthreads on Win32.
+To join, send email to:
+
+ pthreads-win32-subscribe@sources.redhat.com
+
+Unsubscribe by sending mail to:
+
+ pthreads-win32-unsubscribe@sources.redhat.com
+
+
+Acknowledgements
+----------------
+
+See the ANNOUNCE file for acknowledgements.
+See the 'CONTRIBUTORS' file for the list of contributors.
+
+As much as possible, the ChangeLog file attributes
+contributions and patches that have been incorporated
+in the library to the individuals responsible.
+
+Finally, thanks to all those who work on and contribute to the
+POSIX and Single Unix Specification standards. The maturity of an
+industry can be measured by it's open standards.
+
+----
+Ross Johnson
+<rpj@callisto.canberra.edu.au>
+
+
+
+
+
+
+
+