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docs/README.THREADS

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+
+NOTE: this information is obsolete for Mesa 3.1.  Due to the big
+changes in the Mesa code, the threads support is out of date.
+Someone will have to review/update it.
+
+
+Mesa Threads README
+-------------------
+
+Mesa 2.6 is the starting point for an effort to make Mesa 
+safe in multithreaded applications.  The files src/mthreads.c and
+src/mthreads.h provide a platform independent threads API which Mesa
+uses internally to provide thread-safe operation.  At present the mthreads
+code supports three thread APIS:
+  1) POSIX threads (aka pthreads).
+  2) Solaris / Unix International threads.
+  3) Win32 threads (Win 95/NT).
+
+Here's the current list of targets which enable multithreaded handling
+in Mesa:
+
+  linux-386-pthread    for Linux w/ Intel assembly and linuxthreads
+  sunos5-thread        for Suns with SunOS 5.x, using Solaris threads
+  sunos5-pthread       for Suns with SunOS 5.[56] using POSIX threads
+  sunos5-gcc-thread    for Suns with SunOS 5.x and GCC, using Solaris threads
+  sunos5-gcc-pthread   for Suns with SunOS 5.[56] and GCC, using POSIX threads
+
+In order to use Mesa with a multithreaded application, Mesa must be compiled
+using one of the thread-enabled configurations.  In cases where a platform
+supports multiple APIs which are acceptable to Mesa, Mesa must be built
+with the same threads API as the application in order for things to work
+properly.  For example, Solaris >= 2.5 support both POSIX threads and
+Sun's own threads API.  In order to guarantee proper operation, it is
+necessary for both Mesa and application code to use the same threads API.
+So, if your application uses Sun's thread API, then you should build Mesa
+using one of the targets for Sun threads.
+
+Since this effort is still very much a work in progress, not all 
+aspects of Mesa are thread safe.  As of this release (Mesa 2.6) only the
+osmesa drivers have been made MT-safe.  As work continues, other drivers
+such as the X11 drivers will also incorporate MT-safe features.
+
+The mtdemos directory contains some example programs which use 
+multiple threads to render to osmesa rendering context(s).
+
+Linux users should be aware that there exist many different POSIX
+threads packages. The best solution is the linuxthreads package
+(http://pauillac.inria.fr/~xleroy/linuxthreads/) as this package is the
+only one that really supports multiprocessor machines (AFAIK). See
+http://pauillac.inria.fr/~xleroy/linuxthreads/README for further
+information about the usage of linuxthreads.
+
+If you are interested in helping develop MT-safe Mesa, please send email
+to j.stone@acm.org and poliwoda@volumegraphics.com who are the two most
+directly involved in this effort currently.  Similarly, if you have problems
+using the MT-safe builds of Mesa, please send us comments/bugs etc.
+
+Future versions of Mesa will include more extensive documentation related
+to multithreading.  This is the first release of our work, so please bear
+with us.
+
+Regards,
+  John Stone           -- j.stone@acm.org  johns@cs.umr.edu
+  Christoph Poliwoda   -- poliwoda@volumegraphics.com
+
+