ossp-pkg/pth/ANNOUNCE
1.13
____ _ _
| _ \| |_| |__
| |_) | __| '_ \ ``Only those who attempt
| __/| |_| | | | the absurd can achieve
|_| \__|_| |_| the impossible.''
GNU Pth - The GNU Portable Threads
Version 1.4
Pth is a very portable POSIX/ANSI-C based library for Unix platforms
which provides non-preemptive priority-based scheduling for multiple
threads of execution (aka "multithreading") inside event-driven
applications. All threads run in the same address space of the server
application, but each thread has its own individual program-counter,
run-time stack, signal mask and errno variable.
The thread scheduling itself is done in a cooperative way, i.e., the
threads are managed and dispatched by a priority- and event-driven
non-preemptive scheduler. The intention is that this way both better
portability and run-time performance is achieved than with preemptive
scheduling. The event facility allows threads to wait until various
types of internal and external events occur, including pending I/O on
file descriptors, asynchronous signals, elapsed timers, pending I/O
on message ports, thread and process termination, and even results of
customized callback functions.
Pth also provides an optional emulation API for POSIX.1c threads
("Pthreads") which can be used for backward compatibility to existing
multithreaded applications.
Pth 1.4 has an even more extensive support for auto-configuring
the package to work on the different Unix platforms without the
requirement for the end user to manually adjust the package.
Additionally the underlying thread creation and dispatching mechanism
was greatly enhanced and cleaned up, too. With this, version 1.4 now
was successfully built and tested on numerous Unix platforms, ranging
from the major ones like GNU/Linux, FreeBSD, NetBSD, OpenBSD, BSDI,
Solaris, HPUX, Tru64, AIX, IRIX, UnixWare and SCO, to more esoteric
flavors like SINIX, ReliantUNIX, ISC, SCO, NCR, AmigaOS, Rhapsody
(MacOS X), FTX, AUX and Win32/Cygwin.
Additionally the auto-configuration mechanism allows GNU Pth to
automatically adjusts itself to run also on mostly all remaining Unix
platforms, including ancient versions for which a multi-threading
environment never existed before. This is especially achieved in Pth
by not using any assembly code or platform specific solutions and by
using a very tricky but portable thread creation fallback approach
which will be published in great detail on the USENIX 2000 Annual
Conference this summer.
http://www.gnu.org/software/pth/
ftp://ftp.gnu.org/gnu/pth/
Ralf S. Engelschall
rse@engelschall.com
www.engelschall.com
