ossp-pkg/pth/README
____ _ _
| _ \| |_| |__
| |_) | __| '_ \ ``Only those who attempt
| __/| |_| | | | the absurd can achieve
|_| \__|_| |_| the impossible.''
GNU Pth - The GNU Portable Threads
Version 2.0.7 (08-Jun-2006)
ABSTRACT
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 by a priority- and event-based non-preemptive
scheduler. The intention is, that this way one can achieve better
portability and run-time performance than with preemptive scheduling.
The event facility allows threads to wait until various types of
events occur, including pending I/O on filedescriptors, asynchronous
signals, elapsed timers, pending I/O on message ports, thread and
process termination, and even customized callback functions.
Additionally Pth provides an optional emulation API for POSIX.1c
threads (`Pthreads') which can be used for backward compatibility to
existing multithreaded applications.
Finally, Pth guarranties its fixed set of API functionality on
all platforms, i.e., functions like pth_poll(3), pth_readv(3) or
pth_writev(3) are always available, even if the particular underlaying
platform does not actually support their functionality (through the
system calls poll(2), readv(2), writev(2), etc).
Although Pth is very feature-rich, it is a rather small threading
library. It consists only of approximately 7,000 line (or 300 KB) of
ANSI C code which are auto-configured with approximately 400 lines (or
60 KB) of Autoconf/m4 macros and which are documented by approximately
3,000 lines (or 150 KB) of documentation. Additionally the sources
are documented with approximately 3,600 additional lines of comments.
As a result, the whole source tree is just about 1.5 MB in size and
fits into a small tarball less than 350 KB in size. This allows Pth to
fit very well even into the source tree of other applications without
bloating it up very much.
Pth was successfully tested on FreeBSD, NetBSD, OpenBSD, BSDI,
GNU/Linux, Solaris, HPUX, Tru64 (OSF/1), AIX, IRIX, UnixWare, SCO
OpenServer, SINIX, ReliantUNIX, ISC, AmigaOS, Rhapsody (MacOS X), FTX,
AUX and Win32/Cygwin. And it should should automatically adjust itself
to remaining Unix platforms, too.
COPYRIGHT AND LICENSE
Copyright (c) 1999-2007 Ralf S. Engelschall <rse@engelschall.com>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library (see file COPYING); if not, write
to the Free Software Foundation, Inc., 59 Temple Place, Suite
330, Boston, MA 02111-1307 USA, or contact Ralf S. Engelschall
<rse@engelschall.com>.
HOME AND DOCUMENTATION
The documentation and latest release can be found on
o OSSP: http://www.ossp.org/pkg/lib/pth/
o OSSP: ftp://ftp.ossp.org/pkg/lib/pth/
o GNU: http://www.gnu.org/software/pth/
o GNU: ftp://ftp.gnu.org/gnu/pth/
Ralf S. Engelschall
rse@engelschall.com
www.engelschall.com
