____ _ _ | _ \| |_| |__ | |_) | __| '_ \ ``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) 1999-2006 Ralf S. Engelschall 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 . 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