1 ____ _ _
2 | _ \| |_| |__
3 | |_) | __| '_ \ ``Only those who attempt
4 | __/| |_| | | | the absurd can achieve
5 |_| \__|_| |_| the impossible.''
6
7 GNU Pth - The GNU Portable Threads
8 Version 2.0.7 (08-Jun-2006)
9
10 ABSTRACT
11
12 Pth is a very portable POSIX/ANSI-C based library for Unix platforms
13 which provides non-preemptive priority-based scheduling for multiple
14 threads of execution (aka `multithreading') inside event-driven
15 applications. All threads run in the same address space of the server
16 application, but each thread has its own individual program-counter,
17 run-time stack, signal mask and errno variable.
18
19 The thread scheduling itself is done in a cooperative way, i.e., the
20 threads are managed by a priority- and event-based non-preemptive
21 scheduler. The intention is, that this way one can achieve better
22 portability and run-time performance than with preemptive scheduling.
23 The event facility allows threads to wait until various types of
24 events occur, including pending I/O on filedescriptors, asynchronous
25 signals, elapsed timers, pending I/O on message ports, thread and
26 process termination, and even customized callback functions.
27
28 Additionally Pth provides an optional emulation API for POSIX.1c
29 threads (`Pthreads') which can be used for backward compatibility to
30 existing multithreaded applications.
31
32 Finally, Pth guarranties its fixed set of API functionality on
33 all platforms, i.e., functions like pth_poll(3), pth_readv(3) or
34 pth_writev(3) are always available, even if the particular underlaying
35 platform does not actually support their functionality (through the
36 system calls poll(2), readv(2), writev(2), etc).
37
38 Although Pth is very feature-rich, it is a rather small threading
39 library. It consists only of approximately 7,000 line (or 300 KB) of
40 ANSI C code which are auto-configured with approximately 400 lines (or
41 60 KB) of Autoconf/m4 macros and which are documented by approximately
42 3,000 lines (or 150 KB) of documentation. Additionally the sources
43 are documented with approximately 3,600 additional lines of comments.
44 As a result, the whole source tree is just about 1.5 MB in size and
45 fits into a small tarball less than 350 KB in size. This allows Pth to
46 fit very well even into the source tree of other applications without
47 bloating it up very much.
48
49 Pth was successfully tested on FreeBSD, NetBSD, OpenBSD, BSDI,
50 GNU/Linux, Solaris, HPUX, Tru64 (OSF/1), AIX, IRIX, UnixWare, SCO
51 OpenServer, SINIX, ReliantUNIX, ISC, AmigaOS, Rhapsody (MacOS X), FTX,
52 AUX and Win32/Cygwin. And it should should automatically adjust itself
53 to remaining Unix platforms, too.
54
55 COPYRIGHT AND LICENSE
56
57 Copyright (c) 1999-2006 Ralf S. Engelschall <rse@engelschall.com>
58
59 This library is free software; you can redistribute it and/or
60 modify it under the terms of the GNU Lesser General Public
61 License as published by the Free Software Foundation; either
62 version 2.1 of the License, or (at your option) any later version.
63
64 This library is distributed in the hope that it will be useful,
65 but WITHOUT ANY WARRANTY; without even the implied warranty of
66 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
67 Lesser General Public License for more details.
68
69 You should have received a copy of the GNU Lesser General Public
70 License along with this library (see file COPYING); if not, write
71 to the Free Software Foundation, Inc., 59 Temple Place, Suite
72 330, Boston, MA 02111-1307 USA, or contact Ralf S. Engelschall
73 <rse@engelschall.com>.
74
75 HOME AND DOCUMENTATION
76
77 The documentation and latest release can be found on
78
79 o OSSP: http://www.ossp.org/pkg/lib/pth/
80 o OSSP: ftp://ftp.ossp.org/pkg/lib/pth/
81 o GNU: http://www.gnu.org/software/pth/
82 o GNU: ftp://ftp.gnu.org/gnu/pth/
83
84 Ralf S. Engelschall
85 rse@engelschall.com
86 www.engelschall.com
87